Development Of Novel Catalysts For Biomass Liquefaction

Nowadays,on account of the problems of environmental pollution and exhaustion of energy resources becoming worse and worse,people started to find some effective ways to solve these problems.Exploring and using of biomass energy is absolutely a good choice in this respect.Because of its renewable property,clean production process,biomass energy will occupy an important place in the energy structure in the future,but how to implement efficient liquefaction and accomplish clean industry downstream has become a critical challenge.Catalyst has a significant impact on the process of biomass liquefaction and research of the hydrogen donors in terms of biomass is daily deepening.However,little has been reported in biomass liquefaction reaction system simultaneously adding hydrogen donor and catalysts,and the synergistic effect of them is also barely investigated.In this study,based on the former research of hydrogen donor vis-breaking process of sawdust,we introduced a new kind of catalytic technology,which innovatively couples hydrogen donor vis-breaking process and catalytic liquefaction system.At first,sawdust is used as the raw material and the ethanol as solvent to investigate the experimental conditions?reaction time,temperature,mass ratio of raw materials and solvent,hydrogen donors?of biomass liquefaction.The ratio of sawdust to ethanol is 10g/80ml,reaction time is 30min under the temperature at 340?and we chose tetralin as hydrogen donor which takes up 25%of the biomass.With the optimized reaction condition,the liquefaction efficiency is increased from 36%to 48%.Catalyst carrier and promoter types,preparation conditions,metal-loaded proportion and catalyst amount are investigated in order to improve the oil yield and the quality of liquid production with the most effective catalytic system of biomass liquefaction.Activated Carbon?AC?and?-Al₂O₃ are selected as catalyst carriers and Ni loading amount is optimized to 10%and 8%via bi-metal single impregnation process.The result shows that the?-Al₂O₃/Ni-Ag?8%Ni-2%Ag?and AC/Ni-Co?10%Ni-2.5%Co?have the superior performance with the high liquefation yield of 51%and 57%,respectively.By the characterize of BET,XRD,SEM,XPS and GC-MS,the structure and property relationship of catalyst such as surface functional groups,specific surface area,pore structure and the components of liquefaction products,are studied.In the end,the mechanism of catalytic biomass liquefaction with hydrogen donor is studied.This reaction system combines the free radical cracking reaction with catalyst and hydrogen donor to synergistically improve biomass liquefaction efficiency.Thus,our new system makes some contribution to the development and utilization of biomass resources.