Applied Catalysis A: General p. 62 - 69 (2016)
Update date:2022-08-24
Topics:
Sun, Daolai
Takahashi, Yuta
Yamada, Yasuhiro
Sato, Satoshi
Vapor-phase lactonization of levulinic acid to produce angelica lactones, which include α-, β- and γ-form isomers, was performed in fixed-bed down-flow glass reactors over various oxide catalysts. SiO2 and SiO2-Al2O3 showed relatively high catalytic activity. The lactonization of levulinic acid to angelica lactones was found to be an endothermic equilibrium reaction, and the pressure equilibrium constant was calculated to be 0.2?atm at 275?°C. High temperatures and reduced pressures were effective for shifting the equilibrium from levulinic acid to angelica lactones, while the suitable reaction temperature was estimated to be 275?°C because temperatures higher than 275?°C decreased the selectivity to angelica lactones. The highest angelica lactones yield of 87.5% was achieved at a levulinic acid conversion of 95.3% over SiO2 under reduced pressure conditions of ca. 5?kPa at 275?°C. IR, NH3-TPD and TG analyses were performed for characterizing the catalysts used after the reactions together with a silylated SiO2 prepared for studying the active species on SiO2. The silanol groups of SiO2 with weak acidity were proposed to be the active species.
View MoreChongqing Changfeng Chemical Co., Ltd.
website:http://www.changfengchem.com
Contact:+86-23-67896333
Address:30th Floor, Longhu Ziduxingzuo Building A, 1st Branch,YuSong Rd., Yubei District, Chongqing, China
ANHUI CHEM-BRIGHT BIOENGINEERING CO.,LTD
Contact:86-561-4080321
Address:No.8 Lieshan Industrial Zone of Huaibei
Jiangsu Wanlong Chemical Co., Ltd.
website:http://www.wanlongchem.com
Contact:+86-511-86810993 0086-511-8681 0888;
Address:Quanzhou Town, Danyang City, Jiangsu
website:http://www.sdowchem.com
Contact:86-135-2193 7483
Address:8-106 taiyue building
Contact:+86-0311-84455288-844
Address:Mayu Industrial Park, Jinzhou, Hebei, China.
Doi:10.1021/jo01050a047
(1962)Doi:10.1016/j.apcata.2011.12.030
(2012)Doi:10.1021/jo00072a021
(1993)Doi:10.1007/BF00766248
(1990)Doi:10.1007/s10973-008-9204-y
(2008)Doi:10.1021/ja954077c
(1996)