Torrefaction is a slow pyrolysis process that is carried out in the relatively low temperature range of 220-300°C.The influence of torrefaction as a pretreatment on biomass gasification technology was investigated using a bench-scale torrefaction unit,a bench-scale laminar entrained-flow gasifier,and the analysis techniques TGA-FTIR and low temperature nitrogen adsorption.A series of experiments were performed to examine the characteristics of the torrefaction process,the properties of torrefaction products,and the effects of torrefaction on gas composition,cold gas efficiency and gasification efficiency.The results showed that during the torrefaction process the moisture content of biomass were reduced,and the wood fiber structure of the material was destroyed.This was beneficial to storage,transport and subsequent treatments of biomass in large scale.For solid products,torrefaction increased the energy density,decreased the oxygen/carbon ratio,and created a more complex pore structure.These improved the syngas quality and cold gas efficiency.Combustible gases accounted for about 50% of non-condensable gaseous torrefaction products.Effective use of the torrefaction gases can save energy and improve efficiency.Overall,biomass torrefaction technology has good application prospects in gasification processes.
CHEN Qing ZHOU JinSong LIU BingJun MEI QinFeng LUO ZhongYang
Two white-rot fungi Coriolus versicolor B1 and Ganoderma lucidum En were used for biological pretreatment of bamboo. The saccharification rate,the relative contents and the degradation rates of cellulose,hemicellulose and lignin in untreated and pretreated bamboo,were determined. The results indicated that the relative content of cellulose in bamboo was 35.7%,which was just a little lower than hard wood,and bamboo was suitable for cellulosic ethanol production. The saccharification rate of bamboo was significantly improved after biological pretreatment with white-rot fungi. After pretreatment with G. lucidum En for twenty days,the saccharification rate was enhanced for 26.9%. After pretreatment with C. versicolor B1 for thirty days,the saccharification rate was enhanced for 19.2%. These results revealed that biological pretreatment with white-rot fungi was very efficient for promoting enzyme hydrolysis of bamboo and it’s an efficient pretreatment method for bamboo.
