Influence of Microalgal Bio-Oil on the Lubrication Properties of Engine Oil

Abstract

-In order to accelerate and expand the application of bio-energy, two kinds of microalgal bio-oils, prepared via co-liquefaction of Chlorella and Spirulina under sub-and supercritical ethanol conditions, were used as partial substitutes for the engine oil CD SAE 15W-40. The friction and wear behaviors of the oils were tested on a four-ball tribometer, referring to the ASTM D4172 standard conditions. The micro-morphology, profiles, roughness and chemical valences of typical elements on the rubbed surfaces were characterized by Scanning Electron Microscopy (SEM), surface profiler and X-ray Photoelectron Spectroscopy (XPS), respectively. The results showed that both of the bio-oils had good lubrication properties. The suitable weight content of the bio-oils in the engine oil was 10%. The lubrication properties of the Bio-Oil (BO sup ) prepared in supercritical ethanol were a little better than those of the Bio-Oil (BO sub ) prepared in subcritical ethanol. The lubricating mechanisms were ascribed to the combined actions of various lubricating films, including boundary lubrication, and deposited films and tribological chemical reaction films. The stronger tribological chemical effects of BO sup from higher contents of N-containing compounds contributed to its better lubrication properties than those of BO sub .Résumé -Influence de bio-huiles issues d'algues sur les propriétés de lubrification d'une huile moteur -Afin d'accélérer et d'étendre l'application des bioénergies, deux types de bio-huiles issues d'algues, préparées par co-liquéfaction de Chlorella et Spirulina dans de l'éthanol à l'état sous-et supercritiques, ont été utilisés comme substituts partiels de l'huile moteur CD SAE 15W-40. Les comportements d'usure et de frottement avec ces huiles ont été testés sur un tribomètre à quatre billes, en se référant aux conditions de la norme ASTM D4172. La micromorphologie, les profils et la rugosité de surface ainsi que les valences chimiques des éléments typiques sur les surfaces frottées ont été respectivement caractérisés par une microscopie à balayage électronique (SEM, Scanning Electron Microscopy), par un profilomètre de surface et par spectroscopie photo-électronique des rayons X (XPS, X-ray Photoelectron Spectroscopy). Les résultats ont montré que les bio-huiles avaient toutes deux de bonnes propriétés de lubrification. La teneur en poids adaptée des bio-huiles dans l'huile moteur était de 10 %. Les propriétés de lubrification de la bio-huile (BO sup ) préparée dans de l'éthanol supercritique ont été légèrement meilleures que celles de la bio-huile (BO sub ) préparée dans de l'éthanol sous-critique. Les mécanismes de lubrification ont été attribués aux actions combinées de différents films de lubrification (y compris un graissage à film d'huile, et de films de dépôts) et de films de réaction chimique tribologiques. Les effets tribo-chimiques plus forts de l'huile BO sup contenant des teneurs supérieures en composés contenant de l'azote ont contribué à rendre ses propriétés de lubrification supérieur...

Techno-Economic Study of CO2 Capture of a Thermoelectric Plant Using Microalgae (Chlorella vulgaris) for Production of Feedstock for Bioenergy

“…Electric power generating plants, one of the industries with the highest CO 2 emissions, could well consider installing a microalgae cultivation plant at or near their facilities and, thus, feed their effluents both gaseous and wastewater. On the other hand, the biomass obtained (rich in carbohydrates, lipids and proteins) could well be a raw material for the production of bioenergetics, biolubricant oils and other by-products [11,[45][46][47], which can be consumed by themselves or commercialized. These reasons increase the interest in cultivating microalgae as a raw material for obtaining valuable products, providing alternative methods for the use of carbon dioxide emitted by power plants.…”

Synthesis of ZnFe2O4@MoS2 core-shell nanocomposites with enhanced lubrication performance as lubricant additives

“…Three binding energy peaks appeared at 283.9, 284.8 and 285.9 eV in the C1s XPS spectrum, corresponding to C = C, C-C(C-H) and C-O bonds (Yu et al , 2013; Li et al , 2020), and their proportions were 5.9%, 83.3% and 10.8%, respectively, mainly derived from hydrocarbons in the base oil. For the Fe 2p spectrum, it consists of four peaks corresponding to Fe 2 O 3 (711.22 and 724.74 eV, accounted for 51.6% and 24.7%, respectively) and FeS (707.4 and 720.43 eV, accounted for 13.9% and 9.8%, respectively) (Xu et al , 2016). In general, the area ratio of each characteristic peak represents the relative content of the corresponding chemical composition.…”

Preparation of graphene and its tribological properties based on deep eutectic solvent stripping method

“…For the O1s spectrum Fig. 14c, three binding energy peaks were identified at positions corresponding to FeO (529.28 eV), Fe2O3 (531.18 eV), and C=O (532.68 eV) [35] . These findings suggest that oxidation of the Fe element occurred during the friction process.…”