Influence of Mineral Matter in Coal on Decomposition of NO over Coal Chars

摘要

NO-char reaction in the presence and absence of mineral matter was investigated.Four Chinese coals with different ranks from lignite to anthracite were demineralized with HCl/HF,eight chars were prepared by devolatilizing the raw and demineralized coals in a laboratory-scalequartz fluidized bed at a final temperature of 950 for 30 min. The decomposition of NO over thesechars was studied in a quartz fixed bed reactor in inert atmosphere (Ar), 0.2 vol.% O2 and 0.2 vol.%CO atmosphere at atmospheric pressure using a temperature-programmed method. The productgases were continuously monitored by a flue gas analyzer. The results showed that NO was moreeasily reduced on parent coal chars than on the corresponding demineralized coal chars. O_2 andCO enhanced the decomposition of NO over both the raw and demineralized coal chars. Sodium inthe mineral matter catalyzed char-consuming NO-char reaction, while Fe preferably promoted theNO-CO reaction. The influence of mineral matter was decreased in the presence of O_2.