A study of co-pyrolysis of sewage sludge and rice husk for syngas production based on a cyclic catalytic integrated process system

Abstract

To address the challenges of low yield and low heating value of syngas, high yield of tar via pyrolysis, and to promote the resource utilization of syngas, this study prepared high-quality syngas through the secondary cracking of tar in cyclic catalytic pyrolysis steam based on a novel cyclic catalytic integrated pyrolysis system. In this study, the cyclic catalytic integrated pyrolysis system process parameters were synergistically optimized based on the pyrolysis syngas yield and lower heating value as indicators. The results showed that the optimal mixing ratio of sewage sludge and rice husk was 25:75 w/w. The optimal cycle speed and catalyst dosage was 1050r/min and 2.5g respectively. Compared to the normal pyrolysis system based on sewage sludge pyrolysis, the liquid phase product yield reduced 6 wt%, and the gas product yield increased 27 wt%. Regarding energy recovery, the syngas lower heating value increased 41.55%. The sewage sludge and rice husk have a synergistic effect and the long residence time promotes secondary cracking of the tar via pyrolysis, thus improving the yield and quality of the syngas. This study provides a new idea for the co-pyrolysis of different biomass to produce high quality syngas, and is very important for the preparation of renewable energy from biomass for application in power generation systems.