스위치그라스 열분해에 대한 TGA-FTIR 분석

Abstract

This study was conducted to investigate the pyrolysis characteristics of switchgrass using TGA-FTIR instrument. Switchgrass is a high yielding perennial grass that has been designated as a potential energy crop, because of its high energy value. Ground switchgrass were pyrolysed at different heating rates of 10, 20, 30, and <TEX>$40^{\circ}C/min$</TEX> in a TGA-FTIR instrument. The thermal decomposition characteristics of switchgrass were analyzed, and the gases volatilized during the experiment were identified. The thermal decomposition of switchgrass started at approximately <TEX>$220^{\circ}C$</TEX>, followed by a major loss of weight, where the main volatilization occurred, and the thermal decomposition was essentially completed by <TEX>$430^{\circ}C$</TEX>. The pyrolysis process was found to compose of four stages; moisture evaporation, hemicellulose decomposition, cellulose decomposition, and lignin degradation. The peak temperatures for hemicellulose decomposition (<TEX>$306^{\circ}C$</TEX> to <TEX>$327^{\circ}C$</TEX>) and cellulose decomposition (<TEX>$351^{\circ}C$</TEX> to <TEX>$369^{\circ}C$</TEX>) were increased with greater heating rates. FTIR analysis showed that the following gases were released during the pyrolysis of switchgrass; <TEX>$CO_2$</TEX>, CO, <TEX>$CH_4$</TEX>, <TEX>$NH_3$</TEX>, COS, <TEX>$C_{2}H_{4}$</TEX>, and some acetic acid. The most gas species were released at low temperature from 310 to <TEX>$380^{\circ}C$</TEX>, which was corresponding well with the observation of thermal decomposition.