Al_2(SO_4)_3催化纤维素生成乙酰丙酸乙酯的实验研究
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摘要
以Al2(SO_4)_3为固体酸催化剂,考察其在乙醇/甲苯体系中催化纤维素生成乙酰丙酸乙酯的工艺,探讨了共溶剂甲苯的体积分数、反应温度、催化剂用量以及反应时间对乙酰丙酸乙酯产率的影响,同时考察了该催化剂对不同碳水化合物的催化作用及其重复利用性.结果表明:在甲苯体积分数为10%,反应温度为180℃,催化剂用量为0.8 g,反应时间为3 h时,纤维素醇解转化为乙酰丙酸乙酯的摩尔产率高达51.6%;果糖、葡萄糖、蔗糖和菊糖转化生成乙酰丙酸乙酯的摩尔产率分别为54.3l%、47.3%、51.4%和49.6%,Al2(SO_4)_3对碳水化合物醇解生成乙酰丙酸乙酯具有良好的普遍适用性.该催化剂经回收重复使用5次后依然具有良好的催化活性.
Ethyl levulinate( EL) was prepared by Al_2(SO_4)_3 as solid acid catalyst from cellulose in ethanol.The effects of different parameters such as the content of organic solvent,reaction temperature,catalyst dosage and reaction time on EL yield were studied. And the catalysis and the effect of catalyst reuse times on EL yield were further investigated. The optimal reaction conditions for alcoholysis reaction were as follows: ethanol / toluene volume ratio 9: 1,reaction temperature 180 ℃,catalyst dosage 0. 8g,reaction time 3h. The yield of EL is up to 51. 6% under this condition. And under the same condition,the yields of EL from fructose,glucose,sucrose,and inulin were 54. 3%,47. 3%,51. 4% and 49. 6%,respectively. All the results showed that Al_2(SO_4)_3not only had good universal applicability,but still remained high catalytic activity after being used for five times.
Ethyl levulinate( EL) was prepared by Al_2(SO_4)_3 as solid acid catalyst from cellulose in ethanol.The effects of different parameters such as the content of organic solvent,reaction temperature,catalyst dosage and reaction time on EL yield were studied. And the catalysis and the effect of catalyst reuse times on EL yield were further investigated. The optimal reaction conditions for alcoholysis reaction were as follows: ethanol / toluene volume ratio 9: 1,reaction temperature 180 ℃,catalyst dosage 0. 8g,reaction time 3h. The yield of EL is up to 51. 6% under this condition. And under the same condition,the yields of EL from fructose,glucose,sucrose,and inulin were 54. 3%,47. 3%,51. 4% and 49. 6%,respectively. All the results showed that Al_2(SO_4)_3not only had good universal applicability,but still remained high catalytic activity after being used for five times.
引文
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[12]ZHANG Z H,WANG Y M,FANG Z F,et al.Synthesis of 5-ethoxymethylfurfural from fructose and inulin catalyzed by a magnetically recoverable acid catalyst[J].Chem Plus Chem,2014,79(2):233-240.
[13]XU X L,ZHANG X L,ZOU W J,et al.Conversion of carbohydrates to methyl levulinate catalyzed by sulfated montmorillonite[J].Catalysis communications,2015,62:67-70.
[2]CHANG C,XU G Z,JIANG X X.Production of ethyl levulinate by direct conversion of wheat straw in ethanol media[J].Bioresource technology,2012,121:93-99.
[3]WU X Y,FU,LU X Y.One-pot preparation of methyl levulinate from catalytic alcoholysis of cellulose in near-critical methanol[J].Carbohydrate research,2012,358:37-39.
[4]AMARASEKARA A S,WIREDLI B.cidic ionic liquid catalyzed one-pot conversion of cellulose to ethyl levulinate and levulinic acid in ethanol-water solvent system[J].Bioenergy research,2014,7(4):1237-1243.
[5]PENG L C,LIN L,ZHANG J H,et al.Catalytic conversion of cellulose to levulinic acid by metal chlorides[J].Molecules,2010,15(8):5258-5272.
[6]孙培勤,赵世强,常春,等.固体酸USY催化纤维素生成乙酰丙酸乙酯的实验研究[J].郑州大学学报(工学版),2014,35(3):22-26.
[7]GARVES K.Acid catalyzed degradation of cellulose in alcohols[J].Journal of wood chemistry and techonology,1988,8(1):121-134.
[8]TANG X,SUN Y,ZENG X H,et al.Novel Process for the extraction of ethyl evulinate by toluene with less humins from the ethanolysis products of carbohydrates[J].Energy fuels,2014,28(7):4251-4255.
[9]WANG H L,DENG T S,WANG Y X,et al.Efficient catalytic system for the conversion of fructose into 5-ethoxymethylfurfural[J].Biomass technology,2013,136:394-400.
[10]YANG Y,HU C W,MAHDI M.Abu-Omar.Conversion of glucose into furans in the presence of Al Cl3 inan ethanol-water solvent system[J].Bioresource technology,2012,116:190-194.
[11]XU H,CAROLINE L,ALFONS L,et al.Reaction pathways of glucose during esterification:effects of reaction parameters on the formation of humin type polymers[J].Bioresource technology,2011,102(21):10104-10113.
[12]ZHANG Z H,WANG Y M,FANG Z F,et al.Synthesis of 5-ethoxymethylfurfural from fructose and inulin catalyzed by a magnetically recoverable acid catalyst[J].Chem Plus Chem,2014,79(2):233-240.
[13]XU X L,ZHANG X L,ZOU W J,et al.Conversion of carbohydrates to methyl levulinate catalyzed by sulfated montmorillonite[J].Catalysis communications,2015,62:67-70.