E3Tec has developed Heat Integrated Reactive Distillation (HIRD) process equipped with side reactors and PerVaporization (PerVap) membrane for conversion of CO2 to dimethyl carbonate (DMC). Separation of DMC/methanol azeotrope for achieving high-concentration (99.9%+) DMC is energy intensive. E3Tec has developed an integrated distillation for separation of DMC/methanol azeotrope by recovery of the overheat latent heat, internal thermal integration and PerVap integrated with the distillation column. The resulting DMC purity of 99.9%+ was achieved as bottom product and DMC in the overhead methanol-rich stream is reduced. Methanol is recycled in the CO2 conversion process as feed to side reactors; therefore, minimizing DMC content in the recycled methanol stream is preferred for a reversible, equilibrium- controlled reaction. The analysis was based on the ASPEN Plus® simulation of the integrated distillation subsystem. The project was supported by DOE SBIR program.
