Combustion Characteristics and Visualization Analysis of a Biomass Pellet Oriented in Different Positions in a Fixed-Bed Reactor at Different Operating Conditions

Abstract

For all real-world applications, such as fluidized-bed and packed-bed combustion, it is essential to understand the combustion characteristics of an individual solid biomass particle. Under a variety of operating circumstances, investigations on the combustion and mass loss of single pellets of sugarcane (SC) and guava leaves (GL) were conducted. A visualization technique was used to capture the combustion processes of volatile and char. Both homogeneous ignition and hetero–homogeneous simultaneous ignition of both volatiles and char were found. When compared to the material composition and particle-size distribution of the pellet, the brightness of the pellet changed differently with increasing air mass flow rate and hot air temperature. By increasing the hot air temperature and air mass flow rate, the volatile flame of biomass pellets was made shorter and brighter, which lowered the volatile burnout duration. The majority of the entire conversion time is spent on char burning. Compared to other angles, the pellet orientation angle of 30° has a shorter ignition time, a lower surface temperature, and a lower burnout temperature.

CFDs Modeling and Simulation of Wheat Straw Pellet Combustion in a 10 kW Fixed-Bed Downdraft Reactor

“…The study of burning waste or biomass in large industrial furnaces is of utmost importance, as demonstrated by the extensive research on grate furnaces [8,9]. However, due to the challenges and costs associated with collecting detailed data from within these furnaces, researchers primarily rely on smaller, fixed-bed units in labs to replicate real-world operations [10]. Experiments and simulation findings support this approach, suggesting a substantial similarity between fixed-bed and grate combustion.…”

“…Some studies have been extended to include crop residue combustion, as seen in the work of Mätzing, Gehrmann [36]. However, there has been minimal research on numerical models specifically focused on the combustion process of wheat straw pellets [10,37]. Different types of biomasses have distinct chemical structures and compositions [38].…”