Novel eco-efficient process for methyl methacrylate production

Methyl methacrylate (MMA) is an essential chemical used as raw material for the production of other methacrylates and poly-MMA. There are various chemistry routes, available or not at industrial scale, to produce MMA. These routes use the same or different raw materials, and present common chemistry and processing steps. Many of these routes though, have as final step the esterification of methacrylic acid (MAA) with methanol (MeOH) to obtain MMA. However, there is no complete process described in the literature for this final esterification step. This paper is the first to propose a solid-based catalytic process for MMA production starting from MAA and MeOH, in a continuous reaction-separation-recycle (RSR) system. In this specific case, the RSR system is more suitable than reactive distillation due to the unfavorable ranking of boiling points and also due to the presence of several potentially hindering azeotropes. This work also provides an original framework for simulation of other MMA processes, by deriving detailed equilibrium and kinetic parameters based on literature experimental data. Rigorous process simulations are carried out in Aspen Plus and Aspen Plus Dynamics for the design and control of the new process. The flowsheet consists mainly of a fixed-bed tubular reactor followed by a sequence of three distillation columns coupled with a decanter. The results show that the process is technically feasible, cost effective in terms of total annualized costs, and with excellent sustainability metrics, requiring only 2.05 MJ/kg of MMA produced.