TG-FTIR Analysis of Three Crop Straws Pyrolysis

Abstract

The influence of heating rate on pyrolysis characteristic and the products evolution performance of sorghum straw, maize straw and cotton straw had been investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR), and distributed activation energy model (DAEM) was employed to calculate the kinetic parameters. The results show that with the increasing heating rate, the initial pyrolysis temperature and the maximum weight loss temperature shift to high temperature zone, the maximum weight loss rate increases, and the pyrolysis peak of hemicellulose starts to appear. The pyrolysis characteristic parameters of three crop straws were different because of their physical, chemical characteristics and structure characteristics. The activation energy E of sorghum straw, maize straw and cotton straw is 150~223kJ/mol, 141~217kJ/mol and 155~242kJ/mol, while the corresponding pre-exponent factor distributes between 1013and 1019s-1, between 1013and 1017s-1, and between 1014and 1020s-1,respectively. The main pyrolysis products of three crop straws are H2O, CO2, CO, CH4, formic acid and phenol. The research provides certain theoretical reference for energy regeneration utilization of straw biomass.