The effect of fuzzy PID temperature control on thermal behavior analysis and kinetics study of biomass microwave pyrolysis

Abstract

This study aims to investigate the thermal degradation behavior and kinetics of biomass microwave pyrolysis, which was improved and verified with a fuzzy PID control algorithm. Cellulose, xylan (hemicellulose) and lignin were used as model compounds of biomass and the thermal degradation behavior of biomass during pyrolysis was analyzed via microwave-TGA. The transfer function models of the biomass heating process were established. Compared with traditional PID control, the use of the fuzzy PID control algorithm significantly improved the response speed of the system. The response time was reduced from 38 s to only 4 s, and the steady-state improved with the fuzzy PID control. Fuzzy PID control promoted the thermal decomposition temperature to a lower area. The activation energies (E) for microwave pyrolysis of corn stover, lignin, cellulose and hemicellulose were reduced about 15.2 %, 17.3 %, 19.9 % and 11.8 %, respectively. Hence, more precise temperature control via the fuzzy PID algorithm can reduce the error in the experiment and improve the energy utilization efficiency during biomass conversion.