Effect Of The Alkaline Metal's Distribution On Ash Characteristics During Co-combustion Of Biomass

Biomass is a renewable and environmental energy. Its utilization is an effective way to solve the increasing problem caused by energy shortage and environmental pollution. Because the fuel contains the alkaline metal and chlorine richly, biomass is very easy to from the deposition and the slagging after their combustion, which creates the corrosion for the fuel-burning equipment. Compared with the present four methods of spay coating, addition agent, raw material pretreatment and multifuel combustion, all of them can improve the ash corrosion. However, the method of multifued combustion and especially co-firing with coal is the best way that simply and effective. The research indicated that co-firing of biomass and coal is not only mix in pure physics significance, but there much interaction by promoter action or inhibitory action between these two fuel respective ash component, that the interaction will possibly receive the combustion operating mode and the proportion of mixture influence.Firstly, the deposition of co-fuel ash is described in this article, and the paper introduce several kinds inorganic elements that have the influence to the ash corrosion, including Na,Si,Al,S and Cl. Under different temperature, combust fuels to ash in which the above elements'deposition is to be researched, the fuels refer to straw and it's mixture with coal on three proportion. The result indicated that, temperature product tremendous influence on alkaline metal and related elements'deposition in straw ash, but the influence on co-fuel ash is not obvious, and the proportion of mixture almost has no influence on alkaline metal and related elements'deposition in their ash. Carries on the budget to the straw and it's mixture'ash characteristic, and find that the single straw has serious slagging tendency, when mix it with coal, even if only a little coal, the ash clinkering property will be improved largely.Then, straw and coal and their mixture at the mass ratio 1:1 are burnt by the Drop Tube Furnace., and use the DLPI to collect the fine ash produced during fuels'combustion. The research discovered that the co-fuel doesn't change the fine ash's quality grain-sizeThe Financial Support of the National Key Basic Research and Development Program 2002CB211602 distribution, however it promotes the emission of fine ash. Moreover, Through the analysis and Fact software computation of alkaline metal and related elements'deposition, the study discovers that to co-fuel, the biomass'influence is mainly on sub-micron particles while the coal work on super-micron particles.