Modeling of gasification system for solid waste treatment

Abstract

Solid waste treatment has drawn global attention in recent years. Incineration, as a traditional solid waste treatment process, is an effective way to reduce the volume of solid waste by 90%. However, greenhouse gases and toxic gases are produced during the combustion process. Gasification, as a different thermochemical process, not only achieves the purpose of a combustion process, but also has its own unique advantages. Gasification means incomplete combustion and it results in the production of syngases. By controlling the gasification agents (O², CO², air or stream), the concentration of different syngases can be controlled. The gasification process is influenced by a number of parameters which include temperature, concentration, flow rate and reaction surface area. In this study, some existing fluid-solid reaction models are reviewed. The Arrhenius equation is applied in most of the reaction models in which the temperature and gas concentration are usually considered. For solid waste gasification, another parameter, particle size, has a significant effect on gasification rate as most of the solid wastes are not in powder form. In this research, the effects of particle size are investigated by experiment, calculation and simulation. In this study, the effects of different parameters are analyzed. The reaction rate and syngas generation during gasification at different parameters are found by experiment. The effect of concentration of gasification agents and the effect of particle size are investigated. Based on the experimental results, a gasification model is developed. The developed gasification model can predict the gasification rate and syngas generation of different sized particles. A virtual gasification reactor was built based on the results found in this research. The research can be extended by investigating the gasification rates of more materials and a more accurate prediction of the performance of an existing gasification reactor or one that is in the planning stage ascertained.

Date of Award	2014
Original language	English
Awarding Institution	The Hong Kong University of Science and Technology