Subcritical Hydrothermal Autocatalytic And Synergistic Catalytic Pretreatment Technology Of Reed With Various Organic Acids

There are 14 primary reed-producing regions in C hina,the annual output reaches 4550 million tons.Using constructed wetland like reed to treatment sewage has a lot of advantage,but when reeds mature it will produce a lot of biomass,these biomass may pollute surrounding environment if handing improper.The content of cellulose amount to 40% and the content of hemicellulose amount to 30% in reed,and it is abundant of renewable resource.At the same time,with the declining of oil resources and the breakthrough of cellulosic ethanol enzymolysis technique,try to use inexpensive lignocellulose materials to produce ethanol is more and more importance.In this article,reed which riching in cellulose and hemicellulose was studied,using appropriate wetland plants to produce fuel ethanol,and proposed the subcritical hydrothermal autocatalytic and synergistic catalytic of various acids pretreatment process.In one hand it will improving the efficiency in the use of reeds,in another hand it can give a strong impetus to the development of cellulosic ethanol.A subcritical hydrothermal autocatalytic pretreatme nt process was conducted by the direct recycling of spent liquor.The use of rich spent liquor and its byproduct acid was proposed as a method of strengthening liquid hot water pretreatments,which can reduce energy consumption while producing less wastewa ter.Mixed acid content,reaction temperature,reaction time were explored with the goal of pentose yield.The results showed that the optimum processing conditions of subcritical hydrothermal autocatalytic pretreatment process is: reaction temperature 200°C,reaction time 60 min,mixed acid content 1.159 wt%,at which point the pentose yield amount to 71.02%,and by-product concentration levels are lower than the levels that significantly inhibit the growth of fermenting microorganisms.In order to explore the interaction between lactic acid and acetic acid in catalyzing reed pretreatment,synergistic catalytic of lactic-acetic acid pretreatment was conducted.The effects of acetic acid,lactic acid,and lactic-acetic acid with different mixing ratio were a nalyzed by conducting the single factor experiments to guide the pretreatment and regulating the optimal process conditions,and the yield of pentose,glucose,lactic acid,acetic acid,furfural,and HMF were systematically and comprehensively analyzed in the pretreatment process.Then,with the yield of pentose taken as the objective,the optimum operation point was found by means of Central Composite Design,and the factors such as reaction time,reaction temperature,and ratio of lactic acid influencing on the yield of pentose were investigated.The results showed that the optimum processing condition of synergistic catalytic of lactic-acetic acid pretreatment process is: reaction temperature 197°C,reaction time 67 min,lactic acid concentration 1.29 wt%,acetic acid concentration 1.71 wt%,at which point the pentose yield amount to 93.83%.Finally,through the ways of document consultation and experiment,the path in which the lactic acid might be generated was put forward.Then,through simulating the xylose reaction dynamics model in various conditions,synergistic catalytic of lactic-acetic acid was validated.