An Analysis of Pollution Prevention Opportunities and Impediments in the Chemical and Allied Products Sector in Georgia — Part 4

D. Soaps, Detergents, Etc. (284)

In terms of numbers of facilities, this is one of the largest sub-groups. The group consists of SIC 2841 (soaps and detergents), SIC 2842 (cleaning preparations), SIC 2843 (surface agents), and SIC 2844 (perfumes and cosmetics). Common products listed in SIC 2841 and 2842 are aerosol cleaners, automotive cleaners, detergents, floor waxes, janitorial cleaners, household ammonia, sanitary chemicals, and soap. Products of facilities in 2843 are defoamers, emulsifiers, surfactants, and textile chemicals. Cosmetics, hair care preparations, fragrances, lotions, and shaving preparations are examples of products produced in SIC 2844.

Geographically, there is a heavy concentration around metro Atlanta. Facility size in this group varies from two to 450 employees with most being between 20 and 30. The manufacturing operations are nearly all batch processing; whereby, ingredients are formulated to specific recipes and then packaged. Some operations merely repack chemicals from bulk to consumer ready packaging.

Waste Generation

TRI chemical wastes generated in this group have decreased by 72% since 1991 as can be seen in Figure 9. Transfers have historically accounted for the bulk of the waste generated. Air is the next largest media comprising 14% of the total.

Frequently reported TRI chemicals are shown in Table 12. They are predominately solvents and acids, which are used as reactants, formulation components, or cleaning agents. These chemicals become waste as a result of air emissions, process losses, and cleaning.

Figure 9: TRI Chemicals Generated as Wastes in SIC 2841-44

The most common forms of waste as indicated by the biennial reports are: cleanup of spills in storage and unloading areas; expired materials; off-spec product; damaged packaging containers; solvent waste from equipment cleaning (petroleum distillates, glycol ethers, chlorinated solvents); corrosive waste from equipment cleaning (acids and alkalies); spent petroleum oils from maintenance activities; wastewater from washdown activities; and spent solvents from maintenance parts washing.

Table 12: The TRI Chemical Wastes Generated in the Largest Quantities and/or Most Frequently Reported

Source Reduction Techniques

Spill and Leak Prevention

Since VOCs such as alcohols, ketones, and aromatic solvents are the air emission concerns of the industry, much attention needs to be given to the storage, transfer, and processing of these materials. Selection and maintenance of storage, handling, and processing equipment can effectively minimize losses. Regular inspection of piping, pumps, valves, process vessels, storage tanks, and containers, as well as employee training is also critical to prevention efforts.

Raw Material Substitution / Alternative Product Design

The most effective way to eliminate VOCs is to replace the solvents in the products and as cleaning agents.

Production Scheduling

As discussed in section II.C., production scheduling can be used to effectively reduce waste by reducing cleaning. Trade-offs may be higher inventory costs and more capital expenditures on equipment.

Quality Control / Process Optimization

Significant waste reductions can be achieved through better quality control. The use of statistical process control, automation, and employee training can lead to a more efficient operation. Because the cost of generating off-spec material includes the cost of the raw materials, all the labor and overhead costs associated with processing that material, and the disposal costs, it is quite apparent that this is an area that can provide significant economic benefits.

In-process Recycling

Equipment cleaning waste may be reused in some manner. By using the same solvent as in the formulation, the solvent wash can be collected, stored, and reused in the next batch of the same product, displacing virgin material. If that is not possible, the spent solvent wash can be recycled with a solvent distillation unit.

Process Modifications

Tank washing systems can greatly affect the amount of solvent needed to clean tanks, and the amount of waste generated. High pressure spray nozzles can increase the effectiveness of a tank washing system. Tanks and mixers can be pre-cleaned with squeegees or wipers. Use of wipers can increase the yield by recovering material left in the equipment, and reduce the amount of solvent needed for washing. The use of rubber “pigs”, as described in the case study in this section, can increase yields and reduce wastes.

Inventory Control

Many of the ingredients and products have a limited shelf life, and can become unusable. Efficient management of purchasing and production activities can prevent the expiration of materials and reduce waste.

Alternative Packaging

Bulk transportation of raw materials via tank truck or tote bins can reduce solid wastes associated with drums and bags. Working closely with vendors is an effective way to minimize packaging wastes.

Impediments

According to the P²AD survey, the frequently reported impediments are economics, insufficient capital, and product quality.

Case Study (SIC 2842)

This facility is a manufacturer of specialty cleaning products used in maintenance and janitorial services. Liquid, powder, and aerosol products are made via a batch formulation process. Raw materials are received by drums, bags, tote bins, tanker truck, and rail car. These materials are formulated into approximately 3,000 different products. When a batch is completed, the products are packaged for shipment to the customers.

Waste Stream Descriptions

In 1987, it was determined that only 94% of the purchased raw materials were sold as product. This meant that 6% of the raw materials were lost as waste. Material transfers, blending operations, and equipment cleaning were responsible for waste generation. TRI chemicals at the facility included 1,1,1-trichoroethane, dichloroethane, glycol ethers, methanol, toluene, and xylene.

Source Reduction Techniques

The facility made a major process modification to improve the transfer of materials to the production tanks. A pneumatic “pig” delivery system was installed to transfer materials from storage to the production tank. This eliminated the use of dedicated lines. In the new system, a measured amount of material is transferred into a line to the production tank. When enough material has been added the valve at the storage tank is closed, and a rubber pig is moved from the storage tank to the production with compressed air. This forces an residual material into the production tank. Since most formulations require water, it is added last, and flushes the line in the process. As a result, a significant amount of product losses were eliminated. The pig system is also used when unloading tanker trucks to storage tanks.

Production scheduling was changed to incorporate larger batch runs and to reduce changeovers and washouts. An improved weighing and packaging system also help reduce losses.

The results can be seen in Figures 10 and 11, which show the reductions in material losses and TRI chemicals. Annual savings were estimated to be about $4.5 million in 1993.

Figure 10: Reductions in Material Losses

Figure 11: TRI Chemical Generation

E. Paints, Varnishes, Lacquers, Enamels, and Allied Products (2851)

With 54 facilities listed in industry group SIC 2851, manufacturers of paint comprise one of the largest sub-sectors within the chemicals sector. Examples of products made by this group in Georgia are acrylic beads, aerosol coatings, dispersants, enamels, gel coats, lacquer thinners, latex paint, polyurethane coatings, powder coatings, primers, stains, varnishes, and other water-based paints. Half of the facilities are in metro Atlanta with the rest evenly distributed throughout the state. Most of the facilities have between 10 and 30 employees.

The manufacturing operations are mostly batch formulation processes. Some processes using resins have batch reactions. Raw materials used in the process are solvents, organic resins, pigments, and other inert materials. These materials are typically received in bags and drums. The products can generally be categorized as solvent-based or water-based. The process begins with mixing pigments, resins, and extenders with the water or solvents into a paste, which is then milled. Additional solvent, water, and/or specialty chemicals are added to the paste in a mix tank until the proper consistency is reached. Finally, the paint is filtered and loaded in shipment containers.

Waste Generation

This is the only group in the sector to show an increase (9%) in TRI chemicals generated. Transfers account for 82% of the total, and air accounts for 17% of the total. Land, water, and POTW make up 1%. A review of biennial reports indicate the following types of wastes: off-spec raw materials; bags and drums from packaging; filter media contaminated with paint; spent solvent and paint residues from equipment cleaning; rags with solvent and paint residues; spent caustic washwater; caustic sludge; paint sludge; pigment dust; spill cleanup residues; obsolete product; off-spec product; and lab testing materials.

Figure 12: TRI Chemicals Generated as Wastes in SIC 2851

Table 13 shows that the TRI wastes are primarily solvents used in making paint and in cleaning. Methyl ethyl ketone, toluene, and xylene account for the majority of the VOCs in this industry group.

Table 13: TRI Chemicals Generated in the Largest Quantities in SIC 2851

(quantity in pounds)

Source Reduction Techniques

Spill and Leak Prevention

Since VOCs such as methyl ethyl ketone, toluene, and xylene are the primary emission concerns of the industry, much attention needs to be given to the storage, handling, and processing of these materials. Selection and maintenance of storage, transfer, and processing equipment can effectively minimize losses. Employee training is also critical to prevention efforts.

Production Scheduling

As discussed in section II.C., production scheduling can be used to effectively reduce waste by reducing cleaning. Trade-offs may be higher inventory costs and more capital expenditures on equipment.

Raw Material Substitution / Alternative Product Design

The most effective way to eliminate VOCs is to replace the solvents used in manufacturing the products. This ultimately benefits the customers who are facing increased restrictions related to air emissions. Several manufacturers have developed alternative products which have eliminated or reduced hazardous constituents as illustrated in Table 14.

Table 14: Selected Product Reformulations for Paint and Paint Additives

Adapted from Stirring Up Innovation: Environmental Improvements in Paint and Adhesives, John S. Young, Linda Ambrose, Lois Lobo, INFORM, Inc., New York, New York, 1994.

Process Modifications

The design of tank washing systems can greatly affect the amount of solvent needed to clean the tank and the amount of waste generated. High pressure spray nozzles can increase the effectiveness of a tank washing system. Tanks and mixers can be pre-cleaned with squeegees or wipers. Using wipers can increase yield by recovering paint left in the in the equipment, and reduce the amount of solvent needed for washing. The use of rubber “pigs”, as described in the case study in section III.D, can be used in the industry as well.

In-process Recycling

Equipment cleaning waste may be reused in some manner. By using the same solvent as in the formulation, the solvent wash can be collected, stored, and reused in the next batch of the same product, thereby displacing virgin material. If that is not possible, the spent solvent wash can be recycled with a solvent distillation unit.

Impediments

The increased production cost is an impediment to using less hazardous materials in the products. Customers skepticism is another obstacle to replacing solvent-based paints. Caustic washing is not as effective as solvents in equipment cleaning.

Case Study (2851)

This is a small paint manufacturing facility employing 20 people. The main product lines are specialty paints and industrial coatings. The facility has a waste policy and a hazardous waste reduction plan, and initiated its waste reduction efforts in 1990.

A batch process is used to mix the raw materials into a variety of paint products. Raw materials used in the process are solvents, organic resins, pigments, and other inert materials. These materials are received in bags and drums. A milling process is applied to some batches for added pigment dispersion. When a batch is finished, the paint is strained with a nylon or polyester mesh bag as it is loaded from the production tank into a shipment container.

The tanks and processing equipment are cleaned between batches. A recycled mixture of ketones, alcohols, and aromatics is used for cleaning. Cotton mops and rags are used in general clean-up of equipment, bench tops, and the floor.

Waste Generation

Waste is generated during clean-up activities. Washing tanks and other equipment produces a waste containing solvents, pigments, and organic resins. Typical solvents used are methyl ethyl ketone, methyl isobutyl ketone, mixed alcohols, toluene, and xylene. The cleaning activities with their corresponding percent of the total wastestream are: tank washing (75%), mill flushing (10%), and general cleanup (15%).

Other hazardous wastes include straining bags, rags, and mop heads contaminated with solvents. These items are wrung out to remove as much liquid as possible, and then disposed of as hazardous waste.

Figure 13: Hazardous Waste Generation

Figure 14: TRI Chemical Generation

Source Reduction

Source reduction activities investigated at the facility included production scheduling, batch consolidation, raw material substitution/alternative product design, automated tank washing, and improved operating and housekeeping practices. Much of the reductions as seen in Figures 13 and 14 are the result of improving operating practices and training employees to reduce waste. Automated tank washing has reduced the amount of solvent needed to clean a tank from 3 to 2 gallons.

Impediments

While scheduling larger batches would reduce cleaning, it would require carrying more inventory which could lead to obsolete material. Non-hazardous cleaning agents were investigated, but they did not clean the equipment well enough.

F. Industrial Organic Chemicals (286)

Industry group 286 consists of three individual SIC codes. SIC 2861 are manufacturers of gum and wood chemicals. Examples of products are acetates, rosins, turpentine, and wood distillates. Georgia facilities in SIC 2865 list carpet dyes, leveling agents, organic pigments, and textile dyes as products. Anti-adhesives, artificial sweetener, caprolactam, cyclohexanone, deinking compounds, flavors, formaldehyde, fragrances, plasticizers, polyester resins, and rubber accelerators are examples of products produced by facilities listed under SIC 2869.

Geographically, facilities in SIC 2861 and 2869 are located in the industrial areas of Atlanta, Augusta, Columbus, and Savannah. Facilities listed under SIC 2865 are concentrated in northwest Georgia near the carpet industry.

The facilities in SIC 2861 and 2869 do not exhibit many similarities. Processes may be described as either batch formulation, batch reaction, or continuous reaction. Similarities in SIC 2865 are that the processes are batch formulation with either aqueous or solvent equipment cleaning.

Waste Generation

Over 90% of the TRI chemical wastes are generated by a couple of facilities whose processes are very dissimilar. Air emissions account for 73% of the total generated, and are mostly in the form of VOCs. Table 15 shows the significant TRI chemicals and how they were used in the process. Wastewater is also a significant media comprising 18% of the TRI chemicals.

Figure 15: TRI Chemicals Generated as Wastes in SIC 286

Wastestreams listed in the biennial reports include: off-spec raw materials; reaction by-products; spent catalyst; spent process materials; spill cleanup; caustic corrosive sludge; combustible wastes from maintenance activities; wastewater from tank cleaning; ignitable filter bags; waste flammable liquids and solids from solvent recovery process; and lab wastes from quality control sampling.

Table 15: TRI Chemicals Generated as Waste in the Largest Quantities in SIC 2861,65,69

Source Reduction Techniques

According to the P²AD survey, some source reduction techniques currently being used are spill and leak prevention, process optimization, raw materials substitution, and in-process recycling. Because of the diversity of this industry group, there is not a lot of common processes and wastes among these facilities. The general source reduction techniques discussed in section II.C. would be applicable to most of the facilities, in particular, those that are producing organic pigments in batch formulation.

Impediments

Impediments reported in the P²AD survey were insufficient capital, product quality, and technology limitations; however, there is no common problem to focus on in this group.