Bio-oils and Biolubricants 

Bio-oils and biolubricants can be made from a variety of feedstocks such as oil-rich seeds, grasses, algae, food waste, and unrecyclable plastics. Bio-oils can be made from three processes: pyrolysis; hydrothermal liquefaction; or chemical extraction. Biolubricants are further refined from bio-oils.

How bio-oils are made

Bio-oil can be made in a variety of ways, but the most common are pyrolysis and hydrothermal liquefaction.

  • Pyrolysis is the process of heating dry biomass feedstocks at high temperature (450°C or greater) in the absence of oxygen. Other products of pyrolysis include energy in the form of heat, syngas, and biochar.
  • Hydrothermal liquefaction is typically for wet feedstocks such as algae, and is the process of heating concentrated liquid at medium temperature (250-350°C) and high pressure (10-20 MPa) to produce bio-oil.

How biolubricants are made

Typically, biolubricants are made from the induction of branching in alkyl chains of vegetable oils. This process improves low-temperature characteristics, increases stability, and lowers the viscosity index (or reduces the change in viscosity due to temperature change). A new type of branched vegetable oil and associated methyl ester was developed by a group of researchers, including ISTC’s Dr. B.K. Sharma. The process is reversible, uses ferric chloride as a catalyst, and can be carried out at room temperature, saving the energy required to heat reactants to high temperatures. The article, “Preparation of Acetonides from Soybean Oil, Methyl Soyate, and Fatty Esters,” was published in a 2011 issue of the Journal of Agricultural and Food Chemistry.

Related work, in which saturated branched-chain fatty acids and their ester derivatives were prepared from mineral oil and soybean oil using a zeolite catalyst, resulted in biodegradable and non-toxic lubricants and hydraulic fluids from non-petroleum sources. Again, ISTC’s B.K. Sharma contributed to the work. The article, “Synthesis and Physical Properties of Isostearic Acids and Their Esters,” appeared in a 2011 issue of the European Journal of Lipid Science and Technology.