GAS CLEANING METHOD, GAS CLEANING CATALYST, AND EXHAUST GAS CLEANING APPARATUS

摘要

PROBLEM TO BE SOLVED: To reduce NOx in exhaust gas to N2with high efficiency in an atmosphere of presence of high O2concentration using HC, without requiring control of a complicated air-fuel ratio, and to remove remaining HC in exhaust gas.

SOLUTION: NOx contained in exhaust gas from an internal combustion engine is cleaned with a catalyst using HC as a reducing agent, then remaining HC is removed with the catalyst. Cleaning by keeping the NOx removing catalyst lower than a given temperature suppresses combustion of HC and enhances NOx removal performance.

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