Preparation Of Natural Xylanase Loaded Fatty Acid-based Deinking Agent And Its Application In ONP Deinking

To realize the cleaner production of paper regeneration,natural fatty acid based surfactants which can renewable and biodegradable have attracted considerable interest in is more and more attention in waste paper deinking.Xylanase is a kind of biological agent,which having high biological catalysis and good specificity,it is also a kind of green cleaning-products,and the alkaline xylanase has important application prospects in waste paper deinking.This study aims to study the preparation of nature fatty acid based surfactants which has good deinking performance;At the same time,to promote the deinking agent with green,functional and more efficient,this topic does initial exploration to deinking agent which fusing the natural fatty acid based surfactants with alkaline xylanase.Firstly,using renewable natural fatty acid as raw material,prepare the natural fatty acid based surfactants.The optimal preparation technology was discussed,and the deinking properties was analyzed.The results showed that the optimized preparation conditions are that,a duration of 30 min,a temperature of 90 oC,mcoconut oleic acid:mpalmitic acid:mrosin of 2.5:3.5:4,a NaOH concentration of 40%wt.The optimum addition amount of 0.2%.The scanning electron microscope showed that natural fatty acid based surfactants could remove the free ink particles effectively,but the “fiber-ink” which on the fiber could not remove effectively.Secondly,the enzymology properties of alkaline xylanase FX40 was researched,and analyzed its influence on ink particle characteristics of ONP pulp.The research results showed that FX40 has strong stability of temperature and pH,showed good adaptability to high temperature and alkaline environment.When the dosage FX40 is 3.0U·g-1,the ink particle size area which at the scope of 0.005~0.015mm2 increased by 3.32% compared to the blank.By observing below microscope,untreated with alkaline xylanase,ONP waste paper pulp fiber had “fiber-ink” particles and “ink-fiber” particles.After treatment with alkaline xylanase,there were no “fiber-ink” particles.Finally,the preparation and application of green xylanase loaded fatty acid-based deinking agent(GXD)was initial explored.The research results show that,in order to make GXD deinking agent has the best residual enzyme activity,the preparation of an GXD temperature for 55 oC,solid content of 94%,free alkali content is 0.10%,glycerol content is 0.20%.The optimum application process conditions of pH value of 8.5,for the time 35 min,the pulp concentration is 12%,alkaline xylanase content is 15%.Under this condition,compared with using atural fatty acid based deinking agent,tearing and tensile index increased by 13.21% and 10.54% respectively.The whiteness and the ink removal rate respectively were 1.65%ISO,2.05%.And its deinking effect has been better than the deinking agent that is using in enterprise.