Characterization of bio-oil produced by HTL of binary mixture of phenylalanine and glucose

Hydrothermal liquefaction (HTL) is an effective technique to obtain bio-oil from advanced waste biomass without any drying step. However, bio-oil produced from HTL cannot be used directly as a liquid transportation fuel due to its significant heteroatoms content. While oxigen is easy to remove by hydrotreating, nitrogen is more recalcitrant making the bio-oil difficult to integrate in conventional refinery processes. To overcome this problem it is necessary to study the chemical behavior of nitrogen containing compounds during HTL in order to reduce their formation. Doubtless, for optimization and selection of appropriate upgrading strategy the chemical characterization of heteroatom and functionality distribution in bio-oil is crucial. Therefore, in the present study phenylalanine and glucose were employed as representative biomass model compounds of protein and carbohydrate macromolecules. Their interaction behavior during the HTL process was investigated considering the molecular level characterization of the nitrogen-containing species in bio-oil by means of positive electrospray high resolution mass spectrometry (FTICR-MS). Most attention is paid for the carbon and nitrogen transferring into oil products produced from hydrothermal liquefaction.