Preparation Of Solid Acids Supported By Natural Porous Materials And Catalysis Of Furfural Production

As an important bio-based chemical,furfural has broad application prospects.However,industrial production using homogeneous acid as a catalyst has many limitations,such as high cost and environmental pollution.The existing heterogeneous solid acid catalysts have many problems,such as complicated preparation process,low catalyst activity,poor selectivity and stability.The purpose of this rearch is to find a solid acid catalyst with high stability,high catalytic performance,and low cost.What's more,this solid acid can increase furfural yield and reduce production cost.In this paper,three kinds of solid acid catalysts were synthesized and their catalytic performances were studied respectively.The details are as follows:Diatomite-supported solid acids:The addition of SnO2 to the surface enhances the L acid content,sulfonation increases the B acid content,and the acid content of the solid acid is increased by XRD,EDS,Py-IR,and NH3-TPD characterization.Through comparison of the aqueous phase and the organic phase reaction,it was found that the yield of furfural in the two-phase system was 38.81%higher than the single phase,and the optimal furfural yield was 80.97%in the two-phase system of NaCl solution-toluene at 180? for 3 hours.Xylose under the same conditions furfural yield reached 84.39%.The experiment found that solid acid calcination renaturation was superior to the ethanol rinsing method,and the furfural yield could still reach 74.53%after repeated use of solid acid for 5 times.Carbon hybrid diatomite solid acid:The diatomaceous earth loaded with SnO2 is subjected to carbon hybridization and sulphonation,and the surface is loaded with porous carbon and sulfonate.Catalytic studies showed that the carbon hybrid solid acid reacted more favorably in the aqueous phase,and the furfural yield reached 66.24%at 180? for 5 h.The carbon hybrid solid acid was refolded by ethanol washing method.The furfural yield was 52.68%and decreased by 13.56%after repeated use for 3 times,indicating that the method of catalyst renaturation needs to be improved.During the experiment,the furfural yield of the silanized modified diatomite was 32.81%,indicating that the hydrophobic effect was too strong and was not conducive to the catalytic reaction of solid acid.Magnetic pollen solid acid:a variety of magnetic pollen solid acids were synthesized through pollen and sulfonation treatments using pollen as carrier.It was found that when isethionic acid is used as a sulfonating agent,the loss of solid acid magnetic properties can be reduced,and at the same time when Fe ion content is too high,furfural can be easily converted into other by-products.