INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY # 179

1.   Headline:  Conversion of Willow Dust into Biogas at Cotton
     Textile Processing Mill

2.   Background:  See below.

3.   Cleaner Production Principle:  Internal recycling

4.   Description of Cleaner Production Application:  The
     technology involves the conversion of willow dust into
     biogas and organic fertilizer.

     Process and Waste Information:  Textile mills generate
     considerable quantities of solid waste materials during
     different stages of operation.  Willow dust is a waste
     generated from a willow machine.  In India, 30,000 to
     33,000 tons of this material are generated every year.  To
     convert this willow dust into biogas, a pilot plant was
     installed at Apollo Textile Mills in Bombay with
     assistance from the Cotton Textile Research Laboratory
     (CTRL).  This plant has a 12.5 ton/month capacity.  350 m3
     of biogas was produced per 2 tons of willow dust for a
     retention period of 90 days.

     The mill's average production of willow dust is 12.5
     tons/month.  The consumption of liquid propane gas by the
     laboratory alone has been reduced by 65 kg since the
     installation of this converter.

     The scientists at the CTRL have further developed a
     process which needs less water, and double the quantity of
     material can be accommodated in the same unit.
     Improvements have been made so that the calorific value of
     biogas is increased.  Also, the organic substance that is
     a by-product of fermentation can serve as a good
     fertilizer.

     Scale of Operation:  Average monthly production of willow
     dust is 12.5 tons.

     State of Development:  The clean technology is fully
     implemented.

5.   Economics

     Investment Costs:  The investment cost of the project was
     3.4 lakhs (lakh = 100,000 rupees).

     Operational and Maintenance Costs:  Operating costs,
     including water and collection of willow dust and alkali,
     are about 18,000 rupees.

6.   Advantages:

Benefits including biogas and organic fertilizer generation are
as follows:

     Biogas          12,000 m3/year        63,412 rupees
     Fertilizer      24 tons/year           2.400 rupees

Economic benefits will also include reduction in gas
expenditures and waste disposal costs.

7.   Constraints:  No information provided.

8.   Contacts and Citation

     Type of Source Material:  Organizational report

     Citation:  "Production of Biogas from Willow Dust:  A
     Solid Cellulosic Waste from Textile Mills".  Cotton
     Technological Research Laboratory (CTRL).  Adenwala Road,
     Matunga, Bombay - 400 019, India.

9.   Keywords:  India, textile, cotton, textile processing,
     recycling, ISIC 2211, willow dust, fertilizer, biogas,
     fermentation, biotechnology.

10.  Reviewer's Comments:  This case study was originally
     compiled by the UNEP Working Group of Textiles.  It
     underwent a UNEP IE funded technical review in 1994 for
     quality and completeness.  It was edited for the ICPIC
     diskette in July of 1995.

( Docno UNEP 11: DOCUMENT NOT AVAILABLE 11-04 )