Recovering Plastics from Obsolete Appliances

Problem/Opportunity

Traditionally, recycling of appliances has been driven by the value of their scrap steel. In the last 15 years, however, the use of plastics in appliance manufacturing has increased substantially, at the expense of metals. To increase the recycling of obsolete appliances in the future, cost-effective and environmentally acceptable technologies need to be developed to recover, upgrade, and reuse plastics from discarded appliances. It is estimated that more than 300 million pounds of high-value plastics could be recovered and reused, resulting in a reduction of up to 90% in appliance-related solid waste that would otherwise end up in landfills.

Approach

Through collaborative research with industry, Argonne National Laboratory is developing a process for recovering valuable individual plastics from the non-metallic fractions generated by appliance shredding operations. Further, to enhance the market penetration of recycled plastic materials, cost-effective methods for improving the performance of the recovered plastics will be developed.

An estimated 300 million pounds of plastics from obsolete appliances could be recovered and reused.

The recovery process consists of granulating the non-metallic material, which is generated by appliance shredding and disassembly operations, to 1/4-inch size. The granulated material is then processed via mechanical/physical separation methods into several fractions: polyurethane foam and other light materials; thermoplastics, which include high-density polystyrene (HIPS) and acrylonitrile-butadiene-styrene (ABS); and a small fraction consisting of polyvinyl chloride (PVC) nylon and some metals. The thermoplastics fraction is further separated via acid/solvent-assisted methods into two high-value plastics: ABS and HIPS. The ABS materials recovered from appliances could have a market value in the range of 40-70¢/lb.

Results

A laboratory-scale process for recovering ABS and HIPS plastics has been demonstrated, and more than 100 pounds of high-purity ABS has been produced and analyzed to determine its properties and upgrading needs. Tests conducted on the properties of the recovered ABS indicate that this material has good performance characteristics and could be recycled to high-value applications.

Future Plans

A demonstration plant is scheduled to be built in 1996 to evaluate the overall economic and technical performance of this process. A major appliance recycler has tentatively agreed to use one of its facilities for the demonstration of this process. With industry collaboration, the market value of the recovered plastics will be optimized by researching cost-effective strategies for upgrading the properties of the materials.

Principal Investigator:

Dimitrios E. Karvelas

08May97 mv&ls