Hydrofaction® is Steeper Energy’s proprietary implementation of hydrothermal liquefaction which applies supercritical water as a reaction medium for the conversion of biomass directly into a high-energy density renewable crude oil, referred to as Hydrofaction® Oil. Steeper’s unique process mimics and accelerates nature by subjecting wet biomass to heat and high pressure. Hydrofaction® process conditions are carefully chosen to promote reaction pathways that favor high yields of high quality renewable oil. These process conditions, with the operating temperature and pressure well above the critical point of water, and the use of homogeneous catalysts promote chemical reactions which lead to the formation of low-oxygen renewable crude oil. Additionally, recycling of oil and process water effluent is a unique feature of Hydrofaction® which brings synergistic benefits in various parts of the process. Using all the above sophisticated and unique features, Hydrofaction® achieves biomass-to-oil conversions of 45% on a mass basis and 85% on an energy basis.


Hydrofaction® provides significant advantages such as: 

  • Very high oil yields (≈ 45 % on mass basis, 85+ % on energy basis)
  • Very high efficiency: energy efficiencies (80%+) superior to other bio- or thermochemical systems. No requirement to dry feedstocks
  • Very high energy efficiency as no phase change takes place and due to extensive heat recovery
  • Sustainable: bio-crude produces 80%+ fewer CO2 emissions when compared to fossil (well-to-wheel)
  • Carbon conversion ratios > 60%
  • Flexible feed stock
    • No need for drying
    • Feed stocks can be mixed
  • High heating value of the crude oil produced (38+ MJ/kg)
  • Petro-equivalency: upgraded Hydrofaction® Oil compatible with fossil-oil infrastructure


Hydrofaction® utilizes a wide-range of biomass feedstocks and one of the competitive strengths of Hydrofaction® is the ability to process feedstocks as-harvested without the requirement of pre-drying. Steeper Energy has tested over fifty different feedstocks and mixtures including:

  • Forestry and agriculture residues;
  • Energy plants/crops, such as aspen, poplar, willow and miscanthus (elephant) grass;
  • Industrial food processing, sugar refining, oil seed milling, production wastes from alcohols or ethanol;
  • Urban source separated wastes;
  • Animal manures or bio-solids (sewage sludge); and,
  • Aquatic biomass in the form of seaweed, and algae.

Steeper Energy currently is focusing on hardwood & softwood forest and mill residues due to the abundance of these resources. The forest sector offers an interesting opportunity as the industry creates non-merchantable biomass or wastes of up to 60% of the fibre harvested including tops, butts, branches and bark.

Oil Properties

Hydrofaction® Oil is a high quality renewable crude oil that can be upgraded into diesel or jet fuels as well as used as a source of molecules for bio-chemicals and bio-lubricants. Hydrofaction® Oil has a higher energy content and lower oxygen content than bio-oils produced by competing thermochemical pathways.

The energy content of Hydrofaction® Oil is similar to fossil crudes however it has Oxygen rather than Sulphur contamination. Hydrofaction® Oil can be upgraded into renewable diesel, marine and/or jet fuel at existing refineries, where it is co-processed with fossil crudes, or in-situ within built-for-purpose upgraders. Once upgraded, products derived from Hydrofaction® Oil can be used as renewable blendstocks for transport fuels and are functionally equivalent to their fossil counterparts.