Study On Catalytic Pyrolysis Performance Of Tar Using High Temperature Char Bed

Biomass energy is the good alternative energy sources for fossil energy, and the best and most effective technology for biomass use is biomass pyrolysis gasification technology. But the development of the existing biomass pyrolysis gasification is limited by the tar. Due to the harmfulness of tar, the pyrolysis gasification equipment and the quality of the gas are challenged. Using char produced by biomass pyrolysis gasification as a catalyst, which greatly promote the development of biomass pyrolysis gasification. Char has advantages:low cost, abundant resources, excellent catalyst performance and good ability of resistance to carbon deposit. Study on char for tar catalytic cracking is the main direction for tar catalytic research in the future.Firstly, the importance of biomass to deal with the problem of energy are reviewed in the paper. The development of the catalytic technology of biomass pyrolysis technology at home and abroad were summarized. The influence of various catalysts on the catalytic performance was discussed. Considering the cost and life of catalyst and carbon deposit, the char was chosen as catalyst of biomass pyrolysis technology, which was an important route.Secondly, oak is studied in single stage pyrolysis experimental in a laboratory scale, and get the data of the effect of the single stage pyrolysis temperature on pyrolysis product distribution. Tar mainly contains macromolecules of aromatic compounds and their derivatives at below600℃; Tar contain macromolecules of aromatic compounds and their derivatives most or aromatic compounds, but found that there were a lot of direct hydrocarbons at above600℃, which indicated that high temperature can make the cracking of tar.Thirdly, using the inert substance quartz and as blank contrast, two different kinds of char as catalytic material were compared. The tar conversion, gas yield and composition were compared. Oak were better than rice husk carbon and quartz sand in the catalytic performance. For the equipment and materials, the best condition of the experiment pyrolysis temperature was600℃, oak char was as catalyst,800℃was as the best temperature of catalyst bed and the length of catalytic bed was21cm. And the gas residence time was5.81s. At the this time, the rate of tar conversion is83.77%, and the increase percent of gas yield because of catalytic performance is27.50%.Tar mainly contains aromatic compounds and their derivatives before catalytic cracking and mainly produce alkane material after catalytic cracking, which shows oak bed has excellent catalytic performance. Fourthly, the ability of char catalyst mainly rely on the catalysis of macroporous and mesoporous though electron microscopy analysis. And macroporous and mesoporous are not easily blocked during the catalytic reaction process, so it is not easy to deactivate as a catalyst. The carbon deposit can be removed by gasification reaction, which indicates the advantage of char in the catalytic process.