Research On The Catalytic Gasification Characteristics Of Starch Waste

As a brand new gasification technology in the field of biomass,catalytic gasification has highly promising future.Studies have shown that torrefaction can reduce tar formation in the process of catalytic gasification of biomass,and decrease the carbon formation on surface of nickel-based catalysts.Given that the composition of starch waste resembles biomass,so pretreat starch waste via torrefaction not only could decline the ratio of O/C and water content,but also restrict the formation of carbon deposition.For coping with the problem that it is hard to improve the efficiency of gasification further,we advise catalytic gasification to enchance the quality of syngas.Therefore,it is concluded that catalyst should be used in the process of gasification after torrefacation pretreatment.The essay is aimed at the influence of different torrefied temperature and different Ni-based catalysts for the samples which were torrefied firstly and then catalyzed.First of all,the research on fixed bed system under the water vapor atmosphere had done to study gasification characteristics of starchy leftovers,the different torrefied temperature,the influence different gasification temperature and different torrefied temperature.Emphasis was on the effects of torrefied temperature on gasification,especially the torrefied temperature on the structure of the subtle change.At the same time,the reaction of total carbon balance had calculated.The results showed that the best pretreatment of torrefied temperature of starchy leftovers was 240?.Under the temperature of 240?,torrefaction could reduce the O/C ratio and water content,and would not lead to carbonization and rupture of aromatic C-H bond of sample.Incremental torrefied temperature would to a certain extent improve hydrogen production because torrefaction made the alkali metal content of K in the samples obviously improved,and the high content of K was able to produce more hydrogen.Improved gasification temperature could enchance cold gas efficiency because the improved gasification temperature could make tar cracking more sufficient,coke gasification reaction and steam reforming reaction more fully.Compared with Ni/Al₂O₃ catalyst,the crosslinking structure formation in the catalytic activity of Ni/SiO₂ catalysts in nickel improved the catalytic activity more.Optimal adding proportion of Ni/SiO₂ catalyst was 30%.Second,under the way of water vapor atmosphere and the Ni/SiO₂ catalyst,study had done to research torrefied characteristics of gas of different samples.Emphasis was on the effects of catalyst on the gaseous product distribution.In addition,BET,TPR,TEM and XPS had done for catalysts to analyse their characterization,and to explore the mechanism of the catalytic performance of catalysts for auxiliary Ce and Co.Result showed that the catalyst promoted the tar and H₂O reforming reaction,thus more H₂ and CO₂ would be produced.Doped Co into Ni/SiO₂ catalysts,Co-Ni/SiO₂ only further improved the catalytic gasification of H₂ production in the sample of RI.Doped Ce into Ni/SiO₂ catalysts,Ce-Ni/SiO₂ could further improve H₂ yield of all the samples during catalytic gasification.Therefore,Ce could improve the catalytic performamce of Ni/SiO₂ catalysts.Co could improved to some extent Ni dispersion,but Ce could not only improve the dispersion of the Ni,but also enchance the reducibility of catalyst,which is because the Ce could improve the ability of resistance to carbon deposition of catalysts and electronic activity in Ni2p_3/2 orbit.In the Ce-Ni/SiO₂gasification experiment with samples for RI-260,torrefaction and catalytic gasification of the coupling effect was best.H₂ yield could be increased by 199.3%.