Environmental Impacts of Conversion Technologies using MSW Feedstocks

A highly anticipated research report has been delivered to the California Integrated Waste Management Board. Prepared by the highly respected UC/Riverside College of Engineering - Center for Environmental Research & Technology (CE-CERT), it was commissioned specifically to resolve questions about the emissions of conversion technologies that use municipal solid waste (MSW) as feedstock for thermochemical conversion technologies. Several sites were used for the testing: IES' pyrolysis facility in Romoland, California; BRI Energy's Consutech gasification pilot plant in Fayetteville, Arkansas; and IET Technologies' Plasma Enhanced Melter (PEM™) system in Richland, WA.

This report substantiates the claim that the emissions of these conversion technologies fall well below the permit limits set by the Southern California Air Quality Management District as well as US EPA and German limits (which are usually more stringent). CE-CERT also included additional analysis of the "Indirect Impacts of Conversion Technologies" - i.e., the energy and environmental savings that result from potential truck trip reductions by diverting landfill deliveries to localized conversion facilities.

The conclusion of the report is republished below:

---------------------------

Evaluation of Environmental Impacts of Thermochemical Conversion Technologies Using Municipal Solid Waste Feedstocks
-Summary Report-
Prepared for: California Integrated Waste Management Board.
March 29, 2006
University of California, Riverside
College of Engineering-Center for Environmental Research and Technology

Conclusion

Thermochemical conversion technologies are technically viable options for the conversion of post-recycled municipal solid waste (MSW) and offer betters solutions to landfilling and transformation. This conclusion is based on the peer-reviewed information from the Evaluation of Conversion Technology Processes and Product report prepared by UC Riverside, the Life Cycle and Market Impact Assessment of Noncombustion Waste Conversion Technologies prepared by RTI International, the independent evaluation of emissions from three US facilities, and reports from other organizations. Thermochemical conversion technologies possess unique characteristics that have potential to substantially reduce the amount of material that is ultimately landfilled.

While no one technology is suitable for all waste streams, no single waste management practice, be it landfilling, recycling, composting, or conversion, can handle the full array of waste sources. Each can form part of an integrated waste management system, which is based on the idea of an overall approach for the management of waste streams, recyclable streams, treatment technologies, and markets.

AB 2770 requires the CIWMB to identify the cleanest, least polluting technologies. Biological technologies and thermal technologies may each have advantages and disadvantages when compared to each other. However, the studies contain no scientific basis to classify one technology class as less favorable based solely on temperature ranges or the resulting product, which is subsequently combusted. If these were the sole criteria, then secondary smelting of aluminum and glass recycling would be looked at less favorably because of their high temperatures, which lead to dioxin formation. In addition, electricity production from biogas derived from anaerobic digestion or methane from landfills would also be looked at less favorably because the gas is combusted.

Independently-verified emissions test results show that thermochemical conversion technologies are able to meet existing local, state, and federal emissions limits. Today, there are advanced air pollution control strategies and equipment that were not available even ten years ago. It is obvious from the results that emissions control of thermochemical conversion processes is no longer a technical barrier. That said, it is recommended that facilities and agencies provide both continuous and periodic monitoring to keep the public informed and ensure ongoing compliance.

Thermochemical technologies can process a wider variety of feedstocks and can have a greater effect on landfill reduction. Thermochemical technologies can also produce a larger variety of products, which can displace the need for non-renewable traditional sources of energy and fuels. Other indirect effects include eliminating diesel truck trips and reducing landfill gas emissions.



technorati bioenergy, greenhouse, emissions, conversion, California, pyrolysis, gasification