Advanced Assessment of Biomass Materials Degradation in Pneumatic Conveying Systems: Challenges and Applications

In this study, the degradation of wood pellets and dry roasted coffee beans in a pneumatic conveyor was evaluated for high-speed impacts. The change in particle size and generation of fine particles were used as an indicating parameter for the degradation. A four-bends industrial scale conveying system was used for the degradation study in lean phase pneumatic conveying. The effects of operating parameters on the degradation were investigated, including the conveying velocity of particles and particle concentration. The experimental results showed that the degradation and the fines generation increased with an increase in particle velocity. An opposite trend was observed with an increased solid concentration in the pipeline. It was found that the two types of wood pellets traveled at different particle velocities with the same operating conditions, which resulted in significant differences in the degradation. Compared to the wood pellets, roasted coffee beans were found to travel at air velocity. In conclusion, the degradation in a pneumatic conveying system is complex and challenging to evaluate because there are many influential factors, such as the type of materials, equipment, and operation conditions. Early assessments in a laboratory will be beneficial to evaluate the degradation at all controlled operative conditions.