NEW METHOD FOR CONTROLLING THE NOX FROM STATIONARY GAS ENGINES

STATIONARY GAS ENGINES PRODUCE A DISPROPORTIONATELY LARGE SHARE OF THE TOTAL NOX EMISSIONS IN THE U.S., BUT NO AVAILABLE TECHNOLOGY OFFERS A SATISFACTORY MEANS OF REDUCING THEIR EMISSIONS. THESE ENGINES ARE PREDOMINANTLY TWO CYCLE AND PRODUCE AN EXHAUST HAVING A HIGH RATIO OF OXYGEN (O2) TO NITRIC OXIDE (NO). THUS, A SELECTIVE NO REDUCTION TECHNIQUE IS NEEDED WHICH CONVERTS THE NO TO NITROGEN (N2) WITHOUT AFFECTING THE MUCH LARGER AMOUNT OF O2 PRESENT. THE ONLY AVAILABLE REDUCING AGENT, HOWEVER, IS METHANE AND THERE HAS BEEN NO KNOWN METHOD BY WHICH METHANE COULD BE MADE TO REDUCE NO SELECTIVELY. A NEWLY DISCOVERED CHEMICAL REACTION IS DESCRIBED. IN THIS REACTION A PROPRIETARY SOLID UNDERGOES A RAPID REVERSIBLE REACTION WITH NO UNDER OXIDIZING CONDITIONS. THE POSITION OF THIS EQUILIBRIUM IS SENSITIVE TO THE CONCENTRATION OF O2 AND UNDER OXIDIZING CONDITIONS ESSENTIALLY QUANTITATIVE NO REMOVAL CAN BE ACHIEVED BY PASSING AN EXHAUST GAS CONTAINING NO THROUGH THE PROPRIETARY SOLID AT A HIGH SPACE VELOCITY. UNDER REDUCING CONDITIONS, HOWEVER, THE EQUILIBRIUM SHIFTS. A SOLID WHICH IS SATURATED WITH NO MAY BE REJUVENATED, AND THE NO REDUCED TO N2. ORDINARILY REDUCING AGENTS SUCH AS METHANE, HYDROGEN, AND CARBON MONOXIDE ARE ONLY CAPABLE OF REDUCING NO IN A NONSELECTIVE MANNER. IF ONE OF THEM IS USED TO REDUCE NO IN A GAS MIXTURE, IT IS NECESSARY TO SUPPLY ENOUGH REAGENT TO REDUCE ALL THE OXIDIZING SPECIES. THUS BY USING THE SOLID TO TRANSFER NO FROM THE OXIDIZING EXHAUST GAS INTO A REDUCING ENVIRONMENT, THE SOLID ENABLES METHANE TO SELECTIVELY REDUCE NO. A RESEARCH PROGRAM IS DESCRIBED FOR A LABORATORY SCALE DEMONSTRATION OF THE FEASIBILITY OF USING THIS NEW REACTION TO CONTROL THE NOX EMISSIONS OF STATIONARY GAS ENGINES.