Preparation And Application Of Carbon Based Solid Acid Catalyst From Peanut Shell

At present,the catalyst used forα-pinene industrial synthesis ofα-terpineol is a liquid acid with concentrated sulfuric acid as the main component,which has problems such as difficulty in separating the product from the catalyst,strong corrosion of reaction equipment and environmental pollution.The use of solid acid catalyst is to solve the above problems.one of the effective ways to solve the problem.Biomass can prepare carbon materials with high density,multiple catalytic active centers and strongly acidic-SO₃H groups through carbonization and sulfonation process.Pollution to the environment,reusable and other advantages.The use of biomass solid acid to replace traditional sulfuric acid is in line with the concept of green chemical industry and has important economic and social significance.In this thesis,peanut shells（PS）were used as raw material to prepare carbonaceous solid acid catalyst by two-step carbonization-sulfonation method,N₂physical adsorption-desorption（BET）,Fourier transform infrared spectroscopy（FT-IR）,electron microscopy（SEM）,thermogravimetry（TG）,NH₃programmed temperature desorption（NH₃-TPD）and X-ray photoelectron spectroscopy（XPS）,and other instrumental analysis methods to investigate the structure of peanut shells.The structural characteristics and physicochemical properties of the biomass carbon-based solid acids were characterized,and their catalytic performance was determined on a stationary reactor with the conversion ofα-pinene and the selectivity ofα-pinoresinol as evaluation indexes.The main findings are as follows.1.The powdered solid acid catalyst with particle size less than 80mesh was prepared from peanut shell powder,which still maintained the peanut shell structure with good pore structure,and the average pore size of the powdered catalyst reached 3.51 nm;the results such as XPS showed that the acidic group was successfully introduced into the biochar material.The TPD test showed that the catalyst was suitable for the reaction of pinene hydration to prepare pine oil alcohol.The experimental results showed that the conversion ofα-pinene was86.8%and the yield ofα-pinoresinol reached 42.9%with the powdered catalyst at the reaction temperature of 80°C and reaction time of 24 h.2.Using peanut shell as the raw material and phenolic resin as the binder to bond the carbon powder into shape,carbonization-sulfonation was applied to make the granular catalyst;FT-IR,XPS,TG results showed that-SO₃H groups were successfully introduced into the biochar material;the catalyst had high total acid loading and dense active sites.The catalyst possessed rich porosity with an average pore size of 3.94 nm;the formed pellet catalyst catalyzed theα-pinene hydration reaction,and the optimum bonding ratio of toner:phenolic resin:water was determined to be 4:1:2,the optimum sulfonation temperature was 50°C,the optimum conditions for the hydration reaction were the reaction temperature of 80°C,the reaction time of 24 h,the catalyst input amount of 0.75 g,and the conversion rate ofα-pinene The conversion rate ofα-pinene was76.4%and the yield ofα-pinene alcohol was 41.1%,and the catalyst was reused three times and still retained good activation performance.3.The laboratory assembled a simple reaction distillation column device by itself,conducted a small trial reaction and simulated industrial application.Under the condition of full reflux,the catalyst still maintained a relatively good catalytic activity,and the conversion ofα-pinene was 72.7%and the yield ofα-pinene alcohol reached36.2%when the reaction time was 24 h,the catalyst input was 2.5 g,the reaction temperature was 80°C and the solvent volume reached 50ml.