University of Nebraska - Lincoln
DigitalCommons@University of Nebraska - Lincoln
Dissertations, Theses, & Student Research in Food
Science and Technology
Food Science and Technology Department
4-2017
Energy-Water Reduction and Wastewater
Reclamation in a Fluid Milk Processing Facility
CarlyRain Adams
University of Nebraska-Lincoln, [email protected]
Yulie E. Meneses
University of Nebraska-Lincoln, [email protected]
Bing Wang
University of Nebraska-Lincoln, [email protected]
Curtis Weller
University of Nebraska-Lincoln, [email protected]
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Part of the Biomedical Engineering and Bioengineering Commons, Bioresource and Agricultural
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Adams, CarlyRain; Meneses, Yulie E.; Wang, Bing; and Weller, Curtis, "Energy-Water Reduction and Wastewater Reclamation in a
Fluid Milk Processing Facility" (2017). Dissertations, Theses, & Student Research in Food Science and Technology. 81.
http://digitalcommons.unl.edu/foodscidiss/81
This Article is brought to you for free and open access by the Food Science and Technology Department at DigitalCommons@University of Nebraska Lincoln. It has been accepted for inclusion in Dissertations, Theses, & Student Research in Food Science and Technology by an authorized
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Energy-Water Reduction and Wastewater Reclamation in a Fluid Milk Processing Facility
CarlyRain Adams, Yulie E. Meneses Ph.D., Bing Wang Ph.D., Curtis Weller Ph.D.
Department of Food Science and Technology, University of Nebraska-Lincoln, Lincoln, NE 68508, USA
A project funded by the United States Geological Services
Energy Consumption
Wastewater generation
Materials and Methods used:
1. Collected and consolidated utility bills
2. Collaborated with electrical company to install meter that would allow for single
unit identification of kWh consumed
Amount Electricity Consumed During Processing vs.
Materials and Methods used:
1. On site visits were made to determine where wastewater was being
generated
2. Analyzed times of mass water consumption based on inline meters
3. Performed water balance for cleaning stage
Introduction
The energy-water nexus is the inseparable connection linking water and energy.
We are faced with a unique opportunity to co-manage these resources, as
conservation of one is directly linked to the conservation of its counterpart.
Therefore, immediately facing this critical challenge, will lead to tangible impacts
on the water and energy crisis our food system is faced with. Determining the role
of water and energy in the food industry has proved to be the starting point for
reducing the distance between process productivity and resource efficiency.
Therefore, this research focuses on determining opportunities for water-energy
optimization and wastewater reduction and reconditioning in a medium sized dairy
plant processing pasteurized fluid milk. The long term goal of this research is to
transform our findings into a set of industry wide guidelines that will create a
culture of water and energy conservation.
Amount of Natural Gas Consumed per month
Cleaning Stage of Milk Production.
800
700
600
2750
Energy (kWh)
Energy (Therms)
3000
2500
2250
2000
1750
1500
1250
500
Processing
400
Cleaning
PERCENTAGE OF WATER CONSUMED DURING A
Percentage
of Water Consumed During a Standard
PRODUCTION DAY
Production Day
Cleaning
Operations
53%
300
200
100
1000
0
Monday
Tuesday
Wednesday
PERCENTAGE OF WATER COSUMED DURING STAGES
OF CLEANING OPERATION
Thursday
Operating day
Objective 1. To determine the baseline quantities of water and energy consumed
by a medium sized dairy plant and to locate potential areas for source reduction
Percent Energy Use/Processing Unit/Day
Water Heater
4%
Amount of Electricity Consumed per month
Objective 2. To design treatments for reconditioning and reuse of the premier
location of wastewater generation
26,000
Energy (kWh)
Materials and Methods used:
1. Designed a process flow diagram
2. Determined inputs (water, milk, natural gas, electricity) of fluid milk processing
3. Determined outputs( wastewater) of fluid milk processing
Water
tank
Raw Raw Raw
Milk Milk Milk
Tank Tank Tank
3
2
1
22,000
20,000
Homogenizer
32%
18,000
16,000
Homogenizer
:
Water Consumption
Bottle Filler
Raw
Cream
Tank 1
Past. Past. Past.
Milk Milk Milk
Tank Tank Tank
7
8
6
Natural
Gas
Electricity
Materials and Methods used:
1. Collected and consolidated water billed data
2. Installed two inline meters to monitor water consumed by boiler and
hourly water consumption
PERCENTAGE OF WATER CONSUMED BY BOILER
Percentage of Water
Consumed
by Boiler (Natural Gas)
(NATURAL
GAS)
Daily Fresh Water Consumption
5000
Boiler
11%
4500
Boiler
Pouch Filler
Other
Total
4000
Figure 1: Process Flow Diagram of Fluid Milk Processing in a Medium Sized Dairy Plant
Spent Caustic
Water
23%
Spent Acidic
Water
5%
Fluid Milk Processing Consumption
Utility
Unit
Amount used
Electricity
Natural Gas
Fresh Water
kWh/ gal. finished milk
Therms/gal. finished milk
gal water /gal. finished milk
0.13
0.02
0.85
Wastewater
lb. wastewater/gal. finished milk
5.26
Discussion:
• Over 53% of the total water, is taken up by the cleaning
operations. Therefore future focus will be on cleaning operations
as means for source reduction
• The water consumed during cleaning is utilized during multistage
cleaning in place systems, cleaning out of place procedures, floor
cleaning, and the running of the homogenizer
• The homogenizer consistently produces wastewater during the
milk processing in addition to cleaning
• It was determined that 74.35% of the fresh water brought into the
plant became wastewater
Research Impact
1. Assisting dairy plants in process optimization
2. Water and energy conservation and wastewater reduction
3. Reclamation of wastewater generated
3500
Gal.
Discussion:
• It was uncovered that the production of milk involves many high energy
processes, including: receiving, separation, standardization, HTST
pasteurization, cooling , and packaging of milk
• The medium sized dairy plant that this research was conducted in,
produces 7,262 gallons of milk each day
Spent
Sanitizer
Water
17%
Air
Conditioner
Process Room
6%
Chiller Unit
30%
Billing Cycle Month
Liquefier
Milk
Hose Water
22%
10,000
Discussion:
• Electricity and Natural Gas are the two forms of energy used
• 24.84% of the total kWh consumed during an average production day is utilized
for cleaning operations
• Natural gas is solely used to heat water through steam production
• The largest consumer of electricity is the homogenizer. This machine runs during
both the processing and cleaning operations
• The remaining 11% of energy consumers consists of: lights, agitators, tank
pumps, compressors, pouch filler, liquefier, transfer pumps, and pasteurizer panel
Water
Milk Processing
47%
Rinse Water
21%
12,000
Receiving
Past. Past.
Milk Milk
Tank Tank
5
4
Homogenizer
12%
14,000
Separator
Balance
Tank
Bottle Filler,
Bottle Cap,
Conveyor
12%
Seperator
5%
24,000
Process flow
Pasteurizer
Percentage of Water Consumed During Various
Stages of The Cleaning Operation
Billing Cycle Month
3000
2500
2000
Future Steps
1500
1000
500
0
Monday
Tuesday
Wednesday
Thursday
Weekday
Friday
Saturday
Sunday
Other
89%
Discussion:
• Boiler feed water Is utilized during pasteurization, automated, and manual cleaning
• Other water is involved with separation and homogenization of milk and acidic
sanitization
1. To perform a risk-based assessment/ simulation for the reuse of
recovered cleaning in place wastewater
2. To implement recommended protocols for increased source
productivity
3. To determine the effectiveness of implemented recommendations