Activation of anthracite combustion by copper acetate:mechanism,effect of particle size and introduction method

This paper addressed the efect of copper acetate on the combustion characteristics of anthracite depending on the fractional composition of fuel and additive introduction method.Anthracite was impregnated with 5 wt%of Cu(CH_(3)COO)_(2)by mechanical mixing and incipient wetness impregnation.Four anthracite samples of diferent fraction with d<0.1 mm,d=0.1-0.5 mm,d=0.5-1.0 mm,and d=1.0-2.0 mm were compared.According to EDX mapping,incipient wetness impregnation provides a higher dispersion of the additive and its uniform distribution in the sample.The ignition and combustion characteristics of the modifed anthracite samples were studied by thermal analysis and high-speed video recording of the processes in a combustion chamber(at heating medium temperature of 800℃).It was found that copper acetate increases anthracite reactivity,which was evidenced by decreased onset temperature of combustion(ΔT_(i))by 35-190℃and reduced ignition delay time(Δτ_(i))by 2.1-5.4 s.Copper acetate reduces fuel underburning(on average by 70%)in the ash residue of anthracite and decreases the amount of CO and NO_(x)in gas-phase products(on average by 18.5%and 20.8%,respectively).The mechanism for activation of anthracite combustion by copper acetate is proposed.

Ethanol Evaporation Characteristics of the Blends of Fatty Acid Methyl Ester and Ethanol

The evaporation characteristics of fatty acid methyl ester(FAME)mixed with four concentrations of ethanol at 873 K and normal atmospheric pressure are studied herein.FAME is used as base oils,and et hanol mass fractions vary from 10%,20%,30%to 40%。The experimental results show that the evaporation process of the binary component droplets of FAME-ethanol can be divided into two stages:a fuctuation evaporation stage,and an equilibrium evaporation stage.In these four concentration gradients,micro-explosions occur in the droplet evaporation process.The fuctuation evaporation stage is divided into two stages:a strong fuctuation stage and a weak fluctuation stage.After the micro-explosion,there is still a small amount of ethanol in the droplet.Due to the surface tension of the droplet,a small amount of ethanol cannot make the droplet violently fuctuate.The results show that the earlier the droplet micro-explosion occurs,the more intense it is,and the shorter the lifetime of the droplet is.Different concentrations of ethanol have different improvements in droplet evaporation characteristics.Generally,the higher the ethanol concentration is,the shorter the lifetime of the droplet is.However,increasing the ethanol concentration from 20%to 30%has the most obvious effect on the lifetime of the droplet.