| Program/Office: | U.S. Agency for International Development |
| Document Number: | NA |
| Document Type: | Case Study |
| Date: | 1994 |
| Contact: | EP3 Clearinghouse (703) 351-4004 |
The amount of pollutants and waste generated by industrial facilities has become an increasingly costly problem for manufacturers and a significant stress on the environment. Increasingly, companies are looking for ways to reduce pollution at the source as a way of avoiding costly treatment and reducing environmental liability and compliance costs.
The United States Agency for International Development (USAID) is sponsoring the Environmental Pollution Prevention Project (EP3) to transfer urban and industrial pollution prevention experts and information, establish sustainable programs in developing countries, and support efforts to improve environmental quality. These objectives are achieved through technical assistance to industry and urban institutions, training and outreach programs, and an information clearinghouse.
EP3 pollution prevention diagnostic assessments consist of three phases: pre-assessment, assessment, and post-assessment. During pre-assessment, Ep3 in-country representatives determine a facility's suitability for a pollution prevention assessment, sign memoranda of agreement with each facility selected, and collect preliminary data. During assessment, a team comprised of U.S. and in-country experts in both pollution prevention and the facility's industrial process gathers more detailed information on the sources of pollution, and identifies and analyzes opportunities for reducing this pollution. Finally, the team prepares a report for the facility's management detailing their findings and recommendations (including cost savings, implementation costs, and payback times). During post-assessment, the EP3 in-country representative works with the facility to implement the actions recommended in the report.
This assessment evaluated a facility that manufacture lead-acid batteries used in automobiles and trucks. The objective of the assessment was to identify actions that would:
This facility manufactures starting, lighting, and ignition (SLI) batteries. Most of the facility's output is sold domestically, although about 20% is exported. The facility operates one, two, or three 8-hour shifts (depending upon the equipment, process, and season) and employs 220 people. In 1993, they sold 231,000 batteries.
Facility operations can be divided into six main steps:
Pasted plates are cured and then take one or two paths to become battery elements: tank formation or container formation. These processes convert the paste into active material that will electrically charge and discharge throughout the useful life of the battery. In tank formation, this process takes place in large tanks, whereas in container formation, the cured plates are assembled and formed in the battery case itself.
To make the lead oxide paste, lead oxide powder is mixed with de-ionized water, sulfuric acid, and organic expanders. One recipe makes a positive plate, while a slightly different recipe makes a negative plate. The pasted plates then move on a conveyor belt through a drying oven. After pasting and drying, the plates move into a curing chamber for about 48 hours to convert the remaining lead into lead oxide.
In tank formation, the positive and negative plates are immersed in tanks of low specific gravity sulfuric acid, where electrodes pass a current through the plates. In the positive plates, the current converts lead sulfate from the paste into lead oxide. In the negative plates, the reaction converts the paste into sponge lead, a very porous, high surface area form of elemental lead. Container formation employs the same electrochemical process, but occurs in the plastic batter case instead of the tank. Cured plates that are not tank formed must be cut in half and assembled into batter elements, which are then placed into batteries for container formation.
After tank formation, the plates go through a washing and drying process to remove any remaining sulfuring acid. Overall, the plate washing process accounts for over 60 percent of the factory's water contaminated with lead and sulfuric acid.
At the time of the assessment, there were a number of pollution problems at the facility, including:
Overall, this assessment identified nineteen pollution prevention opportunities that could address the problems identified and produce significant economic benefits for the facility. If implemented, these opportunities could save over $1,875,000 in the first 24 months for and investment of $687,000. The pollution prevention strategy is premised on the belief that addressing sources of waste and pollutants also improves the company's economic health by reducing operating costs and improving product quality. In this case, product quality is increased by:
There is additional opportunity to prevent pollution and conserve raw materials in the battery recycling process. Before cracking the battery case, workers could pour the acid into a large plastic plating tank. The acid could be recycled (possibly through ion exchange) and returned to the production process, replacing purchases of high concentration acid.
EP3 has proposed a methodology for measuring and tracking pollution prevention performance. The approach uses simple by critical ratios to compare data among facilities in the same industrial sector.
This assessment identified four critical ratios, as shown in Table 2, Critical Performance Ratios for Battery Manufacturing, [(provided in source document)]. The Assessment Team obtained best industrial performance (BIP) values for these ratios, and found that each of this facility's current values were significantly above the BIP values. The facility should be able to reduce its ratios and come closer to the BIPs by implementing the pollution prevention options listed in Table 1 [(provided in source document)].
The facility has already implemented many of the low/no cost recommendations, including covering recycled lead piles, recycling drop virgin lead into the lead oxide mill rather than into the smelter, recycling waste paste into the hopper rather than sending it to the smelter, and maintaining optimal temperature and humidity in the curing room. In addition, the facility has begun to implement several capital intensive changes. For example, it has placed an order for boost charging equipment ($100,000) and requested price quotes for a liquid lead atomization mill ($240,000).
For further information on this assessment or other activities sponsored by EP3, call the EP3 Clearinghouse at (703) 351-4044 or send a fax to (703) 351-6166.
Last Updated: August 25, 1995