Influence of biomass type on the composition of bio-oils from ablative fast pyrolysis

Abstract One of the easiest ways to minimize the overall costs of bio-oil production is to minimize biomass transportation and, thus, pyrolysis should be performed at or close to the biomass original location. Thus, we applied ablative fast pyrolysis (AFP), as the only potentially mobile pyrolysis unit, to convert residual lignocellulosic biomass into bio-oil. Four different biomass types were converted to bio-oils: beech and poplar wood, straw and miscanthus. To study reliably the influence of biomass type on bio-oil yields, physicochemical properties and composition, pyrolysis was carried out at a constant temperature of 550 °C. Titrations and spectroscopic methods were used for the characterization of the main oxygenate groups. GC-MS was used for the quantification of more than 120 volatile compounds. Such a thorough analytical study of AFP bio-oils, heretofore missing in scientific literature, allowed us to reliably discuss the differences in bio-oils´ relative to the knowledge of biomass composition. Significant differences between the bio-oils were observed, with the lowest content of carboxylic and carbonyl groups in the straw bio-oil. The amount of carboxylic and phenolic groups in all the bio-oils was in the typical range observed for bio-oils unlike the carbonyls´ and levoglucosan content, which was lower than typical for bio-oils from other pyrolysis units.