Abstract

The current global reliance upon petroleum fuel presents unique challenges to develop new, sustainable solutions to address present and future energy demands. This perspective describes the research efforts at the US Naval Research Laboratory (NRL) to address basic research challenges in the capture and utilization of CO2 from seawater, where contemporaneous work in this field is cited. Recent work to optimize CO2 extraction from seawater is briefly highlighted, featuring progress towards the operational scale-up and demonstration of an integrated process. The bulk of this article focuses on concurrent research to develop catalysts and test their performance in the hydrogenation of CO2, where results in transitioning from a continuous-stirred tank reactor (CSTR) system to a more modular and scalable fixed-bed system are detailed. Efforts to further improve and scale-up fixed-bed systems are also pointed out with respect to stabilizing catalysts against degradation effects of water produced in the hydrogenation of CO2.

INTRODUCTION: THE CURRENT AND FUTURE DEMAND FOR SUSTAINABLE CARBON SOURCES

An unmet and direct need to identify renewable supplies for current and future global energy demands presents scientists with a grand challenge to resolve the conventional reliance upon petroleum-based fossil fuels. The heavy dependence upon volatile foreign oil markets results in both a strategic and logistical risk for the US Navy when supplying active battle groups with needed aviation and marine fuel. One proposed solution is the synthesis of fuel at sea, where it is envisioned that liquid hydrocarbon fuels that meet or exceed military specifications would be produced at or near point-of-use (1). In comparison with petroleum-derived fuels, higher product quality is expected from this ‘ground-up’ synthetic approach − further improving the overall cost of fuel production and distribution in-theater. Recent strategies by the US Department of Defense (DOD) to move towards fuel independence include conventional Fischer-Tropsch (FT) synthesis (2) and biomass processing (3). However, these approaches do not solve the risks associated with delivering fuel at sea and they are not ...