INTERNATIONAL CLEANER PRODUCTION INFORMATION CLEARINGHOUSE

CASE STUDY # 146

1.   Headline:  Ultrasonic reactor cleaner reduces waste
     generation and cuts energy costs are reduced.

2.   Background:  See below.

3.   Cleaner Production Principle:  process modification

4.   Description of Cleaner Production Application:   A Chemdet
     Sonic Cleaning system is now used at 3-M to clean batch
     reactors, replacing the old process of filling the reactor
     with caustic or solvent and boiling the solution for one
     or two days.  Cleaning chemicals are pumped under pressure
     through a twin-nozzled rotating spray head to break down
     the waste.  Then, caustic or solvent is sprayed under 600
     lb pressure to complete the dissolution and flush the
     vessel clean.

     Material/Energy Balance and Substitution

     FEEDSTOCKS:  Solvent, caustic

     WASTES:  Spent solvent, caustic, containing adhesives,
     resins, polymers

     MEDIUM:  Liquid

5.   Economics

     CAPITAL COST:  $36,000

     OPERATION/MAINTENANCE:  Reduction in labor costs not
     reported

     MONTHS TO RECOVER:  Savings realized in first year

     DISPOSAL & FEEDSTOCK:  $575,000 in first year, from labor,
     materials and machine costs

6.   Advantages

     FEEDSTOCK REDUCTION: Reduced requirements for solvent and
     caustic not reported

     WASTE PRODUCTION: 1,000 tons/yr of water pollutants were
     eliminated

     IMPACT/PROBLEMS:  Installation of the Chemdet system for
     cleaning the reactors has eliminated the need to fill the
     4,000-8,000 gallon reactors with solvent and caustic,
     which greatly reduces the amount of spent solvent
     generated.  Significant savings were realized in the first
     year.


7.   Constraints:  No information provided.

8.   Contact and Citation:  "Catalogue of Successful Hazardous
     Waste Reduction/Recycling Projects", Energy Pathways Inc.
     and Pollution Probe Foundation, prepared for Industrial
     Programs Branch, Conservation & Protection Environment
     Canada,  March, 1987, page 19.

9.   Keywords:  United States, USA, chemical, process
     modification, ultrasonic cleaning, ISIC 3700, solvent,
     caustic.

10.  Reviewer's Comments:  This case study was originally
     abstracted for the US EPA's Pollution Prevention
     Information Clearinghouse from the Canadian publication
     "Catalogue of Successful Hazardous Waste
     Reduction/Recycling Projects."  It underwent a UNEP IE
     funded technical review in 1994 for quality and
     completeness.  It was edited for the ICPIC diskette in
     July 1995.

( Docno unep05: 450-003-A-337 )