Hydrocarbon biolubricants from hydrotreated renewable and waste derived liquid intermediates

Abstract

There is a need to support the biofuel sector by utilizing waste materials for its production and utilizing co -products through an integrated approach. Due to bio-oil's diverse composition, its applications for foams and resins syntheses are emerging, but most importantly, as biolubricants, product with increasing global demand. In this study, four hydrocarbon biolubricants (HBL) were produced via a hydrotreatment process. Two samples were produced using hydrothermal liquefaction (HTL) of algae (HAL) and sewage sludge (HSS). Additional samples included animal fat (poultry fat; HPF) and non-edible oil (carinata; HCA). All four samples were eval-uated for their tribological properties and compared with the mineral base oil (MBO). These potential bio-lubricants samples had viscosity indices (VI) ranging from 197 to 254, pour points (PP) from-10 degrees C to-20 degrees C, and Noack volatilities between 16% and 23%. The coefficient of friction (COF) for HAL and HSS was lower than MBO, HPF, and HCA, but the wear was higher than HPF. Large amounts of oxygenates and olefins imparted higher VI and lowered PP to HPF. Even though both HSS and HAL demonstrated higher amounts of paraffin, they exhibited lower thermo-oxidative stability, higher PP, and higher volatility than other samples. In the case of HAL and HSS, the aromatics could have played a more prominent role in determining the lubricating properties than the paraffin alone. The HPF had the lowest wear, highest VI, and lower PP but higher COF. The volatility and COF predominantly dependent on the cyclic structures, unsaturation, and heteroatoms. The results indicated that the hydrotreated bio-oil from HTL biocrude and waste precursors could be considered as eco-friendly hy-drocarbon biolubricant blend stock.