| Lignosulfonate obtained from black liquor of papermaking industry was investigated to prepare vanillin through catalytic oxidation process. the element composition, structure, functional group of raw material were analyzed by element analysis and FTIR. The experiments were carried out in a 0.1L autoclave .CuSO4 was used as the catalyst. These reactions investigated the effects of reaction temperature, reaction time, the initial pressure of O2, the contents of NaOH, the proportion of lignosulfonate by orthogonal testing , then got the optimal reaction condition. Finally the macrokinetics of the reaction was investigated.(1 )The element analysis showed that lignosulfonate was composed of C,H,O, S and the formula could express as C9H10.4O3.6S0.4 .The FTIR spectrum showed there were a lot of groups such as methoxy group, hydroxy group, guaiacyl group, syringyl group.(2)The optimal reaction condition was as follows: reaction time 70min, reaction temperature 140℃, concentration of NaOH 2.0 mol.L-1, initial pressure 0.8MPa,. concentration of raw material 30 g.L-1 , the best yield of vanillin from oxygenation of lignosulfonate was about 7.2%.(3)The macroreaction rate equation was obtained by curve fitting, the concentration of vanillin changed in a extensive range. The optimal ending point was about 65min.
|
PDF Full Text Request