Study On The Enzyme-aided Refining And Enzymatic Modification Of HYP

The energy consumption in pulping and papermaking industry is great, and 20% of the energy is used on defining and beating. The purpose of this thesis is test the paper quality and beating energy consumption through treat chemi-mechanical pulp with cellulose and xylanase, including study on the effect of enzyme treatment on APMP, P-RC APMP, BCTMP, and to find out the suitable condition with change treatment time, pH value, temperature and dosage.The treatment condition of Novozymes cellulase N476, Novozymes xylanase 51024 in APMP is studied, including time, pH value, temperature. The results show that the suitable condition of cellulase is: time 80min, pH 6.0, temperature 50oC,the suitable condition of xylanase is: time 100min, pH 6.5,temperature 55oC. In addition, the beating energy consumption decreases a lot after enzyme treatment. The results show that the energy consumption decreases separately 18% and 15.6%, when the dosage of cellulose and xylanase is 20IU/g and 25IU/g. Under the same beating energy consumption, the paper physical quality of enzyme treatment is better than the comparison sample. The physical quality of paper, such as breaking length, tearing index and bursting index get better through enzyme treatment, and the pulp through cellulose treatment is even better than xylanase. On the behalf of optical quality, the brightness is better when use xylanase, however, the opacity is better when use cellulase.The effect of Sukahan cellulase and Novozymes xylanase on P-RC APMP is studied. The results show that the energy consumption decreases 25% and 15% when the dosage of Sukahan cellulase and xylanase is 25IU/g. Under the same beating energy consumption, the physical property get improvement through cellulase treatment, for example the breaking length increase 0.5km and bursting index increase 14%. What's more, the effect of xylanase on tearing index is better than cellulose, which can increase 15%. On the side of optical quality, the brightness get better when use xylanase, which can increase 2%ISO. And optical get better when use cellulose, which can get 2% higher than comparison sample.The effect of Sukahan cellulase and Novozymes xylanase on BCTMP is studied. The results show that the suitable condition of cellulase is time 100min, pH 6.5, temperature 50oC. And the suitable condition of xylanase is time 110min, pH 6.5-7, temperature 55oC. After enzyme treatment, the beating energy consumption on BCTMP is decrease dramatically, which can decrease separately 16% and 15.4% when the dosage of cellulose and xylanase is 20IU/g and 25IU/g. Under the same beating energy consumption, the breaking length increase 0.4km after cellulase treatment, and the brightness increase 1.6%ISO after xylanase treatment, however the opacity is better when use cellulose.Fiber modality after enzyme treatment is studied. The results show that the Ln, Lw, Lww get improvement and thin composition decrease after enzyme treatment through FQA and ESEM analyzed, and the effect of cellulase treatment is better, the fiber surface get depressed, softened, loosed, and debris decreased, however the fiber remain well,do not degrade a lot, and the combine between fibers get increased by the ratio surface area enhance.The pilot of Buzyme modified cellulase on tissue is carried out. The results show that the breaking length of paper get improvement after enzyme treatment without changes the power, such as: MD increase 32.68% and CD increase 23.29% in 18g facial paper, MD increase 35.59% and CD increase 16.45% in 16g facial paper, MD increase 17.52% and CD increase 4.5% in 18g napkin. The energy consumption can get lower with the breaking length increase, for example, 18g tissue decreases 40KW(130KW-90KW), 16g tissue decreases 40KW(180KW-140KW). Beating after enzyme treatment can remain the breaking length, the mechanical force is lower through decrease beating power, which also can increase the bulk of paper.