(628h) The Study on the Kinetics of Coal-Steam Catalytic Gasification for Different Particle Sizes of Coal and Catalyst

Compared with traditional gasification technologies, catalytic gasification technology can increase gasification rate obviously and reduce gasification temperature. So some researchers have paid more attentions to the catalytic gasification technology. The effects of particle size on the steam gasification of the coal char were investigated by the bench equipment. The gasification reaction of coal char and catalyst (K2CO3) with different diameter ranges were calculated with dynamic model to obtain the reaction rate constant for coal-steam gasification characteristics. Firstly, the non-catalytic gasification results of SF char with different particle sizes were analyzed under the condition 650 °C . It’s found that particle size does not obviously affect the gasification reaction rate. Secondly, for the non-catalytic gasification results of SF char with same particle size under 650 °C and different gas rates, it was found that external diffusion can be ignored when the gas rate larger than 100ml/min. Then, catalytic gasification experiments of different chars, SF, YN, ZY, and the potassium carbonate with three particle sizes were conducted under 650 °C. The three experiment conditions are as follows. K2CO3 particle size are 75um, and the char particle sizes change; the char particle size is 200 um, and K2CO3 particle size changes; the char and K2CO3 particle sizes change at same range. The experimental results showed that the smaller the particle size of coal char and catalyst, the higher the gasification reaction rate under the experiment condition. For the catalytic gasification process, the influence of the catalyst particle size on catalytic gasification reaction is better than that of coal char particle size. When the granularity reaches more than 200 mesh, particle size of coal tar and catalyst change in the same range will have a best effect on catalytic gasification, and it is better when the catalyst particle size changes than that of coal char particle size changes also. At last, the mobility of K2CO3 in gasification reaction and the influence of catalyst particle size on gasification reaction are discussed.