Optimization during the process synthesis: enabling the oxidative coupling of methane by minimizing the energy required for the carbon dioxide removal

Optimization is scarcely ever carried out during process synthesis. Nonetheless, this contribution shows that optimization at the design stage can be vital to make new process concepts economically feasible and open up new, cleaner production paths. Herein, a hybrid separation system for the carbon dioxide removal from product gas of the oxidative coupling of methane is investigated. The combination of a polyimide and a polyethylene oxide membrane as well as an amine-based absorption process is investigated, modeled, and subsequently optimized to minimize the required energy while keeping the loss of the reaction product at a minimum. By means of process optimization at the synthesis stage process configurations are discovered, which allows for the realization of an alternative process concept to improve greenhouse gas emission reduction. Furthermore, new reaction paths towards the synthesis of longer hydrocarbons based on natural or bio gas are enabled.