Modelling the influence of pressure inside particle with fractal structure on the tar distribution and Pareto optimal during pulverized coal fast pyrolysis

Pulverized coal fast pyrolysis is a coal conversion technology with high tar yield but low tar quality. Because of the small particle size and high heating rate, significant pressure exists inside the particles, affecting the final product distribution. This study established a cube media according to fractal law and generated coal particles with the same pore structure to calculate the internal pressure distribution. The pressure profile was further coupled with a tar generation mechanism to investigate the pressure effect on tar product. The single Shenfu coal particle pyrolysis was simulated in a drop tube furnace reactor model. The results showed that the total tar yield decreased, and the light fraction increased with the correction of internal particle pressure. Maximum deviation reached 28.86% and 23.09%. A particle size of 25 μm was beneficial to increase the tar yield, while carrier gas temperature of 973 K helped improve the tar quality.