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Show 4. CONCLUSION In order to be efficient, a MSW incinerator should be built at or near the center of an urban area. It is therefore a valuable local power generator, and it is timely to improve its efficiency by using natural gas. This is why the research for repowering is being pursued by various groups. Since natural gas has been nationally acknowledged as a clean energy, the concept of using it to control emission from MSW incinerator would be readi Iy accepted. Avoiding the use of annmonia alone which is regulated and requires careful handl ing should certainly make reburning technology an attractive proposition. It is necessary to confirm first of al I to what extent NOx from Japanese MSW would be lowered. If the result should be equivalent to that achieved in USA, 50 ppm, use of annmonia can be el iminated except in the urban area where the regulation is very strict. Even where the restrictions are very severe, both initial cost and operating cost can be greatly reduced because not the entire amount of exhaust gas needs to be put through the catalytic deNOx converter. Cost-saving alone by el iminating the need for ammonia, or reducing the need for catalytic converter alone would not be enough to justify adoption of natural gas reburning to MSW incineration. Higher price for power sale is indispensable, and where there is a big difference between day and night power rates, gas turbine operation should be I imited to daytime hours. Obviously, the most important factor which determines the economics is the cost of natural gas. Securing a favorable gas price as a large user would be the key issue. REFERENCE LIST: 1) Ryoj i Samej ima, Takuma Co., "REBURNING AND REPOWERING ON MSW COMBUSTION SYSTEMS" 2) Eij i Shigeta, Hitoshi Kanazawa, Kenji Kanazawa, Tokyo Gas; "REDUCTION OF NOx AND CO ON THE MSW COMBUSTOR USING NATURAL GAS REBURNING TECHNOLOGY", PPM January, 1993 3) Yasuj iro Wakamura, Takuma Co., "EMISSIONS CONTROL USING NATURAL GAS", The 2nd Annual Conference of Japanese Waste Management Research, October 10, 1991 . 4) Donald K. Fleming, Mark J. Khinkis, Hamid A. Abbasi, IGT; David G. Linz, GRI; Craig A. Penterson, Ri ley Stoker: "EMISSIONS REDUCTION FROM MSW COMBUSTION SYSTEMS USING NATURAL GAS", The 12th Symposium of Pap Energy Biomass Wastes. 5) L. Barnisk, "INCINERATION MUNICIPAL AND INDUSTRIAL WASTE" Waste Incineration in the FRG 1 5 |