Combustion And Pollutant Emissions Characteristics Of Coals Blended With Biomass

Coal, which occupies an important position in primary energy using, is a kind of worldwide mineral resource. Coal combustion will support the economy developing and do harm to the environment in the meantime. Biomass energy is extremly rich and can partly ease the consumption of primary energy as a fuel. It is ZERO CO2emission since the carbon were made from photosynthesis. Tobacco stem is the by-product in the tobacco industry and could only be casted aside in most of the time. It is a waste of energy and harmful to the environment. Miscanthus is a kind of grass planted with great potential for combustion as a fuel. Combustion for coal blended with biomass is a new complementary way to use biomass. It could optimize the property of coal combustion and reduce the emission of pollutants, making the best of biomass.Thermogravimetry was used in this paper to conduct some combustion experiments on Guizhou lignite, Texas lignite, tobacco stem, miscanthus, different ratios (10%-90%) of Guizhou lignite blended with tobacco stem and Texas lignite blended biomass. The alkali mineral matters were rich in biomass and the effects on the combustion characteristics were discussed, especially on ignition temperature, the maximum rates for the combustion of volatile&fixed carbon and the corresponding temperatures, burnout temperature and integrated combustibility index. Thermogravimetric curves showed alkali mineral matters would promote the combustion for both lignite and biomass and increase the integrated combustibility index. Combustion property for lignites could be optimized by the adding in of biomass. Judging from the thermal analysis data,40%for tobacco in Guizhou lignite and30%for miscanthus in Texas lignite were the perfect rations according to the original lignite combustion properties.Pollutants data were collected through a TG-IR-MS and the results showed the alkali mineral matters could influence the emission temperatures for CO2but not for the total volume. When blended with biomass, coal combustion would decrease the direct emission of CO2, as well as SO2and NO2.