The increase in the price of crude oil, the environmental impact, or the depletion of fossil resources has increased the need for bio-based alternatives. This has led to the search for renewable, biodegradable, and environmentally friendly raw materials to obtain lubricants that meet these characteristics. This review deals with the state of the art of biolubricants along with their most common raw materials and molecular structures, processes of chemical modification of bio-oils, as well as the relationship between their structural features and physicochemical/tribological properties. This review concludes that the production of fatty acid alkyl esters from vegetable oils is the most promising chemical route to produce a wide range of biolubricants through double transesterification reactions. It also highlights the need to explore this route for the production of microalgae-derived biolubricants due to its environmental benefits during cultivation and production processes.
Haematococcus pluvialis microalgae have emerged as a prevalent source of antioxidants in cosmetics and nutritional products. Additionally, numerous researchers have posited the potential of this microalgae to produce fatty acid methyl esters (FAME). Nevertheless, the optimization of the production of FAME from H. pluvialis oil has not been investigated. In this study, the transesterification reaction of H. pluvialis bio-oil was optimized using the response surface methodology, resulting in optimal experimental conditions for an oil to methanol ratio of 1:4.17, at a temperature of 80 °C, with a reaction time of 47 min. The resulting FAME was found to not comply with the biodiesel standard in terms of the content of polyunsaturated fatty acids (6.02%), as well as kinematic viscosity (7.02 mm2/s). Further study is required to reduce these parameters in order to ensure biodiesel quality and compliance with the standard. Nevertheless, its high flash point value of 150 °C and its high thermal stability within the temperature range of 211–290 °C suggest the potential for utilization as a biolubricant.