| Our society is facing huge energy and environmental crises now. Energyconsumption and discharge of pollutant are repeatedly break records. Energy affectsthe rise and fall of a country and energy problems has become the focus of all disputes.Extremely bad weathers come one after another in recent years due to theenvironmental pollution. The development of renewable energy sources has become abig issue that influences human progress.As a eximious and clean renewable energy,biomass has draw the attention of more and more countries. Biomass hasn’t formed acorresponding industry in China due to its late starting and backward technology.After learning from abroad and researching China’s basic conditions we find thatChina is propitious to develop biomass particle fuel. At present in China the mainbiomass particle fuel is that takes crops’ straw as material. This kind of biomassparticle fuel tents to produces slagging which hinder burning. And thus restricts thedevelopment of biomass particle fuel.This article aims to solve the problem of biomass’s slagging and ash fouling.According to the regional characteristics of northeast, corn straw, soybean straw andpeanut shells are used in the research of composite biomass particle fuel hoping tosolve the problem of corn straw ash’s low melting point. CaO，SiO2，MgO，Fe2O3，Al2O3and ChangChun’s local clay are taken as additives in order to heighten the cornstraw ash’s melting point and prevent agglomerate adhesion during burning process.Thermo-gravimetric experiment are conducted to analysis combustion characteristicand combustion kinetics of composite biomass particle fuel.1) Ash melting characteristics of composite biomass particle fuelsPeanut shells and soybean straw these two kinds of biomass the softeningtemperature are very high, up to139℃9and m ore than1520℃,far m ore than the corn straw1102℃. But peanut shells and soybean straw respectively with the cornstraw mixed fuel softening temperature is not high. Test study found, using additive toimprove corn stalk ash melting characteristics effect is obvious. The content of MgOreached3%, corn straw pellet fuel of ash softening temperature (ST) to144℃5, thecontent of Al2O3reached3%, softening temperature (ST) to1450℃, the content ofCaO reached3%, softening temperature (ST) to1355℃.2）Slagging characteristics of composite biomass particle fuelsSimulation of the actual combustion texts of composite biomass particle fuelsshows that evaluation of biomass particle fuel’s ash melting couldn’t reflect the realash slagging during its burning. Because the evaluation is based on compositebiomass particle fuel’s ash softening temperature. Application of simulation burningexperiment can accurately reflect the composite biomass particle fuel’s slaggingcharacteristics. Corn straw in900℃is show ing slagging tendency,in1000℃havebeen fully formed lumps. But when the content of MgO reached3%, compositebiomass pellet fuel in12℃00is com pletely not anti-coking, other additives indifferent content can also improve more than50to100℃.3) combustion characteristics of composite biomass particle fuelsO2and N2are used to conduct thermo-gravimetric experiment and produced twocurves. Particle fuel ignition is judged by combined analysis of this two curves.Research proved that all characteristics of composite biomass particle fuels are betterthan that of the corn straw particle fuels.4）Combustion kinetics characteristics of composite biomass particle fuelsCombustion process of composite biomass particle fuels is a non-isothermalprocess. The Coasts-Redfern method which belongs to integration is adopted todealing with the thermo-gravimetric data. The use of coats-Redfern equation areobtained by linear regression equation of the return of get "dynamic three factors" ofthe apparent activation energy E and frequency factor A. Based on analysis i thinkCoats-Redfern equation can give a good reflection on biomass particle fuelscombustion process. Analysis proved the excellent combustion characteristics of composite biomass particle fuels.The slagging and combusion characteristics of composite biomass particle fuelsare far better than corn straw particle fuel’s. Some composite biomass particle fuel hassolve the slagging problem during the corn straw combustion. The combustioncharacteristics of composite biomass particle fuel are extremely advantageous. Thisplays a positive role in spreading composite biomass fuel and has great significancefor the development of biomass energy in China. |
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