Abstract
In Japan, the dioxin problem with municipal solid waste (MSW) incinerators in the 1990s and the enforcement of the "Fundamental Law for Establishing a Sound Material Cycle Society" with the "Law for the Promotion of Effective Utilization of Resources" in the early 2000s helped drive the change from mass-burn incineration to waste recycling. Among the various recycling methods, carbonization has been identified as a simple and robust technology capable of recovering materials (e.g., char and metal) rather than heat, which can be operated as a decentralized system in small and medium urban centers. Since the first full-scale carbonization facility for MSW treatment opened in 2002, five more facilities have been completed. In this work, we describe the current states of MSW carbonization facilities in Japan, including their process and material flows, operating conditions, char recovery and quality, energy consumption, emission controls, and problem areas, based on the results of a questionnaire, in-person surveys, and a literature survey. We describe the operating conditions, identify current technical and economic problems, and suggest ways to improve the waste-treatment and recycling potential of carbonization facilities.
