Method for extending the service life of aged scr catalyst beds in emission systems from stationary sources of nox

Abstract

A method of extending the service life of an aged selective catalytic reduction (SCR) catalyst bed where nitrogen oxides (NO x ) In the exhaust gas aftertreatment system from a fixed source, in the presence of a nitrogen-containing reducing agent, the catalytic NO x converted to nitrogen (N 2 ), so that the exhaust gas emitted from the system to the atmosphere continues to reach NO x and ammonia emissions, the method comprising the steps of: modifying a honeycomb substrate monolith or sheet substrate comprising a catalyst for reducing ammonia from exhaust gases also containing oxygen downstream of an aged SCR catalyst bed Conversion to nitrogen and water with kNO for honeycomb substrate monoliths containing catalysts for conversion of ammonia in exhaust gases also containing oxygen to nitrogen and water at 300‑400 °C inclusive x Greater than or equal to 80m / h, which has been in the air at 10%H 2 kNO of catalyst samples aged at 450 °C for 48 h in O (as steam) x As determined by SCR activity testing in a laboratory scale reactor using the following gas composition: 50ppm CO, 30ppm NO, 36ppm NH 3 , 15%O 2 , 8% water, 3% CO 2 , margin N 2 .

Description

technical field [0001] The present invention relates to a prolong NO x Methodology for Service Life of Aged Selective Catalytic Reduction Catalyst Beds in Stationary Source Emission Systems. Background technique [0002] Modern electric generators fueled by natural gas, light distillates, or syngas (derived, for example, from coal) drive combined-cycle gas turbines, where the gas is combusted in the gas turbine to generate electricity in the first cycle, and the heat generated by the gas combustion Recovery takes place in a steam-operated heat engine in a second cycle. The combination of these two cycles increases the net overall efficiency of the system. The second cycle is typically carried out in a so-called Heat Recovery Steam Generator (HRSG) system, which typically also contains a catalytic component, which is used to treat components including nitrogen oxidation in the exhaust gas formed by the combustion of the gas in the first cycle matter (NO x ), carbon monoxi...

AI Technical Summary

Problems solved by technology

Ammonia leaks can lead to the formation of ammonium sulfate, which can plug or corrode downstream components and undesirably contribute to the emission of particulate matter (PM2.5) to the atmosphere

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