Hybrid processes for sustainable chemicals production from shale gas and ethanol

With focus on the shale gas-to-chemicals project, systematic studies on process design, techno-economic modeling, and environmental impacts have captured growing attention. This chapter is concerned with the process design and optimization of an integrated shale gas monetization process for chemicals production. From a sustainability point of view, corn-derived bioethanol is incorporated as a renewable feedstock to reduce the environmental footprint of the entire process. Overall, the proposed hybrid process consists of six process areas, namely gas treatment, natural gas liquids cutting, oxidative coupling of methane, cracking and separation, dehydration and separation, and utility. An integrated framework based on evolutionary NSGA-II algorithm is developed for the life cycle bi-objective optimization of the process modeled in Aspen HYSYS. In addition, an energy integration model using mixed-integer linear programming is integrated in the optimization framework. Optimization results show that, even considered as a high carbon feedstock, shale gas can be converted into chemicals in a more cost-effective and environment-friend way.