Study Identifies Pollution Prevention Opportunities in the Chemical Industry

[From the Source - Summer 1997]

The chemical and allied products sector report is now available along with reports from the wood products, pulp and paper, metal fabrication, printing, and transportation equipment industries. The report analyzes facilities listed in the Standard Industrial Classification (SIC) code 28 and presents data on waste generation, source reduction techniques, and pollution prevention impediments. Data collected and analyzed in this report was compiled from site visits, case studies, Toxic Release Inventory (TRI) reports, biennial reports, literature research, and a P²AD sector survey.

According to the Georgia Manufacturing Directory, there were 468 firms listed within the chemical and allied products sector in 1994. These firms operate 502 facilities in Georgia and employ 20,461 workers. Approximately 80% of the facilities have less than 50 employees, and half have less than 20 employees. About 40% of the facilities report on the TRI, and about 15% are large quantity generators of hazardous waste.

The facilities within the sector are engaged in manufacturing a broad array of products. Because of this, there is a wide variety of materials, manufacturing processes, and wastes within the sector. To address the diversity within the sector, the following ten sub-groups were used in this analysis:

• SIC 281x, Industrial Inorganic Chemicals

• SIC 2821, Plastic Materials & Synthetic Resins

• SIC 283x, Drugs

• SIC 284x, Soaps, Detergents, etc.

• SIC 2851, Paints, Varnishes, Lacquers, & Enamels

• SIC 286x, Industrial Organic Chemicals

• SIC 2873-5, Fertilizers

• SIC 2879, Pesticides

• SIC 2891, Adhesives & Sealants

• SIC 2893, Printing Ink

Of the survey respondents, approximately half were TRI reporters and half were not. A typical operation could be described as a small facility engaged in formulating products via a batch processing operation. The sector survey indicated that batch processes outnumber continuous processes by a five to one margin. Most of the manufacturing processes were engaged in the formulation of raw material components into a product. Only one-third of the facilities reported using chemical reactions or other more sophisticated chemical processing beyond formulation or repackaging. Half of the facilities surveyed reported aqueous equipment cleaning, and one-third reported using solvents for equipment cleaning. Some commonly used source reduction techniques were:

• Spill and Leak Prevention - Spill and leak prevention is first and foremost among pollution prevention techniques in the sector. The emphasis on spill and leak prevention has been widespread for more than a decade as a result of early safety and environmental regulations. Most facilities within the sector are required to have a Spill Prevention, Control, and Countermeasures (SPCC) plan.

• Inventory Control - A frequent source of waste is expired or contaminated raw materials. Many materials have a limited shelf life and raw materials are often lost when contaminated or improperly stored. Coordinating the purchasing and consumption of raw materials will help eliminate material spoilage. Good housekeeping, material handling procedures, and container selection can significantly reduce waste from contamination and container damage.

• Process Optimization / Quality Control - Process optimization reduces waste through higher yields. Many facilities reduce waste indirectly through their optimization and quality control efforts. Statistical process control is frequently used to optimize processes through the identification of special causes of wastes which can then be targeted for improvement. Process optimization can be achieved with the use of automated process control devices. Reviewing operating procedures and employee training can also increase yields.

• Production Scheduling - Production scheduling for the batch processing of chemicals was used as a means to reduce cleaning. Optimization of production scheduling can reduce the number of times it is necessary to clean equipment, and in doing so increase plant productivity. This can be accomplished by scheduling the production of the same or similar products in succession so that cleaning the tanks between batches is not necessary.

• In-Process Recycling - In-process recycling is the direct reuse of waste materials in the process to make the originally intended product. This method is particularly effective in processes where quality constraints are not too demanding. In batch processes, equipment cleaning is a significant cause of waste generation, since a solvent or aqueous rinsate is used. Frequently, the rinsate can be collected and used in making a future batch of the same product.

• Dry Cleaning Methods - The use of squeegees or air knives can help to alleviate some of the problems associated with equipment cleaning. Specifically, it will help lower the concentration of residues in the rinsate. Air knives could also be used to pre-clean equipment before a final washing.

• Alternative Packaging - Drums with plastic liners, reusable tote bins, and bulk transfer of materials via tanker truck have all been used in the sector to reduce waste.

A copy of this report may be obtained by contacting P²AD's information center at (404) 651-5120 or on our web page at http://www.ganet.org/DNR/P2AD.

- Matt Barcaskey