Research On The Characteristics Of Biomass Ash And Agglomeration Mechanism

The amount of biomass resource is the fourth in the once energy consumption globally. Biomass plays critical role to human life. It is the only storable and transportable reproducing energy and is an important alternative to energy consumption in the future. However, agglomeration is displayed frequently during the practical biomass combustion and gasification, and disturbs the normal operation. The agglomeration is affected by the characteristics of biomass ash. Hence, it is quite necessary to understand the characteristics of biomass ash, and explore corresponding agglomeration mechanism from the experimental and theoretical respects, so that it can be utilized efficiently.In this study, four typical biomass resources: wood dust, peanut shell, rice shell and rice stem, were selected to make ash in high and low temperature, respectively, to explore the relationship of ash weight with combustion temperature and time. And then the main oxide component, inorganic element composition and microscopic morphologies were analyzed via a scanning electron microscope (SEM) with energy dispersive X-ray analysis (EDX). In addition, the melt point of every biomass ash was measured and analyzed. The results showed that the proportion of silicon and calcium was the most, and the content of K2O and Na2O was also quite high, resulting in the melt point low.To understand the inherent agglomeration mechanism during biomass application and approach preventive measures effectively, the agglomeration problem was analyzed from two aspects of influencing factors related to agglomeration phenomenon and physical and chemical characteristics of bed agglomeration during biomass fluidized-bed combustion. Then the effects of SiO2 and Al2O3 on biomass ash melting characteristic was explored, the melt degree of compound decreased with amount of addition rising, and the influence of temperature was weak for Al2O3. Finally, with the help of dealing with experiment data, the common agglomeration quotient was calculated to determine the agglomeration degree of different biomass through fuzzy mathematics.This thesis supplies essential reference for the forming of biomass characteristics theory, and important aspects of biomass ash characteristics are understood profoundly. It is beneficial for the synthetic researches of biomass agglomeration in the future.