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
The main components and pyrolysis characteristics of Camellia oleifera Abel hells, Castanea mollissima Blume shells, and Castanea mollissima Blume shells were analyzed by using FTIR and thermogravimetric methods. The ...The main components and pyrolysis characteristics of Camellia oleifera Abel hells, Castanea mollissima Blume shells, and Castanea mollissima Blume shells were analyzed by using FTIR and thermogravimetric methods. The experimental results indicated that the main components of the three kinds of raw materials consisted of cellulose, hemicellulose, and lignin. The highest contents of hemicellulose, cellulose, and lignin were in Camellia oleiferaAbel shells (49.34% ± 0.07%), Castanea mollissima Blume shells (27.34% ± 0.01%), and Carya cathayensis Sarg shells (49.78% ± 0.01%), respectively. The pyrolysis processes of three kinds of shells generally included three stages, namely dehydration, pyrolysis, and carbonization. The peak values and the appearance times of their pyrolysis rates were closely related to their compositions.展开更多
A biorefinery process was developed in this study to obtain bioactive compounds and bio-oil from Camellia oleifera shells.Four different extraction techniques(water,ethanol,ultrasound-assisted deionized water,and ultr...A biorefinery process was developed in this study to obtain bioactive compounds and bio-oil from Camellia oleifera shells.Four different extraction techniques(water,ethanol,ultrasound-assisted deionized water,and ultrasound-assisted ethanol)were utilized to extract tea saponin and tannin from C.oleifera shells.Results showed that ethanol had better extraction capacity than did deionized water,and ultrasound could promote the dissolution of tannin and tea saponin in solution.The thermogravimetric curves of the samples treated under the four conditions moved toward high temperatures.This phenomenon indicated the thermal stability of the residue was significantly improved.The pretreatment showed a slight effect on the chemical compositions of bio-oil.Specifically,the samples treated with ethanol and ultrasound-assisted deionized water contained higher phenol contents(81.07%and 81.52%,respectively)than the other samples.The content of organic acid decreased with an increase in the phenol content.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%.
文摘The main components and pyrolysis characteristics of Camellia oleifera Abel hells, Castanea mollissima Blume shells, and Castanea mollissima Blume shells were analyzed by using FTIR and thermogravimetric methods. The experimental results indicated that the main components of the three kinds of raw materials consisted of cellulose, hemicellulose, and lignin. The highest contents of hemicellulose, cellulose, and lignin were in Camellia oleiferaAbel shells (49.34% ± 0.07%), Castanea mollissima Blume shells (27.34% ± 0.01%), and Carya cathayensis Sarg shells (49.78% ± 0.01%), respectively. The pyrolysis processes of three kinds of shells generally included three stages, namely dehydration, pyrolysis, and carbonization. The peak values and the appearance times of their pyrolysis rates were closely related to their compositions.
基金support from the National Natural Science Foundation of China(No.21766019)The Key Research and Development Program of Jiangxi Province(20171BBF60023)+2 种基金China Scholarship Council(201806820035)Science and Technology Research Project of Jiangxi Province Education Department(No.GJJ150213)Research Project of State Key of Food Science and Technology(SKLF-ZZB-201722).
文摘A biorefinery process was developed in this study to obtain bioactive compounds and bio-oil from Camellia oleifera shells.Four different extraction techniques(water,ethanol,ultrasound-assisted deionized water,and ultrasound-assisted ethanol)were utilized to extract tea saponin and tannin from C.oleifera shells.Results showed that ethanol had better extraction capacity than did deionized water,and ultrasound could promote the dissolution of tannin and tea saponin in solution.The thermogravimetric curves of the samples treated under the four conditions moved toward high temperatures.This phenomenon indicated the thermal stability of the residue was significantly improved.The pretreatment showed a slight effect on the chemical compositions of bio-oil.Specifically,the samples treated with ethanol and ultrasound-assisted deionized water contained higher phenol contents(81.07%and 81.52%,respectively)than the other samples.The content of organic acid decreased with an increase in the phenol content.
