Preparation And Performance Evaluation Of Carbon Microsphere Solid Acid Catalyst

Carbon microspheres are carbon materials with high specific surface area and many excellent properties.Carbon microspheres have received widespread attention from many researchers since their inception.To date,carbon microspheres have been widely used in catalyst carriers and flame retardant materials and waste fiber materials utilization and battery electrodes as well as adsorbent materials.Biomass is a renewable resource that is environmentally friendly.Therefore,the preparation of carbon microspheres from biomass is favored increasingly.In this paper,carbon microspheres were prepared by direct hydrothermal synthesis and templating method using glucose as raw material.Then a solid acid catalyst was prepared and applied to the hydrolysis of cellulose.Firstly,carbon microspheres were prepared by direct hydrothermal synthesis and template method and the factors affecting the structure and properties of carbon microspheres were investigated.Secondly,carbon microspheres were prepared into solid acid catalysts with concentrated sulfuric acid as sulfonating reagent and characterized and analyzed.Finally,carbon microsphere solid acid catalyst was used for cellulose hydrolysis to study carbon microsphere solids.The acid catalyst is used for the kinetics of cellulose hydrolysis.The specific research results are as follows:1.After carbonization,the morphology of the glucose changes greatly,from a rod-like structure to a spherical shape.On this basis,the effects of carbonization temperature and carbonization time on the carbon microsphere morphology were investigated.The carbon microspheres prepared by the direct hydrothermal synthesis method and the solid acid catalyst,the carbon microspheres prepared by the catalyst dosage of 0.6 g,the carbonization temperature of 180?and the carbonization time of 7 h are more uniform and regular.And the particle diameter is about 5-10?m.The solid acid catalyst microspheres formed after sulfonation were joined together but the particle size of the sphere did not change significantly.The carbon microspheres prepared by the template method and the solid acid catalyst,the carbon microspheres prepared by using the sodium dodecyl sulfate amount of 0.06 g,the carbonization temperature of 200?and the carbonization time of 9 h are more uniform and regular.And the particle diameters are all 1-5?m.The carbon microsphere solid acid catalyst prepared after sulfonation has a serious agglomeration phenomenon between the balls.2.The prepared carbon microspheres all contain active groups such as-COOH and-OH.The carbon microsphere solid acid catalyst prepared by sulfonation has-COOH,-OH,-SO₃H reactive groups.3.The stability of carbon microsphere solid acid catalyst was characterized by thermogravimetry.The carbon microsphere solid acid catalyst prepared by direct hydrothermal synthesis was stable between 150?and 200?.The carbon microparticle prepared by template method was stable.The ball solid acid catalyst is relatively stable between 100?and 200?.4.Carbon microsphere solid acid catalyst was used for cellulose hydrolysis,and cellulose hydrolysis was used as an index to evaluate the conditions for preparation of carbon microspheres.The optimal carbonization conditions for the preparation of carbon microspheres by direct hydrothermal synthesis are:the catalyst dosage of 0.6 g,the carbonization temperature of 180?and the carbonization time of 7 h;the optimal carbonization conditions for preparing carbon microspheres by template method are:he sodium dodecyl sulfate amount of 0.06 g,the carbonization temperature of 200?and the carbonization time of 9 h.5.The repeated use performance of the two carbon microsphere solid acid catalysts is poor.But the regeneration performance is good.6.The carbon microsphere solid acid was used as a catalyst to study the kinetics of cellulose hydrolysis.The experimental data were nonlinearly fitted with origin and the optimal process conditions as well as kinetic model parameters of cellulose hydrolysis were determined.