Abstract
Lignin was extracted from the rice straw by using the solvent mixture of buthyl alcohol and distilled water. And the experiment of vanillin production from extracted lignin was performed with the oxidation catalysts; CuO, Cu(OH)2 and CuSO4.5H2O. The optimum conditions of lignin extraction are the reaction temperature 12$0^{\circ}C$ and the mixture of 250mL buthyloloohol, 250mL, distilled water and 25g rice straw in the presence of 2.5g p-toluenesulfonic acid. The yield of vanillin from extracted lignin increased linearly with the increase of reaction temperature. And it increased with the order of Cu(OH)<$_2$ CuO$_4\cdot \;5H_2$Oas oxidation catalysts. The maximum yield of vanillin was 9% in the presence of 2.5%(w/v) CuSO$_4\cdot \;5H_2$O under the following conditions: temperature, 18$0^{\circ}C$; pressure, 13atm; pH 4.0 and reaction time, two hours.
부틸알코올과 증류수를 유기용매로 사용하여 볏짚을 전처리하고 리그닌을 추출하였으며, 추출된 리그닌으로부터 적절한 산화촉매(CuO, Cu(OH)$_2$, CuSO$_4$.5H_2$O)하에서 바닐린 생성 실험을 하였다. 볏짚으로부터 리그닌 분리추출의 최적조건은 ptoluenesulfonic acid 2.5g을 촉매로하여 부틸알코올과 물을 1:1로 혼합한 용매 500ml에 볏짚 25g을 넣고 12$0^{\circ}C$하에서 반응시켰을 경우이었다. 한편 리그닌으로부터의 바닐린 수율은 반응온도의 증가에 따라 전형적으로 증가하였고, 촉매 종류에 따라 Cu(OH)<$_2$ CuO$_4\cdot \;5H_2$O를 사용하고 18$0^{\circ}C$에서 2시간 반응시켰을 때 바닐린의 최대 수율은 9%이었다.