Supercritical carbon dioxide fractionation of bio-crude produced by hydrothermal liquefaction of pinewood

Publication date: Available online 4 April 2019Source: The Journal of Supercritical FluidsAuthor(s): Nikolaos Montesantos, Thomas Helmer Pedersen, Rudi Pankratz Nielsen, Lasse Rosendahl, Marco MaschiettiAbstractThe supercritical carbon dioxide extraction of bio-crude, produced by hydrothermal liquefaction of lignocellulosic biomass, was investigated for pressures and temperatures in the range 112 to 400 bar and 40 to 120 °C, corresponding to solvent densities in the range 548 to 882 kg/m3. Total extraction yields ranged from 17 to 42%. For a given solvent density, temperature increase drastically improved both the process operability and efficiency. The extracts showed reduced density as well as 40 % reduction of total acid number compared to the feed. The residue resulted to be partially deoxygenated. Ketones, 1-ring phenols and low molecular weight fatty acids were concentrated in the extract, with recoveries up to 80%, with ketones and phenols exhibiting the highest distribution factors. Observed selectivities suggest the feasibility of downstream separation of the key classes of extractives using supercritical carbon dioxide as a solvent.Graphical abstract

Source: The Journal of Supercritical Fluids - April 5, 2019 Category: Chemistry Source Type: research