REDUCING DIESEL NOX AND SOOT EMISSIONS VIA PARTICLE-FREE EXHAUST GAS RECIRCULATION

DIESEL ENGINES PLAY AN IMPORTANT ROLE IN THE UNITED STATES ECONOMY FOR POWER GENERATION AND TRANSPORTATION. HOWEVER, NOX AND SOOT EMISSIONS FROM BOTH STATIONARY AND MOBILE DIESEL ENGINES ARE A MAJOR CONTRIBUTOR TO AIR POLLUTION. MANY ENGINE MODIFICATIONS AND EXHAUST-AFTER-TREATMENT DEVICES HAVE BEEN PROPOSED AND TESTED TO REDUCE THE NOX AND SOOT EMISSIONS FORM DIESEL EXHAUSTS. SIMPLE TECHNIQUES FOR NOX CONTROL SUCH AS EXHAUST GAS RECIRCULATION (EGR) AND INJECTION TIMING RETARD INCREASE SOOT FORMATION. THE CONTROL OF SOOT FORMATION IS POSSIBLE WITH DIESEL PARTICULATE FILTERS (DPF'S) WITH INTERMITTENT THERMAL OXIDATION OF CARBON SOOT. HOWEVER, SUCH FILTERS HAVE LIMITATIONS ASSOCIATED WITH FILTRATION EFFICIENCY AND DURABILITY. IN THIS PROGRAM, A NOVEL DIESEL EMISSIONS CONTROL SYSTEM WILL BE DEVELOPED. THE SYSTEM WILL UTILIZE A HIGH-EFFICIENCY CERAMIC FILTER TO FILTER THE EXHAUST GAS, THE FILTER WILL GENERATE A PARTICULATE FREE EXHAUST GAS, A PORTION OF WHICH WILL BE USED IN EGR FOR NOX EMISSIONS REDUCTION. THE CERAMIC FILTER WILL BE REGENERATED BY BACKPULSING WITH QUICK PULSES OF COMPRESSED AIR. IN PHASE I, A PROTOTYPE FILTER/EGR SYSTEM WILL BE TESTED WITH EXHAUST FROM A 35 KW DIESEL SOURCE & OPERATED FOR UP TO ONE YEAR.