Production of crude oil from industrial wastes and wastewaters by hydrothermal liquefaction

Hydrothermal Liquefaction (HTL) is a promising thermochemical treatment suitable for the valorization of a wide variety of organic wastes and wastewaters. Many research studies have demonstrated the suitability of HTL to produce bio-oil from biomass wastes, but few works have focused on the application of HTL to industrial wastes and wastewaters. The objective and novelty of this work are the study of HTL suitability over a specific selection of industrial residues that present notable drawbacks when treated by conventional waste management methods, including technical problems or high costs. Most of the wastes presented poor results from the technical or energetical point of view. However, liquid surfactant wastewaters were successfully treated by HTL at 300ºC and 100 bar in a 300 mL stirred batch reactor, producing a crude oil yield of around 16%, with a High Heating Value (HHV) of up to 30 MJ/kg. The composition and quality of the crude oils obtained have also been determined and compared against conventional biomass fuels. Graphical abstract