One-third of global warming comes from methane: fossil fuel exploitation, livestock, and other human related activities. The International Energy Agency contends that 70 % of these emissions can be reduced with existing technology. However, industry has been struggling for decades to implement gas-to-liquids technology (GtL) at any scale. Shell and Sasol have built plants that produced more than 30,000 bbl/day from methane, and dozens of companies have patented and tested alternative technologies under 3,000 bbl/day. The smaller projects have failed to go commercial due to poor economics and technology shortcomings. The World Bank's Global Gas Flaring Reduction initiative and the recent UN IPCC COP26 Global Methane Pledge promise to to limit methane emissions to 30% of those in 2020. Capital expenditures increase with the 0.6 power of scale and so costs are prohibitively high for the small scale. Operational personnel, one of the largest contributors to GtL, is generally independent of scale and revenues are barely sufficient to pay staff. Here, we propose integrating a micro-GtL unit with an oil field battery unit: this configuration leverages plant personnel and facilities: flare, three-phase separator, waste heat recovery, water treatment, and oil and water reservoirs. The micro-GtL process reacts compressed air and methane at 1,000 °C and 20 bar over a FeCr-alloy gauze followed by a fluidized bed Fischer-Tropsch (FT) reactor. The nitrogen dilutes the process gases and reduces reaction rates, but the high nitrogen concentration reduces water vapor partial pressure that reduces deactivation. Recent FT catalyst formulations include: Fe on Si, mesoporous zeolites, core-shell structures with zeolites in the shell and Cu/Fe in the core, ZrO2@FeCu-K with ZrO2 as the core and FeCu as the shell. Controlling the interaction of the active sites and proper support choice increase the yield with high C5+ hydrocarbons. Integrating a micro-GtL with a battery and a high C5+ yield catalyst will meet industry economic objectives but down-turns in the price of oil and long development times have already thwarted dozen of start-up ventures.

Micro-grid gas-to-liquids technology

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.