Design And Experimental Research Of A Novel Biomass Gasifier

The conversion of biomass into synthesis gas is significant to researchand application. The conversion process can be completed at higher reactiontemperature and needs some special gasification agents, like air, steam, etc.The final synthesis gas includes CO, H₂, CH₄and some hydrocarbons.Biomass-tar is one of important by-products from biomass gasification. Itinfluences both the calorific value and components of biomass fuel gas. Thebiomass-tar causes not only serious environmental pollution, but alsoequipmental corrosion. The main object of this thesis is to study the catalyticremoval of biomass-tar.Firstly, it was designed a novel domestic straw gasifier, which wasequipped with a U-shaped tube inside. And the U-shaped tube was filled withporous ceramics as catalytic material in the process of biomass gasification.The U-shaped tube can make porous ceramics contact with the fuel gas easily.Secondly, the biomass gasification was completed in the biomassgasification reaction platform, and the porous ceramics was used as the secondcatalytic reforming material. It was also studied the capacity of hydrogenproduction and the catalytic cracking ability of biomass tar in the process ofbiomass gasification. The experimental results showed that the porousceramics could improve the gas calorific value obviously and were benefit tothe catalytic cracking of biomass-tars. At the same time the reformingtemperature has a significant effect on the calorific value and components ofbiomass fuel gas. The volume fraction of hydrogen increases with thereforming temperature, and the gas calorific value increases as well.Finally, some useful tests were also carried out in the novel domestic strawgasifier. It was proved that the U-shaped tube filled with porous ceramicscould eliminate the biomass-tar and ash content. The calorific value of fuelgas could reach to5.0MJ Nm-3and the biomass-tar content could alsoeliminate to about20mg Nm-3. The structure of novel domestic straw gasifieris practical. It could increase the calorific value of fuel gas and enhance thereactions of tar-cracking. The selection of air volume is one of the mosteffective methods to control the process of biomass gasification. Thereasonable air volume can be adjusted to1.3-1.5m3h-1in the present gasifier.