Reduction of nitrogen oxide(s) in combustion gas from coal - by pretreatment of the coal with hydrogen

摘要

The content of nitrogen oxides (NOx) in the products of coal combustion is reduced by pretreating the coal or its solid derivs to convert the nitrogen present into non-oxidic, gaseous, easily sepd. cpds. Pref. the coal is treated with hydrogen at the end of the coking process and at the coking temp. Used esp. for treatment of coal whose sulphur content is not high enough to justify the known de-sulphurising treatment in hydrogen. Atmospheric pollution by NOx in the combustion gases is reduced.