| Abstract: | This paper is a comprehensive analysis of the characteristics and economics of systems which treat municipal refuse and utilize its contained energy as the energy source to generate not only electric energy but also the heat energy for district heating and cooling. The following two systems are investigated: (1) System A which is composed of a plant to incinerate municipal refuse and a cogeneration system with a bleeder/condensate turbine power generation unit; and (2) System B which is the system proposed here and is composed of a pyrolysis furnace for treating municipal refuse, a two-stage-cleaning process for refining generated pyrolysis gas, and a cogeneration system constructed by a combined cycle power generation unit using cleaned pyrolysis gas as its fuel gas. It was estimated that the maximum net power-generating efficiency of System B is 24.8 percent, and is higher by 63 percent compared to that of System A. Economics of the systems have also been investigated, and it was shown that System A if the extra electric energy of the systems can be supplied directly to various facilities, which is different from the case where it should be sold only to electric companies. Effects of changes in major social and technological factors which affect the economics of the two systems are also analyzed, and it was shown that the possibility is considered to be high that the economics of System B will become more advantageous than that of System A in the future. |
