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.
The role of solvents in the conversion of oleic acid over Pt/C was studied. Three solvent systems (solvent-free, water, and dodecane systems) were employed for the conversion of oleic acid over Pt/C at 350 °C. Decarboxylation, hydrogen transfer, and aromatization were observed in these three reaction systems. In comparison to the non-solvent reaction system, much slower decarboxylation and aromatization rates and fewer heptadecane and aromatic products were observed in the hydrothermal and dodecane reaction systems. The decarboxylation and aromatization rates and yields of heptadecane and aromatics decreased with increased dodecane loading in the dodecane reaction system, and the decarboxylation and aromatization rates and yields of heptadecane and aromatics significantly decreased with the increase of water in the hydrothermal reaction system. The effects of solvent loading, catalyst loading, and reaction time on the reactions (decarboxylation, hydrogen transfer, and aromatization) were investigated. The reaction behaviors of 1-heptadecene with different solvents were studied, and N2 adsorption–desorption and thermogravimetric analysis of fresh and spent Pt/C in the three reaction systems were also performed. The results indicate that the competition of dodecane for the Pt/C active sites is mainly responsible for the slow decarboxylation and aromatization rates. In addition to the similar influencing factor to that in the dodecane system, H+ released from water and hydrogen bonding, which inhibited the ionization of carboxyl groups, was the key influencing factor for the slower decarboxylation and aromatization rates obtained under hydrothermal conditions.
危险品化学品经营许可证（带存储）