Acetic Acid Production Using Calcium Ferrite-Assisted Chemical Looping Gasification of Petroleum Coke With In Situ Sulfur Capture

The global market size for acetic acid is expected to increase at a high compounded annual growth rate over the next few years due to an increased demand from the end-users such as the automobile, furniture, and construction industries. One of the key factors driving the acetic acid production is methanol formation, which in turn depends on syngas generation. The process simulation and reactor modeling study presented here explores the use of a novel petcoke-to-syngas process for acetic acid production where the petcoke is subjected to chemical looping gasification (CLG) using calcium ferrite (Ca2Fe2O5) as the oxygen carrier. The underlying thermodynamics of petcoke partial oxidation are studied through the assessment of parameters such as the syngas purity, carbon deposition, and S# (an indicator of the syngas quality) using computational simulations carried out in Aspen. The effect of natural gas and steam co-injection along with petcoke has also been studied while also focusing on regeneration of the reduced carrier using steam and CO2. As sulfur is an integral part of the petcoke stream, its interaction with the oxygen carrier has also been analyzed and a process configuration is reported that allows the production of a sulfur-free syngas stream. Process simulations reveal an increase in the exergy efficiency of syngas production, syngas yield per mol of carbon, and acetic acid yield per mol of carbon by 32% points, 50, and 14%, respectively, using the Ca2Fe2O5 -assisted CLG process as opposed to the conventional petcoke gasification route, thus rendering acetic acid production using the CLG route economically attractive.