Enhancing the amination reaction of 4-nitrochlorobenzene in a tubular reactor

Abstract

In this work, a tubular reactor with a micromixer was introduced in attempt to enhance the amination reaction of 4-nitrochlorobenzene in terms of the process efficiency and safety. It was found that the reaction system containing a large excess of ammonia water can become homogeneous at high temperature. Thus, as both micromixing and the heat transfer performance were guaranteed, the set-up combining a micromixer and a microtube reactor enabled the reaction to exhibit homogeneous reaction characteristics, meeting the demands of efficiency and reliability. Furthermore, using a multi-channel sampling system connected behind the micromixer, the reaction kinetics were studied in a modified “stop flow” mode, which is adaptable for in-situ fast homogenization, high temperature, and high pressure. The reaction conditions were screened and a kinetic model was developed. Accordingly, we propose and verify a self-circulation strategy to reduce the burden of ammonia separation and recovery in a continuous tubular reactor system.