Study On The Preparation Of Reed Ethanol Lignin:Flocculant

Ethanol-water pulping, takes on the advantages of small investment, high yield, andutilizable effectively of by-products. Above all, the modify utilization of ethanol lignin has avery amplitude long term potential. In this paper, the reaction activating of ethanol lignin isprobed, the purification scheme is optimized, and the synthetic and application of ligninflocculant is syltemic researched.The abstraction and purification of ethanol lignin in the black liquor was researched. Towkinds of cooking process was attempted, one is one stage cooking, and the other is two stagecountercurrent cooking. The yield of thinness pulp is respectively43.87%and44.78%, thepermanganate number is respectively18.97and15.95.When the lignin was abstracted from the black liquor, the acetone-water mixed solventwas used to purification the grossly lignin. The scale of acetone: water is respectively1:3,1:5,1:7,1:9, and the purification effect was compared, the best scale is1:9. The data afterpurification are: the content of klson lignin90.46%, the content of acid-soulble lignin1.53%,total content of lignin91.99%, the extraction yield92.99%, and the sugar content depressed to4.76%.The major research in this paper is the modification of lignin, which is used as flocculant.The synthetic of lignin flocculant has two steps. First, the graft copolymerization of lignin andacrylamide, which used ammonium ceric nitrate and sodium thiosulfate as the initiator.Perendicular experiment was adopted to study the influences of acrylamide dosage, initiatordosage, initiator mixture ratio, reaction temperature and time to the rate of production, and theexperiment condition was also optimized. The optimum condition was ascertained: the massratio of ethanol lignin and acrylamide was1:1.5, the initiator dosage was20mmol/L, the molmixture ratio of initiator was4:1(Na2S2O3: Ce(NH4)2(NO3)3), the reaction temperature was80℃, response time was3h. The rate of production at the optimum condition could reach78.5%. Infrared spectrum analysis confirmed the graft copolymer was existed in the product.The second step, the graft copolymer was made into cation product. Perendicular experimentwas also adopted to study the influence rule of aldehyde amine ratio, methylolation temperature, methylolation time, amine methylate temperature, amine methylate time to thedecolour performance of cation product. It had been discovered that the aldehyde amine ratiowas the key factor which influence the cation product performance. While the aldehyde amineratio is1:1, the decolorization of product was the best. The best cation response conditionswere as follows: The aldehyde amine ratio was1:1, methylolation temperature was60℃,methylolation time was1h, amine methylate temperature was60℃, amine methylate timewas4h. Upon the foundation, the influences of pH and the lignin flocculant dosage to thetreatment were researched. Under the experimental conditions which pH was6.0, cationflocculant dosage was0.495g/L, decolour rate was89.6%, removal of CODCrcould reach93.2%.The photochemical reaction of lignin was explored in this paper. TiO2as a media wasused in the photochemical reaction of lignin which changed with the mixture ratio of ligninand TiO2. The reaction rate became quicker when the mixture ratio was higher. Increased theresponse time was helpful to the process of lignin photochemical reaction. Research foundthat after the photochemical, hydroxyl content of lignin increased clearly, and the reactionactivity became stronger. If use this kind of lignin, the synthesize efficiency of cation ligninflocculant should be higher, and the performance will be more fineness.