Valorization Of Chinese Herb Medicine Residue By The Integrated Process Of Microwave Torrefaction And Pyrolysis

In this research,microwave torrefaction processing of Chinese herb medicine residue（CHMRs）was established for enhancing the valorization,and the microwave effect on torrefaction as well as pyrolysis was comparatively investigated.CHMRs is a residue with high yield and strong re-production capacity,increasing year by year,and it is a kind of high yield biomass.Therefore,it is considered to be of high substance and energy conversion rate of biomass.Higher microwave power level committed higher heating rate and temperature profiles,and resulted torrefied biomass with some definite benefits,such as grindability,energy density and volatile content.The aftereffects of microwave power range and processing time on the proximate and ultimate content,higher heating values,hydrophobicity,energy and mass yields of CHMRs were investigated.120W microwave power level for 10 and 20min processing time was required to get about 88%mass yield and end 89%energy yield for torrefied feedstock.For comparison,conventional torrefaction was also examined at the dif ferent temperature of 218°C and 300°C.Microwave heating was proved to be less time consuming and efficient,although both temperatures showed the same effects on CHMRs.After the torrefaction processes,the pyrolysis of raw and torrefied CHMRs was performed at the temperature of 800°C with the residence time of 30min.The results presented the increase biochar,decrease of liquids and gas at the higher torrefaction temperature.Besides,torrefaction contributed increase fraction of H₂ and CO₂ and decrease fraction of CO and Cm Hn light gas.Additionally,important effects of torrefaction on the liquid production was identified.The torrefaction technique favors in refining the nature of liquids such as removing some water content,acids as well as oxygenated elements.Liquid products showed the increase of aromatic compounds and decrease of acids,phenolic and ketones compounds as compare to raw at higher torrefaction temperature.