United States Environmental Protection Agency Risk Reduction Engineering Laboratory Cincinnati, OH 45268 Research and Development EPA/600/S-95/005 April 1995 ENVIRONMENTAL RESEARCH BRIEF Waste Minimization Assessment for a Manufacturer of New and Reworked Rotogravure Printing Cylinders Marvin Fleischman*, Clay Hansen*, and Gwen P. Looby** Abstract The U.S. Environmental Protection Agency (EPA) has funded a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the expertise to do so. Waste Minimization Assessment Cen- ters (WMACs) were established at selected universities and procedures were adapted from the EPA Waste Minimization Opportunity Assessment Manual (EPM625/7-88/003, July 1988). That document has been superseded by the Facility Pollution Prevention Guide (EPA/600/R-92/088, May 1992). The WMAC team at the University of Louisville performed an assessment at a plant manufacturing cylinders for rotogravure printing. Rotogravure printing cylinders are produced from new stock and used cylinders that require reworking. Cylinders undergo cleaning, plating, lathing, polishing, and grinding. Then the surfaces of the cylinders are engraved, cleaned, polished, and chrome-plated. The assessment team's report, detailing find- ings and recommendations, indicated that significant cost sav- ings could be achieved by melting and reusing copper scrap as anodes in the plating bath. This Research Brief was developed by the principal investiga- tors and EPA's Risk Reduction Engineering Laboratory, Cincin- nati, OH, to announce key findings of an ongoing research project that is fully documented in a separate report of the same title available from University City Science Center. Introduction The amount of waste generated by industrial plants has be- come an increasingly costly problem for manufacturers and an additional stress on the environment. One solution to the prob- * University of Louisville, Department of Chemical Engineering. "University City Science Center, Philadelphia, PA. lem of waste generation is to reduce or eliminate the waste at its source. University City Science Center (Philadelphia, PA) has begun a pilot project to assist small and medium-size manufacturers who want to minimize their generation of waste but who lack the in-house expertise to do so. Under agreement with EPA's Risk Reduction Engineering Laboratory, the Science Center has established three WMACs. This assessment was done by engineering faculty and students at the University of Louisville's WMAC. The assessment teams have considerable direct ex- perience with process operations in manufacturing plants and also have the knowledge and skills needed to minimize waste generation. The waste minimization assessments are done for small and medium-size manufacturers at no out-of-pocket cost to the client. To qualify for the assessment, each client must fall within Standard Industrial Classification Code 20-39, have gross annual sales not exceeding $75 million, employ no more than 500 persons, and lack in-house expertise in waste minimiza- tion. The potential benefits of the pilot project include minimization of the amount of waste generated by manufacturers and re- duction of waste treatment and disposal costs for participating plants. In addition, the project provides valuable experience for graduate and undergraduate students who participate in the program, and a cleaner environment without more regulations and higher costs for manufacturers. Methodology of Assessments The waste minimization assessments require several site visits to each client served. In general, the WMACs follow the proce- dures outlined in the EPA Waste Minimization Opportunity ------- /Assessment Manual (EPA/625/7-88/003, July 1988). The WMAC staff locate the sources of waste in the plant and identify the current disposal or treatment methods and their associated costs. They then identify and analyze a variety of ways to reduce or eliminate the waste. Specific measures to achieve that goal are recommended and the essential supporting tech- nological and economic information is developed. Finally, a confidential report that details the WMAC's findings and recom- mendations (including cost savings, implementation costs, and payback times) is prepared for each client. Plant Background The plant produces chrome-plated engraved copper-plated steel and aluminum cylinders for rotogravure printing from new stock and customer returns. It operates 6,240 hr/yr to produce over 7,000 cylinders annually. Manufacturing Process Rotogravure printing cylinders are produced from new stock (primarily steel or aluminum) and used cylinders requiring re- working. New cylinders are cleaned and degreased before processing. Then the aluminum cylinders are passivated in a wash tank containing an acid mixture, and zincated in a zinc oxide solu- tion. Next, all aluminum and steel cylinders are nickel-plated and then copper-plated. Used cylinders undergo cleaning, acid stripping, and lathing and are then copper-plated. The plated cylinders then undergo lathing, polishing, and grinding. Customer-provided artwork is used to create plating images which are then mechanically engraved on the surfaces of the cylinders. The engraved cylinders are cleaned, polished, and chrome-plated. Cylinders are then tested in the proofing department. Those cylinders that pass inspection are packaged and shipped. The cylinders that fail inspection are stripped of chrome (using acid) and are either replated with chrome or lathed and returned to the copper-plating baths for reprocessing. An abbreviated process flow diagram is shown in Figure 1. Existing Waste Management Practices This plant already has taken the following steps to manage and minimize its wastes: • Metal shavings (primarily copper) from turning, polishing, and electronic engraving are recovered and sold for reclama- tion. • Cylinders are rinsed with deionized water directly above the tanks after nickel and copper plating in order to eliminate drag-out of plating solution. • Film with a very low silver content is used in image processing in order to reduce the amount of waste silver generated. • Silver is recovered onsite by electrolytic deposition. • Recovered silver and waste film are sold to a recycler. • Electronic engraving is used for etching cylinders in order to eliminate the wastes that would be generated using chemical etching. • Cylinders are rinsed over the plating tanks and fume scrub- ber water is reused as plating bath make-up in order to eliminate the need for chromium removal from wastewater. • Chromic acid fume and evaporative losses are reduced through the use of tank covers and floating plastic balls. Plant personnel are currently evaluating the following options for managing and minimizing plant wastes: • The plant plans to switch to computer-generated image- making as a replacement for photographic image process- ing. • Ceramic coating of the cylinders to replace nickel-, copper, and chrome-plating is being investigated. • An alternative to the ink solvent that contains methylene chloride is being sought. Waste Minimization Opportunities The type of waste currently generated by the plant, the source of the waste, the waste management method, the quantity of the waste, and the annual waste management cost for each waste stream identified are given in Table 1. Table 2 shows the opportunities for waste minimization that the WMAC team recommended for the plant. The minimization opportunity, the type of waste, the possible waste reduction and associated savings, and the implementation cost along with the payback time are given in the table. The quantities of waste currently generated by the plant and possible waste reduction depend on the production level of the plant. All values should be considered in that context. It should be noted that the economic savings of the minimiza- tion opportunity, in most cases, results from the need for less raw material and from reduced present and future costs asso- ciated with waste treatment and disposal. Other savings not quantifiable by this study include a wide variety of possible future costs related to changing emissions standards, liability, and employee health. It also should be noted that the savings given for each opportunity reflect the savings achievable when implementing each waste minimization opportunity indepen- dently and do not reflect duplication of savings that would result when the opportunities are implemented in a package. Additional Recommendations In addition to the opportunities recommended and analyzed by the WMAC team, several additional measures were consid- ered. These measures were not completely analyzed because of insufficient data, minimal savings, implementation difficulty, or a projected lengthy payback. Since one or more of these approaches to waste reduction may, however, increase in attractiveness with changing conditions in the plant, they were brought to the plant's attention for future consideration. • Reduce or eliminate spillover from the nickel- and copper- plating tanks by installing plastic guards around the tank edges. • Evaluate the necessity for and standardize the use of sol- vents in cleaning cylinders. • Recover chromium or hydrochloric acid from the spent acid stripper solution. • Replace disposable filters used for filtering nickel- and cop- per-plating solutions with reusable stainless steel filters. This research brief summarizes a part of the work done under Cooperative Agreement No. CR-814903 by the University City Science Center under the sponsorship of the U.S. Environmen- tal Protection Agency. The EPA Project Officer was Emma Lou George. ------- New cylinders (aluminum, steel) 1 Used cylinders 1 Cleaning, degreasing Al cylinders i r Passivation zincating \ Steel cylinder r Nickel plating Cleaning, acid stripping, lathing 5 , j Copper plating Lathing, polishing Grinding Artwork /es Acid stripping Figure 1. Abbreviated process flow diagram for rotogravure printing cylinders. ------- Table 1. Summary of Current Waste Generation Waste Generated Source of Waste Waste Management Method Annual Quantity Generated (Ib/yr) Annual Waste Management Cost1 Butyl acetate, acid stripping solution, and rinse water Wastewater Passivating and zincating solutions Wastewater Cleaning water Copper- and nickel-plating sludge Copper anode nuggets Chromium sludge Wastewater Copper sludge Scrap metal Wastewater Water overflow Silver Waste film Copper dust Solvent-based ink Water-based ink Spent etch bath and rinse water Ethanol Wastewater Rags Paper towels Preparation of used cylinders Preparation of used cylinders Preparation of new cylinders Preparation of new cylinders Cleaning of copper-plating tanks Copper- and nickel-plating tanks Copper plating Chrome-plating tank Chrome plating Grinding Cutting, lathing, and polishing Cleaning of film processors Film processors Onsite electrolytic silver recovery Image processing Engraving Proofing of cylinders Proofing of cylinders Re-etching of cylinders Re-etching of cylinders Re-etching of cylinders Various plant operations Various plant operations Drained to storage tank; shipped offsite for 144,600 disposal as hazardous waste Drained to holding tank; neutralized; sewered 607,900 Drained to storage tank; shipped offsite for 21,520 disposal as hazardous waste Drained to holding tank; neutralized; sewered 349,780 Drained to storage tank; shipped offsite for 160,130 disposal as hazardous waste Shipped offsite for disposal as hazardous waste 1,320 gal Sold to recycler/reclaimer 1,440 Shipped offsite for disposal as hazardous waste 550 gal Drained to holding tank; neutralized; sewered 3,002,400 Shipped offsite for disposal as hazardous waste 26,000 gal Sold to recycler/reclaimer 93,700 Drained to storage tank; shipped offsite for 15,000 disposal as hazardous waste Drained to holding tank; neutralized; sewered 676,540 Shipped offsite for further recovery 100 Sold to reclaimer 750 Sold to recycler/reclaimer 120 Shipped offsite for fuels blending 8,700 Shipped offsite for ink reblending 900 Drained to storage tank; shipped offsite for 3,000 disposal as hazardous waste Drained to holding tank; neutralized; sewered 4,300 Drained to holding tank; neutralized; sewered 16,010 Laundered offsite; returned for reuse 15,000 units Shipped to landfill 300,000 units 10,530 1,460 11,520 7,320 -1,330 2,540 2 15,600 -79,580 1,080 -3,780 -7,560 -110 1,540 160 640 not available 3 1 Includes waste treatment, disposal, and handling costs. 2 Included in total POTWand onsite treatment costs of $32,750/yr. 3 Included in total landfill disposal costs of $34,200/yr. ------- Table 2. Summary of Recommended Waste Minimization Opportunities Minimization Opportunity Annual Waste Reduction Waste Reduced Quantity (Ib/yr) Per cent Net Annual Savings Implementation Cost Simple Payback (yr) Melt copper scrap resulting from turning and cutting cylinders, polishing, en- graving, and plating in a furnace and reuse as anodes in the plating bath. A degreasing system may be required for cleaning of the copper scrap prior to melting. Install a drip board on the chrome plating bath so that dragout can be captured and returned to the plating bath. Currently trapped dragout in the core tape used on the cylinders is lost on the floor and in the rinse tank and eventually is sewered. Install a filter press in order to recover copper from the grinding sludge. Sell the recovered copper to a re- claimer and sewer the removed water. Copper shavings, particles, and spent anode nuggets Chromic acid 43,200 45 $35,890 57,100 1.6 1,530 n/a 1,760 40 0.1 Copper sludge 26,000 gal1 100 47,460 16,820 0.4 Reuse spent butyl acetate once for subsequent cleaning. Use a small distillation unit to reclaim spent butyl acetate for reuse. Remove metal from the spent cleaning water from copper-plating tank clean-out using electrolytic metal recovery. Sell recovered copper to a reclaimer and sewer the water. Butyl acetate Butyl acetate Cleaning water 5,150 7,210 160,130' 50 70 100 2,960 3,740 17,450 640 3,700 35,520 0.2 1.0 2.0 Install high pressure spray rinses and automatic shut-offs in certain process areas in order to reduce water consumption. Replace the ethanol rinse with a hot deionized water rinse followed by hot air blowing. This measure will also reduce BOD (Biological Oxygen Demand) and BOD surcharges. Install a distillation unit to recover ethanol for reuse. This measure will also reduce BOD and BOD surcharges. Install an in-line evaporator to remove water from the waste going to the waste disposal tank for later disposal as hazardous waste. Base sewer charges on actual wastewater effluent rather than on water consumption. Nonhazardous rinse water Hazardous rinse water Ethanol 1,200,960 6,765 4.3002 50 50 100 4,120 2,740 1,150 290 0.3 0.1 Ethanol Hazardous liquid waste Not applicable 3,000 384,360 70 62 1,670 24,040 7,600 3,700 37,700 4,140 2.2 1.6 0.5 1 Waste has been changed in form to one that is less costly for plant to manage. 2 A wastewater stream of the same quantity will be generated if this opportunity is implemented. ------- United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 EPA/600/S-95/005 ------- |