ON-BOARD GENERATION IGNITION IMPROVERS FOR METHANOL DIESELS

METHANOL FUELED DIESELS ARE AN ATTRACTIVE MEANS OF MEETING STRINGENT 1994 DIESEL PARTICULATE STANDARDS, AND ARE A TOPICOF INTENSE INDUSTRIAL INTEREST. UNFORTUNATELY, BECAUSE OF METHANOL'S AUTOIGNITION TEMPERATURE IS HIGH AND ITS IGNITIONDELAY IS LONG, SOME MEANS OF IMPROVING ITS IGNITION IS REQUIRED IF IT IS TO BE USED IN A DIESEL ENGINE. THE BEST CURRENT METHOD, USE OF HIGH EXHAUST GAS RECIRCULATION WITH A GLOW PLUG ASSIST REDUCES FUEL ECONOMY, INCREASES THE COMPLEXITY AND COST OF THE ENGINE, AND INCREASES MAINTENENCE COSTS. A PROMISING SOLUTION IS ON-BOARD GENERATION OF THE GASEOUS IGNITION ENHANCER DI-METHYL ETHER (DME). THIS SYSTEM WILL REQUIRE MINIMAL MODIFICATIONS TO THE ENGINE DESIGN AND WILL NOT DEGRADE THE THERMAL EFFICIENCY OF THE ENGINE. HOWEVER, NO QUANTITATIVE INFORMATION IS AVAILABLE ON HOW TO INTEGRATE DME INTO THE COMBUSTION PROCESS, AND ON ITS EFFECT ON EMISSIONS. THEREFORE, TDA RESEARRCH WILL MEASURE THE AMOUNT OF DME REQUIRED FOR EFFICIENT OPERATION AS A FUNCTION OF ENGINE LOAD AND SPEED, AND TO DETERMINE THE EFFECT OF DME ASPIRATION ON THE EMISSION OF CO, NOX, UNBURNED HYDROCARBONS(PARTICULARLY METHANOL AND FORMALDEHYDE), AND PARTICULATES.