Hydrothermal treatment of biomass for energy and chemicals

Pyrolysis oils are a product of fast pyrolysis or liquefaction of biomass. Those dark brown organic liquids are chemically a complex mixture and/or emulsion of water and degradation products of lignin (e.g. guaiacols, catechols, syringols, vanillins), cellulose (such as levoglucosan, dehydrated sugars, di-sugars, furancarboxaldehydes), and hemicellulose (such as acetic acid, formic acid). Composition strongly depends on conditions of pyrolysis process and great variety of biomass feedstock such as grasses and trees, and other sources of ligno-cellulosic material, derived from municipal waste, food processing wastes, forestry wastes and pulp and paper by-products. The present contribution will present an overview of current high pressure processes for treatment of biomass for production of energy and chemicals as well as the fundamental studies of phase equilibria of the systems pyrolysis oil/gas, which are crucial in biorefinery process design. In particular, phase equilibria of binary and ternary systems consisting of pyrolysis oil/supercritical fluid (pyrolysis oil/CO2) and (pyrolysis oil/H-2) was studied in addition to the phase behavior of ternary systems of (pyrolysis oil/diesel/CO2) and (pyrolysis oil/tail water/CO2). These data are important for design of separation processes as well as for the application of these substances for commercial fuels. (C) 2016 Elsevier Ltd. All rights reserved.