Experimental Of The Catalytic Cracking Of Biomass Tar

Ni-based catalyst has a good active to crack tar, but the catalyst can easily be inactivatedby surface carbon deposition and sintering; Olivine has abrasion resistance and difficultsintering characteristics; Metal additives can increase the resistance to coking capacity anddegree of dispersion of Ni. The purpose of the study is to prepare a tar cracking catalysthaving good activity. Through a combination of the low temperature cracking activity ofolivine and the high temperature stability and reforming activity of the nickel-based catalyst,combining the advantages of the two catalysts and metal additives, additives on cracking oftar over Ni-Ce supported Olivine was prepared. The catalyst was prepared by theconventional impregnation method and the ordinary drying method, with olivine as carrier,different load percentages of Ni,Ce and metal additive (Cu, Fe, Mg). The crude gas was usedas reducing gas, the catalyst was reduced at500℃for two hours, then the activity andstability tests was taken on an evaluation device of a tar cracking. The tar crackingperformance of different additives and additive content was investigated. then explored theinfluence of the Ni content of3%Cu-10%CeO2/Olivine catalyst on the cleavage activity andthe influence of the Cu content of10%Ni-10%CeO2/Olivine catalyst on the cleavage activity.Finally, we discuss the different process conditions (reaction temperature, crude gas airspeed,tar concentration, etc.) on the catalytic cracking of tar performance.Through the above study, we fromed a method for tar cracking catalyst in biomassgasification, The catalyst composition was10wt%of NiO,3wt%of CuO,10wt%of CeO2,the rest is olivine carrier. The catalyst has a relatively large specific surface area and themesoporous structure, contribute to the mass and heat transfer of the catalyst.. Metal promoterof Cu, Fe and Mg improved the cleavage reaction activity. The order of the activity as well asresistance to carbon deposition performance is Cu>Fe>Mg. At the same time, the additiveshad a great impact on the cleavage product selectivity, Cu, Fe increased the content of H2, COand hydrocarbons, and Mg increased the content of CO2. At a space velocity of5000-10000h-1,a temperature of800℃, tar concentration below6g/Nm3conditions, the activity and stabilityof the catalyst reached the top level, the tar conversion rate reached98%or more. Theexperimental operation50h data show that: the conversion rate of the catalyst had been more than97.5%, the stability of the catalyst was good, while the content of the H2, CO andhydrocarbons in the product gas had been no change.