Gas-to-liquid (GTL) and SMR–CaL–DMR integration for advanced environmental and economic performance

Abstract

The natural gas-based gas-to-liquid (GTL) process has emerged as a potential replacement technology for crude oil-based aviation fuel production. However, within the GTL process, steam methane reforming (SMR) produces CO₂ and generates syngas that is unsuitable for Fischer–Tropsch synthesis (FTS). To address these challenges, this study proposes a novel GTL process that integrates SMR with calcium looping, dry methane reforming, and FTS and analyzes its overall performance. Energy analysis reveals an energy efficiency of 40.8 %, while techno-economic analysis shows a decrease of 46.0 % and 48.3 % in the minimum selling price of aviation fuel and diesel, respectively. Life cycle assessment also finds that the proposed system reduces greenhouse gas emissions by 13.89 % compared to conventional aviation fuel. If at least 73 % of the grid electricity consumption in the process is supplied from alternative electricity sources, the process can meet the sustainable aviation fuel (SAF) criteria. Similarly, carbon-based scenario analysis reveals the carbon utilization efficiency to be 94.6 %. Two-variable sensitivity analysis of electricity utilization and carbon tax also determines that nuclear electricity is found to be the most economically advantageous option across all scenarios. The uncertainty analysis estimated a 98.3 % probability of achieving a price below the market price with grid electricity and a 100 % probability of remaining below the 2050 SAF cost with nuclear electricity. Therefore, the proposed system offers a feasible pathway for liquid fuel production while providing a sustainable alternative that meets increasingly stringent environmental regulations.