Several edible and non-edible oil sources are currently being developed as renewable basestocks for biolubricant production. However, these feedstocks possess undesirable physicochemical properties limiting their lubricant applications. Chemical modification and additive-based routes could be used to modify their properties -suitable for different biolubricant applications. The first part of this study compares how the selected modifications affect the properties of the basestocks. Next, the techno-economic analysis (TEA) was conducted to study 4 selected biolubricants and a potential biolubricant derived from marine microalgae biomass. Oxidative stabilities of chemically modified biolubricants followed the order of epoxidation> triesterification> estolide. Pour points of triesters showed minimal increments and reduced for estolides, whereas epoxidation increased pour points. Estolides exhibit maximum kinematic viscosity increment among chemical modification routes, followed by TMP-transesterification and epoxidation. The oxidative stability of chemically modified biolubricants was higher than additized biolubricants; conversely, the viscosity increments and pour point reductions for additized biolubricants were higher than chemically modified biolubricants. TEA results show that the unit cost for producing 1-kg estolide was the highest among the chemical modification routes. The unit cost per kilogram of jatropha biolubricant produced using the additive-based route was lower than chemically modified biolubricants. Due to a high microalgal oil feedstock cost, the unit cost per kilogram of additized microalgae oil biolubricant was more than the unit cost of additized Jatropha oil. The techno-economic feasibility of biolubricant production from marine microalgal oil could be improved by adopting a biorefinery approach.
Keywords: Additization; Epoxidation; Estolide formation; Microalgae; Techno-economic analysis; Transesterification.
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