Syngas production using a catalytic engine

Abstract

There are many industrial processes, such as shale hydraulic fracturing, where small throughput of natural gas is considered a low-value waste or, at best, a nuisance. The natural gas is remote from potential users or from pipelines, making it too expensive to transport to market. As a consequence, it is simply burned (flared) to form carbon dioxide to dampen its environmental impact (i.e. methane has a higher global warming potential than carbon dioxide). At the Sloan Automotive Laboratory, we have been investigating new processes to convert methane into a valuable liquid fuel product in a compact unit that could avoid the need for flaring, and to do so in an economical way. The processes use internal combustion engines as a chemical reformer to convert natural gas to syngas by means of fuel-rich, incomplete combustion. This thesis project parallels a project that uses homogeneous reforming in-cylinder without a catalyst, with air or oxygen-enriched air (partial oxidation). This experiment explores the use and effects of a catalyst deposited on metallic foams placed in a one-cylinder compression-ignition engine, operating either in partial oxidation mode in combination with dry reforming. The metallic foam is attached to the bowl in the piston to carry out the chemical reaction. We determine composition of the reformate to determine conversion and selectivity. The product composition is determined with a gas chromatography. The metal foam catalyst is an effective means of syngas generation. We explore the impact of changing parameters such as equivalence ratio, CO2 content, and intake temperature and pressure.