Design Of A Pilot-scale "Double-solution" Technology For Domestic Waste And Study On The Process

A kind of villages and towns domestic waste disposal technology,pyrolysis gasification is suitable for decentralized disposal model and has been applied since its unique advantages.However,there are some disadvantages for the MSW pyrolysis gasification process in the industrial application.For instance,the performance of the gasification process is instability due to the complex compositions of unsorted MSW;a huge amount of energy needs to be supplied to the reactors for the gasification system and this would significantly reduce the gasification efficiency.This has motivated the development of new research studies focused on designing new efficient and effective strategies that can increase thermal efficiency and provide better process performance to achieve precise control.Based on the analysis of physical characteristics of domestic waste,and combined with the analysis of pyrolysis and gasification modeling of domestic waste and the analysis of engineering test results,this study design a pilot-scale complete set of equipment to deal with domestic waste in Chinese towns so as to promote its application on a large scale.The main studied contents and conclusions are listed below:(1)Analysis of the characteristic of domestic waste including physical composition,moisture content,heating value and proximate and ultimate analysis in China towns was summarized,and the TG-FTIR was used to study its pyrolysis characteristics.The results showed that the water content was 40%,the heating value was 4812 kJ/kg,and the pyrolysis temperature was between 200-600 ?.The CO,CH4,tar and other complex mixture could be formed under this temperature range.(2)Designed a flue gas circulation model of pyrolysis and gasification,and a gasification process of domestic waste was simulated by Aspen Plus software.The optimum reaction temperature was 900 ?,the appropriate A/F was 0.4,the appropriate ER was 0.5,and the appropriate amount of steam was beneficial to the pyrolysis gasification reaction.The drying,pyrolysis,gasification and combustion system were developed and integrated into the atmospheric fixed-bed gasifier with heat provided by itself,which can be used in towns.(3)Based on the balance method,a physical model and a mathematical model was established by using principle of material balance and energy balance of the"double-solution" furnace.From the material and energy balance analysis,the"double-solution" furnace model is reliable that meet the self-heating mode.(4)Based on the demonstration project for 10 t/d domestic waste disposal in"double-solution" technique,completed the overall design of the "double-solution"technique.Under the technological experiments,the temperature distribution,flues emissions,and ash properties were analyzed based on the engineering operational data.The domestic waste was disposed by the "double-solution" furnace,the ignition loss of slag was 4.94%,belonging to the general solid waste.The CH4,CO of the flue-gas circulation chamber could be re-combustion.The pollutants composition in gas was lower than the state standards.