CASE STUDY #222
1. Headline: Reduction of COD and water consumption in a
textile slant.
2. Background: The company process about 850 tons of textiles
per year. The main operations are coloring, washing, peroxide
bleaching, apperature treatment, drying and calendaring. The
raw materials are mainly woven textiles, but also some yarn.
The company have 54 employees and have yearly turnover of 50
mill NOK. The case study was performed from January to November
1993.
3. Cleaner Production Principle: internal recycling, material
substitution, process modification
4. Description of Cleaner Production Application: The project
was aimed at generating and implementing cleaner production
options. An overall control group ran the project. The groups
were directed and assisted from the control group. The
employees were informed through a meeting before the project
started and when the project was finished.
The working groups made mass balances and evaluated and
proposed improvements. The proposals were then evaluated by the
control group. Proposed process changes or improved process
control with improvements for the environment and the economy
include:
1. Take care of the rest-bath from Rollenkufe, and in addition
calculate the smallest possible volume of the bath.
2. Improved monitoring of the water consumption by installing a
fully automated system. Replaced a machine with a machine which
is more water conserving.
3. Exact calculation of bath consumption on Babcock have given
savings and smaller effluents.
4. Run cotton- and polyester/cotton textiles on KKV instead of
on jigs, resulted in a savings of about 158 with respect to the
pigments effluent.
5. Use of pigment which gives improved absorption and lower
effluents. The company have already started to use Remasole
pigments.
6. Improvements in the recipes resulted in inexpensive recipes
and improved absorption of pigments on fur till example. The
company is continuously working on improvements with respect to
price and quality of their products.
7. The use of carriers in the production have been reduced
considerably and results in a more environmentally friendly.
8. The company got a recipe for a paste which they wish to test
to see if it is possible to use less chemicals in the
pretreatment.
9. A product register was compiled with possible replacements
for each of the chemicals in use.
10. Registration of loss on finished product, gross/net meters.
11. Remainders and end cut-offs are sewed together and sold, or
sold as pieces.
12. Investment in a new Air-flow machine which could take over
the production of two machines results in savings in pigment
consumption and chemicals. In addition, the cooling water can
be recycled in the fur department. A such new machinery can
also result in savings in labor and give a higher capacity in
the production.
13. Investments in expanding the wash installation results in
savings in labor, water and energy. This will also increase the
production capacity.
14. Work to get a lower COD-value, with smaller variations in
the waste water.
(Options to improve water and energy economy:)
15. Before drying on Famatex the textiles are centrifuged.
16. A new business agreement regarding purchasing of fuel was
worked out.
17. Recovering of cooling water from the jet machine results in
a lower water consumption and lower effluent stream. In
addition, there are savings in energy to heat the water when it
is used in other machines.
(Options for reduction of waste)
18. They are working with a recycling system for barrels, to
reduce waste costs.
19. They want to change to packaging which can be recycled.
20. They have ordered buckets to collect dry-cell batteries.
21. They want to start to recycle office paper, which reduces
waste costs and conserves the resources.
Work to reach a lower COD-value, with lower variations in the
effluent water, option 14. The main source of organic
substances, which causes COD in the effluent water are from the
pretreatment of the raw materials. The raw materials they buy
contain some soluble organic substances. This paste is added in
the textile factory, and partly natural substances from the
cotton fibers outer wall. Paste added in the textile factory
can be of many kinds, like starch, polyvinyl alcohol,
polyacrylate or carboxymethyl cellulose. The substances from
the cotton fibers are mainly wax and pectin. At the
pretreatment when the textiles are washed and colored, some of
the added substances will dissolve into the water. This is the
reason for the organic substances in the effluent water, which
gives the COD-values. There are two ways to reduce the organic
substances in the effluent.
The first way is to remove the substances from the effluent
water. That can be done by either ultrafiltration or
electro-flocculation. For a company like Seierborg, this
equipment will be costly. Another problem is that there are
many different substances in use, each textile are treated with
a different substance.
The other way to solve the problem is to collaborate with the
supplier of raw materials. Raw material with low contents of
soluble organic substances can be found, however this may take
time as the factories are located in India.
The options 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 15, 16, 18, 19, 20
and 21 are carried out or close to be carried out. The options
12, 13, 14 and 17 are under consideration financially. When it
comes to option 12 and 17 there are a choice between one or the
other. Option 12 gives is the best for the environment and the
production quantum, but is the one with the highest investment
cost. Option 2 is evaluated to be non profitable and is
recommended not carried out.
Level of Commercialization: Option 5 is dependent on the
suppliers. They have developed and produced some pigments.
Which have been taken into use at Seiersborg tekstil. New
pigments will even be produced in the future.
The option which involve the largest degree of uncertainty is
option 14. It demands testing of the raw materials together
with the supplier which is located in China, and there exist
cultural and linguistic problems. They have taken the first
step by visiting the supplier.
Material/Energy Balances and Substitutions:
The following are estimates of waste and pollution after the
options are carried through
Quantity
Before Quantity
After
Amount of waste water, m3/yr 80,750 71,100
COD, tons/year 58.2 N/A
COD max. measured value mg O/L 1000 800
Consumption of fuel oil,
tons/year
606 515
Emission to air, SO2 tons/year 1.55 1.32
Emission to air, C02 tons/Year 1, 909 1. 623
Waste , tons/year 66.5 57
The other data for effluents and emissions will hardly be
affected. The pH in the waste water will be kept within the
specified limits. Phosphorus and sulphur in the waste water
will be reduced some.
There is hardly possible to reduce the consumption of raw
material, but there are possible to reduce the pigment and
chemical consumption by about 10 percent.
The options 12, 13, 15 and 17 will decrease the energy
consumption with about 17 percent. The options 2, 12, 13 and 17
could reduce the water consumption with about 11 percent. It is
specially option 12 and 13 which can give a chance for an
increased production volume.
The waste streams will decrease if the options 18, 19, 20 and
21 are implemented. The streams can be reduced with about 15
percent.
Option 14 will decrease COD, and it is supposed that after 3-4
years would the waste water have a stable COD value below
today's value.
The options 1, 3, 4, 5, 6, 7, 8, 9 and 12 will reduce the
pigment and chemical consumption totally with about 10 percent.
The options 12, 13, 15, 16 and 17 will all decrease the fuel
consumption. This will give a reduced C02 and S02 emission, a
reduction of about 15 percent. Besides it will give a
corresponding lower heat energy to the recipient.
5. Economics:
Investment Costs:
In the list of 21 options, the typical investment options, are
options 12, 13 and 17. It is possible to carry out option 12 or
17. The investments for option 12 are 2.5 mill. NOK, for option
17 are 0.1 mill. NOK and for option are 13 1.6 mill. NOK.
The investment projects have the following calculated yearly
payback
Option no. 12 535,000 NOK/year
Option no. 13 417,000 NOK/year
Option no. 17 100,000 NOK/year
For the following investments will the operational revenue
increase with the following amount the first year after the
investment
Option no. 12 34,762 NOK
Option no. 13 97,000 NOK
Option no. 17 80,000 NOK
The following options are the ones which do not have any
essential investments, but have the following positive effect
on the operational revenue.
Option no. 3 5,000 NOK
Option no. 4 23,000 NOK
Option no. 5 0 NOK
Option no. 6 0 NOK
Option no. 7 5,000 NOK
Option no. 8 65,000 NOK
Option no. 9 0 NOK
Option no. 10 0 NOK
Option no. 11 0 NOK
Option no. 15 95,000 NOK
Option no. 16 250,000 NOK
Option no. 18 1,000 NOK
Option no. 19 5,000 NOK
Option no. 20 0 NOK
Option no. 21 0 NOK
____________________________________________
SUM 449,000 NOK/year
Payback Time
The payback time for the three options with some investment
cost, are as follows:
Option no. 12 4.7 years
Option no. 13 3.8 years
Option no. 17 3.0 years
6. Advantages
The proposed options will not have any essential effect on the
market or the product quality, apart from a possible public
relation effect, because the company has a less environmental
harmful production.
7. Constraints: See Description of Cleaner Production
Application.
8. Contacts:
State Pollution Authority,
Att: Uno Abrahamsen
Postboks 8100 Dep.,
0032 OSLO, Norway
TEL: + 47 22 57 34 00
Oestfold Research Foundation
Att: Mie Vold
P.O.Box 276
N-1601 Fredrikstad
TEL.- +47 69341900
Seiersborg tekstil a.s
Att: Head of Laboratory Lise Marie Grindal
Postboks 23, 1601 FREDRIKSTAD,
Norway
TEL: + 47 69 31 12 65
9. Keywords: ISIC Codes 3211, spinning, weaving and after
treatment of textiles, 32111, production of yarn, 32112,
Production of woven textiles textile pretreatment, mercerizing,
COD, wastewater, pigments, cotton