Study On The Separation And Application Of Degradation Glycan In Reed Ethanol Digester Waste Liquor

In the paper the reed ethanol pulp was received by two stage counter-current cooking.Results showed that the yield of coarse stock in first stage was60.77%. The yield of coarsestock and screened stock in second stage was63.75%and59.20%respectively.Ethanol lignin was extracted from the first stage pulping black liquor. Then thePVC/lignin composite materials were prepared with lignin and PVC. Through testing thePVC/lignin composite materials’ mechanical properties, results revealed that the impactstrength, tensile strength, bend strength of PVC/lignin composite materials were decreasedwith the increase of lignin dosage.Ten groups of extraction program were designed and the hemicelluloses were extractedfrom the first stage pulping black liquor. Then the lignin content in hemicelluloses of the tengroups was measured by ultraviolet-acetobrom and the purity of hemicelluloses was received.The optimum extraction method-alkaline treatment was determined through comparing theextraction purity and amount of extraction quantity. The reaction condition was optimized bysingle-variable experiment of pH value and reaction temperature. The optimum extractionconditions were as follows: pH value was12.30which adjusted with10%KOH, thetemperature was40℃, small quantity KBH₄was added to protect hemicelluloses, reactiontime was155min, extraction purity was84.96%.The hemicelluloses were modified with self-made etherifying agent3-chloro-2-hydroxy-propyl trimethyl ammonium chloride. The infra-red spectrogram ofhemicelluloses before and after modification showed that the hemicelluloses were etherifiedand the quaternary ammonium group was grafted on the macromolecular chain ofhemicelluloses. The electropositive and water solubility of etherified hemicelluloses wasimproved greatly. The effect of etherified hemicelluloses on the bond strength （include burststrength, tension strength, folding strength） was enhanced obviously. However theimprovement of etherified hemicelluloses on tear strength was small through comparing thephysical property of paper sheet with soft wood pulp and straw pulp. As for straw pulp, theeffect of etherified hemicelluloses on burst strength, tension strength and fold strength was less evident than on tear strength.