Experimental determination of particle size distribution of biomass

Abstract

This thesis provides an overview of the importance of particle size distribution (PSD) in biomass applications and investigates PSD of birch-derived biomass by using two imaging-based analytical methods: the high precision Morphologi G3 system and a more accessible smartphone camera-based technique. Through multiple step sample preparation, which includes chopping, grinding and sieving particles to produce three different size samples (fine, medium and coarse), and image analysis, the research evaluates key size and shape parameters such as circle equivalent (CE) diameter, circularity, elongation and aspect ratio of the particles by comparing their median, maximum and minimum values as well as the percentiles and standard deviations. Results reveal distinct advantages and disadvantages of both methods by comparing their accuracy and practicality. Morphologi G3 system provided more detailed and higher resolution data, which successfully captured a broad particle size range, while the smartphone method, though more accessible and cost effective, showed limitations in resolution and reproducibility due to various limitations. The research further discusses how these parameters influence biomass behavior in thermochemical processes such as combustion, gasification and pyrolysis. Results highlight the tradeoffs between measurement accuracy and practicality, pointing out the relevance of method selection. By comparing methodologies, the findings offer valuable insights for selecting context appropriate PSD determination techniques and optimizing the analysis to improve biomass processing efficiency and enhancing the sustainability of renewable energy systems.