The rapid growth of economics and population in Thailand is bringing a great amount of solid waste, originating from various industrial factories and households. Big places of area needed for filling all of them. Waste elimination procedures chosen by most of municipalities in Thailand are still classical; waste decomposition and burning are widely practiced since the cost is not too high and the operation is quit simple and rapid. Nevertheless the use co classical furnace has shown inadequate efficiency. This thesis work introduced a fluidization combustor with sand circulation in the bed. In this study involves three steps. First and second steps were carried out in a 15 cm. diameter combustor. The air flow rates from 120.33 m(superscript 3)/hr to 227.62 m(superscript 3)/hr, solid waste feed rates from 3.04 Kg/hr to 13.06 kg/hr and LPG flow rates from 1.07 kg/hr to 1.69 kg/hr in order to get optimal operating condition of high efficiency. Third step, combustor has a diameter of 20 cm. LPG were rates 28.00 kg/hr and the air flow rates 240.03 m(superscript 3)/hr. The results showed that the optimum operating conditions, in first and second steps were air flow rates 187.17 m(superscript 3)/hr and 211.67 m3/hr, solid waste feed rates of 9.69 kg/hr and 10.99 kg/hr, respective, and LPG flow rates at 1.40 kg/hr. In third step, LPG flow rates of 2.38 kg/hr. The continuous operation would achieve to highest combustion efficiency of 99.93 percent and the operating cost of LPG was 0.91 baths per kilogram of municipal solid waste.
