Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of ...Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of which is as much as 16% (based the dried nut shell). In early time, mineral acids were employed as typically catalyst for preparing of furfural from the nut shells. These mineral acids could pollute water and corrode equipment. In this paper we used various mineral acids coating with niobic acid as catalysts to investigate reactions for preparation of furfural. Among these catalysts, the catalyst of sulfuric acid coating with niobic acid was found to be very effective, which had higher hammett acidity and better effect of hydrolysis of the nut shells;The catalysts of sulfuric acid coating with niobic acid was characterized, and the conditions of preparation of the catalyst were investigated. The optimum conditions were: sulfuric acid as coating acid, the concentration of sulfuric 1.1 mol/L, impregnation time 8 h, calcination time 8 h and calcination temperature 450°C. Then hydrolysis of the nut shells was explored, the optimum conditions were as follows: dose of catalyst 20%, ratio of solid to liquid 1:15, reaction temperature 100°C, reaction time 4 h;Under this condition, the yield of furfural was 8.7%.展开更多
By varying the concentration of APS aqueous solution, reaction time and temperature, a series of silica pillared layered niobic acids with different interlayer distances, surface areas, pore sizes and thermostability ...By varying the concentration of APS aqueous solution, reaction time and temperature, a series of silica pillared layered niobic acids with different interlayer distances, surface areas, pore sizes and thermostability were successfully prepared. It was shown that increasing the concentration of APS aqueous solution under a certain level(from 2.1% to 10%) led to the formation of silica pillared layered niobic acids with a gradually increased interlayer distance, surface area and silica pillar density, and therefore a gradually decreased pore size, but the same thermostability. On the other hand, reducing reaction time from 3 days to 1 day caused the decrease of the interlayer distance, surface area and thermostability, but the increase of pore size due to lower pillar density. Furthermore, the reaction at room temperature gave rise to the silica pillared layered niobic acid with a smaller interlayer distance and pore size, a slightly larger specific surface area and a lower thermostability.展开更多
文摘Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of which is as much as 16% (based the dried nut shell). In early time, mineral acids were employed as typically catalyst for preparing of furfural from the nut shells. These mineral acids could pollute water and corrode equipment. In this paper we used various mineral acids coating with niobic acid as catalysts to investigate reactions for preparation of furfural. Among these catalysts, the catalyst of sulfuric acid coating with niobic acid was found to be very effective, which had higher hammett acidity and better effect of hydrolysis of the nut shells;The catalysts of sulfuric acid coating with niobic acid was characterized, and the conditions of preparation of the catalyst were investigated. The optimum conditions were: sulfuric acid as coating acid, the concentration of sulfuric 1.1 mol/L, impregnation time 8 h, calcination time 8 h and calcination temperature 450°C. Then hydrolysis of the nut shells was explored, the optimum conditions were as follows: dose of catalyst 20%, ratio of solid to liquid 1:15, reaction temperature 100°C, reaction time 4 h;Under this condition, the yield of furfural was 8.7%.
基金supported by the National Natural Science Foundations of China(21476132,51536009,51406109 and 21506118)National High Technology Research and Development Program of China(863 program,2012AA101808)~~
文摘By varying the concentration of APS aqueous solution, reaction time and temperature, a series of silica pillared layered niobic acids with different interlayer distances, surface areas, pore sizes and thermostability were successfully prepared. It was shown that increasing the concentration of APS aqueous solution under a certain level(from 2.1% to 10%) led to the formation of silica pillared layered niobic acids with a gradually increased interlayer distance, surface area and silica pillar density, and therefore a gradually decreased pore size, but the same thermostability. On the other hand, reducing reaction time from 3 days to 1 day caused the decrease of the interlayer distance, surface area and thermostability, but the increase of pore size due to lower pillar density. Furthermore, the reaction at room temperature gave rise to the silica pillared layered niobic acid with a smaller interlayer distance and pore size, a slightly larger specific surface area and a lower thermostability.
