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Evaluation of the selective NOx recirculation technique using activated carbon [electronic resource] /

by Zimmerman, Andrew James.

Abstract (Summary)
Evaluation of the Selective NOx Recirculation Technique Using Activated Carbon Andrew James Zimmerman A research program conducted at West Virginia University’s Engine and Emissions Research Laboratory focused on the reduction of oxides of nitrogen (NOx) formed by stationary lean burn natural gas engines. The project was sponsored by the US Department of Energy through the Advanced Reciprocating Engine Systems (ARES) program under contract number, DE-FC26-02NT41608. NOx gases are harmful to the environment as well as poisonous to people. When a natural gas engine operates, many products are released in the exhaust stream including but not limited to CO, CO2, NOx, and unburned hydrocarbons. These products are released directly into the atmosphere unless first treated either in the engine itself or in the exhaust system. In this thesis a possible model to implement the Selective NOx Recirculation Technique (SNR) was proposed. SNR is a NOx abatement aftertreatment technique that consists of four stages. The first stage involves cooling the exhaust stream. The cool exhaust is then directed through a sorbent chamber when NOx is adsorbed. Periodically the sorbent chamber is desorbed through the addition of heat and concentrated NOx is directed back into the engine for decomposition under high temperature combustion. The NOx decomposition phenomenon was investigated by injecting nitric oxide (NO) into the intake and exhaust of a Cummins L10G natural gas engine. An experimental NOx adsorption system, provided by Sorbent Technologies, was composed of a NOx adsorption chamber, demister, hot air blower, two heat exchangers and a particulate matter (PM) filter. Data were gathered during the adsorption and desorption phases of the operation. A bench model adsorption system was later constructed in order to further analyze NOx adsorption/desorption characteristics. The bench model NOx adsorption/desorption system was instrumented with four thermocouples, an in-line heater, a mass flow controller and a Rosemont Analytical NOx analyzer. Using temperature controlling devices the bench model system data was used to characterize two different types of activated carbon. Inside bed temperatures as well as flow rates of the incoming gases were all closely analyzed during the adsorption/desorption phases. Initial runs on the bench model apparatus allowed the bed to be filled with dry NO from a high pressure cylinder. These runs showed poor mass of NO to carbon adsorption ratios when compared to the runs performed on the actual adsorption system by a Cummins L10G natural gas engine. Further runs were performed on the bench model system using actual diesel exhaust, NO from a high pressure cylinder mixed with water, and NO from a high pressure cylinder mixed with water and compressed air. These later runs contained both NO2 and NO in the injections and showed more promising mass of NOx to carbon adsorption ratios. A maximum NOx to carbon mass adsorption percentage of 1.93 by was achieved by injecting NO mixed with compressed air and water into the bench model. iii
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School:West Virginia University

School Location:USA - West Virginia

Source Type:Master's Thesis

Keywords:natural gas vehicles nitric oxide carbon activated

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