Atmospheric-Pressurized Process for Dimethyl Carbonate/Methanol Separation with and without Heat Integration: Design and Control

Abstract

Process economy and dynamic controllability are critical for DMC/MeOH separation via the PSD process. In this paper, rigorous steady-state and dynamic simulations of atmospheric-pressurized process for DMC/MeOH separation with no, partial, and full heat integration have been carried out with Aspen Plus and Aspen Dynamics. Further investigations have been conducted into the economic design and dynamic controllability of the three neat systems. Simulation results indicated that: the separation process via full and partial heat integration provided TAC savings of 39.2 and 36.2%, respectively, compared to that of no heat integration; the non-heat-integrated system displays good dynamic performance, critical dynamic penalties were demonstrated for both partial and full heat integration processes, while the partial one exhibited a more robust control except for precisely maintaining XB2(DMC); a PCTC scheme with a CC/TC cascade control was proposed to precisely maintain the product concentration for the fully heat-integrated PSD process. A comparison of the economy between atmospheric-pressurized and pressurized-atmospheric sequences indicated that the former is more energy efficient. Further, a comparison of the economy between atmospheric-pressurized and pressurized-atmospheric sequences indicated that the former is more energy efficient. This study will provide new insights into the energy efficiency and has some implications for design and control of DMC/MeOH separation in the industrialization process.