The Co-combustion Of Biomass And Its Semi-char

With the increasingly critical situation of energy utilization, environmental pollutionbecomes more and more serious with each passing day. The reasonable development andutilization of renewable energy tend to be the necessary choice for us to solve the energyand environmental problems. As the only available storage and transport of renewableenergy resource, the high efficiency and clean utilization of biomass has become theresearch hotspot in recent years. As the result of the low volatile, high ash characteristicsof the biomass char, it is much difficult to combust it alone. Through in-depth analysis ofthe combustion characteristics of biomass and biomass char, we have found that the twohave great complementarities. So I considered conducting the mixed burning experimentaccording to a certain proportion in order to improve the energy utilization rate.In this paper, thermogravimetry analyzer was used to study the combustioncharacteristics of the mixed powder of different mixing ratio. The influence of differentmixed ratio on combustion characteristics was investigated, and then knew that theco-combustion improved the combustion kinetic characteristics of semi-char, The resultsshow that the ignition was decreased from385.8℃to249.9℃and the burnouttemperature was from775.1℃to547.2℃with the increase of the proportion of biomass.When the static combustion experiments on different mixing ratio of biomass and charwas conducted to study the composition, crystalline phase and microstructure of the ash ofthe mixed power after burning. The results show that the volatile combustion is the mainlyphase of biomass combustion, it is not obvious for fixed carbon combustion. So theignition and burnout temperature of biomass is lower while the ignition and burningtemperature is higher because of only fixed carbon combustion of char. The mixed burningexperiment showed that with the increase of the proportion of biomass the ignition andburnout temperature of the mixed powder decreased.The combustion performance wasimproved dramatically.The co-firing experiment was carried out on a self-designed device. The study hasdetermined the optimum blending ratio, excess air coefficient, particle size and moistureratio of biomass: a mass ratio of8:2, the excess air coefficient is1.4, the powder particlesize of0.177mm (80mesh), biomass water content is controlled below8%can lead to thebest burning performance and the most reasonable economy cost.Meanwhile, a variety ofanalytical instruments were used to analyze the slag and corrosion of flue gas pollutantand ash, the feasibility and economy of the co-firing was also studied.