Study On The Gasification-Incineration Of Municipal Solid Wastes In Circulating Fluidized Bed

In recent years the waste treatment technology gets tremendous development. Combined the high efficiency of circulating fluidized bed with the gasification technology, the gasification-incineration of municipal solid waste has fine environmental protection characteristics. This thesis focus on theory analysis of the gasification of waste in terms of thermodynamics and dynamics separately to seek the best operation and process condition of waste gasification and the relevant research of 23t/h circulating fluidized bed pyrolysis -incineration of wastes has also been done to study the feasibility of gasification-incineration of wastes in terms of changing conditions.Aspen Plus is used to calculate the composition of syngas of waste gasification to reveal the relationship of gasification agent and the chemical results. It is concluded that high value syngas can be obtained from the gasification of the typical waste in Shanghai with 60% rich oxygen air as gasification agent. With the increase of air quantity, the concentration of H₂ is first increasing and then reduced. The equivalence ration in 0.55-0.65 can reach the max concentration of H₂ and CO and the highest calorific value of syngas.The gasification characteristic of waste-char with CO2 has been researched in a TG-DSC apparatus. With the increase of reaction temperature and pressure, the reaction rate increases and the time for reach the max reaction rate becomes short. The kinetic parameters were obtained in different ways. The relation of time and the carbon conversion ration is fitting out by the shrinking-core model and the reactivity order of the three char is Jiegan>Ganzhe>Muxie. The results also show that when the pressure is higher than 2.0 MPa, the increase of pressure has no effect on the reaction rate.In this thesis, ash and energy balance of 23t/h CFB waste gasification-incineration was analyzed and the basic restriction conditions of changing operation conditions for waste gasification-incineration were investigated. Compared to circulating carbon, municipal solid waste has low heating value. So considerable carbon incineration circulations supply this gap and enhance the quality of waste gasification products.After all, the CFB gasification-incineration technology is an effective way to treat the municipal solid wastes with high efficiency and low pollutants.