PYROLYSIS CHARACTERISTICS OF RICE STRAW EMAL

Rice straw lignin was isolated by the enzymatic/mild acidolysis method known as enzymatic/mild acidolysis lignin (EMAL). The pyrolysis characteristics of rice straw EMAL were studied by thermogravimetric analysis (TGA) at heating rates of 10, 20 and 30 K/min. To detect the thermal degradation products Of EMAL, pyrolysis gas-chromatography mass spectrometry (Py-GC/MS) was applied to analyze rice straw EMAL at 800 degrees C. The key marker compounds identified were derivatives of the three kinds of lignin basic units (guaiacyl, syringyl and p-hydroxyphenyl units). The Coats-Redfern law was adapted to simulate the dynamic equations of rice straw EMAL pyrolysis. The results showed that the kinetic model of rice straw EMAL pyrolysis was a first-order reaction. In the paper, the distributed activation energy model (DAEM) was used to reveal the complex reactions developed during rice straw EMAL pyrolysis, and the activation energy distributing curves were plotted. The kinetic results indicate that the reaction activation energy increased with increasing both weight loss rate and heating rate.