The role of particle size and other properties on silo discharge behaviour of chipped wood biomass

Abstract

To achieve net-zero carbon emissions by 2050, the UK government emphasizes the pivotal role of sustainable bioenergy in electricity, transportation, and heating. However, challenges persist in handling biomass particulate solids in production facilities, leading to economic impacts. This study investigates the flow characteristics of stemwood chips from four tree species using a novel drum chipper. Experimental analyses include bulk density measurements, silo discharge studies, biomass flow property assessments, and wall friction measurements. Comparative analyses are performed using Jenike's procedure for building wedge-shaped silos, with a focus on predicting the critical opening size to prevent arching. Additionally, the paper delves into the creation of statistical models aimed at identifying key factors influencing the flow behaviour during silo discharge. Emphasis is placed on understanding potential discrepancies between theoretical predictions and experimental results concerning critical silo openings for arch-free discharge. The results contribute to understanding the factors influencing the flow behaviour of wood chips, informing silo design considerations. Our findings suggest limitations in applying traditional silo design methods, urging further research for more accurate predictions.