The Study On Catalytic Pyrolysis Of Sawdust With Bio-char

As a clean renewable energy,biomass energy can alleviate the pressure of fossil energy shortage.Biomass can be converted into clean and high-quality gas through catalytic pyrolysis process,and it can be efficiently and environmentally friendly for energy conversion from biomass.However,there are many problems in the process of biomass pyrolysis,such as the low content of high-quality gas and the viscous and corrosive tar produced in the pyrolysis process.In the process of biomass pyrolysis,the common tar catalysts include natural ores and nickel-based catalysts,but these catalysts will have the problem of carbon deposition and deactivation and need timely regeneration,which increases the cost and complicates the process.Bio-char is a solid by-product of biomass pyrolysis,which is porous and carbon-rich,and has catalytic effect on tar.Bio-char comes from the pyrolysis of biomass itself,and carbon deposition is no longer a problem.From raw materials to catalysts,the conversion between the two can form a virtuous cycle,and the pyrolysis process can be optimized in terms of cost and process.Therefore,in the process of biomass pyrolysis,with wide sources and no pollution,biochar was used as catalyst to conduct XRF analysis,XRD analysis,BET analysis and thermogravimetric analysis.The results show that the main component of biochar is amorphous carbon,which also contains a small amount of graphite carbon.Mesopores are the main structure in biochar,and there is a wide body and thin neck structure similar to ink bottle,which leads to the unclosed adsorption desorption curve.Bluffs weightlessness of biochar appeared after 760?,namely the solution loss reaction of carbon will react obviously after 760 ?,therefore the experiment temperature is set to 750? in this paper.In this paper,three methods of biomass catalytic pyrolysis were studied by taking the loading mode and quality of bio-char as variables,producing more high-quality gas and reducing recombinant tar as targets.In the first method,bio-char was used as a catalytic bed below the sawdust,and the experimental study on ex-situ catalytic pyrolysis of sawdust was carried out.In the second method,bio-char was mixed with sawdust to carry out an experimental study on in-situ catalytic pyrolysis of sawdust.In the third method,the mixture of bio-char and sawdust is filled in the upper section,and the lower section is filled with bio-char catalytic bed.The method 3 combined the method 1 and method 2,and experimental research on co-situ catalytic pyrolysis of sawdust is carried out.The tar and gas were analyzed by the GC/MS and GC respectively,the experimental results show that the amount on the total output of gas and hydrogen content followed by method 2,method 1,method 3 from small to large,restructuring the tar content order.The restructuring the tar content decreased from 6.99%to 1.21%,the hydrogen content increased from 1564.0 to 3155.7 mL(standard conditions),so the method 3 was better than the others.