Studies On The Process And Properity Of Salix Torrefacted Coal

As biomass materials was rich in resources, widely distributed, a renewable, no pollution to environment. These advantages caused widespread concern around the world. Rational development and utilization of biomass energy could not only provide abundant clean energy for us, but also protect environment, reduced rely on the fossil fuels. Thus, it could provide an available way with the energy issues. But as a strong dispersion, high moisture content of biomass restricted its long transportation and enlarged its storage costs. They led to biomass energy hard to be large-scale used. The essay studied on the torrefacted nature of biomass materials-Salix, water absorption properties, pyrolysis and combustion. It offered an important theoretic reference for the further optimization of torrefacted biomass. Furthermore, it was important to efficient utilization of biomass.At first, put the Salix samples in the Muffle furnace to torrefact respectively at200℃,230℃,260℃,290℃in30min periods. Then, use the equipments made a comprehensive understanding from micro to macro by specific surface area analyzer, scanning electron microscopy, FT-IR, laser analyzer atc. The studies showed:Firstly, after torrefaction, salix’s apparent morphology changed. As the temperature increased, char physical form of Biomass has changed. Solid products transferred yellow into black. Its volume was decreasing, products became fragile and brittle, the shapes changed in Cylindrical or spherical Secondly, after torrefaction, grindability of salix improved increasing and got a great improvement. Extended the torrefacted time had not a obvious influent on biomass character. Therefore, a right temperature, a reasonable time will enhanced pyrolysis character and provided required quality synthesis gas generating heat. It caused a strong support. Thirdly, it could be seen by surface area analyzer:torrefaction could changed biomass themselves micro-structure. After torrefaction, solid products Voids became development, it was beneficial to transferred mass and heat in the process of combustion and gasification, Furthermore, the faction of thermo-chemical conversion process can be promoted to make gas-solid reaction quickly. Fourthly, the mass and energy yield were reduced after torrefaction, but energy yield could be reduced more slowly than mass yield. Fifthly, during the biomass torrefacted, the number of oxygen-containing functional groups was significantly reduced, the energy density has improved. The last, salix torrefacted charcoal studied by SEM analysis in order to have a change in the surface morphology characteristics. Not only could it provided some references, but also could be more intuitive understanding of the nature of torrefacted charcoal.Then, the study on the water absorption of salix torrefacted-coal by Humidity Chamber aimed to explore the water absorption. The results showed that first the water absorbation of salix torrefacted-coal included two parts:fast absorbing water when the initial and slowly absorbing water when the last. Second, the water absorption of Salix was relative to temperature, When the temperature was improving, it was obvious that biomass had a hydrophobic. Third, water absorption was relatively grown slowly, as the humility increased; water absorption rate became faster growth in a low humidity. At last, absorbed water character of biomass could be declined in a high temperature.Remove water can improve effective conversion of biomass, therefore, It had a significance for biomass later transportation and subsequent thermo-chemical conversion.At last, Salix samples and baked samples were experiment on pyrolysis and combustion. The results showed that it was mainly Salix dehydrated and dried(<200℃) Pyrolysis of hemicelluloses. Volatiles caused and combustion process carbonized and burning phase. At about240℃.Hemicelluloses began to have a fast pyrolysis. In a high temperature, It could be benefit torrefact for the process of torrefaction. Finally, the main gas products were H2O and CO2, a little containing oxygen organic carbohydrates C=O in final period. Furthermore, after torrefaction, the biomass of flash point shapely decreased.When the temperature rising, Corresponding to the maximum peak temperature of Salix became lower, torrefaction after the high temperature was obviously higher than the amount of heat in the low temperature section.The essay showed that torrefacted salix was better to fast pylysis and rapid combustion, solid products got well improved. In addition, it was conducive to biomass conversion, utilization of high quality and large-scale applications.