Branched Bio-Lubricant Base Oil Production through Aldol Condensation

The modification and adoption of biolubricants as alternatives in the automotive industry

Lubricants are pivotal in mitigating friction and wear between surfaces, ensuring seamless movement of solid objects. However, the predominant use of petroleum-based lubricants in the automotive and industrial ssectors raises substantial concerns for future energy security. The exploration of vegetable oils as an alternative lubricant in the automotive industry was motivated by the depletion of fossil fuels and escalating environmental concerns. The post-pandemic surge in environmental awareness has intensified the focus on biolubricants. Over the past two decades, the biolubricants field has burgeoned with numerous research, signaling a heightened interest in eco-friendly and sustainable lubrication solutions. This underscores biolubricants as a dynamic and evolving research area with lasting prominence, especially amid ongoing environmental innovation. The review centrally revolves around naturally sourced lubricants, primarily focusing on vegetable oils, which stand out as appealing substitutes for conventional petroleum-based lubricants due to their biodegradability, high lubricity, and elevated flash points. The article delves into modifications to enhance vegetable oil properties, explores the role of additives, and provides insights into current and future prospects. The paper also investigates diverse applications in engine oil, grease, hydraulic oil, and more.

A Review on the Effect of Metal Oxide Nanoparticles on Tribological Properties of Biolubricants

This review provides a comprehensive and accessible literature review on the integration of nanoparticles into biolubricants to enhance wear and friction regulation, thus improving the overall lubricated system performance. Nanotechnology has significantly impacted various industries, particularly in lubrication. Nanobiolubricants offer promising avenues for enhancing tribological properties. This review focuses on oxide nanoparticles, such as zinc oxide (ZnO), aluminum oxide (Al2O3), copper oxide (CuO), titanium dioxide (TiO2), zirconium dioxide (ZrO2), and graphene oxide (GO) nanoparticles, for their ability to enhance lubricant performance. The impact of nanoparticle concentration on biolubricant properties, including viscosity, viscosity index, flash point temperature, and pour point temperature, is analyzed. The review also addresses potential obstacles and limitations in nanoparticle incorporation, aiming to propose effective strategies for maximizing their benefits. The findings underscore the potential of nanobiolubricants to improve operational efficiency and component lifespan. This review aims to provide valuable insights for researchers, engineers, and professionals in exploring and leveraging nanotechnology's potential in the lubrication industry. This review paper explores the basics of tribology along with its significance, green principles, mechanisms, and energy savings because of friction, wear, and lubrication. Condition monitoring techniques are also explored to achieve brief knowledge about maintaining reliability and safety of the industrial components. Recent advances in tribology including superconductivity, biotribology, high-temperature tribology, tribological simulation, hybrid polymer composite's tribology, and cryogenic tribology are investigated, which gives a thorough idea about the subject.

Synthesis of Long Chain Oxygenates via Aldol Condensation of Furfural and Acetone over Metal-Organic Frameworks

Enormous efforts have been made to convert biomass to liquid fuels and products catalytically. Long molecules with a suitable structure are ideal precursors for fuels and value-added products. Here, a C21 oxygenate was synthesized for the first time in one step through aldol condensation of furfural and acetone over the amine-functionalized zirconium-based metal-organic framework (MOF), UiO-66-NH2. Structural changes of UiO-66-NH2 were investigated to improve the yield and evaluate the role of the ligand, cluster node, defectiveness, modulator, surface area, and textural properties on the product distribution. We demonstrate the possibility of making long-chain oxygenates without using vegetable oil-derived fatty acids toward 100% waste biomass-derived renewable fuels, lubricants, and surfactants.

Site and Structural Requirements for the Dehydra-Decyclization of Cyclic Ethers on ZrO2

In this study, we examined the site and structural requirements for the dehydra-decyclization of cyclic ethers, tetrahydrofuran, and tetrahydropyran to produce conjugated dienes over ZrO2-based catalysts, a reaction that could be an important step in the use of biomass-derived sugars as a starting material to produce monomers for the plastics industry. To help identify the active sites for this reaction, studies were conducted in which ZrO2 surfaces were decorated with Na. These studies showed that Na was effective at poisoning the activity for the ring opening of cyclic ethers, but much less so for the dehydration of the resulting adsorbed alkoxides. The studies of the activity of different types of ZrO2 for the dehydra-decyclization reaction, including single crystals and ultra-thin films supported on MgAl2O4 and silica, also showed that the reaction was dependent on the local structure of the ZrO2 surface. The insights these results provide for identifying the active sites on the ZrO2 surface are discussed.

Accelerating Manufacturing for Biomass Conversion via Integrated Process and Bench Digitalization: A Perspective

We present a perspective for accelerating biomass manufacturing via digitalization. We summarize the challenges for manufacturing and identify areas where digitalization can help. A profound potential in using lignocellulosic biomass...

Selective Hydrogenolysis of Erythritol over Ir-ReOx /Rutile-TiO2 Catalyst

Partial hydrogenolysis of erythritol, which can be produced at large scale by fermentation, to 1,4-butanediol (1,4-BuD) is investigated with Ir-ReO_x /SiO₂ and Ir-ReO_x /rutile-TiO₂ catalysts. In addition to the higher conversion rate over Ir-ReO_x /TiO₂ than over Ir-ReO_x /SiO₂ , which has been also reported for glycerol hydrogenolysis, Ir-ReO_x /TiO₂ showed higher selectivity to 1,4-BuD than Ir-ReO_x /SiO₂ , especially at low conversion levels, leading to high 1,4-BuD productivity of 20 mmol_1,4-BuD  g_Ir ^-1  h^-1 at 373 K (36 % conversion, 33 % selectivity). The productivity based on the noble metal amount is higher than those reported previously, although the maximum yield of 1,4-BuD (23 %) is not higher than the highest reported values. The reactions of various triols, diols and mono-ols are tested and the selectivity and the reaction rates are compared between catalysts and between substrates. The Ir-ReO_x /TiO₂ catalyst showed about twofold higher activity than Ir-ReO_x /SiO₂ in hydrogenolysis of the C-OH bond at the 2- or 3-positions in 1,2- and 1,3-diols, respectively, whereas the hydrogenolysis of C-OH at the 1-position is less promoted by the TiO₂ support. Lowering the loading amount of Ir on TiO₂ (from 4 wt % to 2 or 1 wt %) decreases the Ir-based activity and 1,4-BuD selectivity. Similarly, increasing the loading amount on SiO₂ from 4 wt % to 20 wt % increases the Ir-based activity and 1,4-BuD selectivity, although they remain lower than those for TiO₂ -supported catalyst with 4 wt % Ir. High metal loadings on the support seem to be important.

Synthesis of Branched Biolubricant Base Oil from Oleic Acid

The mature manufacturing of synthetic lubricants (poly-α-olefins, PAO) proceeds through oligomerization, polymerization, and hydrogenation reactions of petrochemical ethylene. In this work, we utilize the inexpensive bio-derived oleic acid as raw material to synthesize a crotch-type C₄₅ biolubricant base oil via a full-carbon chain synthesis without carbon loss. It contains several cascade chemical processes: oxidation of oleic acid to azelaic acid (further esterification to dimethyl azelate) and nonanoic acid (both C₉ chains). The latter is then selectively hydrogenated to nonanol and brominated to the bromo-Grignard reagent. In a next step, a C₄₅ biolubricant base oil is formed by nucleophilic addition (NPA) of excessive C₉ bromo-Grignard reagent with dimethyl azelate, followed by subsequent hydrodeoxygenation. The specific properties of the prepared biolubricant base oil are almost equivalent to those of the commercial lubricant PAO6 (ExxonMobil). This process provides a new promising route for the production of value-added biolubricant base oils.