Design of a novel dual function membrane microreactor for liquid–liquid–liquid phase transfer catalysed reaction: selective synthesis of 1-naphthyl glycidyl ether

Abstract

An innovative dual function three-channel membrane microreactor was conceptualized and developed for conducting liquid–liquid–liquid (L–L–L) phase transfer catalysed (PTC) reactions wherein it is possible to separate and reuse the middle catalyst phase and also operate the reactor continuously. The simultaneous reaction and separation were conducted in a single microreactor with the help of two membranes. The dual function microreactor is a combination of a microreactor and phase separator, which has three channels for each phase with a hydrophilic membrane between the bottom and the middle channel and a hydrophobic membrane between the top and middle channel. Synthesis of 1-naphthyl glycidyl ether was taken as a model reaction. Selectivity of 100% was achieved at different conversions using the microreactor with continuous reuse of the middle catalyst phase without any post-treatment. The microreactor ensures complete recycling and continuous reuse of the catalyst without any post-treatment. The reactor can be operated with all three phases in a continuous manner, thereby using a small quantity of catalyst for large throughput. A total 94% overall yield was obtained with a microreactor capacity of producing 2.17 gm h⁻¹ of 1-naphthyl glycidyl ether.