Fast Pyrolysis Biochar Flammability behavior for Handling and Storage

Abstract

Biochar is a fairly new material in the research arena with limited information on safety aspects related to transportation, storage, disposal or field application methods. The objective of this research was to assess the flammability characteristics of fast pyrolysis biochars with test methods EPA 1030 and ASTM 4982. Results indicated that biochar is a non-flammable substance when tested with EPA 1030 ignitability of solids. However, when tested with ASTM D4982, a fast screening method, biochars showed potential risks of flammability. However, the addition of 20-50% moisture reduced any flammability concern. Fast pyrolysis biochar was more prone to be flammable than traditional charcoal and slow pyrolysis biochar tested in this study. Still, fast pyrolysis biochars presented lower flammability potential (ASTM 4982) in comparison to its precursor biomass. The flammability propagation measured with EPA 1030, had high correlations with oxygen content and surface area of the fast pyrolysis biochar. The combustion reaction of fast pyrolysis biochar is a flameless combustion process, with a slow burning rate, and most commonly exhibiting a hot ember smoldering propagation front. This paper illustrates the necessity of performing recurring tests due to biochar’s intrinsic variability stemming from the different modes of production and feedstock used.