Using On-board Fuel Reforming by Partial Oxidation to Improve SI Engine Cold-Start Performance and Emissions

A cold-start partial oxidation (POX) system was integrated with a modern flexible fuel engine to assess its impact on cold-start performance and emissions. The POX reactor, a small combustion device operating fuel rich, converts liquid fuel into gaseous fuel species (reformate). The reformate from the reactor, when mixed with combustion air, replaces or supplements the standard fuel consumed during an engine start. This prototype integrated cold-start system has successfully reduced emissions from a cold-start on fuel grade ethanol (E95) at 5°C. The integrated POX system reduced the time-averaged hydrocarbon (HC) and carbon monoxide (CO) emissions by 80 and 40 percent, respectively. Starts on E95 reformate were achieved in less than 10 seconds at temperatures as low as -20°C.