On piston engines as hydrocarbon gas reformers for modular, distributed chemical production

•Perspective on technical, economic, and environmental aspects of engine reforming.•Mass-produced piston engines can be repurposed for low-cost chemical production.•Syngas production cost from small, distributed reformers similar to large plants.•Methanol produced from wellgas that would otherwise be flared is carbon negative. Hydrocarbon gases, and especially stranded gases such as those produced as a byproduct of tight oil production, are an underutilized feedstock that is often flared, vented, or reinjected. Improved utilization of stranded gas faces two primary technical/economic challenges. First, the gas is inherently distributed geographically and the supply varies temporally, which requires rethinking the characteristics of the chemical plant used to process the gas. Second, methane—the primary constituent of hydrocarbon gases—is relatively inert and requires activation through a synthesis gas intermediate prior to conversion to useful products. This methane activation step requires reforming chemistry which adds to the cost and complexity of the plant. This paper explores the potential of piston engines as non-catalytic, partial-oxidation reformers, providing an enabling technology for distributed production of chemicals from stranded gas resources. The motivation for using an engine in this process is to take advantage of the modular, scalable, fast-responding characteristics of engines, leveraging this highly developed and mass-manufactured device for purposes beyond power generation or transportation. This paper provides a perspective on technical, economic, and environmental aspects of engine reforming for production of low-carbon fuels and chemicals from stranded gas.