TALL OIL PRODUCTION AT ITS BEST
Swedish Tall oil Solutions, STS, is a part of the Projektengagemang® group which specializes
in solutions in recovering tall oil. Besides from our own tall oil production plant concept, we also
deliver engineering services with main focus on optimizing soap quality. Our team also provides
feasibility studies regarding all aspects of the mill when a new tall oil plant is to be installed.
Our mission is to give our customers the best possible solution when it comes to producing tall
oil. The goal is to deliver a complete function, taking all aspects of tall oil production into account.
As this is specific for each individual mill, we customize every plant to fit our customers’ needs.
The STS team always aims to optimize both function and results.
The name Tall oil originates
from the Swedish word
Tallolja (pine oil).
MODERNIZED TECHNOLOGY FOR OPTIMIZED TALL OIL PRODUCTION
Based on efficient and proven technology, Swedish Tall oil Solutions offers a modern and high performing plant for
producing tall oil. Our plant is a result from a close collaboration with experts and operators with practical experience of
tall oil production.
It all started with a vision to produce high quality tall oil in a safe, easy and cost effective way. In order to make our plant
as effective and easy operated as possible, the development team identified a few important problem areas within existing
techniques on the market. Furthermore, specific limitations connected with batch technology were listed as important
factors for improvement.
Today, thanks to the thorough work carried out by our development team, STS is proud to offer a modernized plant with
significant improvements in areas such as:
•
•
•
Yield, quality and consumption of media
Plant operation
Maintenance and availability
•
High yield, quality
and availability
•
Simplified plant
operation
•
Reduced maintenance and media
consumption
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IMPROVED YIELD & HIGHER QUALITY
When producing tall oil, the quality of the soap is a vital keystone. Functional skimming methods and large storage
volumes are important factors for an optimized soap handling and enhanced tall oil production. But even if the mill
does not provide a satisfactory soap handling system, the STS plant is the best alternative available on the market.
It performs remarkably well even when the quality of the soap is not optimal.
By increasing the reaction time between soap and acid in the STS plant, we have managed to enhance the quality
of the tall oil as well as improving the yield. To verify the high quality of the end product, it is measured in-line as the
tall oil leaves the reactor. In addition, the operator can visually inspect the tall oil from the control room via camera
surveillance. Thus, proper quality for further processing is secured both visually and by in-line measurement.
In order to make our plant as competitive and effective as possible, the media consumptions have been optimized
to a minimum. Since the process requires minimal usage of water, there is no need to dry the tall oil and decrease
its water content. Furthermore, due to long reaction time, the usage of acid can be kept low. In the STS plant, even
the electrical costs are optimized to a minimum, since the pumps is the only equipment requiring electrical power.
Every plant is optimized for the specific needs of each mill; no equipment is oversized and electrical power is set to
correct levels. In every project STS performs extensive laboratory researches on the specific soap of each mill, in
order to find the optimal dosage of chemicals and size of equipment.
SIMPLIFIED PLANT OPERATION
One of the highlighted problem areas in former batch techniques was the time consuming operation of the plant.
With modern control equipment and built-in cleaning sequences, the operator of the STS plant can easily operate
other departments in the mill simultaneously.
All components in the STS
plant come from high quality
manufacturers and suppliers.
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Modern control
equipment and
built-in cleaning
sequences simplifies
plant operation.
There are only a few operating sequences included in each batch, and none of them requires the operator to leave the
control room. The operator can visually inspect the produced tall oil at any time from the control room, since a camera
is located above the reactor hatch. Hereby, time spent on operation is significantly reduced and control room work is
made as easy and effortless as possible. Normally, less than 5 minutes of active control room work is required during a
full process cycle.
EXCELLENT PLANT AVAILABILITY
The STS plant is adaptive and highly functional, even in poor production conditions. For example, when soap has high
contents of calcium, fibre, lignin or dirt, the plant is still able to perform remarkable results. Compared to many other
techniques available on the market, variations in soap quality are handled significantly well.
Quite frequently, many pulp mills has irregular production of soap, depending on season, or if using hardwood or softwood in the production. Furthermore, the content of tall oil in the soap depends on the storage-time of the wood, and
season of the year. However, these irregularities are not a problem, as the STS plant does not require a minimal flow
in order to function. Instead, tall oil is produced whenever enough soap is available for one batch, which guarantees
effective production.
After each batch is completed, the reactor and the surrounding equipment in the STS plant are rinsed in the built-in
cleaning sequence. This feature enables short shutdown and start up times between productions.
REDUCED MAINTENANCE
Since cost effective operation depends on high availability and steady production, the maintenance in the STS plant is
kept to a minimum. Thanks to the built-in cleaning sequence there is no need for manual cleaning, and the plant is
optimized for short shut down and start up times.
Furthermore, since all the components in the plant come from high quality manufacturers and suppliers, and since
there are no moving or internal parts in the reactor, the need for repairs and maintenance can be kept low.
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HOW THE PLANT WORKS
Tall oil production in the STS plant involves seven process
stages, which the plant operator performs in four sequences
from the control room:
1. Tall oil reaction
2. Separation
3. Emptying of reactor
4. Cleaning
A full process cycle of the plant is approximately 6 hours,
but normally the operator does not have to spend more
than 5 minutes in the control room in order to carry out the
process. However, during the reaction sequence (around
70 minutes), the operator is recommended to monitor the
process from time to time, in order to guarantee a good
result.
Daily supervision of the plant shall be carried out, but as
mentioned earlier, there is no need for maintenance of the
STS plant during normal operation thanks to built-in rinsing
sequences. At total, with a tall oil production of 10 000
tons/year, less than 20 hours/year are normally needed
for manual cleaning and supervision of the plant.
PRODUCTION OF TALL OIL IS BEST
EXPLAINED IN SEVEN STAGES.
1.
2.
3.
4.
5.
6.
7.
Soap handling
Tall oil reaction
Separation of tall oil and residues
Drying of tall oil
Acid water recovery
Residues and rinsing water to evaporation plant
Ventilation and gas handling
1. Soap Handling
As mentioned earlier, the key to successful tall oil production
is proper soap handling.
Soap, consisting of fatty acids, is released from wood
when pulp is produced. The soap is separated from the
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black liquor and since its density is lower, the soap floats
on top of the liquor. The difference in density between the
soap and the liquor makes it possible to separate the soap
by skimming and store it in a soap tank before it is being
processed into tall oil.
Tall oil production starts by pumping soap from its storage
to the homogenization tank until it has reached a satisfactory level. The purpose of the homogenization tank is
to maintain a high and even soap quality throughout the
whole batch.
Before the soap enters the reactor, it is possible to drain it
from liquor even further.
This process is carried out in the homogenization tank by
draining the soap from liquor and pumping the drained
liquor back to the evaporation plant. When the draining is
completed, soap homogenization takes place by circulation
of the soap in the homogenization tank.
The homogenization tank is an extra option for the plant,
since good quality soap can be pumped directly from the
soap storage tank to the reactor.
2. Tall oil Reaction
2. Tall oil Reaction
Before the process starts, the reactor is heated by direct
injection of low-pressure steam. When the temperature in
the reactor reaches a sufficient level, the soap is pumped
from the homogenization tank – where it has been
circulating – into a static mixer. Here, the soap is being
mixed with sulphuric acid before entering the reactor.
The temperature is constantly monitored and thus also
the reaction. The main reaction proceeds as long as acid
and soap is still being pumped to the reactor. When the
whole batch has entered the reactor, the soap, acid and
steam flows are shut off. Then, the mixture settles and
the separation process starts.
Tall oil leaves the reactor in the upper part where it
overflows, either to a storage tank or to the optional dryer
cyclone. Recovered acidulation water, pumped from the
acid water tank, slowly presses the tall oil upwards and
causes it to overflow. The conductivity of the tall oil is
measured when it leaves the reactor. The in-line conductivity measurement controls the overflow; overflow is
stopped when conductivity changes, hence all of the tall
oil is recovered from the reactor.
4. Drying of Tall Oil
3. Separation of Tall Oil and Residues
Tall oil separates from the residues as its density is lower.
Since this separation occurs slowly during a long period of
time in the STS plant, it enables the remaining reactions
in the process to be completed. Furthermore, it creates
an even better separation between tall oil and residues
than other plants.
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The goal is to deliver
a complete function,
taking all aspects of
producing tall oil into
account. As this is
specific for each individual mill, we customize
every plant to fit our
customers’ needs.
When producing tall oil with other techniques, water is
normally added to the process, resulting in a need for drying
the oil before further processing. In our plant, however, the
produced tall oil has a water content of less than 1,5 %,
when leaving the reactor. Hence, there is no further need
of drying.
However, if our customers specifically request the water
content to be below 1 %, the tall oil can be further dried in
the STS plant through our optional vacuum drying system.
5. Acid Water Recovery
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The residues from the reaction can be handled in the
mill’s evaporation plant. In order to minimize the load in
the evaporation plant, acid water is recovered to the acid
water tank to be used in the next batch. As soon as the tall
oil has left the reactor, the fluid is pumped back to the acid
water tank until it is full.
During the recovery process, the acid water is mixed with
cold water in order to reduce temperature of the fluid and
thereby minimize its impact on the piping system.
6. Residues and Rinsing Water to Evaporation Plant
When all recoverable acid water has been retrieved, adding
NaOH in the reactor neutralizes the remaining residue.
Then, the neutralized fluid is pumped to the evaporation
plant where it is mixed into the mill’s liquor system.
When sulphuric acid reacts with soap, hydrogen sulphide
H2S is formed. The gases from the reactor are led to a
scrubber where they are washed with white liquor in order
to remove the H2S. The fan evacuates the gases into the
atmosphere or to a suitable gas collecting system.
After each batch, the reactor and surrounding equipment
are rinsed with hot water. As soon as the reactor is emptied
from residues and rinsing water, it is ready for next batch.
When the STS plant is running at full capacity, the
preparation of soap has already taken place at this point.
This means that the reaction sequence can start immediately after the reactor has been emptied.
7. Ventilation and Gas Handling
THE STS PLANT IN STATISTICS
CONSUMPTIONS (KG/TON TALL OIL)
RECOVERED CRUDE
TALL OIL PROPERTIES
Cold water (20°C)410
Sulphuric acid (96 %)190
White liquor100
Hot water (55°C)90
Low pressure steam60
NaOH (50 %)50
Water content
without drying
0,8 – 1,5 %
Water content
with drying
< 1%
Acid number
>140
* Based on typical Swedish softwood
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KEY FEATURES OF THE PE PLANT
Modern & Easy Operated Technology
The STS plant is one of the most modern plants on
the market. All its functionality is based on well-proven
technique of producing tall oil. With up-to-date control
equipment and only a few minutes of active control room
work, there is no need for a separate operator. Instead,
another department, such as the evaporation, can operate
the plant. Furthermore, the production of tall oil can be
stopped at any time, if there should be a need for this,
without any further actions such as cleaning or draining.
Availability and Yield
Thanks to its highly adaptive functionality, the STS plant is
less sensitive to calcium, lignin, fibre and dirt. This means
that the plant performs remarkably well even when the
quality of the soap is not optimal. As a result from the
increased reaction time, the tall oil yield is improved. In
good production conditions more than 95 % of all available
tall oil in soap can be recovered. The quality of the produced
tall oil is secured by in-line measurement and visual
inspection through camera.
Built in cleaning sequences, in combination with no
moving internal parts and high quality suppliers, assure an
average availability of above 97%.
No Minimum Requirement for Operation Flow
Since soap is processed whenever it is available, the STS
plant is ideal when pulp is produced in campaigns between
hardwood and softwood, or when soap production is
subjected to other irregularities.
Cost Effective Operation
Thanks to the plant’s effective and modern technique,
together with a mill specific optimization, the media
consumption is kept to a minimum throughout the whole
process. The low media consumptions, combined with the
energy efficiency of the plant, leads to a very cost effective
operation. Additionally, the maintenance of the plant is
kept to a minimum.
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REASONS TO CHOOSE SWEDISH
TALL OIL SOLUTIONS
Each STS Plant is Customized According to Your
Conditions
Since your production and effectiveness is crucial to us,
our plants are customized to fit your demands, whatever
they are. For example, each STS plant is tailored according
to mill capacity and quality of raw material, in order to
make it as effective as possible.
Furthermore, we can help you adapt your new STS plant
into an existing building. We also offer the possibility to
reuse some of your existing equipment and implement it to
your new plant.
Engineering Services and Feasibility Studies
Our specialists are available for analyzing all steps in your
process having an impact on tall oil production. By optimizing soap skimming, soap storage, usage of media and all
other aspects having an influence on a new STS plant,
successful tall oil production can be ensured.
Our experts can also assist with a variety of feasibility studies,
including determining the impact on existing mill when tall
oil production is initiated. The STS team delivers a complete
solution when it comes to optimized tall oil production.
Logistics
Finance
Together with our partners, STS are able to provide
transportation solutions of tall oil to refineries.
STS can provide financial counseling, and find ways for
investments, in order to help our customers to secure
the project funding.
Soap handling
Feasibility studies
Our experienced process team has
many years of experience with improving
existing liquor and soap systems. The
team can provide recommendations of
actions needed in order to have the best
possible conditions for high quality tall oil
production, with high yield and availability
of the plant.
STS can provide a pre-engineering
phase, where we execute a processand mill mapping of existing systems.
The feasibility studies can include:
•
The STS team can:
•
•
Collect process data from the black
liquor and soap recovery, and
compare these with theoretical
process values to determine the
efficiency of the system.
Perform mechanical inspections
of existing soap skimming system
and tanks.
•
Perform mass balances of the
black liquor and soap system.
•
Study current routines and strategy
on how soap is recovered from the
system.
Studies, reports and recommendations on actions that should be
taken to prevent issues that may
occur in the evaporation plant,
when a tall oil plant is installed at
the mill.
•
Mill mapping and recommendation on actions of improvements,
regarding existing process media
systems needed in new tall oil
production plant.
•
inding the best possible location
and providing a layout proposal
for the new tall oil plant in
existing mill.
•
Recommendations on how to
reuse existing equipment in the
tall oil production.
Service
Service of our tall oil production plants is performed by our service team. A part
of our service concept is also to make improvements and upgrades of existing
tall oil production processes.
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Sales Manager
Jan Ljunglöf
Mobile: +46 (0) 70 510 83 42
Tel: +46 (0) 10 516 06 60
Fax: +46 (0) 10 516 06 61
[email protected]
Swedish Tall oil Solutions
Projektengagemang i Stockholm
Strågatan 3
653 43 Karlstad Årstaängsvägen 11
100 74 Stockholm
SwedenSweden
[email protected]
www.swedishtalloil.se
projektengagemang.se