Safety profiling of technical lignins originating from various bioresources and conversion processes

In this work, a set of eight technical lignin samples from various botanical origins and production processes were characterized for their chemical composition, higher heating value, size distribution, dust explosion sensitivity and severity, thermal hazard characteristics and biodegradability, in further support of their sustainable use. More specifically, safety-focused parameters have been assessed in terms of consistency with relating physico-chemical properties determined for the whole set of technical lignins. The results emphasized the heterogeneity and variability of technical lignins and the subsequent need for a comprehensive characterization of new lignin feedstocks arising from novel biorefineries. Indeed, significant differences were revealed between the samples in terms of hazards sensitivity. This first comparative physico-chemical safety profiling of technical lignins could be useful for the hazard analysis and the safe design of the facilities associated with large scale valorisation of biomass residues such as lignins, targeting "zero waste" sustainable conversion of bioresources.