Reprint of: Enhancing natural gas-to-liquids (GTL) processes through chemical looping for syngas production: Process synthesis and global optimization.

•Two chemical looping processes are modeled using parameter estimation and disjunctive programming.•Chemical looping is incorporated into the GTL process synthesis as an alternative for producing syngas from natural gas.•A comprehensive GTL process superstructure is globally optimized to investigate the benefits of chemical looping.•Chemical looping can drastically improve break-even oil prices for GTL refineries.