Intensification of diethyl methylphosphite synthesis based on kinetics study and CFD modeling

Abstract

AbstractA “pre‐dissolving ammonia” intensification method for continuous production of diethyl methylphosphite (DEMP) was proposed based on kinetics study of methyl dichlorophosphine (MDP) substitution and DEMP acidolysis. The method was verified in a continuous synthesis system consisting of a small jet reactor. Compared with the selectivity of ~80% obtained in a stirred flask, the selectivity reached 98% by the intensification method. Eliminating the resistance of gas–liquid mass transfer and enhancement of mixing enabled rapid removal of the produced HCl, thus, the DEMP selectivity was greatly increased. The high DEMP selectivity obtained was insensitive to reaction temperature, reactor size and ammonia to chlorine ratio in the studied range. A computational fluid dynamics (CFD) model was proposed for this liquid turbulent reactive flow. Numerical simulations revealed that HCl could be removed rapidly by the neutralization reaction, which was limited by micromixing efficiency. The CFD simulation further indicates the feasibility of “pre‐dissolving ammonia” for industrial production.