MINI GRANT PROJECT SUMMARY
Please complete the project summary and return the completed form to April Snyder, Associate Administrator for
the Institute on the Environment at [email protected]. Paper copies will not be accepted. Please also attach
any photos, publications, brochures, event agendas or other materials that were a result of the mini grant
summary.
Date of Report Submission:
10/5/2015
Project PI & Dept/School
Michael A. Rother, Chemical Engineering, SCSE
Project Title:
Sustainable UMD Biodiesel
Grant Amount $:
$2800
Project Context & Purpose
Please include the original project purpose statement and revise for any changes that occurred in the project after
the start date with a short explanation of the changes.
The project will explore the feasibility of converting food service grease waste to biodiesel, including promoting
sustainability, environmental responsibility and cross-disciplinary education.
Work Completed
Please provide a summary of the work that was completed for the mini grant project.
Experimental and theoretical work was done to develop an economical process to convert the waste grease to
biodiesel. Philip Galloway, an undergraduate researcher, conducted experiments to determine the best alcohol,
catalyst and temperature for the chemical reaction. Two design groups also contributed to the laboratory work.
In the end the students determined that methanol and potassium hydroxide mixed with the waste grease at 50 oC
gave the best results.
An economic analysis was also performed to determine profitability. Both design groups found that the process
could save the university money in the long run. However, the savings amounted to about $1000 per year, which
would require a significant payback for an initial capital investment on the order of $10,000 or more. It should be
pointed out that profit is not the only driving force for the project, with sustainability and education also being
important considerations.
Partnerships & Collaborations
Please provide a summary of the project personnel, partnerships and collaborations that worked directly on the
project or were started as a direct result of the mini grant project.
Philip Galloway, a senior chemical engineering student, worked on the project for about eight months, including
the summer and fall of 2014. He was paid through the mini-grant as an undergraduate researcher.
Two senior design groups in the Department of Chemical Engineering worked on the biodiesel project, one in the
spring of 2014 and one in the spring of 2015. During the spring they were involved in the design project, the
students were not paid. The relevant students were Terry Anderson, Mike Baumann, Alex Fisher, Jesse Hunter
and Eric Serantoni in 2014 and Philip Galloway, Martin Moen, Samuel Nichols, Ayotunde Olatunbosun, and Nathan
Welle in 2015.
Project Outcomes & Impacts
Please provide a summary of the outcomes and /or impacts of the mini grant project including future plans for the
project.
As supplementary material, I have attached the final design reports from the two groups who worked on the
biodiesel project. The students were able to develop a feasible method for producing biodiesel from the waste
grease produced from food services. However, during the spring of 2015, the students were told that the
university, i.e., Facilities Management, will be filtering and selling their waste grease at a price of $1.10 per gallon.
If Facilities Management allowed the filtered oil to be used in the production of biodiesel, rather than selling it,
the process could still be viable. Whether the university actually uses any biodiesel, the projects certainly helped
raise sustainability awareness in the one hundred students who were involved in senior design the last two years.
Several unanswered questions remain. The students never accurately verified that the biodiesel produced met
ASTM standards and could be used in cars belonging to the UMD fleet. One difficulty is that testing is expensive,
and funds were limited. The disposal or use for the significant quantity of glycerol generated as a byproduct was
not addressed in sufficient detail. Finally, prepackaged units, which start with vegetable oil and make biodiesel
meeting ASTM standards, are available. They are priced competitively (approximately $10,000) and could be a
reasonable option.
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Executive Summary:
As the University of Minnesota strives to become a more sustainable institution; focus on
reducing, reusing, and recycling waste has increased. A big portion of the University’s waste
comes from the fryers operated by the Dining Services. The used fryer oil is currently outsourced
to Sanimax, who pays the school to relocate the oil to their processing facility. The used oil is
then converted into biodiesel and sold to vendors. The University took this opportunity to
educate the school on the advantages of keeping the waste oil “in house”. Throughout the course
of a semester, intensive research was conducted on the pros and cons of implementing a process
that would turn the used oil into biodiesel. Initial findings suggested that for this project to work,
interdepartmental communication between the Dining Services and Facilities Management had
to be strong. This is because the used oil being refined is coming from Dining Services and the
fleets that would use the biodiesel are operated by the Facilities Management. Results from an
economic analysis showed that there would be a net profit of $700 per annum. This is accounting
for the raw materials needed for processing and the labor. Based on these findings, the project is
economical and would yield a payback period of 5.1 years. Finally, this project will lower the
University’s carbon footprint and thus making the institution more sustainable.
Introduction:
Business Background:
For the past few decades the University of Minnesota Duluth has been actively working towards
being an environmentally sustainable organization. To be an environmentally friendly many
different methods must be applied to become sustainable. The university has gone through great
efforts to have Leader in Energy and Environmental Design certified buildings, dining facilities
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that offer zero waste and offer a variety of modes of transportation that are beneficial to both the
user and the environment. The next iteration of the sustainability initiative is to change the fuel
that keeps the university in operation.
Traditionally, the fuel used in the majority of work vehicles is petrol-diesel. Petrol-diesel is
widely produced, available, and economically affordable. However, it has devastating effects on
the environment. To combat the damage to the environment while still maintaining a fleet of
work vehicles, biodiesel is now being looked at as a viable fuel supplement. A mixture of
biodiesel and petrol-diesel (B20) can be used instead of pure petrol-diesel [1]. Compared to pure
petrol-diesel, B20 has comparable performance with much lower carbon dioxide emissions [1].
Growing concern for the environment as well as limited oil reserves has driven an increase in
demand for biodiesel. The market is growing well enough that kitchens are beginning to sell
used-fryer oil. What used to be considered a burden is now becoming an advantage [2].
Technology has noticed the increase in interest and has responded with methods of converting
common waste into fuel. The process was once tedious and expensive, now it has advanced into
the realm of possibility. Biodiesel can be made in a simple four step process with common
reagents. Diesel engines are now commonly being made to accept petrol-diesel or the mixture
[1]. This allows the average person with the option of “going green”. This provides two sectors
for business to focus on, commercial and residential use.
With the difference in cost between the fuels becoming more negligible the advantages of biodiesel can be further looked at [2]. The chemical structure of biodiesel is significantly different
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from petrol-diesel, this leads to different properties. Due to the different structure it has a
“cleaner burn”; this means that it has reduced carbon dioxide emissions as well as well as most
other air pollutants [1]. Along with lower carbon dioxide emissions, the origin of biodiesel is
from plants. The plants used to create biodiesel convert carbon dioxide to oxygen. It has the
potential to be a closed loop, producing oxygen at a higher rate than the carbon dioxide emitted
during combustion. It is non-toxic; if there is a spill there will not be as devastating on the local
ecosystem. Since it is biodegradable, if there is a spill it will have non-permanent effects due to it
decomposing [3].
With a steadily increasing student population there is an increased need for diesel fuel. More
buildings will need to be constructed and more diesel vehicles will be operated. With growing
demand for biodiesel there is also a growing supply of the raw material. The growing student
population means an increase in on campus food consumption which will result in larger
quantities of fryer oil being available. The price for biodiesel is correlated to the price of petroldiesel. The general trend for fuel prices has been steadily increasing, however, looking at smaller
time frames shows that the price for fuel is very volatile.
Despite its great potential, there are several challenges that must be overcome before this project
is fully realized. The most difficult challenge posed is the financial challenge. Without proper
funding this project will never implemented and all work will be moot. An initial estimated cost
of $3,000 will be necessary for the project to proceed beyond a theoretical and experimental
status. With the chemistry already proven to be feasible, the second challenge is meeting the
necessary quality standards. If the standards are not met the environmental advantages are
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mitigated through decreased efficiency and increased material fatigue. The final barrier that must
be overcome is the design, construction and location of the process. A permanent location must
be allocated to the project that meets several criteria. The location must facilitate safe transport
of all materials, ease of access for student workers and must have the proper facilities for
potentially hazardous conditions.
Technical Background:
Biodiesel or fatty acid methyl ester (FAME) is made through a process known as
transesterification which reacts methanol with Triglycerides as shown below in Figure 1.
Figure 1: The transesterification of Triglyceride with Methanol and KOH to form Biodiesel and
byproduct Glycerol.
The transesterification chemical reaction, which is exothermic, lowers the viscosity of the
triglyceride to an optimum flow for diesel fuel engine. This process which is carried out in the
present of a catalyst, Potassium Hydroxide (KOH), helps replace one type of alcohol in an ester
compound with a CH3 molecule. Triglycerides are commonly known as oil or grease from
animal and plant matter. These ester molecules are composed of free fatty acid (FFA). Waste
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cooking oil has a higher level of impurities than unused oil. To counteract the higher percentage
of FFA, more catalyst needs to be used to carry out the reaction. Glycerol is a profitable
byproduct in this reaction which can be used to make soap among other substances.
Although this transesterification reaction is very popular, there are alternatives to making
biodiesel. Instead of Methanol another alcohol can be substituted, for example Ethanol.
Depending on the availability of these two chemicals is a deciding factor on which one is used.
Instead of making FAME this will create an ethyl ester which is suitable as biodiesel. Sodium
Hydroxide (NaOH) is a relative cheap catalyst and can be substituted for KOH. Depending on
the consistency of the waste oil and the percentage of FFA either of these two catalysts is
appropriate for the breakdown of FFA is also a deciding factor choosing between these two
alcohols. Instead of doing a base catalyzed transesterification of the oil with alcohols one popular
alternative is to do a direct acid catalyzed esterification of oil with methanol. The reason why the
base catalyzed transesterification is the most popular method to making biodiesel is because it is
the most economic friendly route and the high percentage of biodiesel yield [5].
For years, UMD had given away its used cooking oils for free while purchasing biodiesel for use
in their fleet of tractors. Implementation of this process would not only save the school some
money, but also reinforce the school’s mission to be sustainable. What makes this process
interesting is the fact that it is solving a waste issue that the UMD department of dining services
has to constantly deal with. And instead of hiring a contractor to solve the issue, it is being
tackled by students from the university.
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The snow tractors that the school uses consume B20, a blend of biodiesel that is normally used
during colder temperatures. According to biodiesel.org, obtaining B20 in Duluth requires driving
approximately 25 miles, which means that gasoline powered vehicles are used for the purchase
[4]. Essentially, more carbon monoxide is being emitted by the university every time tractors
need to be fueled up. A major advantage to this process being done on the schools grounds is that
the 25 mile trips would no longer be required. Other advantages include creating research
opportunities for undergraduate students once the project has been implemented, and
encouraging other branches of the University of Minnesota system to get on board.
The first factor to consider is various products that will be made. Biodiesel and glycerin are
direct products of the process; however the biodiesel will undergo an additional step and become
B20. B20 is a mixture of petrol-diesel and biodiesel. The glycerin produced is a byproduct that is
non-harmful to the environment, biodegradable, and safe to handle. Additional byproducts that
must be disposed of are the solid sediments from the raw materials. This can safely disposed of
in a landfill. The biodiesel that will be produced must be of high quality and meet ASTM
standards to be usable in university vehicles.
The second factor to examine is the details of the production facility. The production facility will
be located at either on campus or at the UMD farm. The farm is not an ideal location due to
transportation difficulties. If it is located on campus (at a yet undetermined site) there will be
minimal transportation issues as it does not need to be moved far distances and with many
vehicles. The facility will not be a large facility; it will have intermediate production capability.
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The next factor is production. The raw materials needed will be used fryer oil from University
Dining Services. Other necessary raw materials are methanol and potassium hydroxide.
Necessary utilities for the operation are water, electricity, ventilation and possibly natural gas.
Product storage will most likely not exceed 200 gallons. The raw material storage is dependent
on the University Dining Services; however, it is not expected to exceed product storage.
After the implementation of the project there will be several effects within the local community.
The first effect seen will be a decrease in carbon emissions from university vehicles. This will
result in a possible improvement to the local environment. Another effect will be several
additional jobs within the university to operate the process. Additional jobs will most likely
impact undergraduate chemical engineering students. The final effect is to decrease the
university’s dependence on outside fuels and further push environmental and sustainability
initiatives.
The final and most important factor of this project is safety. The greatest hazard with this project
is the use of methanol in close proximity to a heat source. This can be countered with proper
ventilation. Another hazard of methanol is when it comes in contact with certain synthetic fabrics
there can be undesired reactions. Another possible hazard is if a gas based heat source is used.
There is the potential for a gas leak or gas explosion.
Scope:
Ultimate goal is to make a more environmentally friendly university
Evaluate between a student made process and a process available from a vendor
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Evaluate economics, safety and educational opportunity
Biodiesel must meet several quality standards for use in university vehicles
The ultimate goal of the project is to create a recommendation for UMD sustainability. The
recommendation will encompass three different possible outcomes. The first possible outcome is
that the project will proceed with the design team creating and implementing a process for the
manufacture of biodiesel. The second possible recommendation is to procure a finished product
from an outside company that will produce biodiesel. The final possible recommendation is that
the project should not proceed forward.
Process Design:
Process Chemistry
Biodiesel or fatty acid methyl ester is produced in a transesterification reaction as shown in
Figure 1. This transesterification reaction is exothermic and lowers the viscosity of the
triglyceride to provide better flow properties. This process which is carried out in the presence of
a catalyst, Potassium Hydroxide, helps replace one type of alcohol into an ester compound with a
CH3 molecule. However old oils can have oxidized ends on the free fatty acids. An acid is added
to reduce the oxidized ends. Triglycerides are commonly known as oil or grease from animal and
plant matter. Waste cooking oil has a higher level of impurities than unused oil. To counteract
the higher percentage of FFA, more catalyst needs to be used to carry out the reaction. Glycerol
is a profitable byproduct in this reaction which can be used to make soap among other
substances.
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Vegetable oil contains a range of the length of the carbon chains between 13 and 21 carbons.
These chains also have a distribution of being branched and linear, while diesel molecules are
primarily linear. Both are on average roughly 16 carbons long. This becomes the cetane rating of
the fuel. The petrol-diesel molecules have a larger distribution of carbon chains, 10 to 28
carbons. These different molecular structures as well as the ester groups give biodiesel different
properties than petrol-diesel. Biodiesel has higher viscosity and lower vapor pressure.
Block Flow Diagram:
Figure 2: BFD of the production of Biodiesel from waste cooking oil through transesterification.
Figure 2 suggests that the preliminary titration and calculation has been done to figure out the
waste oil FFA level and how much catalyst needs to be added to neutralize it. Before the reaction
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can take place the waste oil will be prepared by being put through a 30 mesh filter which will
separate any impurities left in the oil from the storage. The oil that is filter will enter straight into
the 25 gallon vessel and heated up to 58°C. While the oil is being heated up the Potassium
Hydroxide pellets should be added to the Methanol solution and mixed at room temperature.
There will be heat generated from the solution so caution is needed. The reaction will take place
at 50 °C and there will be temperature lost once the CH3OH and KOH is added to the preheated
oil. It is important that the reaction does not exceed 64°C because that is the boiling point of
methanol. If the reaction temperature gets too high the methanol will not have enough time to
react and consequently leave the reaction. The reaction will take place for one hour will the
mixture is being agitated and kept constant at 50°C and atmospheric pressure. The mixture
should be left to settle and separate for 48 hours. Glycerol will be drained off the bottom into a
storage tank while the FAME will go into a washing tank for purifying.
Process Description
Refer to the Process Flow Diagram in Appendix J with respect to the following procedure.
Filtered oil is then hand pumped using P-102 through stream 1 to R-101. Methanol and
potassium hydroxide are poured into V-101, where they are mixed. This mixture is poured
through stream 4 to R-101. Sulfuric acid is added to R-101. The reactants are then heated to
50℃. The agitator is turned on and reactions proceeds for 90 minutes.
After 4 hours, glycerol is drained through stream 8 to V-105. Biodiesel is pumped through
stream 4 to V-103. Water is then added and V-103 is heated to 30℃. After the initial wash is
completed, water is drained. Water is then added again to V-103 and heated to 30℃. After the
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second wash is completed, air is sparged into V-103. Water is drained through stream 6.
Biodiesel is drained through stream 9 to V-104.
Process Discussion
The process begins with filtering the raw material (fryer oil) to remove any solid particulates
above 70 micrometers. If the particulates are not removed, the system will quickly deteriorate
due to fouling. Any particles below the target size will be removed later in the process.
The filtrate will be run through a 50 mesh screen followed a 200 mesh screen. The filter sizes
were chosen based on the finest grade mesh readily available for use with a 55-gallon barrel.
This provides feed material with the least particulate while accommodating ease of filtration.
After filtration the oil is transferred to a reaction vessel where it begins to undergo heating.
While heating, the methanol and potassium hydroxide are prepared. For 40 gallons of fryer oil, 8
gallons of methanol, 2 kilograms of potassium hydroxide and 170 milliliters of concentrated
sulfuric acid are needed. Any alcohol may be used to facilitate the reaction, methanol was chosen
due to economic reasons. It is cheaper than alternative alcohols on a mole basis. Potassium
hydroxide was chosen instead of sodium hydroxide due to its ability to produce a superior
product. This was ascertained through laboratory testing. Sulfuric acid is not a necessary reagent;
however, it is a primer that helps yield biodiesel instead of soap.
The reaction is heated to increase kinetics which reduces the amount of time required to react.
The set temperature of 50℃ is chosen because it allows the reaction to proceed at a high rate,
without creating concerns about boiling methanol off. The boiling point of methanol is 64℃.
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After the reaction is completed and the mixture separated the glycerin is drained from the tank.
During the draining process there is a color and viscosity change. The transition between
biodiesel and glycerin can be identified from a viscous brown fluid to a much less viscous yellow
fluid.
The wash process will mist on a low setting for 4 hours and allowed to settle, followed by
another mist at a higher setting for 4 hours. After the initial mist the water is drained out in a
similar fashion to draining the glycerol. Following the second mist, the mixture undergoes
sparging for 24 hours. After the mixture settles the water will again be bottom drained. The
washing process is performed to remove methanol and any solid particulates that the filter
process did not remove. The sparging that follows also removes methanol. The separation of
water from the biodiesel is extremely important, if it is not properly done serious engine damage
is possible.
Discussion of Process Alternatives and Design Choices
Throughout the project alternate methods were considered. The first area of concern centers on
the reactor, particularly the separation of glycerol and biodiesel. The current process uses gravity
separation. An explored alternative is a coalescer. A coalescer works by first filtering out solids
from the mixture. Solids can increase the stability of a mixture, preventing emulsion. Glycerol
droplets are then created and separated from bulk fluid and captured by a coalescer medium.
Droplets are then separated in a settling zone. This process is advantageous for a continuous
process, therefore it deemed to be a suboptimal method for the designed process. [9]
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The second area of concern centers on the washing phase. The current method being used is a
wet wash process. The alternative method is a dry wash using an ion exchange resin working by
the principles of adsorption. This method was is preferable to a wet wash due to there being no
possibility of an emulsion. It is also able to be operated at lower costs. This method was not used
due to prohibitive initial costs. [10]
Key Assumptions
•
FFA content is below 5%
•
Raw feed is consistently 40 gallons of fryer oil per week
•
Ambient temperature is always 20℃ and ambient pressure is atmospheric.
•
The average molecular weight of oil is 850 g/mole
•
There is perfect mixing
•
No glycerin is present during the washing stage
•
Constant temperature during reaction
•
Oil is prefiltered
Energy & Material Balances:
The summary of the mass and energy balances is found below. The density of the materials was
experimentally determined in the laboratory. The raw materials include methanol, fryer oil,
KOH, H2SO4 and water. There are five vessels that will be used for storage and mixing during
the process. The energy consumption in this process will come from heating up the fryer oil in
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the reactor, heating up the water in the wash tank, running the agitator, and running the air
compressor.
Stream
1
2
3
4
5
6
Fryer Oil/kg
134
-
-
-
-
-
Methanol/kg
-
23.7
-
3.3
-
3.3
Potassium Hydroxide/ kg
-
2.03
-
0.6
-
0.6
Glycerol/kg
-
-
5
-
-
-
Sulfuric Acid/kg
-
0.17
-
-
-
-
Water/kg
-
-
-
36
-
36
Biodiesel/kg
-
-
-
117
117
-
Total/ kg
134
25.8
5
70.9
31
39.9
Temperature/℃
Ambient
Ambient
Ambient
Ambient
Ambient
Ambient
Pressure/ Atm
1
1
1
1
1
1
Name
V-105
R-101
F-101
Temperature
(°C)
30
50
Ambient
Pressure
(Atm)
1
1
1
Orientation
Vertical
Vertical
Vertical
MOC
HD Polyethylene
Steel
304 SS
Height
(m)
1.12
1.22
0.15
Diameter
(m)
0.27
0.58
0.56
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Volume
(gal)
32
55
-
Mesh
(micron)
N/A
N/A
177 & 74
Heat Input
(kJ)
-
10,000
-
Impeller Energy Input
(kJ)
-
2700
-
Equipment Design
Major Equipment Listing
•
V-101: Catalyst/reactant vessel
•
V-102: Filtered waste oil storage tank
•
V-103: Washing tank
•
V-104: Biodiesel storage tank
•
V-105: Glycerol storage tank
•
R-101: Batch reactor
•
P-101: Manual methanol pump
•
P-102: Manual oil pump
The reaction that creates the biodiesel is performed in R-101. The reactants are mixed and then
heated to temperature; this is done to increase kinetics. The reaction is composed of three steps,
each step consists of a carbon tail being removed from the glycerol chain, and each reaction is
reversible. At the specified temperature and pressure, and a 67% excess methanol, conversion
reaches up to 80%. Within the reactor the first separation occurs. The first separation is a density
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separation of biodiesel and glycerol. The methanol is in both the biodiesel and glycerol, with a
higher affinity for glycerol.
The wash of the biodiesel is done in three stages in V-103. First it is misted two times. Then it is
bubbled. The washes are a form of a liquid-liquid extraction. The primary contaminant is
glycerol, other chemicals are assumed to have similar mass transfer properties as glycerol.
Glycerol prefers water over biodiesel, since it is completely miscible in water. In the mist, water
is sprayed onto the glycerol. Droplets are formed and contaminants are absorbed into the water.
[7]The effectiveness is dependent on the droplet size, temperature, and the total surface area in
contact with biodiesel. The particle size will increase as the particles fall through the biodiesel
since the biodiesel and water an immiscible. Once the water droplets fall to the bottom, a water
layer accumulates at the bottom. Water in this layer collects impurities at a negligible rate.
During the bubble stage, air is sparged into the bottom of the wash tank. Bubbles are formed in
the bottom water layer. Since the bubbles are formed here, the bubbles will be encased in water
until they reach the top of the tank. The water then falls back down to the bottom of the column.
Throughout the rising and falling of the water, glycerol is absorbed by the water. The water can
continue absorbing glycerol until the water reaches its solubility limit. The drawback of wet
washing is biodiesel oxidation and polymerization. [8] To prevent oxidation and polymerization,
biodiesel is dried at 64℃ for 20 minutes. This drying is done in R-101 after the reactor is
cleaned.
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All vessels are commonly found materials due to the inert nature of the products. The stored
materials will be waste water. Wastewater will be contaminated with methanol, glycerol and
solid particulates. The glycerol contaminants will consist of methanol and solid particulates.
Catalyst vessels will contain potassium hydroxide and methanol.
All pumps in this process will be identical. They will be manual pumps specifically chosen for
the ability to safely pump methanol. The flow rate will be dependent on the rate at which the
operator can rotate the handle. The given specification is 8 fluid ounces per rotation.
Economics
In calculating the economics several assumptions had to be made. The first was that there is a 5%
discounting parameter, there will be an additional 20% added to the initial investment due to
unanticipated expenses. The installation of safety equipment and storage will be at the expense
of another department. There was no tax included due to it being for the University. Glycerol
disposal is free. Utility costs are negligible. The cost of labor is $10/hr and the food services runs
for 10 months a year.
The reactor is the majority of the costs, $1,200; this is due to the material of construction and
ancillary parts needed to make it function. The agitator is the next highest cost at $360, the
agitator is industrial grade. The third highest component is the costs of the storage vessels at
$240. The sum of all components is $2,400.
The estimated cost of manufacturing per anum is $5,700. This consists of a raw material cost off
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$2,500 and an annual labor cost of $3,200. The value of the biodiesel produced will have an
estimated value of $6,400. This provides a net positive difference of $700; this will be in reality
savings for the university per year.
The discounted payback period for this project is just over 5 years at 5% interest. The nondiscounted payback period for this project is approximately 3 years. This is a reasonable payback
period for the university; this project is not intended to produce money so a long payback period
is acceptable.
Safety & Environmental Concerns
The main safety concerns are methanol and sulfuric acid. The methanol is harmful to breathe and
the reactor must be run below 64℃. Electrical equipment should be avoided from being near the
reactor and any that must be there such as the mixer must be well ventilated to avoid explosion
hazard. The sulfuric acid is 98% pure and is very caustic and must be handled with care. Eye
washes and chemical showers are available for accidents. KOH is a safety hazard, solid KOH
and liquid KOH are skin irritants.
Methanol is used in this process and excess is released into the atmosphere or poured into the
sewers in low concentrations. Methanol is hazardous to the environment in large concentrations.
If a batch of biodiesel is ruined it must be shipped to a location where it can be disposed of in an
environmentally friendly way.
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Control Issues
The process has controls at three different points. The first area of control is the temperature of
the reactor. The heater belts utilize temperature control. It will heat up to a specified temperature
and then adjust the heat output to maintain at the desired set point.
The second area of control is during the wash stage. The water will be pre-measured to guarantee
that the wash vessel is not overfilled during both wash stages. The final area of control is during
the sparging. A timer is used to ensure that the process does not proceed indefinitely, allowing
the final product to settle.
One area of control that can be improved is during the drainage of glycerol from the reactor. The
current method employed is a visual confirmation of color and viscosity change. A better
alternative method is a digital hydrometer to verify that the specific gravity has changed. A
change in the specific gravity would indicate a change in the fluid flowing past the sensor. This
can be incorporated with an automatic shutoff valve to close the reactor once the glycerol has
been drained.
Conclusions
This is an economically feasible process with minimal revenue being generated. It has a long, but
reasonable, payback period. This process can be done in-house, provided that space is made
available. There is room for improvement; the main emphasis is to make the process more
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autonomous as well as incorporating more controls into the process. Autonomy will result in a
more consistent product as well as reducing the amount of labor, operating costs; more controls
in the process will reduce waste as well as reducing the number of failed batches.
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Appendix A: Equipment Specification Tables
Name
Temperature
(°C)
V-101
V-102
Ambient Ambient
V-103
V-104
Ambient
30
Pressure
(Atm)
1
1
1
1
Orientation
Vertical
Vertical
Vertical
Vertical
MOC
Steel
Steel
Height
(m)
0.89
0.35
0.88
0.88
Diameter
(m)
0.58
0.30
0.59
0.59
Volume
(gal)
55
5
55
55
Heat Input
(kJ)
-
-
-
9000
Bubbling Energy Input
(kJ)
-
-
-
1300
HD
HD Polyethylene
Polyethylene
Name
V-105
R-101
F-101
Temperature
(°C)
30
50
Ambient
Pressure
(Atm)
1
1
1
Orientation
Vertical
Vertical
Vertical
MOC
HD Polyethylene
Steel
304 SS
Height
1.12
1.22
0.15
Group 3 | Biodiesel Final Report
(m)
Diameter
(m)
0.27
0.58
0.56
Volume
(gal)
32
55
-
Mesh
(micron)
N/A
N/A
177 & 74
Heat Input
(kJ)
-
6750
-
Impeller Energy Input
(kJ)
-
2700
-
Group 3 | Biodiesel Final Report
Appendix B: Equipment Design Calculations
Find: Heating requirements of reactor, as well as time required to heat up.
Known:
20 gauge walls on reactor are 0.95mm thick Ksteel=15w/mK
ri=0.2921m
ro=0.29305m
l=0.889m
cp=1670J/(kgK)
m=134kg
G=1200w
T∞=20°C
T0=20°C
Tf=50°C
Assumptions: Convective heat transfer coefficient outside the reactor is 20 w/(m2K)
Convective heat transfer coefficient inside the reactor is 800 w/(m2K)
Heat loss at top and bottom of the reactor is negligible due to thicker metal at bottom and
no liquid touching the top surface.
The reactor is well mixed: the temperature is the same throughout the reactor.
Use two heater bands to heat up the reactor and one to maintain heat
Heat loss to radiation is negligible
Analysis:
𝑈𝑈𝑈𝑈 =
1
r
ln o
r
1
1
+ i+
2𝜋𝜋ℎ𝑖𝑖 𝑙𝑙𝑟𝑟𝑖𝑖 2𝜋𝜋𝜋𝜋𝜋𝜋 2𝜋𝜋ℎ𝑜𝑜 𝑙𝑙𝑟𝑟𝑜𝑜
Group 3 | Biodiesel Final Report
𝑈𝑈𝑈𝑈
=
1
0.29305
ln 0.2921
1
1
+
2𝜋𝜋 ∗ 800𝑤𝑤
20𝑤𝑤
15𝑤𝑤 +
∗ 0.889𝑚𝑚 ∗ 0.2921𝑚𝑚 2𝜋𝜋0.889𝑚𝑚 ∗
2𝜋𝜋 ∗ 2 ∗ 0.889𝑚𝑚 ∗ 0.29305𝑚𝑚
𝑚𝑚𝑚𝑚
𝑚𝑚2 𝐾𝐾
𝑚𝑚 𝐾𝐾
= 31.9𝑤𝑤/𝐾𝐾
𝑞𝑞𝑠𝑠𝑠𝑠 = 𝑈𝑈𝑈𝑈�𝑇𝑇𝑓𝑓 − 𝑇𝑇∞ � =
𝑐𝑐𝑝𝑝 𝑚𝑚
33.9𝑤𝑤
∗ (50 − 20)°𝐶𝐶 = 957𝑊𝑊
𝐾𝐾
𝑑𝑑𝑑𝑑
= 𝐺𝐺 − 𝑈𝑈𝑈𝑈(𝑇𝑇 − 𝑇𝑇∞ )
𝑑𝑑𝑑𝑑
𝑡𝑡ℎ𝑒𝑒𝑒𝑒𝑒𝑒 = 𝑐𝑐𝑝𝑝 𝑚𝑚/𝑈𝑈𝑈𝑈 ∗ (ln(−𝑇𝑇𝑜𝑜 𝑈𝑈𝑈𝑈 + 𝑇𝑇∞ 𝑈𝑈𝑈𝑈 + 𝐺𝐺) − ln�−𝑇𝑇𝑓𝑓 𝑈𝑈𝑈𝑈 + 𝑇𝑇∞ 𝑈𝑈𝑈𝑈 + 𝐺𝐺�)
𝑡𝑡 = 1670 ∗
134
∗ (ln(−20 ∗ 31.9 + 20 ∗ 31.9 + 2400) − ln(−50 ∗ 31.9 + 20 ∗ 31.9 + 2400)
31.9
= 1ℎ𝑜𝑜𝑜𝑜𝑜𝑜
At steady state:
𝑞𝑞𝑡𝑡𝑡𝑡𝑡𝑡 = 𝑞𝑞ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 + 𝑞𝑞𝑟𝑟𝑟𝑟𝑟𝑟
𝑞𝑞𝑟𝑟𝑟𝑟𝑟𝑟 =
776𝑗𝑗
1
∗ 441𝑚𝑚𝑚𝑚𝑚𝑚 ∗
= 95𝑊𝑊
𝑚𝑚𝑚𝑚𝑚𝑚
3600𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠𝑠
𝑞𝑞ℎ𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 = 957𝑊𝑊 − 95𝑊𝑊 = 862𝑊𝑊
Group 3 | Biodiesel Final Report
Find: Pumping requirements
Known:
V=40 gal
vol/crank=8 oz/crank
Assumptions: A person can pump 53 cranks/minute
Same inlet and outlet diameter
Elevation change is one meter
Analysis:
𝑡𝑡 =
𝑡𝑡 = 40 𝑔𝑔𝑔𝑔𝑔𝑔 ∗
𝑉𝑉
𝑞𝑞 ∗ 𝑟𝑟
1 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 1 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 128 𝑜𝑜𝑜𝑜
∗
∗
= 12.1 𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚
8 𝑜𝑜𝑜𝑜
53 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 1 𝑔𝑔𝑔𝑔𝑔𝑔
Find: Energy Requirements of the reactor
Known:
ρoil=3362 g/gal
Voil=40 gal
∆Hformation=776kJ/kgk ρEtOH=791 kg/m3
T∞=293K
Tfinal=323K
Cpoil=1.67 kJ/kgK
CpEtOH=79.5J/molK
Group 3 | Biodiesel Final Report
VEtOH=8 gal
CpKOH(at 308K)=65.54J/molK
mKOH=56.1g/mol
MWKOH=56.1 g/mol
Assumptions: ambient air is 293K
Heat loss to surroundings is negligible in heat up
Heat loss to surroundings is less than heat generated during exothermic reaction
Average heat capacities can be used since temperature range is small
Molecular weight of the oil is roughly 300 g/mol
Equations:
𝑞𝑞 = 𝑚𝑚𝑚𝑚𝑚𝑚∆𝑇𝑇
𝑚𝑚 = 𝜌𝜌𝜌𝜌
Calculations:
moil = poil Voil =
3362 g
1 kg
∗ 40 gal ∗
= 134.5 kg
1 gal
1000 g
𝑞𝑞𝑜𝑜𝑜𝑜𝑜𝑜 = 𝑚𝑚𝑜𝑜𝑜𝑜𝑜𝑜 𝐶𝐶𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜 ∆𝑇𝑇 = 134.5 𝑘𝑘𝑘𝑘 ∗
𝑚𝑚𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 = 𝜌𝜌𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝑉𝑉𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 =
1.67 𝑘𝑘𝑘𝑘
∗ 30 𝐾𝐾 = 6738.5 𝑘𝑘𝑘𝑘
1 𝑘𝑘𝑘𝑘𝑘𝑘
791 𝑘𝑘𝑘𝑘
1 𝑚𝑚3
∗
∗ 8 𝑔𝑔𝑔𝑔𝑔𝑔 = 23.95 𝑘𝑘𝑘𝑘
1 𝑚𝑚3 264.17 𝑔𝑔𝑔𝑔𝑔𝑔
𝑞𝑞𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 = 𝑚𝑚𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 𝐶𝐶𝐶𝐶𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 ∆𝑇𝑇 = 23.95 𝑘𝑘𝑘𝑘 ∗ 0.0795
𝑘𝑘𝑘𝑘
1 𝑚𝑚𝑚𝑚𝑚𝑚
∗
∗ 30𝐾𝐾 = 3173.4 𝑘𝑘𝑘𝑘
𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 0.018 𝑘𝑘𝑘𝑘
Group 3 | Biodiesel Final Report
𝑞𝑞𝐾𝐾𝐾𝐾𝐾𝐾 = 𝑚𝑚𝐾𝐾𝐾𝐾𝐾𝐾 𝐶𝐶𝐶𝐶𝐾𝐾𝐾𝐾𝐾𝐾 ∆𝑇𝑇 = 2.03 𝑘𝑘𝑘𝑘 ∗ 0.06554
𝑘𝑘𝑘𝑘
1 𝑚𝑚𝑚𝑚𝑚𝑚
∗
∗ 30𝐾𝐾 = 71.1 𝑘𝑘𝑘𝑘
𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 0.0561 𝑘𝑘𝑘𝑘
𝑞𝑞 = 𝑞𝑞𝑜𝑜𝑜𝑜𝑜𝑜 + 𝑞𝑞𝐸𝐸𝐸𝐸𝐸𝐸𝐸𝐸 + 𝑞𝑞𝐾𝐾𝐾𝐾𝐾𝐾 = 6738.5 𝑘𝑘𝑘𝑘 + 3173.4 𝑘𝑘𝑘𝑘 + 71.1 𝑘𝑘𝑘𝑘 = 9983 𝑘𝑘𝑘𝑘
Find: Money Saved From Process
Known:
55- gallon drum: quantity 2, $120/unit
Bottom draining attachment: $75
5 gallon pail: $27 quantity 2
Drum heater: $190
Hand Pumps: quantity 2 cost $255/2units
Drill and mixer attachment: $116
Filters: $180
Washing kit: $210
Plastic 55 gal drum: $60
Methanol cost: $2/L
KOH:$1.27/lb
Sulfuric Acid: $1/gal
B100: $4/gal
biodiesel production: 40 gal/week
KOH: 2 kg/week
Methanol: 8 gal/week
Assumptions:
3% for discounting parameter
20% cost will be added for unanticipated expenses
Installation of safety equipment and storage will be at the expense of another department
University of Minnesota does not have to pay tax
Group 3 | Biodiesel Final Report
Glycerol is free to dispose
Utility costs are negligible
University labor is $10/hr
Food services runs for the equivalent of 10 months a year
Equations:
𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼 = 𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟 − 𝑒𝑒𝑒𝑒𝑝𝑝𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒
𝑁𝑁𝑁𝑁𝑁𝑁 = −(𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐) ∗ (1 + 𝑖𝑖)𝑛𝑛 + 𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 ∗ �
1
1 + 𝑖𝑖 𝑛𝑛
𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼𝐼 𝑐𝑐𝑐𝑐𝑐𝑐𝑐𝑐 = [2 ∗ $120 + $75 + 2 ∗ $27 + $190 + $255 + $116 + $180 + $210 + $60
+ 600] ∗ 1.2 = $2380
𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟𝑟 =
𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒𝑒 =
40𝑔𝑔𝑔𝑔𝑔𝑔 $4
∗
= $160/𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤
𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤 𝑔𝑔𝑔𝑔𝑔𝑔
𝑔𝑔𝑔𝑔𝑔𝑔
$1.27 0.454𝑙𝑙𝑙𝑙 2𝑘𝑘𝑘𝑘
$1 3.79𝐿𝐿 0.2𝐿𝐿 $10
$2 3.79𝐿𝐿
∗
∗8
+
∗
∗
+
∗
∗
+
𝐿𝐿
𝑔𝑔𝑔𝑔𝑔𝑔
𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤
𝑙𝑙𝑙𝑙
𝑘𝑘𝑘𝑘
𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤 𝑔𝑔𝑔𝑔𝑔𝑔 𝑔𝑔𝑔𝑔𝑔𝑔 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤 ℎ𝑟𝑟
∗ 8ℎ𝑟𝑟 = $142.55/𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤
𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖𝑖 = $160 − $142.55 =
$17.45
𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤
∗
4𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤
𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚ℎ
𝑁𝑁𝑁𝑁𝑁𝑁3 = −$2380 ∗ 1.035 + 698 ∗ (
∗
10𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚ℎ𝑠𝑠
𝑦𝑦𝑦𝑦
= $698/𝑦𝑦𝑦𝑦
1
1
1
+
+
) = $198.38
1.05 1.052 1.053
Group 3 | Biodiesel Final Report
NPV1=-1028.01
NPV2=-389.82
NPV3=198.36
𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 = 2 +
0 + 389.82
0 − 𝑁𝑁𝑁𝑁𝑁𝑁2
=
= 2.66 𝑦𝑦𝑦𝑦𝑦𝑦𝑦𝑦𝑦𝑦
𝑁𝑁𝑁𝑁𝑁𝑁3 − 𝑁𝑁𝑁𝑁𝑁𝑁2 198.36 + 389.82
Find: Performance of wash tower
Known:
HA=0.7891
VW=0.147m3
µ=0.00369 Pas
Vb=0.589m3
ρw=1000kg/m3
kca=0.1316min-1
ρoil=900 kg/m3
CA0water=0 g/cm3
C0oil=0.05 g/cm3
twash=60 min
Assume: Water droplets will remain the same size and have a diameter of 3mm
Well mixed biodiesel
Glycerol is the primary contaminant and all other contaminants will behave similarly
Analysis:
𝑘𝑘𝑐𝑐 𝑎𝑎(𝐶𝐶𝐴𝐴∗ − 𝐶𝐶𝐴𝐴 ) =
𝐶𝐶𝐴𝐴∗ = 𝐻𝐻𝐴𝐴 𝑋𝑋
𝑑𝑑𝐶𝐶𝐴𝐴
𝑑𝑑𝑑𝑑
Group 3 | Biodiesel Final Report
𝑉𝑉𝑤𝑤
𝑋𝑋 = 𝑋𝑋0 − 𝐶𝐶𝐴𝐴 � �
𝑉𝑉𝑏𝑏
𝑢𝑢 =
2�
𝑢𝑢 =
9
2 (𝜌𝜌𝑤𝑤 − 𝜌𝜌𝑜𝑜𝑜𝑜𝑜𝑜 ) 2
𝑔𝑔𝑅𝑅
9
𝜇𝜇𝑜𝑜𝑜𝑜𝑜𝑜
1000𝑘𝑘𝑘𝑘 900𝑘𝑘𝑘𝑘
−
�
𝑚𝑚
𝑚𝑚3
𝑚𝑚3
9.8 2 (0.003𝑚𝑚)2 = 0.531𝑚𝑚/𝑠𝑠
𝑠𝑠
0.00369 𝑃𝑃𝑃𝑃𝑃𝑃
0.589𝑚𝑚
1𝑚𝑚𝑚𝑚𝑚𝑚
ℎ 0.531𝑚𝑚
= 1.11𝑠𝑠 ∗
= 0.185𝑚𝑚𝑚𝑚𝑚𝑚
𝑡𝑡 = =
60𝑠𝑠
𝑢𝑢
𝑠𝑠
0.05𝑔𝑔
3
0.789 ∗
𝐻𝐻𝐴𝐴 𝑋𝑋0 − 𝐶𝐶𝐴𝐴0
3 − 0𝑔𝑔/𝑐𝑐𝑚𝑚
𝑐𝑐𝑚𝑚
𝐶𝐶𝑎𝑎 =
+ 𝐻𝐻𝐴𝐴 𝑋𝑋0 =
= 0.080𝑔𝑔/𝑐𝑐𝑚𝑚3
𝑒𝑒𝑒𝑒𝑒𝑒(−𝑘𝑘𝑐𝑐 𝑎𝑎𝑎𝑎)
exp(−0.132𝑚𝑚𝑚𝑚𝑛𝑛−1 0.185min)
𝐶𝐶𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 = 0.040 𝑔𝑔/𝑐𝑐𝑚𝑚3
𝑑𝑑𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜
−𝐶𝐶𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏0
𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜 ∗ 𝜈𝜈 =
𝑉𝑉
𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜0
𝑑𝑑𝑑𝑑 𝑜𝑜𝑜𝑜𝑜𝑜
𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜
𝐶𝐶
−𝑡𝑡 ∗ 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏0 ∗ 𝜈𝜈
−60 ∗ 0.8 ∗ 0.00245
𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜0
= 𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜0 𝑒𝑒𝑒𝑒𝑒𝑒 �
� = 0.05 ∗ exp �
� = 0.041
𝑉𝑉
0.589
Repeat calculations for run 2
For bubble run
Integrated equation is:
𝐶𝐶𝑜𝑜𝑜𝑜𝑜𝑜2 = 0.034
Group 3 | Biodiesel Final Report
𝑉𝑉
𝐶𝐶𝐴𝐴 �𝐻𝐻𝐴𝐴 𝑉𝑉𝑊𝑊 + 1� − 𝐻𝐻𝐴𝐴 𝑋𝑋0
𝑏𝑏
= exp(−𝑘𝑘𝑐𝑐 𝑎𝑎𝑎𝑎)
𝑉𝑉𝑊𝑊
𝐶𝐶𝐴𝐴0 �𝐻𝐻𝐴𝐴 𝑉𝑉 + 1� − 𝐻𝐻𝐴𝐴 𝑋𝑋0
𝑏𝑏
𝐶𝐶𝐴𝐴 = 0.022 𝑔𝑔/𝑐𝑐𝑚𝑚3
Appendix C: Cost Estimates
55 gal Reactor
$1200
Silicone Band Heater $180
Agitator
$360
Washing
$190
Filter
$150
Mixing
$60
(2) Storage Tank
$240
Total
$2380
Group 3 | Biodiesel Final Report
Appendix D: Economic Analysis
Group 3 | Biodiesel Final Report
Appendix E: Simulation Results
Group 3 | Biodiesel Final Report
d(TG) / d(t) = -k1*TG*A+k2*DG*A-k7*TG*A^3+k8*A*GL^3
TG(0) = 0.88
d(DG) / d(t) = k1*TG*A-k2*DG*E-k3*DG*A+k4*MG*E
DG(0) = 0
d(MG) / d(t) = k3*DG*A-k4*MG*E-k5*MG*A+k6*GL*E
MG(0) = 0
d(E) / d(t) = k1*TG*A-k2*DG*E+k3*DG*A-k4*MG*E+k5*MG*A-k6*GL*E+k7*TG*A^3k8*GL*E^3
E(0) = 0
d(GL) / d(t) = k5*MG*A-k6*GL*E+k7*TG*A^3-k8*GL*E^3
GL(0) = 0
A=4.12-E #inintial methanol conc minus ester conc
k7=0
k8=0
Ea1=13145
Ea2=9932
Ea3=19860
Ea4=14639
Group 3 | Biodiesel Final Report
Ea5=6421
Ea6=9588
T1=223
T0=223
R=1.99
k1=.05*exp(Ea1/R*(1/T1-1/T0))
k2=0.011*exp(Ea2/R*(1/T1-1/T0))
k3=0.215*exp(Ea3/R*(1/T1-1/T0))
k4=1.228*exp(Ea4/R*(1/T1-1/T0))
k5=0.242*exp(Ea5/R*(1/T1-1/T0))
k6=0.007*exp(Ea6/R*(1/T1-1/T0))
t(0) = 0
t(f) = 60
x=(0.88-TG/0.88)
Group 3 | Biodiesel Final Report
Appendix F: MSDS
Group 3 | Biodiesel Final Report
Appendix H: Safety Tables
Group 3 | Biodiesel Final Report
References:
Group 3 | Biodiesel Final Report
1) Sheehan, John. An Overview of Biodiesel and Petroleum Diesel Life Cycles. Golden, CO:
National Renewable Energy Laboratory, 1998. Web.
2) Harlan, Van Gerpen Jon. Business Management for Biodiesel Producers: August 2002January 2004. Golden, CO: National Renewable Energy Laboratory, 2004. Web.
3) "Advantages and Disadvantages of Biodiesel Fuel." ConserveEnergyFuture. N.p., 22
May 2013. Web. 07 Feb. 2015.
4) National Biodiesel Board. "Retail Map - Biodiesel." Biodiesel - America's Advanced
Biofuel. N.p., n.d. Web. 07 Feb. 2015.
5) "Biodiesel Production." Biodiesel. Web. 6 Feb. 2015. <http://www.biodiesel.org/docs/ffsproduction/production-fact-sheet.pdf?sfvrsn=4>.
6) "Heavy Duty Drum Band Heaters." Heavy Duty Drum Band Heaters / Metal Drum Band
Heater. Utah Biodiesel Supply, n.d. Web. 06 Mar. 2015.
7) Enweremadu, C. C., and M. M. Mbarawa. “Technical Aspects of Production and
Analysis of Biodiesel from Used Cooking Oil- A Review.” Elsevier.com. Renewable and
Sustainable Energy Reviews, 9 June 2009. Web. 24 Apr. 2015.
8) Washing Calculations: Mindaryani, Aswati. “Optimization of Biodiesel Washing by
Water Extraction.” World Congress on Engineering and Computer Science: WCECS
2007: 24-26 October, 2007, San Francisco, USA. By Suprihastuti S. Rahayu. Hong
Kong: Newswood Limited, 2007. 1-4. Print.
9) "Centrifugal vs. Coalescing Separation Technologies." Biodiesel Magazine. N.p., n.d.
Web. 07 May 2015.
10) "A Dry Wash Approach to Biodiesel Purification." Biodiesel Magazine. N.p., n.d. Web.
07 May 2015.
Conversion of UMD’s
Waste Oil to Biodiesel
Nathan, Samuel, Philip, Martin, Ayotunde
What are you going to learn?
●
●
●
●
●
●
●
●
What we are doing?
What are the benefits of biodiesel?
How’s the market?
What challenges were overcome?
What was the chemistry?
What was the process we developed?
Is it safe?
Is it economical?
Executive Summary
●
●
●
●
●
●
University scale biodiesel production
Goal to be economically feasible
$2,400 initial investment
5.1 year payback period
Student Operated
Inter-departmental cooperation
Environmental Benefits of Biodiesel
●
●
●
●
Lower Carbon Emissions
Non-Toxic
Biodegradable
Crops used to make
biodiesel produce O2
● Renewable
http://www.afdc.energy.gov/vehicles/diesels_e
missions.html
Market trends
● Increasing Market
● Restaurants sell used
fryer-oil
● Vehicles now being
designed for biodiesel
● Focus on B20
http://theenergycollective.com/sites/theenergycollective.com/files/imagepicker/476416/NelsonChart.png
http://www.afdc.energy.gov/data/10325
Challenges
● Location
o
o
o
o
Transportation hazards/difficulty
Security access
Utilities and ventilation
Size
Challenges (cont.)
● UMD Administration Interest
o
o
Waste oil currently contracted to outside company
Interdepartmental communication
● Quality
o
Biodiesel must meet ASTM standards
Technical Background
● Chemistry
Methyl Esters (3)
Technical Background
Chemistry continued:
● Exothermic reaction (776 kJ/Kmol)
● lowers viscosity
● low FFA (Free Fatty Acid) required (<5%)
● Sulfuric acid used to reduce oxidized FFA
● Different bonding (Methyl Esters) than petrol diesel
o This leads to different viscosity and vapor pressures
Cash Flow: Initial Investment
●
●
●
●
●
●
●
●
Breakdown Price
Reactor
○ $1200
Agitator
○ $360
(2) Storage Tank
○ $240
Washing Tank
○ $190
Silicone Band Heater
○ $180
Waste Oil Filter
○ $150
Mixing Tank
○ $60
Total: $(2380)
Cash Flow: Production
Cash Flow: Diagram
Discounted
i = 5.0%
NPV6= $500
PBP=5.1
5.1
Process Flow Diagram
Overall
● 40 gal/batch
● 1 batch/3 days
● ~80% conversion
Input
● 40 gallons oil
● 8 gallons methanol
● 2Kg of KOH
● 150 mL of H2SO4
Output
● ~40 gallons biodiesel
● ~8 gallons glycerol
Design Methods: Reactor
Objective: Achieve nearly
steady state conversion
● Use kinetics to find batch
time
o Result: React for 1
hour at 50℃
Design Methods: Washing Vessel
Objective: Remove 75 wt% of contaminants
● Model as liquid liquid extraction
● Used literature mass transfer coefficient of glycerol to
water from biodiesel
o For mist, based on time the water is in contact with
biodiesel
o For bubble, equilibrium is being reached
 Result: Mist 1 hour twice and bubble 8 hours
Design Methods
Most vessels
● Small excess volume and compatible material
Pumps
● Compatible materials and no electrical
components
● Provide fast enough flow to pump a batch in ~5
minutes
Design issues
Reactor
● Corrosive acid and base added: high grade
stainless steel needed
● Bottom draining for separation
● Sight glass for confirmed separation and
removal
● Minimal exposure to atmosphere
Design Issues
Washing Vessel
● Create a stand
Storage Vessel
● Nitrogen rich environment
Safety
● Methanol: flammable and poisonous if
ingested
o
No electrical equipment and open flames to prevent
fire
● Sulfuric acid: caustic
● Potassium Hydroxide: caustic
o
All chemicals must be stored separately
Reactor Safety Analysis
●
●
●
●
Corrosion Based Rupture
Spill
Runaway Reaction
Fire
Environment
Glycerol Disposal
● Sewarable waste
https://extranet.fhcrc.org/EN/sections/ehs/hamm/chap6/section6.html
http://www.epa.gov/region07/biofuels/noncombiodiesel/waste.htm
Ruined Batch
● Contact chemistry department for waste disposal
Biodiesel advantages
● Carbon from short term sinks
● Lower VOC emissions
Process Summary
●
●
●
●
●
●
Filtering
Mixing
Reaction
Separation
Washing
Sparge
Recommendations
●
●
●
●
●
Sight glass
Digital hydrometer
Dry Wash
Continuous Process
Autonomous Process
Results/Conclusions
● Process is possible to make in house
● Process is economically feasible
o
5.1 year payback period with 5% discounting criteria
● Still has room for improvement
o
o
o
Needs a better location
Need to minimize labor costs
Process needs to be more autonomous
Questions?
APPENDICES
Vegetable oil directly into car?
ruin engine
void warranty
much more viscous
-waste oil crystallizes in cold weather
blocking fuel filters
Why KOH?
● KOH is more soluble
● Glycerol from NaOH has a lower viscosity
● Less likely to turn into soap
o
Still a chance but less likely to emulsify
● Makes separation better
o
If recovery desired it makes it easier.
Why Methanol?
● Methanol is cheaper
● Less sensitive to water
● Lower reaction time
Calculations: Reactor
Polymath code
●
Differential equation:
d(TG) / d(t) = -k1*TG*A+k2*DG*A-k7*TG*A^3+k8*A*GL^3
TG(0) = 0.88
d(DG) / d(t) = k1*TG*A-k2*DG*E-k3*DG*A+k4*MG*E
DG(0) = 0
d(MG) / d(t) = k3*DG*A-k4*MG*E-k5*MG*A+k6*GL*E
MG(0) = 0
d(E) / d(t) = k1*TG*A-k2*DG*E+k3*DG*A-k4*MG*E+k5*MG*Ak6*GL*E+k7*TG*A^3-k8*GL*E^3
E(0) = 0
d(GL) / d(t) = k5*MG*A-k6*GL*E+k7*TG*A^3-k8*GL*E^3
GL(0) = 0
A=4.12-E #inintial methanol conc minus ester conc
Calculations: Reactor
● Arrhenius: k1=.05*exp(Ea1/R*(1/T1-1/T0))
3 Reversible reactions
● Each tail leaving glyceride
● At reactor temperature, 80% conversion
Calculations: Wash tank mist
Mass transfer:
Equilibrium-Henry’s Law:
Residence time- Stokes law:
Concentration of a bubble:
Calculations: Wash tank mist cont.
Concentration of oil at end of wash:
After wash 2: Coil2= 0.034g/cm3
Initial glycerol concentration = 0.05g/cm3
Calculations: Wash tank bubble
Mass transfer equations and Henry’s law
equations
Mass Balance:
Combine and integrate:
After 2, 8 hr bubbles:
CA=0.013 g/cm3
Appendix A: Equipment Specification Tables
Name
Temperature (°C)
Pressure (atm)
Orientation
MOC
Height(m)
Diameter (m)
Volume (L)
R-101
50
1
Vertical
SS 316
1.3
0.63
400
Name
Type
Flow (gpm)
Inlet Diameter (in)
Outlet Diameter (in)
Air Supply Pressure (psi)
Shaft Length (in)
MOC
Reactors and Vessels
V-101
V-102
V-103
50
25
25
1
1
1
Vertical
Vertical
Vertical
SS 316
SS 316
SS 316
1.1
0.67
1.3
0.56
0.34
0.63
280
60
400
V-104
25
1
Vertical
SS 316
1.1
0.54
240
Pump, Compressor, Agitator
P-101
C-101
A-101
A-102
Diaphragm Electric Pneumatic Pneumatic
35
1
1
150
40
40
40
40
CS
CS
SS 316
SS 316
Name
Type
Diameter (in)
MOC
Name
MOC
Power Required (V)
Duty (KW)
Valves/Filter
F-101
Ball
30 Mesh
1
3
SS 316
SS 316
Immersion
Heater
E-101
Steel
120
2
1
Appendix B: Equipment Design Calculations
All vessels were sized using the process material balance to determine the vessel sizes that
would be required for each step. All vessels are assumed to be cylindrical and vertically
oriented, with their height being twice their diameter. Calculations are shown below:
The volume for V-101, grease storage and heating, was calculated using the volume of the
grease that needs to be stored, from the MEB. A 20% safety factor was added.
280.38 𝐿𝐿 𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 ∗ 1.2 = 276.45 𝐿𝐿 → 280𝐿𝐿 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇
Microsoft Excel’s solver was used to determine the exact dimensions of the cylindrical vessel.
The assumption was made that the vessel height was twice the diameter, and the calculated the
dimensions of the tank given the volume and the constraints.
𝑑𝑑 = 0.56 𝑚𝑚 ℎ = 1.126 𝑚𝑚
Volume for V-102, mixing tank, was calculated using the volume of methanol for a batch, with a
negligible volume of KOH solids which will be dissolved into solution. A 20% safety factor was
used.
49.62 𝐿𝐿 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀 ∗ 1.2 = 59.54 𝐿𝐿 60 𝐿𝐿 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇
The method to determine the dimensions of the tank are the same as V-101.
𝑑𝑑 = 0.336 𝑚𝑚 ℎ = 0.674 𝑚𝑚
Volume for V-103, waste tank, was calculated using the volume of glycerol, wash water, and
residual KOH and MeOH solution used or produced per batch plus a 20% safety factor.
348.03 𝐿𝐿 𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊𝑊 ∗ 1.2 = 417.6 𝐿𝐿 → 400𝐿𝐿 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇
The method to determine the dimensions of the tank are the same as V-101.
𝑑𝑑 = 0.634 𝑚𝑚 ℎ = 1.268 𝑚𝑚
Volume for V-104, product holding tank, was determined by finding the volume of biodiesel
produced per batch, plus a 20% safety factor.
205.18 𝐿𝐿 𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵𝐵 ∗ 1.2 = 246.2 𝐿𝐿 → 240𝐿𝐿 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇
The method to determine the dimensions of the tank are the same as V-101.
𝑑𝑑 = 0.535 𝑚𝑚 ℎ = 1.069 𝑚𝑚
2
The volume for the batch rector, R-101 was determined by adding the volumes of grease and
methanol+KOH solution for a batch, with an additional 40% factor for safety in case the reactor
must be filled with water to quench a runaway reaction.
280 𝐿𝐿 𝑔𝑔𝑔𝑔𝑒𝑒𝑎𝑎𝑎𝑎𝑎𝑎, 𝑀𝑀𝑀𝑀𝑀𝑀𝑀𝑀/𝐾𝐾𝐾𝐾𝐾𝐾 ∗ 1.4 = 392 𝐿𝐿 → 400𝐿𝐿 𝑇𝑇𝑇𝑇𝑇𝑇𝑇𝑇
The method to determine the dimensions of the rector are the same as V-101.
𝑑𝑑 = 0.633 𝑚𝑚 ℎ = 1.268 𝑚𝑚
The pump was sized using a pump curve provided by the manufacturer. Below is the pump
curve.
First the air can be supplied at 20 psi. This will be attained by using a regulator. The blue line
corresponding to 20 psig is followed, and intersects the vertical 6 gpm discharge flow line. 6
gpm is a reasonable flow rate since this is a batch process and isn’t dependent on flow rates. A
horizontal line is then drawn to the left until it intersects the y axis. This corresponds to a head of
about 30 ft. The required head was determined to be14 ft, the top of the reactor (needs to be
elevated due to gravity separations, etc.). Since 30 ft>14 ft, this 1” diaphragm pump run with an
air supply of 20 psi will be sufficient.
The process piping was chosen to be 1” SS 316 This is a standard pipe size, and the material
will be able to withstand the chemicals. The valves will be 1” SS 316 hand operated ball valves.
The agitators were sized according to shaft length, and air pressure required. The shaft length
needed to reach near the bottom of the tanks, so a length of 0.5 m-0.6 m was desired for V-102
agitator and 1.0 m -1.1 m. The air pressure requirement for pneumatic agitators of this size is
50-80 psi.
3
The compressor size was calculated according to required pressure and air flow in order to
operate 2 of the 3 air operated pieces of equipment at a given time. This is consistent with what
will happen during the production process. The pump requires an air flow of less than 10 SCFM
at a max pressure of 20 psi. The agitators operate at 50-80 psi at an unknown flow rate. The
compressor is assumed to be able to provide this, given its max flow rate is 15.5 SCFM.
The filter is a sieve that rests on top of V-101. 30 mesh is used, since it is fine enough to
separate out large food chunks from the remaining oil. Any particles large enough to fit through
30 mesh will likely dissolve during the reaction. A particle size analysis was done using Dr.
Lodge’s analyzer. The mean particle size in the oil was found to be roughly 4 micons, far too
small to filter. For this reason, a finer filter was not used. The results are included below.
4
It was decided to use an immersion heater to preheat the grease to the desired reaction
temperature of 50°C before sending it to the reactor. As the vapor pressure of the oil is next to
nothing, worries about being intrinsically safe in regards to oil vapor were not significant This
immersion heater was sized with the objective of increasing the temperature of the grease from
20°C to 50°C, and it was assumed that there is only heating of the exact quantity of grease that
needed per batch, about 216.5 kg. That being said, a few different heaters were chosen with
varying duties, and calculated the amount of time it would take to heat the grease to 50°C. A 2
KW immersion heater was chosen, with a 2 hour requirement to heat the grease, assuming
negligible heat loss to the surroundings. The calculation is shown below:
𝐽𝐽
𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚𝑚 (216.5 𝑘𝑘𝑘𝑘)(2.1 𝐾𝐾𝐾𝐾 ∗ 𝐾𝐾)(30°𝐶𝐶)
𝑄𝑄
=
=
= 6819.75𝑠𝑠 = 1.89 ℎ𝑜𝑜𝑜𝑜𝑜𝑜𝑜𝑜
𝑡𝑡 =
𝐽𝐽
𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑
𝑑𝑑𝑑𝑑𝑑𝑑𝑑𝑑
2000 𝑠𝑠
5
Appendix C: Equipment Cost Estimates
The vessels and reactor were priced using CapCost. A screenshot is included below. The sum
of the equipment purchased cost was used as the bottom line.
The price of the pump was taken from Grainger. There were multiple options; the cost was
estimated to be about $1000.
<http://www.grainger.com/product/ARO-Metallic-Diaphragm-Pump-WP74680>
The immersion heater was priced from the online source Gordo Sales. The cost is $323.15.
<http://www.gordosales.com/store/pc/GB-2-0006-M1p1888.htm?gclid=CJaEyZek3r0CFclDMgodVUgAaA>.
The prices of the valves were estimated at $150.00 per valve, according to Grainger.
<http://www.grainger.com/search?searchQuery=valve>.
One of the agitators was included in the pricing of R-101. The other agitator was priced using an
online source, and was estimated to be $1000.00. This was a cost competitive to those provided
by Grainger.
<http://www.grainger.com/search?searchQuery=agiator>
The price of the compressor was priced using Grainger. Many of the compressors had similar
specs. The price was estimated at $500.
<http://www.grainger.com/product/INGERSOLL-RAND-1-Stage-WP105292/_/N-1z0r4ya/Nttcompressor?_=1399475878381&sst=subset&s_pp=false>
The price of the filter was priced using Global Gilson.
6
Appendix D: Economic Analysis
The following CapCost screenshot illustrates the parameters used to calculate the cumulative
cash flow diagram and the sensitivity analysis for the base case.
7
The $1200 tax credit was added in to the revenue as $1200/yr of additional profit. The other
COM information was calculated in Excel and simply inserted into CapCost. CapCost was not
used to analyze the alternatives, as the table found in the Manufacturing Cost Estimate section
shows that the ethanol alternative would make significantly less money.
The table used to plot the sensitivity analysis is shown below.
Parameter
Waste Treatment,
Value
Waste Treatment, NPV
Raw Materials, Value
Raw Materials, NPV
Operating Labor, Value
Operating Labor, NPV
-0.50%
0
0.50%
S
651.76
655.00
658.280
0.09719
2518.350
0.09713
2069.60
0.09708
0.09720
2531.00
0.09720
2080.00
0.09720
0.09722
2543.66
0.09727
2090.40
0.09733
4.58E06
5.53E06
1.2E-05
8
Appendix E: Experiments
Alcohol Solution Preparation
Solution
Volume (mL, approx)
Methanol +
NaOH
Methanol + KOH
Ethanol + NaOH
Ethanol + KOH
20
Mass Alcohol (g,
exact)
15.84
Mass Catalyst (g,
exact)
1.05
20
30
30
15.84
23.67
23.67
2.65
1.09
2.75
Alcohol Addition Ratios
Solution Description
MeOH+NaOH
MeOH+KOH
EtOH + NaOH
EtOH + KOH
Ratio: g solution / g oil
0.169
0.184
0.238
0.254
Experimental Design
Run
1
2
3
4
5
6
7
8
Alcohol Type
Methanol
Ethanol
Methanol
Ethanol
Methanol
Ethanol
Methanol
Ethanol
NaOH or KOH
NaOH
NaOH
KOH
KOH
NaOH
NaOH
KOH
KOH
Temperature
50.0°C
50.0°C
50.0°C
50.0°C
Ambient
Ambient
Ambient
Ambient
9
Appendix F: MSDS
10
Appendix G: HAZOP
Item
Deviation
Causes
System
Response
Safeguards
Action Items
No Flow
(Stream
2)
No
No power to
Pump P101
No grease
flow from V101
Power indicator
Check power
No Flow
(Stream
2)
Plugged
Filter F-101
No grease
flow from V101
Operator
monitoring
Check sight
glass
No Flow
(Stream
2)
Tank low
level V-101
No grease
flow from V101
Operator
monitoring
Check tank level
No Flow
(Stream
3)
Tank low
level V-102
No flow from
V-102
Operator
monitoring
Check tank level
No
agitation
No agitator
power
Slow reaction
Power indicator
Check power
No
reaction
No or low
flow from
streams 2
and/or 3
No biodiesel
production
Operator to ensure
flows from V-101
and V-102
Check sight
glass
No
reaction
Water
added
before
completion
Soap
production
and rxn
quenching
Operator to ensure
no water addition
Operator
training
Tank low
level V-101
Low grease
flow from V101
Operator
monitoring
Check tank level
Less
Flow
(Stream
3)
Tank low
level V-102
Low flow from
V-102
Operator
monitoring
Check tank level
Less
Flow
(Stream
2)
Low Pump
P-101 amps
Pump P-101
not running
Power indicator
Check power
Less
Flow
(Stream
2)
Plugged
Filter F-101
Low grease
flow from V101
Operator
monitoring
Operator
training
Less
Flow
(Stream
2)
Less
11
Low
Level
Stream 4
valve open
R-101
draining
Operator
monitoring
Operator
training, check
sightglass
Low
Level
Stream 5
valve open
R-101
draining
Operator
monitoring
Operator
training, check
sightglass
Low
Level
Closed
valve from
V-101
R-101 not
filling
Operator
monitoring
Operator
training, check
sightglass
Low
Level
Closed
valve from
V-102
R-101 not
filling
Operator
monitoring
Operator
training, check
sightglass
Low
Level
No water
flow
Product not
washed
Operator
monitoring
Check sight
glass
Low
temp
Electrical
malfunction
V-101
heater
Long reaction
time/Pump P101 damage
Power indicator,
temperature
indicator
Operator
training and
monitoring
Low
Temp
Rxn not
progressing
No biodiesel
production
Temperature
indication
Operator
monitoring
Low
Temp
Low
pressure
Slow reaction
Temperature
indication
Operator
monitoring
Low
pressure
Low
temperature
Slow reaction
Temperature
indication
Operator
monitoring
Overflow
Level indication
Overflow
Level indication
High
Level
High
Level
More
Open valve
from V-101
Open valve
from V-102
Operator
monitoring
Operator
monitoring
High
Level
Stream 4
valve
closed
Overflow
Level indication
Operator
monitoring
High
Level
Stream 5
valve
closed
Overflow
Level indication
Operator
monitoring
High
Level
Excess
water flow
Overflow
Level indication
Operator
monitoring
12
High
temp
Electrical
malfunction
V-101
Excessive
heat
Temperature
indication/water
quench
Operator
monitoring/alarm
High
temp
Runaway
reaction
Excessive
heat
Temperature
indication/water
quench
Operator
monitoring/alarm
High
Temp
High
pressure
Excessive
heat
Temperature
indication/water
quench
Operator
monitoring/alarm
High
pressure
High temp
Excessive
heat
R-101 high
level
Grease
contamination
Reverse
flow
stream 2
Reverse
Temperature
Operator
indication/Pressure
monitoring/alarm
relief
Check valve
Operator
monitoring
13
Appendix H: Safety Tables
Equipment
V-102
Mixing
Tank
Failure
Scenarios
Operator
overfill
Operation
Deviations
Overflow
Potential Passive
Solution
• Containment
Dike
Potential Active
Solution
• Operator
observes
tank level
Procedural Solution
•
•
V-102
Mixing
Tank
Excess
KOH
added
Overheati
ng
•
Design
mixing tank
to
accommodat
e maximum
temperature
•
•
•
High
Temp
alarm
Activate
cooling
jacket
Quenchin
g system
Fill without
filter
•
Filter
Clogging
Low flow
•
Use larger
filter
•
V-101
Grease
Storage
and
Heater
V-101
Grease
Storage
and
Heater
V-101
Grease
Storage
and
Heater
V-103
Waste
Tank
Heater
control
fails
Overheati
ng
•
•
High temp
alarm
•
Vessel
puncture
Leaking
•
Design
vessel to
accommodat
e high
temperature
Containment
Dike
•
Low level
alarm
•
Operator
cleanup
Operator
overfills
Overflow
•
Containment
Dike
•
Cease
filling
•
Operator
cleanup
Vessel
puncture
Leak
•
Containment
Dike
•
•
Drain to
substitute
vessel
V-103
Waste
Tank
Operator
overfills
Overflow
•
•
•
Store waste
in reactor
V-104
Product
Tank
Operator
drains
waste
stream to
product
tank
Vessel
puncture
Overflow
•
•
Overflow
alarm
•
Store
product in
reactor
Leak
•
Size waste
tank to
accommodat
e full reactor
volume
Size product
holding tank
to
accommodat
e full reactor
volume
Containment
Dike
Avoid
initiating
run until
fixed
Overflow
alarm
•
Drain to
substitute
vessel
•
Drain to
substitute
vessel
V-104
Product
Tank
•
•
Operator
ceases
filling
Chemical
spill
cleanup
Allow
vessel to
cool
Washing
Change
filter
Shutoff
heater
14
V-104
Product
Tank
Fire
Over
temperatu
re
•
•
Tank sealed
to prevent
oxygen
source
Sprinkler
system
•
•
Fire Alarm
•
•
Sprinkler
system
Firefighting
foam
system
15
Appendix I: Environmental Calculations
An estimate of the project’s overall impact on air pollution was conducted. The EPA and
other US agencies use a standard CO2 emission factor for gasoline-powered engines4:
8887
g CO2
metric tons CO2
�gallon = 8.887 × 10−3
�gallon
The Federal Highway Administration estimates that passenger vehicles (defined as any 4wheel, 2-axel car, light truck, van, or sport utility vehicle) drove an average of 11,398 miles
during 2012 and had an average fuel economy of 21.6 miles per gallon5. Average CO2
emissions per vehicle-year are thus:
1 gallon�
−3 metric tons CO2
11398 miles�vehicle ×
�gallon
21.6 miles × 8.887 × 10
metric tons CO2
= 4.69
�vehicle − year
To account for pollutants other than CO2, a conversion factor is used which accounts for both
the potency and concentration of each species, expressed in a quantity of CO2-equivalents
(CO2E). In 2011, this value was 0.988 for passenger vehicles6.
4.69
metric tons CO2
1 CO2 E
�0.988 CO
�vehicle − year ×
2
metric tons CO2 E
= 4.75
�vehicle − year
The CO2E savings from substituting the petro-diesel fuel with biodiesel produced from this
process must be determined. 10,084 grams of CO2 are released per gallon of petro-diesel fuel
burned by motor vehicles7. Using biodiesel from waste grease results in an overall reduction in
CO2 emissions of 86% versus petro-diesel8 on a per-distance basis. If this project produces
1580 gallons of biodiesel annually (61 gallons per batch, 26 batches per year), then the total
reduction in CO2 emissions is:
1580
gallons�
grams CO2 E
�gallon × 10−6 metric ton�gram × 0.86
year × 10,084
metric tons CO2 E�
= 13.7
year
Taking the ratio between the results in the vehicles removed:
13.7
metric tons CO2 E�
metric tons CO2 E
�vehicle − year = 2.9 vehicles
year ÷ 4.75
16
Appendix J: Lab Standard Operating Procedure for Biodiesel Experiments
Methoxide preparation
Density of oil: 0.94 g/mL
Ratio NaOH: 9.9g of NaOH pellets per 1L of grease
Ratio KOH: 24.86 g of KOH pellets per 1L of grease
Make sure the solutions are fully dissolved before using. This can take between 10-30 minutes.
Procedure
Preparation of Alcohol Solutions
1. Label 4 50mL volumetric flasks (Methanol+NaOH, Methanol+KOH, Ethanol+NaOH,
Ethanol+KOH).
2. For each flask, place on a scale and tare. Add alcohol via pipette according to table 2.
Record mass of alcohol added.
3. Add anhydrous base to flasks according to table 2. Record mass of base added.
Experiment Procedure
1. Set up the jacketed beaker--connect to water bath set at 50.0°C.
2. Label 8 test tubes (one for each run in table 1).
3. Place a large (200 mL or more) beaker on a scale. Place one of the test tubes (cap
removed) in the beaker and tare.
4. Pipette 10g of stirred grease into the test tube. Record the mass of grease added. Cap
and set aside.
5. Repeat steps 2 & 3 for the remaining 7 test tubes.
6. Add the 4 test tubes that will be reacted at elevated temperature to the jacketed beaker.
Add the 4 ambient runs to a large beaker filled with ambient water. Place a
thermocouple in the ambient water bath. Allow 5-10 minutes to acclimate.
7. Place a small beaker on a scale and tare. Pipette alcohol solution into the beaker
according to Table 3. Record mass of solution.
8. Uncap the test tube and add the measured amount of alcohol solution. Recap and mix
by inversion. Start the stopwatch upon addition of alcohol solution.
9. Set a stir bar into the jacketed flask and turn on the stir plate until moderate agitation of
the test tubes has been achieved.
10. Repeat steps 7 & 8 for each additional test tube, recording the stopwatch time upon
each alcohol solution addition.
11. At time intervals (t=30 mins, 60 mins, 24 hours), determine the extent of the reaction
(See below).
12. Dispose of all wastes in provided receptacle.
Determination of Extent of Reaction (is it complete?)
1. Remove by pipette 1 mL of solution from the middle of the top (biodiesel) layer. Place
into a 50 mL beaker.
2. In a 10mL graduated cylinder, measure 9 mL of methanol. Add to beaker.
3. Stir beaker contents with stir rod.
4. Allow contents to settle overnight.
5. Reaction completeness will be assessed by examining the glycerol layer formed.
1.
2.
3.
4.
Determination of Quality
Take out a 1 mL sample from a test tube and put in a small vial or test tube.
Add 1 mL of water
Shake vigorously
Observe any separation or emulsion over time
17
References
[1] Chris Collins (2007), “Implementing Phytoremediation of Petroleum Hydrocarbons, Methods
in Biotechnology 23:99–108.
[2] Rapier, Robert. Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks-Chapter 7: Renewable Diesel.
Springer 2008.
[3] Sarin, A. (2012). Biodiesel: Production and properties. Cambridge: Royal Society of
Chemistry.
[4] Speight, J. (2011). The biofuels handbook. Cambridge: Royal Society of Chemistry.
[5] Pacific biodiesel. (2014). Retrieved from
http://www.biodiesel.com/index.php/biodiesel/history_of_biodiesel_fuel
[6] Addison, Keith. "The Biodiesel Bible." Journey to Forever: Handmade Products. The
Journey to
Forever Project. Web. 1 Mar 2014. <http://journeytoforever.org/biodiesel_make.html>.
[7] "ASTM D6751-12." ASTM Standards Products. ASTM International. Web. 1 Mar 2014.
<http://www.astm.org/Standards/D6751.htm>
[8] "Automation Direct." . AutomationDirect.com, n.d. Web. 13 Apr 2014.
<http://www.automationdirect.com/adc/Home/Home?gclid=CM6Zk5Gi3r0CFQsSMwod
HhEAMA&s_kwcid=AL!3683!3!33373310903!p!!g!!automation
direct&ef_id=U0ruygAABGJXf23S:20140413200842:s>.
[9]"Valve." Grainger Homepage. W.W. Grainger Inc., n.d. Web. 13 Apr 2014.
<http://www.grainger.com/search?searchQuery=valve>.
[10] "Screw Plug Immersion." Gordo Sales Inc.. Gordo Sales Inc.. Web. 13 Apr 2014.
<http://www.gordosales.com/store/pc/GB-2-0006-M1p1888.htm?gclid=CJaEyZek3r0CFclDMgodVUgAaA>.
[11]United States Goverenment. Enviromental Protection Agency Department of Transportation.
Federal
Register. 2010. Web. <http://www.gpo.gov/fdsys/pkg/FR-2010-05-07/pdf/20108159.pdf>.
[12] Turton, Richard, Richard C. Bailie, Wallace B. Whiting, Joseph A. Shaeiwitz, and
Debangsu Bhattacharyya. Analysis,
Synthesis, and Design of Chemical Processes. : Prentice Hall, . Print.
[13] Fisher, Tim (a chemist) from Western Lake Superior Sanitary District. Phone interview. .
[14] Baumann and Serantoni, Andy Kimble. Personal interview. .
[15] "Husky 60-Gal. Stationary Electric Air Compressor." . Home Depot, n.d. Web. 19 Mar.
2014.
<http://www.homedepot.com/p/Husky-60-Gal-Stationary-Electric-Air-Compressor-
18
C601H/203187350>.
[16] BOSWELL, CLAY. "Methanol Recedes From Recent Highs." Chemical Week 176.11
(2014): 30. Business Source Premier. Web. 3 May 2014.
[17] "120/240V 1PH 2KW Immersion Heater 17-1/2" Immersion." . ISE Inc., n.d. Web. 29 Mar.
2014. <http://www.iseincstore.com/120-240v-1ph-2kw-immersion-heater-17-1-2immersion.aspx?gclid=CPPt3aLOkL4CFcpcMgoduRYA7w>.
[18] "ASTM Round Test Sieves." . Gilson Company Inc., n.d. Web. 25 Apr. 2014.
<http://www.globalgilson.com/selectionguides/sieves.asp>.
[19]"What's the difference between gasoline, kerosene, diesel, etc?." . HowStuffWorks, n.d.
Web. 30 Apr. 2014.
<http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/question1051.htm>.
[20] "Clean Cities Alternative Fuel Price Report." . US Department of Energy, 1 Jan. 2014. Web.
28 Mar. 2014. <>.
[21] Fisher, Serantoni, Anderson, Baumann. Claudia Engelmeier. Personal interview.
[22] Fisher, Serantoni, Anderson, Baumann. Mindy Granley. Personal interview.
[23] Fisher. Karl Novek. Personal interview.
[24]Fisher.Lake Superior Testing. Personal interview.
[25] "BioPro™ 380 Automated Biodiesel Processor." . Springboard Biodiesel, n.d. Web. 1 May
2014.
<http://www.springboardbiodiesel.com/biopro380/biopro380>.
[26] "Frequently Asked Questions - Methanol Institute." Frequently Asked Questions - Methanol
Institute. Methanol Institute, 1 Jan. 2011. Web. 8 May 2014. <http://www.methanol.org/healthand-safety/frequently-asked-questions.aspx>.
19
UMD Sustainable
Biodiesel
Terry Anderson, Mike Baumann, Alex Fisher, Jesse
Hunter and Eric Serantoni
Content
●
●
●
●
●
●
●
●
Scope
Background
Experiment
PFD
Operating details
Costs/Economics
Safety
Conclusion
Objective
Provide preliminary design specifications and
an economic analysis for creating a
vegetable oil to biodiesel conversion system
at UMD.
Introduction
● Convert UMD’s waste cooking oil to
biodiesel
● 21,000 lbs of vegetable oil used annually by
dining services
● Working in conjunction with the UMD Office
of Sustainability
● Midwest Grease takes waste cooking oil
away for free
Background
● Biodiesel = Fatty acid methyl ester
● Petrodiesel = Hydrocarbon chains (C12-C20)
● Biodiesel is more viscous than petrodiesel, so it’s
typically blended with petrodiesel
● B20 is the most common biodiesel blend
● Concentrations exceeding B20 require engine
modifications
Chemistry
Experiments
● Free fatty acid titration for amount of catalyst
● 23 Factorial Design
○ Catalyst (NaOH vs KOH)
○ Alcohol (methanol vs ethanol)
○ Rxn temperature (50°C vs ambient)
○ Took samples at: 30 mins, 1 hr, 2 hrs,3 hrs (some) 6
hrs (some), 1 day
Experiments cont.
● Two quality tests (emulsion and rxn completion)
● Optimal rxn: KOH, methanol, 50°C
Reactor
Separation
Emulsion Test
Completion Test
Material Balance / BFD
Grease
215 kg
Biodiesel
150 kg
Methanol
39 kg
Process
Waste
265 kg
KOH
6 kg
Wash
Water
155 kg
Operating Details
● ~ 2 batches per month
● 50°C (122°F)
● 2 hour preheating duration (raise oil to
reaction temp)
● 35 min reaction time
● 1.5 gal/min cooling water
● 24 hour settling duration
● 3 water washes or until wash water is clear
Operating Details Cont.
● 46 gal of biodiesel produced per batch (1200 gal/yr)
● 15 diesel powered vehicles
o 2 vehicles modified
● 6200 gallons diesel used /year
● Excess can be used for the biodiesel vehicles
Equipment Details
● Stainless steel 316excellent resistance to
KOH
● 30 mesh filter
● 60 gal air compressor
● 1 Diaphragm pump
● Air-powered agitators
Capital Costs
Total Capital Cost: $26,500
Annual Operating Cost
Net Product Worth
$5,500
Tax Incentive
$1,200
Raw Materials
$(2,500)
Utilities
$(50)
Labor Costs
$(2,000)
Waste Disposal
$(650)
Total
$1,500
Cash Flow
● PBP with tax
incentive: 41 years
● Dependent on price
of biodiesel
ASTM Standards
● ASTM D975-14 and 7467-10
● Key concerns:
o
o
o
o
Free & total glycerin … < 0.020 & 0.240 mass %
Methanol content … < 0.2 mass %
Water content … < 0.05 vol %
Acid number … < 0.5 mg KOH/g
Environment
● 17.2 metric tons CO2 equivalent annual emissions
reduction
● Equivalent to removing 2.9 cars from the road
Location
● Fabrication of dedicated housing
○
Most ideal, but expensive
○
DOT regulations
○
○
If treated as lab - no permit needed
Approval from city fire marshal
Liquor license for ethanol use
Selling requires additional permits
● Duluth Farm
● Permits required
○
○
Waste
● University waste processing
● Hazardous - near pH 14
○ less than 24% methanol content
● Western Lake Superior Sanitary District
● $20 / 55 gal drum or less
● $200 hauling license for 5 yrs
Process Alternatives
●
●
●
●
Ethanol Process
Process to recycle methanol
Separation of glycerol for soap
Automated Biodiesel Processor
Future Considerations
● Reaction optimization
● External testing
○
○
Waste
ASTM standards
● Expansion to outside UMD
● Selling excess biodiesel
Reactor Hazard Analysis
●
●
●
●
●
●
Reactor size
Reactor contents
Runaway reaction
Temperature control
Over-pressurization
Material of construction
Safety
●
●
●
●
●
●
●
Bonding & grounding
Air powered equipment
Pump pressure - regulator
Proper ventilation
Operator training - procedure
Waste handling - waste storage
Proper PPE
Conclusion
● Equipment costs $26,500
● Will save $1,500 annually
● Improves environmental image, 17.2 metric
tons CO2 saved
● Chemical safety considerations
● Process alternatives should be considered
References
[1] Chris Collins (2007), “Implementing Phytoremediation of Petroleum Hydrocarbons, Methods in Biotechnology 23:99–108.
[2] Rapier, Robert. Biofuels, Solar and Wind as Renewable Energy Systems: Benefits and Risks--Chapter 7: Renewable Diesel.
Springer 2008.
[3] Sarin, A. (2012). Biodiesel: Production and properties. Cambridge: Royal Society of Chemistry.
[4] Speight, J. (2011). The biofuels handbook. Cambridge: Royal Society of Chemistry.
[5] Pacific biodiesel. (2014). Retrieved from http://www.biodiesel.com/index.php/biodiesel/history_of_biodiesel_fuel
[6] Addison, Keith. "The Biodiesel Bible." Journey to Forever: Handmade Products. The Journey to
Forever Project. Web. 1 Mar 2014. <http://journeytoforever.org/biodiesel_make.html>.
[7] "ASTM D6751-12." ASTM Standards Products. ASTM International. Web. 1 Mar 2014.
<http://www.astm.org/Standards/D6751.htm>
[8] "Automation Direct." . AutomationDirect.com, n.d. Web. 13 Apr 2014.
<http://www.automationdirect.com/adc/Home/Home?gclid=CM6Zk5Gi3r0CFQsSMwodHhEAMA&s_kwcid=AL!3683!3!3337
3310903!p!!g!!automation direct&ef_id=U0ruygAABGJXf23S:20140413200842:s>.
References Cont.
[9]"Valve." Grainger Homepage. W.W. Grainger Inc., n.d. Web. 13 Apr 2014.
<http://www.grainger.com/search?searchQuery=valve>.
[10] "Screw Plug Immersion." Gordo Sales Inc.. Gordo Sales Inc.. Web. 13 Apr 2014.
<http://www.gordosales.com/store/pc/GB-2-0006-M1-p1888.htm?gclid=CJaEyZek3r0CFclDMgodVUgAaA>.
[11]United States Goverenment. Enviromental Protection Agency Department of Transportation. Federal
Register. 2010. Web. <http://www.gpo.gov/fdsys/pkg/FR-2010-05-07/pdf/2010-8159.pdf>.
[12] Turton, Richard, Richard C. Bailie, Wallace B. Whiting, Joseph A. Shaeiwitz, and Debangsu Bhattacharyya. Analysis,
Synthesis, and Design of Chemical Processes. : Prentice Hall, . Print.
[13] Fisher, Tim (a chemist) from Western Lake Superior Sanitary District. Phone interview. .
[14] Baumann and Serantoni, Andy Kimble. Personal interview. .
[15] "Husky 60-Gal. Stationary Electric Air Compressor." . Home Depot, n.d. Web. 19 Mar. 2014.
<http://www.homedepot.com/p/Husky-60-Gal-Stationary-Electric-Air-Compressor-C601H/203187350>.
[16] BOSWELL, CLAY. "Methanol Recedes From Recent Highs." Chemical Week 176.11 (2014): 30. Business Source
Premier. Web. 3 May 2014.
References Cont.
[17] "120/240V 1PH 2KW Immersion Heater 17-1/2" Immersion." . ISE Inc., n.d. Web. 29 Mar. 2014.
<http://www.iseincstore.com/120-240v-1ph-2kw-immersion-heater-17-1-2immersion.aspx?gclid=CPPt3aLOkL4CFcpcMgoduRYA7w>.
[18] "ASTM Round Test Sieves." . Gilson Company Inc., n.d. Web. 25 Apr. 2014.
<http://www.globalgilson.com/selectionguides/sieves.asp>.
[19]"What's the difference between gasoline, kerosene, diesel, etc?." . HowStuffWorks, n.d. Web. 30 Apr. 2014.
<http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/question1051.htm>.
[20] "Clean Cities Alternative Fuel Price Report." . US Department of Energy, 1 Jan. 2014. Web. 28 Mar. 2014. <>.
Questions?
Executive Summary
Background and Introduction
UMD Dining Services uses 21,000 lbs of raw vegetable oil annually [1]. Some of the vegetable
oil is absorbed into the food and the remainder is discarded. Currently, this waste grease is
taken away by Midwest Grease Company at no cost [1]. The UMD office of sustainability has
asked to develop a system that will turn waste food grease into biodiesel in order to further
promote its sustainable image [2]. Relative to petrodiesel this process will save 13.7 metric tons
of CO2 per year. This is a significant reduction in CO2 pollution.
Conclusions
It is our intent to make B20, a 20:80 biodiesel:petrodiesel mix by volume. UMD currently has 15
diesel vehicles with two that are modified to run on pure biodiesel [3]. As of 2013, they used
6200 gallons total per year [3]. Dining services produces enough waste grease to about two
batches, or 300 kg of biodiesel will per month. Annually, this equates to around 1200 gallons.
The proposed design could fully supply the fuel demand of UMD’s diesel fleet with B20 blend.
Excess product will be used to fuel the two vehicles that are modified to run on pure biodiesel.
Before any of the biodiesel would be used, it and the blended biodiesel would need to comply
with certain ASTM standards[4] . Key concerns include: water content, methanol content, free &
total glycerin, and amount of KOH still present. Testing to ensure these standards are met will
cost several thousand dollars [5].
Recommendations
It was found from lab testing that methanol, KOH, and 50°C were the most ideal alcohol,
catalyst, and temperature conditions, respectively.Testing indicates that the mean particle size
in the waste grease was less than 10 microns. The reaction will be run at 50°C for 35 minutes
before washing with water. The biodiesel and glycerol will be given 24 hours before being
washed with water.
In order for the process to be put into place, a permit will need to be obtained from the city fire
marshal and extra permits will be required in order for the biodiesel to be sold [6]. If ethanol is
used as a process alternative, a liquor license will be needed [6]. Ideally this location will be
placed in fabricated housing on the UMD campus although the UMD farm is also an option [6].
As for waste, the UMD department of Environmental Health and Safety has offered to take our
waste and treat it without our help [6]. This would be optimal although the university would still
have to pay for the waste. Otherwise another option would be to haul the waste to the Western
Lake Superior Sanitary District (WLSSD). A hauling license would cost $200 but would be good
for 5 years [7]. WLSSD estimates that our waste will most likely cost $20 or less per 55 gal drum
although testing would need to be done before getting an exact estimate [7]. However, before
the waste would be taken to WLSSD it would need to be treated with acid in order to lower the
pH of the waste to a non-hazardous level. The methanol content of the waste is low enough to
not be hazardous [8].
Economic Analysis
1
This process will require fixed capital investment of $26,500 but will save UMD $1,500 per year.
This number will vary as the process is sensitive to raw materials and the price of biodiesel as
well. The payback period for this project is expected to be 41 years. It should be noted that this
project is not economically driven. The profits for this project are abstract as it could potentially
bring future students to UMD, lessening the payback period. It is recommended that UMD look
into an automated biodiesel processor. The processor contains the entire process in a housed
system and is comparable in cost to the process proposed [9].
As for remaining technical challenges, there are a couple things that could be done with this
process. First, the methanol and glycerol could be separated with more advanced separation
techniques, although this may not be economically feasible. Ideally, the methanol would be
recycled while the glycerol would be used to make another sustainable product, soap [10].
Then, the process could be further optimized. While we found conditions that worked in the lab
there could potentially be better conditions that exist to run the reaction at. In the future, the
process could be expanded to outside UMD. An example would be processing waste grease
from nearby fast food restaurants. Testing will need to be run both on the waste and to ensure
the ASTM standards[7] [4].
Problem Statement and Objective
Currently, the university generates waste vegetable oil, mainly due to deep frying foods on
campus (Dining Services) [1]. UMD allows an outside company to come pick up the grease,
without seeing a dime for this service [1]. The objective of the project is to instead develop a
process that will allow the university to chemically convert the used grease into usable biodiesel
to be put into, and fuel any on-campus vehicles that can run on diesel/biodiesel. This will
effectively improve the university’s image of sustainability, and will help the university save
money by replacing some of its petrodiesel consumption with this biodiesel. Additionally, the
environmental implications of replacing this petrodiesel can be explored.
2
Introduction
It is estimated that UMD Dining Services purchases around 21,000 lbs. of vegetable oil for its
frying and cooking needs on a yearly basis [1]. Not all of this oil is disposed of as waste, as
some is absorbed into the food that is cooked. While general material losses (e.g. vaporization)
can account for some, the remainder is disposed of after it is used. A company by the name of
Midwest Grease makes frequent trips to the university to collect this waste grease[1] . By
utilizing an esterification process, this waste grease can be reacted with an alcohol to create
fatty acid esters, also known as biodiesel [11]. There are currently 15 vehicles on campus that
can run on a diesel/biodiesel blend, so this process would be appreciated if implemented [3].
This project will potentially be funded by the UMD Office of Sustainability, in hopes of improving
the university’s sustainable image [2]. It is important to note that this project is not economically
driven [2].
Historical Background
The first demonstration of the use of biofuels was in 1900, at a World’s Fair [12]. After this
demonstration, many others started to gain interest in this interesting alternative to petrodiesel.
Rudolph Diesel also became involved with this idea, and touted the benefits of biodiesel to
farmers, believing they could produce their own fuel [12]. After Diesel’s death, petroleum based
diesel fuel became standard, and the diesel engine was redesigned to match the properties of
petroleum diesel fuel [12]. Petro-diesel’s low cost discouraged development of alternatives[5].
During times of shortages and high prices, the need for an alternative is created and vegetable
oils, biofuels, are researched. In 1937 a Belgian inventor proposed a process that converts
vegetable oil into three smaller molecules [12]. These smaller molecules are easier to burn in a
diesel engine. This method was the transesterification reaction. Biodiesel has grown further
since the start of this century [12]. It has become one of the fastest growing alternatives to fuels
in the world because of its ease of use and clean emissions profile and many other benefits.
Biodiesel has become a safe alternative to petroleum because of its renewability.
Technical Background
Biodiesel is composed of fatty acid esters while petrodiesel is composed of long carbon chains,
typically C12-C20 [13]. Using methanol to produce biodiesel will produce methyl esters while
ethanol will produce ethyl esters [11]. Using ethanol makes the process more costly to operate
due to the high raw material cost, longer reaction time, and licensing[11]. Using methanol
makes the project more profitable due to fewer licenses, lower raw material costs, and
decreased reaction time [11]. The process to produce methyl esters via trans esterification was
the desired process[11] . Pictured below is a methyl ester molecule.
[11]
Biodiesel is much more viscous than petrodiesel, so the two are usually blended together [14].
The common blend ratio is 20% biodiesel and 80% petrodiesel by volume and is called B20
[14]. Thus, this is the intended blend ratio for this project. Also, diesel engines can run off B20
without modifications but blend ratios higher than B20 require specially modified engines [14].
The selling price of B20 is around $3.82/gallon [15] . This is the most common blend of
3
biodiesel, and is becoming even more popular [14] . Its price is slowly decreasing, thus over
time this project could become less profitable if the trend continues.
Challenges
Since the chemical reaction is the key point of this project, making sure the reaction was
efficient, safe, economical, and robust was a very important point. It was important to select
cheap and efficient raw materials, and to ensure the reaction produced a quality product. Being
able to separate and purify the biodiesel was of significant concern, due to the strict ASTM
standards it is required to meet. Waste production and disposal was an important investigation
as well. Ensuring proper waste disposal is particularly important due to the “green” nature of this
process.
Scope
Product Specifications
The biodiesel product will need to comply with national standards. Two ASTM standards were
identified that are relevant to this project. To ensure the biodiesel will perform in an engine
without causing damage or ill-effects, the blended fuel will need to meet the standard D975-14.
Compliance with D975-14 is also required to receive the tax incentive of $1.00 per gallon [4].
Additionally, compliance with standard D7467-10, which specifies requirements for blended B20
fuel, is necessary [4].
Location
Before this proposed design is implemented, a permanent location must be determined. Two
primary options have been identified as to where this location could be; somewhere here oncampus, or on university property located off-campus such as the UMD Farm [6]. More so,
depending on how far away from campus this destination would be, transportation costs enter
the equation, and the environmental emissions due to said transportation could be counterproductive.The system requires 300 square feet of space and a minimum 14 feet of vertical
clearance. Unfortunately, suitable housing on-campus doesn’t exists, and would likely require
the structural fabrication of permanent housing. The other concern about building a new, albeit
small facility on-campus is finding the space. There is not a lot of free space.
Either way, after a location has been determined, a question regarding environmental/safety
permits arises; which permits, if any, would be needed? Ideally, if the determined location
resides on campus property, the goal would be to have this process, and its housing treated as
lab space. This would require no additional permits, and would be covered under the
university’s current laboratory permits, per Andy Kimball (UMD EH&S representative) [6].
Process Design
The process centers around the reaction; it was important to determine which alcohol, catalyst,
temperature, and reaction time would yield the best results. Reactions were done in the lab to
further investigate this. Based on these results, the MEB could be constructed. The design of
the actual, physical process would center around the MEB.
Process Chemistry
4
The trans esterification reaction occurs between triglycerides (the oil) alcohol, and a base
catalyst [11]. Esters are produced as the biodiesel product, and glycerol is produced as a
byproduct [11]. In the chosen reaction, methanol is the alcohol and potassium hydroxide is the
base catalyst. The reaction is pictured below.
Experiments
Experiments were conducted in the lab in order to optimize the reaction [11]. The purpose of
these experiments were to determine which reaction conditions produced the highest yield of
biodiesel. The full procedure can be found in Appendix E. First, extra catalyst was needed to
neutralize the free fatty acids present in the waste grease. To do this, a titration was done on
the waste grease using 0.1 wt to volume solutions of KOH and NaOH pellets in water. It was
found that 5.8 mL of NaOH solution was required to titrate the grease while 18.5 mL of KOH
solution was required to titrate the same amount grease. The NaOH was 99% pure while the
KOH was only 86.5% pure. For clean vegetable oil 3.5 g of NaOH is required per liter of oil
while 4.9 g of 100% pure KOH (5.8 g/liter at 85% purity) is needed [10].
Three factors we considered in the experiments: alcohol type, catalyst, and temperature. A 23
factorial was designed in order to run the experiments. In all the experiments a 5:1 ratio of
alcohol:grease by mole was used. Samples were taken at: 30 mins, 1 hr, 2 hrs, 3 hrs, 6 hrs, and
1 day. A jacketed beaker was used to control the temperature of the reaction.This was
especially important because methanol boils at 64°C. The alcohol and catalyst were mixed and
given 30 mins to mix before being added to the grease. Also, the grease was heated to 50°C
before the alcohol-catalyst mixture was added. Samples were agitated before the reaction. After
reacting, the biodiesel and glycerol formed separate layers. The biodiesel formed an opaque
yellow layer that floated on top of the dark brown glycerol layer. These solutions were made
According to the Alcohol Solution Preparation table in Appendix E.
Then, the amount of mixture added to the grease was found by using the Alcohol Addition Ratio
table located in Appendix E.
The factorial design varied alcohol type (ethanol or methanol), catalyst (NaOH or KOH), and
temperature (50°C or ambient). The Experimental Design table is located in Appendix E
5
There were two qualitative tests to determine the reaction quality. In the emulsion test 1 mL of
reactor sample was added to 1 mL of DI water. The test tube was then shaken. If a clear
separation of layers occurred within 10 minutes the sample passed the test [10]. If the layers
instead formed a milky white emulsion the sample failed the test [10]. Then, in the completion
test 1 mL of reactor sample was added to 9 mL of methanol. Unreacted material then formed on
the bottom of the test tube. The more material at the bottom of the test tube, the worse the
sample. The following samples were deemed to have performed well based on the criteria from
the two quality tests.
Alcohol
Catalyst
Time
Temperature
MeOH
KOH
2.5 hrs
ambient
MeOH
KOH
35 mins
50°C
EtOH
KOH
50 min
50°C
EtOH
KOH
2.5 hrs
50°C
EtOH
KOH
6 hrs
50°C
It was found that methanol with KOH at 50°C and a reaction time of 35 minutes produced the
optimal results. This reaction had a quick separation in the emulsion test and left no visible
residue in the reaction completion test. Ergo, our group used these conditions for the rest of the
design.
Please refer to the lab operating procedure in Appendix J
BFD
6
The main process that is being proposed involves reacting used vegetable grease with
methanol, in the presence of a potassium hydroxide catalyst. On a per batch basis, it can be
expected to react about 215 kg of this used grease with about 40 kg of methanol. This will
produce about 150 kg of biodiesel product. The product will be water washed to remove water
soluble impurities, and this step will consume 155 kg of water. It is expected that approximately
265 kg of waste will need to be disposed of for per batch.
PFD
A more detailed explanation of the process is located in the PFD Appendix.
Process Description
Used cooking grease is put through a mesh filter, F-101, then put into the holding vessel V-101.
The filter removes food particles and other solid contaminants. Then the heated grease is fed
into the reactor vessel, R-101. Meanwhile, sodium hydroxide is mixed with methanol in V-102,
the mixing tank. This solution will be allowed to mix for 30 minutes. When fully mixed, the
solution will be gravity fed into the reactor, R-101, and the reaction will be begin.
The reactor contents will be stirred for 35 minutes as it reacts, then will be allowed to settle for
24 hours. When sufficient settling has occurred, two product layers will be formed: a dark,
viscous layer consisting primarily of glycerol and excess methanol (bottom) and a lighter layer
composed of biodiesel (top). Elevation will be used to gravity-drain the glycerol layer into V-103.
Valves must be aligned to ensure the flow is not traveling to the product holding tank. A sightglass will be used to indicate when a complete drain-off of the glycerol layer has occurred, as an
interface between layers will be present.
The biodiesel layer still remains in the reactor at this point. A washing step will be performed to
remove any methanol and KOH, as well as any water soluble impurities left in the biodiesel. The
reactor will be spray filled with domestic water, stirred, and allowed to gravity-separate into two
layers: water and methanol (bottom) and biodiesel (top). The water layer will be drained into the
waste tank, V-103.
Presently, we estimate that three washing steps will be required to remove enough methanol to
meet national standards (ASTM D975-14 and 7467-10 ) [4].
After three washings have been conducted, or until the settled wash water is clear, the biodiesel
will be drained to the product holding tank, V-104. The biodiesel is now ready to be used (either
straight or blended with petroleum-diesel). The waste tank contents, V-103, will be properly
disposed of by a hazardous waste treatment company.
It is important to note that the diaphragm pump, P-101, and the agitators on the mixing vessel
and reactor are air powered, with the compressor, C-101, providing the air supply. This is done
to keep the process intrinsically safe.
Operating Details
This is a batch process. Approximately 2 batches will be run per month using 215 kg of waste
grease and producing 150kg of biodiesel per batch. However, the number of batches run per
month will be variable depending on the food court and dining center’s usage of grease.
Conditions for the reaction will be in accordance to the optimized experimental results. First, the
grease will be given 2 hrs to reach 50°C. Then, the reaction will be run at 50°C in a jacketed
7
reactor in order to control the temperature of the reaction. An average of 1.5 gal/min will be ran
through the cooling jacket. This number will be variable however as the amount of heat
produced will be larger at the start of the reaction. This assumes that the water will be fed at
20°C and have a maximum increase of 15°C.The reaction will be given 35 minutes to run with
agitation. Then, excess cooling will be ran through the cooling jacket in order to quench the
reaction. After 35 minutes the biodiesel and glycerol will be given 24 hrs to gravity separate.
Next, the glycerol layer will be taken off using a sight glass to discern the differences between
the layers. Three water washes will be run on the biodiesel or until the water is clear. Waste
water is drained to waste after each wash and finally the biodiesel will be drained to the product
holding tank.
Our process makes 46 gallons of biodiesel per batch, which comes out to about 1200 gal/yr
although it was noted that summer usage will vary greatly. UMD has 15 diesel powered vehicles
on campus, two of which have been modified to run on concentrations higher than B20 [11].
According to fleet services UMD purchased 6200 gallons of diesel fuel in 2013 [11]. Thus, the
amount of biodiesel produced would be very close to the 20% needed for the B20. Excess
biodiesel would be used in the two vehicles that can run B100. Also, selling excess biodiesel is
an option although it would not be optimal as additional permits would be needed [16].
Process Alternatives
There are some interesting process alternatives that should be investigated more thoroughly.
The first alternative process could use ethanol instead of methanol, which would eliminate many
of the safety considerations needed for methanol. In order to get the same amount of product as
the methanol reaction, more ethanol will have to be used. This will increase the raw materials
cost significantly. This process would also require a liquor license in order to store and use the
ethanol on campus [6].
Recycling methanol can also be incorporated to the existing process by taking the waste
products and distilling the methanol out. This would save a significant amount of money on
methanol. This process is very energy intensive, using heat to separate the methanol from the
waste, which contains methanol, glycerol, potassium hydroxide, unreacted cooking oil, and
water.
A continuous methanol process using a membrane reactor is also another option. The
membrane reactor would split streams of biodiesel and methanol-glycerol-water products, and
recycle the methanol back into the system. This process is very different from the process that
was recommended, but produces the same final results with respect to biodiesel production.
This process is advantageous because it separates the product while it is reacting, pushing the
reaction forward. This process is very difficult because it requires the reaction to be around
65°C and the methanol ratio has to be watched very carefully for the reaction to take place. The
membrane also needs to be replaced regularly.
The last suggestion would be purchase an automated, off-the-shelf biodiesel machine. For
instance, the BioPro 380 is capable of performing the reaction, washing, and separation steps
8
with little human interaction [9]. The capital investment associated with this unit is comparable to
the process suggested. This only takes into account the reaction vessel, other vessels will still
have to be connected for this machine to work.
Key Design Assumptions
● 20% Safety factor for vessels
● Constant methanol miscibility
● No heat lost to environment
● KOH doesn’t add volume
Material and Energy Balances
The final material balance is available below.
Component
1
2
3
4-glycerol
drain
4-wash
#1
4-wash
4#2
wash#3
5
Grease (kg)
216.5
216.5
-
-
-
-
-
21.7
Methanol
(kg)
-
-
39.3
-
5.6
4.1
2.9
5.5
KOH (kg)
-
-
5.71
-
1.77
1.31
0.92
1.72
Water (kg)
-
-
-
-
98.8
105.9
111.2
-
Glycerol (kg)
-
-
-
20.3
-
-
-
-
Biodiesel
(kg)
-
-
-
-
-
-
-
153.4
Total Mass
(kg)
-
-
-
-
-
-
-
-
Total volume
(L)
230.4
230.4
49.6
16.1
105.9
111.1
114.8
205.2
Four distinct flows utilize stream 4, the glycerol drain and three washes.
Utility
Cooling
water
(gal/min)
Electric
(kW)
E-101
C-101
P-101
R-101
Agitator
-
-
-
1.5*
-
2.0
3.4
-
-
-
9
Pressurized
Air, 20 psig
(SCFM)
-
-
10
-
5
*mean flow rate during reaction step
Equipment Design
The equipment used in this process is typical in chemical process. The full equipment list and
their technical specifications are listed in Appendix A. Please refer to Appendix B for the
equipment design calculations. Brief descriptions of the design and pricing of the equipment is
listed below:
The vessels in this process (4 total) were priced using CapCost by specifying orientation, size,
and material of construction [17] . There were some assumptions made with respect to pricing
vessels. All vessels are oriented vertically. All vessels are cylindrical. The diameter of each
vessel is half of the height. Vessel volumes were calculated from the amount of material the
vessel would need to contain from the MEB, +20% as a safety factor. Solver was used in
Microsoft Excel, by setting the volume of a cylinder equal to a given volume. Diameter and
height were set to change, as diameter was constrained to be half the height of the vessel. Tank
V-101 or V-104 may be a drum instead of a hard piped vessel. This will depend on the location
of the process. Most of the vessels and piping will be made with stainless steel 316 due to its
excellent resistance to damage from KOH [18].
The reactor R-101 was priced using CapCost [17]. Multiple assumptions were used in this
estimate. It was priced as a jacketed, agitated reactor. The volume of the reactor was estimated
using the information from the MEB. The vessel jacket is going to be used to maintain the
reaction at 50°C, and it may also be used if reactor temperature adjustment is desired [14].
Process control equipment could be used to keep the temperature of the vessel at 50°C. Please
refer to Appendix B for specific calculations. This design includes: analog in & out, digital in &
out, a control cabinet, and a control valve [19]. Also, it assumes that an old computer could be
donated by the school.
An agitator, filter, and valves were priced from an online source [20][21][22].The agitators are
going to be pneumatically powered. As noted in the experiments section the mean particle size
in the waste grease was less than 10 microns. Ergo, the filter will mainly be used to separate
large pieces of debris from the unreacted oil. For this purpose a 30 mesh filter will be used[20] .
Valves were assumed to be 1” stainless steel hand operated ball valves [21]. Please refer to
Appendix B for specific calculations.
An immersion heater was priced from an online source [23]. This heater will be inserted into the
grease storage tank, V-101, in order to preheat the oil to 50°C for the reaction. With it’s given
heat rate, it was calculated that the preheating process would take roughly 2 hours, which is a
reasonable amount of time. Please refer to Appendix B for specific design calculations.
10
The pneumatically powered diaphragm pump will be used to transfer heated oil from V-101 to
R-101[24]. This was sized by assuming the inlet and outlet was 1” to fit the pipe. A target flow
rate was chosen and matched to a total head which needed to be greater than the height
needed to pump. Please see Appendix B for specific calculations.
An air compressor will be used to provide pressure to drive the pump, as well as the agitators
[25]. A large “shop” air compressor should be sufficient for this process [25]. Appendix B
contains the specific design calculations.
Other Studies
Waste Handling
There are two main options for handling our waste. First, the waste could be taken and treated
by the UMD department of environmental health and safety [6]. This would be optimal although
the university would still have to pay for waste treatment. The second option would be treat the
waste at the Western Lake Superior Sanitary District’s (WLSSD) sanitary site [7]. However, this
poses a number of issues. First, the pH of the waste will be extremely high due to the almost 6
kg of unreacted KOH remaining in the waste. The pH of the waste would need to be 12.5 or less
in order to be non-hazardous so acid would need to be added at the end of the process [26].
However, the waste is less than 24% methanol by mass so the methanol content in the waste
would not be a problem [8]. Then, the waste would need to be tested in the WLSSD lab in order
to determine an exact cost for treating the waste [7]. According to a chemist at WLSSD the cost
of treating the waste would be about $20 per 55 gallon drum or less [7]. Also, the waste would
need to be hauled to WLSSD. Hauling would not need to be considered if the waste was treated
by the UMD department of EHS [6]. Hauling the waste to WLSSD would require a $200 hauling
license that is good for 5 years [7]. The waste can be hauled in any vehicle [6].
Future Considerations
Once this process has been built, the reaction will have to be optimized. Experimentation has
been done at ambient temperature and 50°C, where 50°C was found to produce the least
amount of glycerol. This was the result of our experimentation, though this does not mean there
is not a more optimum temperature. This will have to be investigated further after the process
has been built. It will be important to test the biodiesel that is produced from this process to
ensure it complies with ASTM standards. If it is not able to pass the ASTM standards, the
washing step will have to be reengineered, and the biodiesel will have to be tested again [4].
Once the biodiesel has been tested completely and the reaction optimized, UMD will have the
option of sharing this idea with others in the community. If UMD is able to convince other food
services to donate their used waste oil, they could potentially make a larger profit.
Economic Evaluation
This section of the report will cover the economic analysis done with respect to the biodiesel
production process. The following will be explored: assumptions, equipment cost, fixed capital
investment, manufacturing costs, investment analysis, sensitivity analysis, base case
comparisons, and a discussion.
11
Key assumptions
● Since there is uncertainty as to the location of the process, cost of land or a building
were not included in the capital costs.
● 26 batches would be run per year
● Price of biodiesel is constant
● Price of raw materials is constant
● 1 year construction period
● 525.4 was used as the CEPCI
Equipment cost summary
The vessels and reactor were priced using CapCost [17]. The compressor, agitator, valves,
filter, heater, and pump were priced using various online sources [21][23][20][22][24]. Below is a
summary of the equipment capital costs. More detailed information can be found in Appendix C,
which includes CapCost printouts.
Equipment name
Cost
R-101
$11,200.00
V-101
$2,810.00
V-102
$2,810.00
V-103
$3,110.00
V-104
$2,810.00
Compressor
$500.00
Diaphragm pump
$1,000.00
Filter
$32.50
Agitator 1
$1,000.00
Agitator 2
Included
6 Valves
$900.00
Heater
$300.00
Total Purchased Cost $26,472.50
Fixed Capital Investment
In CapCost it was assumed that the FCI was $32,900. This includes the total equipment
purchased cost, raw material costs, utilities, waste treatment, and operating labor. Please refer
to the CapCost screenshot in Appendix D.
Manufacturing Cost Estimate
Raw material prices are shown in the table below, and were priced using Business Source
Premier [27][30]
12
Raw Material
Methanol
Potassium Hydroxide
Ethanol
Biodiesel
Total (using methanol)
Total (using ethanol)
Cost/Batch
$
59.31
$
185.66
$
47.62
N/A
$
244.97
$
233.28
Value/Batch
N/A
N/A
N/A
$
239.95
$
239.95
$
239.95
Cost/Year
$ 1,067.53
$ 3,341.85
$
857.15
N/A
$ 4,409.38
$ 4,199.00
Value/Year
N/A
N/A
N/A
$ 4,319.08
$ 4,319.08
$ 4,319.08
When only considering the cost for raw materials and the projected sale price for each batch,
both methanol and ethanol appear to be economically feasible options. When factoring in the
cost of utilities, the esterification process using methanol is still profitable, however using
ethanol is no longer a profitable alternative.
The cost of utilities is insignificant when compared to the raw material cost. The table below
summarizes yearly utility costs.
Utility
Cost ($/yr)
Electricity
27.44
Cooling
Water
17.84
Wash Water
3.84
As far as operating cost, a student or operator would be paid $20.00/hr to operate the process.
This equates to $2080/yr assuming 4 hr/batch. This is one reason why it is advantageous not to
run smaller batches in smaller vessels. As equipment would decrease in size, labor costs would
go up. The process is very sensitive to labor costs, as explored in the sensitivity analysis.
Waste disposal is a significant piece of the cost of manufacturing. For reasons explained in the
Waste Handling section of the report, the waste cost estimate would likely be around $650/ year
based on the volume of waste produced per year from the MEB [7].
It is important to note that there is additional cost savings associated with this project due to a
tax incentive for biodiesel production. Assuming the biodiesel would meet the required ASTM
standards, UMD would be eligible for a $1 tax credit for every gallon of biodiesel produced [29].
Based on production of roughly 1200 gallons produced per year, this credit would equate to
$1200/yr of additional savings.
The money saved by producing biodiesel is very significant. The use of biodiesel is essentially
displacing the purchase of regular diesel, resulting in cost savings. The price of biodiesel is
$3.94/gallon [15] and the current price of diesel is $3.89/gallon [15], so they are comparable in
cost. After subtracting operating cost, the product produced in this process is worth roughly
$5500. The tax credit makes this product even more valuable.
13
Sensitivity Analysis
A sensitivity analysis was done using CapCost. The following parameters were changed ±0.5%:
raw materials, operating labor, and waste treatment. While the sensitivity analysis table is
located in Appendix D the graph is included below.
According to the table in Appendix D, changing the operating labor had the largest effect on
NPV, thus the largest sensitivity. This implies that if wages were lowered, the project would be
more profitable more quickly, than if waste treatment costs were cut by the same proportion.
Investment Analysis
This project is profitable, but only after a long period of time. The cash flow diagram is shown
below. [17]
14
The operating costs are fairly high as well as the capital costs, and this drives the NPV down. It
eventually starts to climb after 20 years. The equation of the positive-slope line was calculated
and the process was calculated to break even after 41 years.
It is important to note that this project is not economically driven [2]. There are additional factors
that will affect payback period that are not accounted for quantitatively. For example, if the price
of biodiesel decreases, this project will become less profitable since eventually the cost of
manufacturing will be greater than the equivalent savings from producing the fuel at UMD. On
the contrary, the project would be economically beneficial to the school if additional students
enrolled or resources were provided due to this project being green and attractive.
Other Important Considerations
Safety
Safety was considered throughout the entire process design. Methanol is a flammable liquid
[30], so all of the containers should be bonded and grounded. Grounding strips will be required
wherever the process is placed. Air powered agitators and pump were used in order to eliminate
spark hazards from the electrical motors [22][24]. Regulators will be present on the pump air
supply in order to prevent a large increase in pressure. Containment dikes will surround all
tanks. Methanol is used in this process, so the facility house will need to be thoroughly
ventilated and have adequate exchange with outside air [30]. Operators will need to be
extensively trained using the process. A standard operating procedure will be posted next to the
equipment in order to make the process easier to understand. Materials and waste will be kept
in special areas and containers. The another important aspect of safety is that the operators
should wear proper personal protective equipment. Gloves and goggles should be worn at all
times. A respirator should be worn while working with the methanol. A lab jacket should be
15
worn. Static eliminating boots with steel toes should also always be worn. If there is a splash
hazard the operator may want to wear a face guard and apron as well.
Please refer to Appendix H for the safety tables.
HAZOP
The HAZOP was done around R-101, the Batch Reactor. Many of the hazards are related to
filling issues, heat issues, and reaction progression. The action items usually require operator
input, since this process is a manual batch process. This puts a lot of responsibility on the
operator and assumes they are competent. Process control, which is discussed below, could
reduce some operator input and aid in safety. Please refer to Appendix G for the reactor
HAZOP.
Environmental
An analysis was conducted to determine the project’s environmental impact. The analysis was
performed by assuming the total annual biodiesel production will be used to replace an
equivalent amount of petrodiesel. The analysis indicates that total greenhouse gas emissions
will be reduced by 13.7 metric tons of carbon-dioxide equivalent, annually. Although the
biodiesel combustion itself does not result in a net addition of carbon-dioxide to the environment
(as the grease is sourced from biological sources), other greenhouse gases--primarily methane
and carbon-monoxide--are released [14]. Additional pollutants are released during the
production of methanol and KOH, and for product, reactant, and waste transportation. A full
description of the analysis is available in Appendix I.
Control Issues
Although our design does not include a control system, a control system for the flow rate of
cooling water on the reactor is available for $2000 [19]. This includes: digital in, digital out,
analog in, analog out, control valve, and control cabinets. This has several advantages to just
having a flow meter. First, the heat given off by the reaction will be variable as the reaction
proceeds [31]. Having controls in place would adjust the cooling water flow rate accordingly. If
for some reason the reaction heat too quickly and runs away, it could automatically activate a
water quench to immediately stop the reaction [30]
Discussion of Results
This process will cost $26,500 but will save UMD $1500 annually. The payback period for the
project is expected to be 41 years. This project can be used to bring in additional students with
interest in sustainability to UMD, which would be an additional financial benefit. Our process will
produce 1200 gallons of biodiesel per year. Since this is more than 20% of what UMD currently
uses, all the B20 produced could be used by 15 diesel vehicles present on campus. Excess can
either be used in the two modified vehicles that can run B100 or sold with additional permits.
Next, this project meets the objectives set by the UMD department of sustainability and will
conserve 13.7 metric tons of CO2 per year. A location for the waste will still need to be found or
fabricated which will incur additional costs. Approval from the city fire marshal will be needed
wherever the process is located. Also, the biodiesel will need to be tested to ensure it meets
16
ASTM standards before it can be used. With respect to waste, better separation techniques can
be used in the future to separate out the glycerol and methanol although this could potentially
very costly. Automated biodiesel processors are available that contain the entire process in a
housed system and are comparable in price to our process.
Conclusions
This project meets the sustainable guidelines set forth by the UMD office of sustainability [2].
Compared to the current situation it will save a significant amount of CO2 from entering the
atmosphere each year. It is sustainable because it reuses waste grease. From our findings, this
project is economically feasible over a long period of time. A quality product is anticipated to be
produced from this process.
Recommendations
Further investigation should be conducted on alternative processes before a final design is
considered. Making a decision of where the process should be located should also be
considered before moving further with the project, since the design can become greatly affected
by this. Careful analysis on the amount of money being spent on this project should be
analyzed. Safety issues should be resolved before any large scale production has begun.
References
Appendix A: Equipment Specification Tables
IN excel spreadsheet, uploaded in drive. Will insert after report exported to word
Appendix B: Equipment Design Calculations
All vessels were sized using the process material balance to determine the vessel sizes that
would be required for each step. All vessels are assumed to be cylindrical and vertically
oriented, with their height being twice their diameter. Calculations are shown below:
The volume for V-101, grease storage and heating, was calculated using the volume of the
grease that needs to be stored, from the MEB. A 20% safety factor was added.
280.38 L grease*1.2 = 276.45 L → 280L Tank
17
Microsoft Excel’s solver was used to determine the exact dimensions of the cylindrical vessel.
The assumption was made that the vessel height was twice the diameter, and the calculated the
dimensions of the tank given the volume and the constraints.
d = 0.56 m h = 1.126 m
Volume for V-102, mixing tank, was calculated using the volume of methanol for a batch, with a
negligible volume of KOH solids which will be dissolved into solution. A 20% safety factor was
used.
49.62 L MeOH*1.2 = 59.54 L 60 L Tank
The method to determine the dimensions of the tank are the same as V-101
d = 0.336 m h = 0.674 m
Volume for V-103, waste tank, was calculated using the volume of glycerol, wash water, and
residual KOH and MeOH solution used or produced per batch plus a 20% safety factor.
348.03 L Waste*1.2 = 417.6 L → 400L Tank
The method to determine the dimensions of the tank are the same as V-101
d = 0.634 m h = 1.268 m
Volume for V-104, product holding tank, was determined by finding the volume of biodiesel
produced per batch, plus a 20% safety factor.
205.18 L Biodiesel*1.2 = 246.2 L → 240L Tank
The method to determine the dimensions of the tank are the same as V-101
d = 0.535 m h = 1.069 m
The volume for the batch rector, R-101 was determined by adding the volumes of grease and
methanol+KOH solution for a batch, with an additional 40% factor for safety in case the reactor
must be filled with water to quench a runaway reaction.
280 L grease, MeOH/KOH*1.4 = 392 L → 400L Tank
The method to determine the dimensions of the rector are the same as V-101
d = 0.633 m h = 1.268 m
The pump was sized using a pump curve provided by the manufacturer. Below is the pump
curve.
18
First the air can be supplied at 20 psi. This will be attained by using a regulator. The blue line
corresponding to 20 psig is followed, and intersects the vertical 6 gpm discharge flow line. 6
gpm is a reasonable flow rate since this is a batch process and isn’t dependent on flow rates. A
horizontal line is then drawn to the left until it intersects the y axis. This corresponds to a head of
about 30 ft. The required head was determined to be14 ft, the top of the reactor (needs to be
elevated due to gravity separations, etc.) Since 30 ft>14 ft, this 1” diaphragm pump run with an
air supply of 20 psi will be sufficient.
The process piping was chosen to be 1” SS 316 This is a standard pipe size, and the material
will be able to withstand the chemicals. The valves will be 1” SS 316 hand operated ball valves.
The agitators were sized according to shaft length, and air pressure required. The shaft length
needed to reach near the bottom of the tanks, so a length of 0.5 m-0.6 m was desired for V-102
agitator and 1.0 m -1.1 m. The air pressure requirement for pneumatic agitators of this size is
50-80 psi.
The compressor size was calculated according to required pressure and airflow in order to
operate 2 of the 3 air operated pieces of equipment at a given time. This is consistent with what
will happen during the production process. The pump requires an airflow of less than 10 SCFM
at a max pressure of 20 psi. The agitators operate at 50-80 psi at an unknown flow rate. The
compressor is assumed to be able to provide this, given its max flow rate is 15.5 SCFM.
The filter is a sieve that rests on top of V-101. 30 mesh is used, since it is fine enough to
separate out large food chunks from the remaining oil. Any particles large enough to fit through
30 mesh will likely dissolve during the reaction. A particle size analysis was done using Dr.
Lodge’s analyzer. The mean particle size in the oil was found to be roughly 4 microns, far too
small to filter. For this reason, a finer filter was not used. The results are included below.
19
We decided to use an immersion heater to preheat the grease to the desired reaction
temperature of 50°C before sending it to the reactor. As the vapor pressure of the oil is next to
nothing, we were not worried about being intrinsically safe in regards to oil vapor. This
immersion heater was sized with the objective of increasing the temperature of the grease from
20°C to 50°C, and we assumed that we are only heating the exact quantity of grease that we
will need per batch, about 216.5 kg. That being said, we picked a few different heaters with
varying duties, and calculated the amount of time it would take to heat the grease to 50°C. We
20
settled on a 2KW immersion heater, with a 2 hour requirement to heat the grease, assuming
negligible heat loss to the surroundings. The calculation is shown below:
J
mCp ΔT (216.5 kg)(2.1 Kg*K)(30°C)
Q
=
=
= 6819.75s = 1.89 hours
t =
J
duty
duty
2000 s
Appendix C: Equipment Cost Estimates
The vessels and reactor were priced using CapCost. A screenshot is included below. The sum
of the equipment purchased cost was used as the bottom line.
The price of the pump was taken from Grainger. There were multiple options, the cost was
estimated to be about $1000 [24]
The immersion heater was priced from the online source Gordo Sales. The cost is $323.15 [23].
The price of the valves were estimated at $150.00 per valve, according to Grainger [21].
One of the agitators was included in the pricing of R-101. The other agitator was priced using an
online source, and was estimated to be $1000.00. This was a cost competitive to those provided
by Grainger [22].
The price of the compressor was priced using Grainger. Many of the compressors had similar
specs. The price was estimated at $500 [25].
The price of the filter was found using an online source, and costs $35 [20]. A 30 mesh filter is
appropriate.
21
Appendix D: Economic Analysis
22
The following CapCost screenshot illustrates the parameters used to calculate the cumulative
cash flow diagram and the sensitivity analysis for the base case.
23
The $1200 tax credit was added in to the revenue as $1200/yr of additional profit [32]. The other
COM information was calculated in Excel and simply inserted into CapCost. CapCost was not
used to analyze the alternatives, as the table found in the Manufacturing Cost Estimate section
shows that the ethanol alternative would make significantly less money.
The table used to plot the sensitivity analysis is shown below.
Appendix E: Experiments
Alcohol Solution Preparation
Solution
Volume (mL, approx)
Methanol +
NaOH
Methanol + KOH
Ethanol + NaOH
Ethanol + KOH
20
Mass Alcohol (g,
exact)
15.84
Mass Catalyst (g,
exact)
1.05
20
30
30
15.84
23.67
23.67
2.65
1.09
2.75
Alcohol Addition Ratios
Solution Description
MeOH+NaOH
MeOH+KOH
EtOH + NaOH
EtOH + KOH
Ratio: g solution / g oil
0.169
0.184
0.238
0.254
Experimental Design
Run
1
2
3
4
5
6
7
8
Alcohol Type
Methanol
Ethanol
Methanol
Ethanol
Methanol
Ethanol
Methanol
Ethanol
NaOH or KOH
NaOH
NaOH
KOH
KOH
NaOH
NaOH
KOH
KOH
Temperature
50.0°C
50.0°C
50.0°C
50.0°C
Ambient
Ambient
Ambient
Ambient
Hazop somewhere down here
Appendix #: Lab Standard Operating Procedure for biodiesel experiments
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26
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