Powder, Powder Spouted Bed Half Dry Flue Gas Desulfurization Reaction Of Numerical Simulation

In recent years, with the development of human society, the requirement of energy increases continuously, which leads to the serious environment pollution. Especially coal is the main energy source of China, so it is a major issue to control the emission of sulfur dioxide (SO2) and NOx through coal/oil combustion. A new semidry flue gas desulfurization process with a powder-particle spouted bed (PPSB) developed in Japan has many advantages, such as effective sorbent utilization, high SO2removal efficiency, simple configuration, low investment and so on, and has been widely used in industry, agriculture, manufacture et al.In this study, the semidry flue gas desulfurization process with a PPSB was investigated using a CFD numerical simulation method. A dynamic mathematical model for water evaporation had been established based on theoretical analysis of water vaporizing. The results showed that the Fountain and the Annulus are the main areas for gas-liquid-solid three phases mass and heat transfer, and water evaporative process.In addition, in order to predict the main control procedure and the main area of SO2removal process in the PPSB, we analyzed the two main control procedures of the desulfurization process:gas phase mass transfer process and liquid phase mass transfer process. The simulation results showed that the control procedure of the Fountain and the Annulus is gas phase mass transfer process and the control procedure of the Spout is liquid phase mass transfer process, but only the Fountain and the Annulus are the main areas for desulfurization process.At last, the effects of approach to saturation temperature(▽Tα)、Ca/S molar ratio and the size of Ca(OH)2sorbent particles on SO2removal efficiency were investigated in this paper using numerical simulation method, and the simulation results were compared with experimental results obtained by Ma et al. The comparison results showed that:(1)on the one hand, the simulation results had the same tendency with experimental results, which proved that gas-solid two phases model, water evaporation model and the desulfurization model above are effective;(2)but on the other hand, the simulation results showed that SO2removal efficiency was far lower than experimental results, which may be caused by the complexity of the computational models and the limit of computing time. So in order to reduce computing time, the computational models about desulfurization should be further optimized.