Studies On The Catalytic Sulfonation Of Soda Lignin Of Wheat Straw And The Ralative Application In Enhanced Oil Recovery

In view of the polydispersity and unhomogeneous molecular weight of soda lignin in pulping black liquor, the method which firstly classify lignin then react in homogeneous system has been adopted for a long-term to chemically modify the soda lignin, in order to improve the integral performance of lignin technical products effectively. However, there are following drawbacks in this technology: the low utilization of lignin, and difficult seperation from the reaction system. In order to utilize lignin effectively, base on the situation in China, the study was carried on systematically, centering around the topic of two step sulfomethylation of the soda lignin of wheat straw ( the first step is methylolation, the second is sulfonation ) and its application. The main purpose is to develop a heterogeneous catalytic system which not only catalyzes but also homogenizes the lignin molecule in the reaction.According to the study of chemical properties of fractinated soda lignin of wheat straw, the method which design and prepare the solid catalyst (Zeolite) has been forwarded. The new route of heterogeneous catalytic hydroxymethylation was developed and established. The catalytic mechanism of the Zeolite catalyst was also advanced via the analysis of methylolated lignin prepared under the new technological condition. To more understand the catalytic mechanism and to prepare for the future megascopic experiments, kinetics of methylolation had been studied, either. Last, sulfonation of the methylolated alkaline lignin and its application in Enhanced Oil Recovery had also been discussed.Study on the fractionated alkaline lignin of wheat straw shows that there is a regularity between fractional weight and functional groups such as phenylhydroxy, methoxy, carbonyl and so on. Combining the analysis of structural units proportion of different lignin fraction, the fractionation of lignin are benefit to improve the integral performance of modified products. This imply that it is feasible to solve the lignin unhomogeneous problem through altering the reacting system and using the heterogeneous reaction during the modification .The designing principle of Zeolite catalyst instructs that using active centers of the specified pore can realize the selective catalysis, thus altering the known reacting path and the product's selectivity. On the basis of the Zeolite catalyst which is fit to lignin methylolation had been synthesized. Its elemental composition formula is (1-5)M_2/n: Al₂O₃:(1¹0)SiO₂:(0¹0)H₂O(M represents an exchangeable cation, n represents the valance of cation), the pore diameter is among 3-13 A.The optimum condition got from orthogonal experiments is: temperature is 80℃, time is 240min, catalyst charge is lwt%. Besides this, the result of heterogeneous...