Thermodynamic study of direct amination of isobutylene to tert-butylamine

• Published in: Chinese journal of catalysis 2017-01, Vol.38 (1), p.106-114
• Main Authors: Gao, Shangyao, Zhu, Xiangxue, Li, Xiujie, Wang, Yuzhong, Zhang, Ye, Xie, Sujuan, An, Jie, Chen, Fucun, Liu, Shenglin, Xu, Longya
• Format: Article
• Language: English
• Subjects: Amination; Isobutylene; Tert-butylamine; Thermodynamic calculation; ZSM-11 zeolite
• ISSN: 1872-2067; 1872-2067
• DOI: 10.1016/S1872-2067(16)62550-0

On basis of thermodynamic empirical equations, the thermodynamic parameters for the direct amination of isobutylene to tert-butylamine, an atomically economic and green chemical reaction, were calculated. In particular, the equilibrium conversion of isobutylene under various reaction conditions close to those used in industry was calculated and discussed. Isobutylene amination is a temperature sensitive reaction due to its exothermic nature and isobutylene equilibrium conversion decreases with temperature. However, kinetically, the amination reaction will be faster at a higher temperature. Thus, there must be an optimum temperature for the reaction. A high pressure and n(NH3)/n(i-C4H8) molar ratio promote the transformation of isobutylene to tert-butylamine. Developing a highly efficient catalyst under mild reaction conditions is preferred for the amination process. The reaction was investigated over a series of acidic zeolites. ZSM-11 zeolite exhibited the best performance with 14.2% isobutylene conversion (52.2% of the equilibrium conversion) and > 99.0% tert-butylamine selectivity. The effect of reaction conditions on the performance of the ZSM-11 catalyst agreed with the thermodynamic results, which provides guidance for further catalyst development and reaction condition optimization. Thermodynamic calculation of the direct amination of isobutylene to tert-butylamine, an atomically economic and green chemical process, provide guidance for developing a highly efficient catalyst and reaction condition optimization.