Study On The Preparation Of Structured Solid Acid Catalyst Packing And Its Application On Dehydration Of Xylose To Furfural

With the increasing depletion of fossil energy and the gradual deterioration of environmental problems,the world is facing a crisis of energy and environment.As a kind of important organic chemical intermediates and biomass platform compounds,furfural has caused the concern of researchers extensively,but the production process of various environmental problems as well as the raw material using is not sufficient and other unfavorable factors become the focus of researchers.At present,more researches are focused on the two step process of furfural in the dehydration of xylose dehydration step.This thesis also pays close attention to xylose dehydration and cyclization of furfural as the research content and in packed column of furfural production as the goal,system,mainly by filler type solid acid catalyst,and the effects of the xylose dehydration and cyclization of catalytic activity in the reaction of furfural.In this paper,porous anodic alumina（AAO）was used as the matrix,the filler type solid acid catalyst AAO/SBA-15-SO₃H was prepared by the direct method,the SBA-15 bit carrier and the sulfonic acid group are the active components.Because the amount of product is too small,the AAO film cannot be removed after the characterization,the precursor solution in the same conditions to deal with other characterization.FTIR analysis was used to analyze the changes of surface groups during the process of catalyst preparation.The results showed that the direct method was used to prepare the filler type solid acid catalyst AAO/SBA-15-SO₃H containing the proton acid center-SO₃H.SEM and TEM results show that SBA-15 in AAO mesoporous structure is columnar vertical matrix growth,SBA-15 structure and morphology of the precursor solution of P123 concentration.When the AAO melt and the obtained product is fibrous,some will show a special morphology,mainly because of the AAO in the presence of structural defects.TG results showed that the catalyst has good thermal stability.N₂ adsorption desorption showed that the catalyst has a large specific surface area,that is,more active components of the contact site,to improve the catalytic performance of the catalyst to further provide a proof.The experimental results show that the catalyst prepared by the direct method has high catalytic activity,the xylose conversion rate can reach 90%and the selectivity of the catalyst is 50%.After the reaction of SEM,we found the side reaction product covering the AAO surface,so the activity of the catalyst decreased mainly due to the side reaction occurs in response to carbon deposition has hindered the full contact between the reactant and the catalyst.Using hydrogen peroxide to regenerate the deactivated catalyst,the catalyst surface is changed from black to light yellow,but it takes a long time,about 20days.