Internal combustion engines, catalytic reactors, selective reduction, nitrogen oxides, air pollution

This paper presents a comparison of test results for a platinum reduction reactor in an NH3-SCR system with varying ammonia dosing into the exhaust system of a compression-ignition engine. The comparison was made to evaluate the reactor’s ability to convert nitrogen oxides using ammonia. The paper includes results of physical-chemical studies of the reactor’s active surface structure performed using an SEM microscope.Surface topography images and point analysis of its chemical composition are presented. The study contains calculation results for NOX and NO conversion and the share of NO in NOX as a function of reactor operating temperature, along with characteristic operating parameters determined for it. The article includes results of ammonia slip measurements taken after the reactor. The obtained test results demonstrated the possibility of using a platinum reactor for the reduction of nitrogen oxides with ammonia only within a narrow temperature range. The influence of increasing ammonia concentration before the reactor on the increase in achieved NOX conversion levels and the increase in NH3 slip was demonstrated.
ESTIMATION OF AMMONIA DOSE INFLUENCE ON NOX CONVERSION LEVEL IN PLATINUM SCR REACTOR
Abstract
This paper contains results comparison of platinum catalytic reactor working as a reduction reactor for NH3-SCR system with different ammonia doses in Diesel engine exhaust gases. Results comparison was made in aspect of reactor ability estimation in nitric oxides conversion by use of ammonia. In this study results of physical-chemical investigations under reactor active surface are presented. Investigations were made by use of SEM microscope and they contains reactor surface topography views and chemical composition analysis. Article contains calculation results of NOX and NO conversion and NO contribution in NOX in function of reactor temperature. Characteristic reactor work parameters were also determinate in this paper. Results of ammonia slip measurements after reactor are included.
Obtained results have shown that platinum reactor can be used for nitric oxides reduction by use of ammonia only in narrow temperature range. Influence of ammonia concentration increase before reactor on NOX conversion levels increase and ammonia slip increase was reported. (…)