Study On Pretreatment Of Regenerated Plant Fibers For Enhanced Hydrolysis

Coal,petroleum,and other petrochemical energy sources have always been human beings lazy to survive,since the beginning of the industrial revolution in the mid-eighteenth century.However,with the continuous reduction of these non-renewable energy sources and the many environmental problems brought about by the energy consumption process,energy structures have been created.The reform has become a hot topic in the society.As a kind of biomass renewable energy source,plant fiber provides a choice for improving China’s energy structure.Among them,the secondary fiber is a derivative product of plant fibers and is mainly composed of cellulose,hemicellulose and lignin.The degradation of carbohydrates can generate xylose,arabinose,glucose,fructose,and mannose,which can be produced by fermentation.Xylitol,ethanol and other chemical fuels.In this paper,the daily office culture waste paper is used as the raw material of the secondary fiber,and the purpose of improving the secondary fiber saccharification efficiency is achieved by comparing different pretreatment methods.The main research content and results are as follows:1.The effects of different pretreatment methods on the structure and composition of secondary fibers were studied,including pretreatment methods such as ball milling,steam explosion,ionic liquid,cellulase,ultrasonic wave,and deinking.The results show that the deinking can be used as the initial treatment process for secondary fiber recovery,thus collecting relatively clean cellulosic raw materials for reuse in papermaking or other uses;ultrasound and cellulase pretreatment increase the specific surface area of the fiber to a certain extent.It helps to accelerate the penetration of the liquid,but has limited impact on the fiber structure;ball milling,steam explosion and ionic liquid pretreatment are more effective secondary fiber pretreatment methods,but the energy consumption of pretreatment of secondary fibers by ball milling and ionic liquids Higher,steam explosion is a more cost-effective secondary fiber pretreatment.2.In order to obtain the best secondary fiber pretreatment effect,steam explosion was selected as the entry point for secondary fiber pretreatment.Chemical pre-impregnation steam explosion was used to pretreat secondary fibers.The chemical impregnation chemicals were H₂SO₄ and NaOH.The results showed that the chemical impregnation of the chemical liquid during the steam explosion process caused the fiber to swell and chemically degrade the hemicellulose and lignin in the process of high temperature and high pressure,and more cellulose was exposed.At the same time,due to the steam explosion process,The mechanical force causes the fiber to split and break,which reduces the degree of fiber polymerization and crystallinity to a certain degree,and increases the specific surface area and accessibility of the fiber to improve its reaction performance.3.The effect of chemical pre-impregnation steam explosion pretreatment on the secondary fiber saccharification was studied.The results showed that when pre-impregnated with 3%H₂SO₄,the yield of reducing sugar reached 65.68%when the secondary fibers were treated for 40 minutes after hydrolysis,which was 22.80%higher than that of the untreated second fiber.When pre-impregnated with 3%NaOH concentration,the yield of enzymatic hydrolysis of secondary fiber after blasting treatment reached 69.11%,which was11.08%higher than that of untreated secondary fiber.Compared with dilute acid hydrolysis and enzymolysis products,the product of cellulose hydrolysis was relatively concentrated,and the selectivity for cellulose saccharification was higher.The content of glucose sugar accounted for 89.65%.