Xiaowei Wu,Yuqin Li,Zhengquan Yang,Mingyu Peng,Tian Gui,Xiangshu Chen,Hidetoshi Kita
A beta zeolite membrane reactor was first applied to improve conversion on the esterification of oleic acid and n-butanol at low temperature by rapidly removing the by-product water. In the pervaporation (PV)-esterification at low temperature of 353 K, the final conversion of oleic acid was significantly improved to 99.2 % in a short reaction time of 4 h. Even at an incredibly low esterification temperature of 333 K, the conversion of oleic acid reached 95.7 % in 4 h. Besides, the beta zeolite membrane reactor exhibited good hydrothermal and acid stabilities with a high oleic acid conversion (maintained above 99 %) after 5 reaction cycles. Through XRD and SEM characterization, it was found that the membrane kept complete crystal structure. Process intensification through a beta zeolite membrane reactor aided by PV was successfully used to enhance the esterification at low temperature in a short time, which was a promising coupling technology.
Zhengquan Yang,Mingyu Peng,Yu Li,Xiaowei Wu,Tian Gui,Yuqin Li,Fei Zhang,Xiangshu Chen,Hidetoshi Kita
In this work, a dense and acid-resistant beta zeolite membrane was applied to improve the esterification of citric acid and n-butanol, for the first time. Through the continuous removal of the by-product water via pervaporation (PV), the conversion of citric acid was significantly enhanced from 71.7% to 99.2% using p-Toluenesulfonic acid (PTSA) as catalyst. PTSA was a well-known strong acid, and the membrane kept almost no change after PV-esterification, indicating the superior acid resistance of beta zeolite membrane. Compared to the use of acid-resistant MOR zeolite membrane by PV-esterification, a consistently higher conversion of citric acid was obtained using a high-flux beta zeolite membrane. The results showed that high water permeation on the beta zeolite membrane, with good acid resistance, had a strong promoting effect on esterification, leading to an improved conversion. In addition, the citric acid conversion of 97.7% could still be achieved by PV-esterification at a low reaction temperature of 388 K.Keywords:improved esterification;Tributyl citrate;beta zeolite membrane;PV-esterification;high conversion
危险品化学品经营许可证（带存储）