生物质再燃还原NO_x的机理分析

生物质是用于煤粉炉再燃脱硝的重要燃料。分析了生物质快速热解还原NOx的机理。生物质热解的主要产物是H2、CO、CO2、CH4、C2H2、C2H4、C2H6、C3H6、C3H8、焦炭、焦油和灰分等。生物质中的氮热解转化为HCN和NH3,二者对还原NOx有很大的影响。生物质再燃主要是通过碳氢化合物还原NOx,HCCO+NOx和CHi(特别是CH3)+NOx是最重要的反应,CHi在CH4脱硝过程中最重要,HCCO在C2脱硝过程中占主导作用。CO、H2、焦油和灰中的碱金属对还原NOx起到一定的促进作用。

Discussion on Mechanism of Nitric Oxide Reduction by Biomass Reburning

Biomass is one kind of important fuel for NOx reduction by reburning.The mechanism of nitric oxide reduction by biomass reburning was discussed.The main products of biomass rapid pyrolysis are CO2,CH4,C2H2,C2H4,C2H6,C3H6,C3H8,char and tar.While the Nitrogen in the biomass converses to NH3 and HCN during rapid pyrolysis,which both are important in reducing NOx.NOx reduction by biomass reburning is achieved mainly by the reaction between hydrocarbon and NOx,where HCCO NOx and CHi(especially CH3) NOx reactions are most important.The CHi NOx reaction is the dominant reaction when using methane as reburning fuel,while the HCCO NOx contributes significantly to remove NOx when C2 hydrocarbons are used as reburning fuels.CO,H2,tar and alkali metal have potential to promote NOx reduction.