Selective Catalyst Reduction (SCR) Using Zeolite for Reduction of NOx Emissions in CI Engines

Abstract

The current study is aimed at the reduction of NOx emission (oxides of nitrogen) from a direct injection CI engine by selective catalytic reduction (SCR) technology. The SCR system was developed originally at the Centre for Alternate Energy and Renewable (CAER) in which zeolite was used as a catalyst. The developed SCR system was integrated with a single-chamber direct-injection CI engine of 3.7 kW rated power at 1500 rpm. Experimental test results revealed a significant reduction of NOx emission with the SCR system at all engine loads. The experimental design of the investigation typified obtaining standard behavior of the engine, i.e., without SCR, followed by the engine’s information after the presentation of the SCR framework. It is investigated from the results of exploratory tests that hydrocarbon (HC) emission was highest of about 20 ppm at 10 kg load, yet at 4 kg load, it decreased to 16 ppm. Carbon monoxide (CO) emission was moderately increased with the SCR system. NOx emission is minimum with SCR at all engine loading conditions as compared to without the SCR system. An experimental time study is also done and the readings are taken at the time interval of 5 min. A difference of 10 ppm hydrocarbon emission has been measured between 15 and 20 min. In the NOx emissions, a difference of 97 ppm has been observed while using the SCR system. Henceforth, the introduction of SCR to the engine minimizes the emissions and enhances the combustion performance along with the benefit of reduction in NOx emissions. After the complete analysis of the data, the outcomes demonstrate a positive impact on the selective catalyst reduction (SCR) system setup with the engine.