Ethylene production using oxidative dehydrogenation: effects of membrane-based separation technology on process safety & economics

Abstract

Previous work from this group utilized a HYSYS simulator to predict the performance of an ethylene oxidative dehydrogenation (ODH) production facility using alternative diluents and separation technology not currently used in the standard industrial process. An ODH process system has been previously modeled with ethane being fed along with air into a reactor with simultaneous mixing with pure methane to lower the product gas temperature. The methane feed was later separated from the other product gases and eventually fed into a recycle stream. This process was fairly expensive due to the use of a demethanizer within the process recycle stream. Safety and operational improvements for the ODH process was another aspect of this analysis that yielded interesting results. By the inclusion of storage vessels before and after the ODH reactor, the reactor unit can operate even in the event of an upstream or downstream failure, resulting in less downtime for the process.This current work has investigated the development of membrane-based separation technology for the production of ethylene for the oxidative dehydrogenation (ODH) reaction of ethane using a HYSYS simulator with MEMCAL extension software in concert with economic and safety analyses. The application of polymer-membrane separation and non-cryogenic distillation alternatives, such as bottom-flash, heat-pump assisted and low-temperature distillation, were simulated and evaluated individually and in-tandem with membrane separation.