INTERNAL COMBUSTION ENGINES ARE USED IN A VARIETY OF STATIONARY APPLICATIONS RANGING FROM POWER GENERATION TO INERT GAS PRODUCTION.
BOTH SPARK AND COMP. ENGINES CAN BE FOUND.
A VARIETY OF FUELS CAN BE USED FOR I.C.ENGINES.
THE OPERATION OF I.C ENGINES RESULTS IN THE ENISSION OF HYDROCARBONS,CO,NOX,, & PARTICULATE MATTER

INTERNAL COMBUSTION ENGINES ARE USED IN A VARIETY OF STATIONARY APPLICATIONS RANGING FROM POWER GENERATION TO INERT GAS PRODUCTION.
BOTH SPARK AND COMP. ENGINES CAN BE FOUND.
A VARIETY OF FUELS CAN BE USED FOR I.C.ENGINES.
THE OPERATION OF I.C ENGINES RESULTS IN THE ENISSION OF HYDROCARBONS,CO,NOX,, & PARTICULATE MATTER.

CATALYST CONTROL TECHNOLOGY-
PRINCIPLE- USED FOR CONTROLLING THE GASEOUS EMISSION OF A STATIONARY I.C. ENGINES ? THE CATALYST CAUSES CHEMICAL REACTIONS WITHOUT BEING CHANGED OR CONSUMED. CATALYST TRANSFORM POLLUTANTS INTO HARMLESS GASES.

EMISSION CONTROL TECHNOLOGY FOR INTERNAL COMBUSTION ENGINES

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INTRODUCTION
Internal combustion (IC) engines are used in a variety of stationary applications ranging from power generation to inert gas production. Both spark ignition and compression ignition engines can be found. Depending on the application, stationary IC engines range in size from relatively small (~50 hp) for agricultural irrigation purposes to thousands of horsepower for power generation. Often when used for power generation, several large engines will be used in parallel to meet the load requirements. A variety of fuels can be used for IC engines including diesel and gasoline among others. The actual fuel used depends on the owners/operators preference but can be application dependent as well.
The operation of IC engines results in the emission of hydrocarbons (NMHC or VOC), carbon monoxide (CO), nitrogen oxides (NOx), and particulate matter (PM). The actual concentration of these criteria pollutants varies from engine to engine, mode of operation, and is strongly related to the type of fuel used.
Various emission control technologies exist for IC engines which can afford substantial reductions in all four criteria pollutants listed above. However depending on whether the engine is being run rich, lean, or stoichiometrically and the emission control technology used, the targeted emissions vary as do the levels of control. For example, an oxidation catalyst can be used to control NMHC, CO, and PM emissions from diesel engines which inherently operate in a lean environment, whereas selective catalytic reduction (SCR) could be used to additionally control NOx emissions. More recently, lean-NOx catalysts have been demonstrated to provide greater than a 80 percent reduction in NOx emissions from a stationary diesel engine, while providing significant CO, NMHC, and PM control as well.

PM emissions from stationary diesel engines are more of a concern than those for IC engines using other fuels. Several emission control technologies exist for diesel engine PM control. Oxidation or lean-NOx catalyst can be used to not only reduce the gaseous emissions associated with the use of diesel engines but further provide significant PM control. Likewise, diesel particulate filter systems can be used to achieve up to and greater than 90 percent PM control while in some instances, also providing reductions in the gaseous emissions.
Additionally, special ceramic coatings applied to the combustion zone surfaces of the piston crown, valve faces, and head have shown the ability to significantly reduce NOx and PM emissions in diesel engines. These ceramic coatings can be used by themselves or combined with an oxidation catalyst to give even greater reduction of PM. Ceramic engine coatings change the combustion characteristics such that less dry, carbon soot, is produced. Also, when combined with an oxidation catalyst, ceramic coatings allow retarding of the engine to reduce NOx, while CO and particulates are maintained at low levels.

Emission Control Technology for Stationary Internal Combustion Engines

In the case of gaseous fuels, ceramic coatings have shown the ability to allow the user to operate their engines with timing significantly advanced generating higher power levels. Also, wider ranges of fuel composition and ambient air temperature fluctuations are tolerated without the deleterious effects of precombustion. Tests are currently underway to evaluate the effects of the coatings on specific emissions from gaseous fueled engines.
Emission control technology for stationary IC engines is currently available and can be used to provide substantial reductions in the CO, NMHC, NOx, and PM emissions from these sources in a cost-effective manner.

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EMISSION CONTROL TECHNOLOGY
FOR INTERNAL COMBUSTION ENGINES
INTRODUCTION
 INTERNAL COMBUSTION ENGINES ARE USED IN A VARIETY OF STATIONARY APPLICATIONS RANGING FROM POWER GENERATION TO INERT GAS PRODUCTION.
 BOTH SPARK AND COMP. ENGINES CAN BE FOUND.
 A VARIETY OF FUELS CAN BE USED FOR I.C.ENGINES.
 THE OPERATION OF I.C ENGINES RESULTS IN THE ENISSION OF HYDROCARBONS,CO,NOX,, & PARTICULATE MATTER.
TECHNIQUES USED TO CONTROL
CATALYST CONTROL TECHNOLOGY-
 PRINCIPLE- USED FOR CONTROLLING THE GASEOUS EMISSION OF A STATIONARY I.C. ENGINES – THE CATALYST CAUSES CHEMICAL REACTIONS WITHOUT BEING CHANGED OR CONSUMED. CATALYST TRANSFORM POLLUTANTS INTO HARMLESS GASES.
SELECTIVE CATALYTIC REDUCTION
 INTRODUCING A REDUCING AGENTS SUCH AS AMMONIA,UREA,MAKES THE NECESSARY CHEMICAL REACTIONS POSSIBLE.
 THE REACTIONS ARE:-
 4NO+4NH3+O2--à 4N2+6H2O
 2NO+4NH3+2O2--à 3N2+6H2O
OXIDATION CATALYSTS
 OXIDATION CATALYSTS CONTAIN PRECIOUS METALS IMPREGNATED INTO A HIGH GEOMATRIC SURFACE AREA CARRIER AND ARE PLACED IN THE EXHAUST STREAM THEY ARE VERY EFFECTIVE IN CONTROLLING CO&HYDROCARBON EMISSION.
CATALYTIC CONVERTER
 WORKING
 HELP IN REDUCING EMISSIONS
BY CONTROLLING EXHAUST BEFORE IT LEAVES THE ENGINE.
BY CONTROLLING THE AIR TO FUEL RATIO(IDEAL RATIO 14.7:1 )
HOW REDUCE POLLUTION
 Most modern cars are equipped with three-way catalytic converters. "Three-way" refers to the three regulated emissions it helps to reduce -- carbon monoxide, VOCs and NOx molecules. The converter uses two different types of catalysts, a reduction catalyst and an oxidation catalyst. Both types consist of a ceramic structure coated with a metal catalyst, usually platinum, rhodium and/or palladium. The idea is to create a structure that exposes the maximum surface area of catalyst to the exhaust stream, while also minimizing the amount of catalyst required (they are very expensive).
DIAGRAMS
TYPES
 There are two main types of structures used in catalytic converters -- honeycomb and ceramic beads. Most cars today use a honeycomb structure.
TYPE 1
 The Reduction Catalyst
The reduction catalyst is the first stage of the catalytic converter. It uses platinum and rhodium to help reduce the NOx emissions. When an NO or NO2 molecule contacts the catalyst, the catalyst rips the nitrogen atom out of the molecule and holds on to it, freeing the oxygen in the form of O2. The nitrogen atoms bond with other nitrogen atoms that are also stuck to the catalyst, forming N2. For example:
 2NO => N2 + O2 or 2NO2 => N2 + 2O2
TYPE2
 The Oxidization Catalyst
The oxidation catalyst is the second stage of the catalytic converter. It reduces the unburned hydrocarbons and carbon monoxide by burning (oxidizing) them over a platinum and palladium catalyst. This catalyst aids the reaction of the CO and hydrocarbons with the remaining oxygen in the exhaust gas. For example:
 2CO + O2 => 2CO2
CONTROL SYSTEM
 The third stage is a control system that monitors the exhaust stream, and uses this information to control the fuel injection system. There is an oxygen sensor mounted upstream of the catalytic converter, meaning it is closer to the engine than the converter is. This sensor tells the engine computer how much oxygen is in the exhaust. The engine computer can increase or decrease the amount of oxygen in the exhaust by adjusting the air-to-fuel ratio. This control scheme allows the engine computer to make sure that the engine is running at close to the stoichiometric point, and also to make sure that there is enough oxygen in the exhaust to allow the oxidization catalyst to burn the unburned hydrocarbons and CO.