Toward More Cost-Effective and Greener Chemicals Production from Shale Gas by Integrating with Bioethanol Dehydration: Novel Process Design and Simulation-Based Optimization

A novel process design for a more cost-effective, greener process for making chemicals from shale gas and bioethanol is presented. The oxidative coupling of methane and cocracking technologies are considered for converting methane and light natural gas liquids, into value-added chemicals. Overall, the process includes four process areas: gas treatment, gas to chemicals, methane-to-ethylene, and bioethanol-to-ethylene. A simulation-optimization method based on the NSGA-II algorithm for the life cycle optimization of the process modeled in the Aspen HYSYS is developed. An energy integration model is also fluidly nested using the mixed-integer linear programming. The results show that for a good choice optimal design, the minimum ethylene selling price is $655.1/ton and the unit global-warming potential of ethylene is 0.030 kg CO2-eq/kg in the low carbon shale gas scenario, and $877.2/ton and 0.360 kg CO2-eq/kg in the high carbon shale gas scenario. (C) 2014 American Institute of Chemical Engineers