ABSTRACT
In the last two decades of the twentieth century, environmental action groups and the regulatory community put the spotlight on air and ash emissions from MWCs. This scrutiny and new data on the health effects of a wide spectrum of heavy metals and chemical compounds fostered vigorous opposition to proposed plants, to the adoption of increasingly stringent emission and ashmanagement requirements, and to other restrictive statutes at the federal, the state, and even the local level. One response in this adversarial environment is to upgrade the processes and enhance the control technology for “conventional” mass burn and RDF-type MWC systems. As described in previous chapters, the engineering and scientific skills of the mass burn industry, worldwide, have aggressively and successfully pursued this strategy. An alternative approach, however, is to develop altogether new thermal processing technologies that are inherently low in emissions yet still achieve the goal of minimizing landfill space consumption while accepting the wide range of feedstocks comprising MSW. One such class of new, environmentally benign technologies is based on the gasification of refuse coupled with intensive cleanup of the product gas. Members of this class have been given the name “conversion processes” by the waste management community.
