tga-ft-ir analysis of evolution of oxygenated organics by isothermal low-temperature decomposition of rice straw hydrolysis residue

The study presents a tga-ft-ir analysis of low-temperature thermochemical transformations of rice straw hydrolysis residue (rshr). isothermal decomposition of rshr was carried out for 3 h, at decomposition temperatures of 200, 250, 300, and 350 oc. at 200 oc, the rate of mass loss never exceeds %1/min and except for the first five minutes, it is less than %0.5/min. the initial rate of mass loss at 250 oc is %1.6/min which quickly drops to %0.6/min in the first 10 minutes and goes on further decreasing thereafter. at 300 oc, there is a rapid initial mass loss with the initial rate peaking at %8.8/min. at 350 oc, there is an initial burst of volatiles accounting for most of the mass loss with the initial rate of mass loss being %50/min. the residual mass obtained after these runs was 81.5, 38, 24, and 15%, respectively. ft-ir spectra of evolved gases suggest that volatile oxygenated organics along with non-condensable components like co2, and co are evolved during low-temperature thermal decomposition of rshr. carbonyls – acids, esters, aldehydes, and ketones – are the main functional groups in the volatiles. strong absorption bands ranging 3400 – 3900 cm-1 indicated the presence of alcohols and phenols as other functional groups. decomposition residues, the biochar, were demethoxylated and dehydrogenated compared to rshr but retained their basic lignocellulosic nature.