Influence of Chemical Treatment on Rice Straw Pyrolysis by TG-FTIR

The influence of treatment on pyrolysis characteristic and the products evolution performance of rice straw had been investigated by thermogravimetric analyzer coupled with Fourier transform infrared spectrometry(TG-FTIR). The results showed that after chemical treatment such as acid and alkali treatment, the initial pyrolysis temperature and the maximum weight loss temperature shifted to high temperature zone, the maximum weight loss rate increased, and the shoulder peaks of DTG went to fade. The ranges of E (activation energy), which was calculated through Flynn-Wall-Ozawa method, were 198∼219 kJ/mol, 184∼216 kJ/mol, 175∼205 kJ/mol, 184∼216 kJ/mol, and 205∼230 kJ/mol for raw-RS, H2SO4-RS, H3PO4-RS, HCl-RS, and NaOH-RS, respectively. The thermodynamic parameters of ΔH, ΔG, andΔS were calculated at the DTG peak temperature. After chemical treatment, most of alkali metals were removed, and the absorbance intensities of CO2 and CO decreased comparing to that of raw sample, while the evolution of pyrolysis products including C-H, C-O-H, and C–O–C functional groups were enhanced through acid. Particularly, C=O functional groups were decreased through acid, but increased through NaOH.