To meet the needs of biomass-oriented depolymerization and value-added pretreatment technology,rice straw(RS)was taken as the raw material.To explore the mechanism of thermochemical coupling for physical quality control,the chemical composition,thermal stability,crystallinity,and functional group types of RS after low-temperature torrefaction were analyzed using thermogravimetric(TG)analysis,X-ray diffraction(XRD),and Fourier transform infrared spectroscopy(FT-IR).The results showed that the crystallinity of RS increased slightly and then decreased at 120,160 and 200 ℃,with crystallinity of 35.45％,36.03％,and 32.42％,respectively.Compared to RS-180,under the torrefaction condition of 200℃,the content of cellulose decreased by 1.59 percentage points,while hemicellulose and lignin content increased by 1.35 percentage points and 1.73 percentage points,respectively.Under the torrefaction condition of 200℃,the weight loss of RS was 12.79％.Compared to RS,the maximum degradation rate of RS-200 at the sharp peak of cellulose weight loss increased from 15.81 to 17.11％/min,indicating improved thermal stability.Furthermore,compared to untreated RS,the total acid groups increased by 9.04％,carboxyl groups decreased by 33.33％,and phenolic hydroxyl groups increased by 105.56％.The equilibrium moisture content decreased from 11.56％to 8.20％,and the hydrophobicity improved.
关键词
低温烘焙/化学组成/结晶度/含氧官能团/疏水性
Key words
low temperature torrefaction/chemical composition/crystallinity/oxygen-containing functional groups/hydrophobicity
维普
万方数据