Bio-based Lubricants Research Articles

Tribological performance of modified jatropha oil containing oil-miscible ionic liquid for machining applications

Modifying physicochemical and tribological properties of a bio-based lubricant is essential in improving its lubrication performances. This paper presents the effectiveness of a fully oil-miscible Ionic liquid (IL) as lubricant additive into a bio-based lubricant. Methyltrioctylammonium bis(trifluoromethylsulfonyl)imide (AIL) was selected as IL additive to improve the tribological performance of the biobased lubricant. Additive was mixed into the bio-based lubricant at three levels of mass concentrations (1 wt.%, 5 wt.% & 10 wt.%). Tribology tests on steel/steel contacts were conducted to evaluate the lubricant samples. Test outputs were benchmarked against the neat bio-based lubricant. Results revealed good synergistic effect of the AIL additive blended into the bio-based lubricant. MJO+AIL10 % has shown good corrosion inhibition, superior friction reduction (48 %), lower worn surface area (23 %), excellent surface finish (46 %) and increased tapping torque efficiency (8 %). MJO+AIL10 % provided excellent tribological performances which corresponds to the energy saving and environmental benefit for sustainable machining applications.

Sustainability of polanga oil based blended lubricant at different load and sliding distance

ABSTRACTDisposal of lubricants after use creates problem to the environment as they are non-biodegradable and also produce toxic elements during emission from the vehicle. There is a worldwide demand for a bio-based lubricant that should be non-toxic, environmentally friendly, and biodegradable. In this study, the tribological performance of the polanga oil-based lubricant has been carried out by using pin-on-disc tribometer. SAE2040-grade mineral oil was blended with polanga oil in the 15, 30, and 50% by volume. The applied loads were 50, 100, and 150 N. The sliding velocity of the disc was 3.8 m/s at each applied load. Lubrication regime that occurred during the test was boundary lubrication, and the wear obtained was abrasive and adhesive in nature. 15% blend of polanga oil shows minimum wear among all the blends. Moreover, the addition of 15% blend reduced friction between the sliding surfaces in contact.

Performance of modified jatropha oil in combination with hexagonal boron nitride particles as a bio-based lubricant for green machining

Abstract This study evaluates the machining performance of newly developed modified jatropha oils (MJO1, MJO3 and MJO5), both with and without hexagonal boron nitride (hBN) particles (ranging between 0.05 and 0.5 wt%) during turning of AISI 1045 using minimum quantity lubrication (MQL). The experimental results indicated that, viscosity improved with the increase in MJOs molar ratio and hBN concentration. Excellent tribological behaviours is found to correlated with a better machining performance were achieved by MJO5a with 0.05 wt%. The MJO5a sample showed the lowest values of cutting force, cutting temperature and surface roughness, with a prolonged tool life and less tool wear, qualifying itself to be a potential alternative to the synthetic ester, with regard to the environmental concern.

Development and tribological characteristics of bio-based lubricant from Jatropha curcas oil

ABSTRACTThis paper outlines the tribological characteristics of Jatropha oil (JO)-contaminated bio-lubricant by using a pin-on-disc tribometer. To formulate the bio-lubricants, JO was blended at the ratios 15, 30, and 50% by volume with the base lubricant SAE 20 W 40. The tribological characteristics of these blends were carried out at 3.8 m/s sliding velocity and 50, 100, and 150 N load were applied. Experimental results showed that the lubrication regime that occurred during the test was boundary lubrication whereas the main wear mechanisms were abrasive and adhesive wear. During testing, the lowest wear was found with the addition of 15% JO, and above this contamination, the wear rate was increased considerably. With increase in load, viscosity of all the bio-lubricants increases and meets the ISO VG 100 requirement at 40°C except for JB 50. The addition of JO in the base lubricant acted as a very good lubricant additive, which reduced the friction and wear scar diameter during the test. It has been concluded that JB 15 can act as an alternative lubricant to increase the mechanical efficiency at 3.8 m/s sliding velocity and contribute in reducing the dependence on petroleum-based products.

Antiwear Behavior of CuO Nanoparticles as Additive in Bio-Based Lubricant

This work presents and discusses the anitwear characteristics of surface modified CuO nanoparticle suspensions in bio-based lubricant. 1.0 wt% unmodified as well as surface modified CuO nanoparticles (nominal size of 50 nm), were dispersed in base oil using an ultrasonic probe. Wear protection was evaluated by using Four-Ball Extreme Pressure (EP) testing and sliding wear tests. The scanning electron microscopy (SEM) and energy dispersive spectrometry (EDS) analysis of the worn surface shows that: surface modification helped to improve the dispersion stability of CuO nanoparticles and related suspension show high EP characteristics in terms of load wear index and low cylinder liner wear due to surface mending effect of nanoparticles.

Synthesis, characterisation and tribological evaluation of surface-capped molybdenum sulphide nanoparticles as efficient antiwear bio-based lubricant additives

PurposeThe purpose of this study is to synthesise and characterise surface-capped molybdenum sulphide (SCMS) nanoparticles using the solvothermal method and to investigate their tribological behaviour towards friction improver and wear reduction for bio-based lubricant oil additives.Design/methodology/approachThe design of the experiment was to use freshly prepared molybdenum (II) acetate, thioacetamide, fatty acid and hexane as the solvent inside an autoclave vessel which is heated at high temperature and pressure. Various types of fatty acids were used as the capping agent, such as caproic, lauric, stearic and oleic acid. The SCMS nanoparticles formed were characterized by Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray diffractometry, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and thermal gravimetric analysis. These nanoadditives were then blended into pentaerythrityl tetracaprylate/caprate ester at 0.05 Wt.% concentration. The formulated bio-based lubricant oil samples were tested for viscosity, viscosity index (VI) and density based on standard method ASTM D445 and ASTM D2270. A four-ball test was carried out for determination of coefficient of friction and wear scar diameter. The wear scar formed on the surface of the ball bearing was analysed using scanning electron microscopy.FindingsThe characterisation results showed that SCMS nanoparticles were successfully formed with amorphous ball-like structure, and the presence of the capping layer surrounding the nanoparticles was confirmed. Then, the formulated bio-based lubricant oil with addition of nanoadditives displays improved tribological properties in term of VI, antifriction and wear reduction.Originality/valueThis research provides a synthesis method of producing SCMS nanoparticles using the organomolybdenum complex as the chemical precursor through the solvothermal reaction approach. Besides that, it also gives an alternative antifriction and antiwear nanoadditive for formulation of the bio-based lubricant oil.

Influence of pore size and loading for Nb2O5/SBA-15 catalysts on synthetic ester production from free fatty acids of castor oil

In this study, the influence of the pore size in mesoporous silica (SBA-15) and the loading of niobium oxide species (Nb2O5) have been evaluated on the esterification reaction of free fatty acids from castor oil to obtain products that can be used as bio-based lubricant feedstocks. Characterization techniques such as XRD, N2 sorption, Raman spectroscopy, NH3-TPD, XPS and TEM have been employed to characterize the synthesized catalysts, demonstrating the high dispersion of the niobia species. The catalytic results showed that the SBA-15 support with an average pore size of 8.5nm and a loading of 12wt.% of Nb2O5 was the best catalyst to obtain higher conversion values in the esterification reaction of ricinoleic acid. This fact was probably due to the pore diameter of this catalyst was the most suitable for the diffusion of reagents and products. The textural properties were more relevant than the acidic properties for Nb2O5 supported on silica catalysts. The reuse data indicated that the conversion values decrease after each cycle probably due to the formation of carbonaceous deposits in the active sites, discarding the niobium leaching which is negligible. The catalytic activity could be almost thoroughly recovered by using a thermal regeneration treatment.

Ionic Liquids: A Plausible Future of Bio-lubricants

This paper reviews the development of bio-lubricants from conventional impeller pressed natural oils to a new class of green bio-lubricants referred to as ionic liquids (ILs) at room temperature. The attraction to bio-lubricants began with natural oils due to their low friction and wear characteristics owing to high lubricity. To better control the tribological behavior, natural oils were introduced to additives, such as lamellar solid powders. Looking to the future, room-temperature IL lubricants derived from biological feedstock are seen as prospective alternatives and solutions to the issues associated with currently available bio-lubricants. Hence, a comprehensive investigation on the tribological properties of novel bio-based IL lubricant is carried out. A simplistic IL feasibility study has also been performed wherein pin-on-disk tests were conducted to analyze the friction and wear behavior under ambient conditions. The ILs demonstrate improved tribological performance when compared to conventional petroleum-based and bio-based lubricants in their purified forms at various levels. The mechanisms concerning the chemical composition of the ILs and their tribological properties imbibed by the bio-lubricants are discussed while highlighting its plausible industrial application.

Chemically active oil filter to develop detergent free bio-based lubrication for diesel engine

In diesel engine lubricants, over-based detergent additives are typically used to neutralize acids. These additives are required for long service life, but their use results in hazardous emissions, which mainly include sulfur and ash content. To address this problem, this study investigates the detergent-free bio-based lubricant conditioning approach by using a chemically active oil filter. A standard filter element impregnated with sodium oxide particles was used to improve lubricant quality. In this research, palm trimethylolpropane ester was synthesized for use as the base oil for formulation of a detergent-free bio-based lubricant. A condition-based approach, in which two engine endurance tests were carried out, was adopted. Lubricant samples from new and engine-aged conditions were tested for viscosity, total acid number, total base number, and corrosion. Piston ring-cylinder sliding tests were conducted to determine the wear protection and friction behavior of lubricant samples. A comparative analysis showed that lubricant conditioning by a modified filter improved the alkaline reserve and controlled the viscosity increase, thus extending the bio-based lubricant service life from 80 h to 200 h. The bio-based lubricant conditioned by a chemically active filter exhibited reduced cylinder liner wear and friction coefficient by 9.2% and 12.9%, respectively.

English

English

Tribological behaviour of modified jatropha oil by mixing hexagonal boron nitride nanoparticles as a bio-based lubricant for machining processes

An increasing concern on environmental and health problems caused by petroleum-based oil leads to the development of environmentally benign metalworking fluids from crude jatropha oil (CJO). Commonly, CJO is commercially utilized in food industry but in this current work, is selected to be used as a base stock due to its renewability and biodegradability. CJO was modified through transesterification processes and mixing with solid lubricant nanoparticle additive, hexagonal boron nitride (hBN) in order to improve the lubrication properties. The lubrication properties of modified jatropha oils (MJOs) as base oil, in comparison with synthetic ester (SE) and CJO were explored. Two types of tribological tests, comprising Four Ball test and tapping torque test were performed. The samples labelled as MJO1, MJO3 and MJO5 were formulated at various molar ratios of jatropha methyl ester (JME) and trimethylolpropane (TMP). These MJOs were blended with various concentrations of hBN particles, ranging from 0.05 to 0.5 wt%. The results obtained indicated that MJO5-base mixed with 0.5 wt% of hBN nanoparticle provided the best physicochemical properties due to lowest thermal expansion coefficient of hBN nanoparticles. High formation of TMP triester in MJO5 formed a strong lubrication film which significantly affected the lubrication and tribological behaviour. MJO5 sample exhibited better friction and wear behaviour by 75% and 20% reduction, respectively, especially when compared to SE. An addition of 0.05 wt% of hBN nanoparticles in MJO5 (MJO5a) was found to reduce the friction and wear up to 76% and 24%, respectively. MJO5a also recorded the highest tapping torque efficiency of 118%. Conclusively, the performance of MJO5a sample has the potential impact on the lubricant market place in regard to the environmental concern and energy saving.

A Review on the Science and Technology of Natural and Synthetic Biolubricants

Bio-based lubricants have gained prominence over conventional petroleum-based oils, progressively over the last two decades as biolubricants. This trend is observed in almost every industry that has been dependent on lubricants and oils irrespective of their applications. Factors that initiated and fueled this trend vary from stringent government regulations over petroleum-based oils to the high passed depletion of oil reserves. But the most concerning factor that has fast-tracked the need for biolubricants is the toxic and harmful effect of used petroleum oils has on the environment and ecological factors. It is estimated that nearly 50% of all lubricants produced are introduced to the environment which has spurred the interest in biolubricants. This review discusses various types of eco-friendly bio-lubrications that will become a sustainable and economical alternative to the conventional petroleum-based lubricants by being sourced from renewable resources. Biolubricants are seen to be feasible and versatile lubricants with higher lubricity, lower volatility, higher shear stability, higher viscosity index, higher load-carrying capacity, and superior detergency and dispersancy when compared to petroleum-based lubricants. The review also investigates in detail the poor thermal-oxidative stability, biological deterioration, their poor solidification at low temperatures, and hydrolytic instability as well as mechanical and chemical enhancements that seek to rectify these issues. Furthermore, economical and legislative landscape of biolubricants is discussed.

Brajendra K. Sharma and Girma Bireshaw (Eds): Environmentally Friendly and Biobased Lubricants

Brajendra K. Sharma and Girma Bireshaw (Eds): Environmentally Friendly and Biobased Lubricants

Dispersion Stability and Tribological Characteristics of TiO2/SiO2 Nanocomposite-Enriched Biobased Lubricant

ABSTRACTThe stable dispersion of nano-additives is highly desirable for the effective lubrication performance of nanolubricants. The compatibility of base oil with selected nano-additives is required for uniform and stable dispersion. This research evaluated the dispersion stability and tribological characteristics of nano-TiO2/SiO2 (average particle size 50 nm) as an additive in a biobased lubricant. The wear protection and friction reducing characteristics of the formulations were evaluated by four-ball extreme pressure tests and piston ring–cylinder liner sliding tests. Surface analysis tools, including scanning electron microscopy, energy-dispersive X-ray spectroscopy, and atomic force microscopy, were used to characterize the worn surfaces. Results showed that the nanolubricants demonstrated appreciable dispersion capability in the absence of a surfactant and an improvement in load-carrying capacity, antiwear behavior, and friction reduction capability.

Friction and wear characteristics of jatropha oil-based biodiesel blended lubricant at different loads

ABSTRACTAround the globe there is demand for the development of bio-based lubricants, which will be biodegradable, nontoxic, and environmental friendly. This paper outlines the friction and wear characteristics of jatropha biodiesel-contaminated bio-lubricant using a pin-on-disc tribometer. To formulate the bio-lubricants, jatropha oil-based biodiesels were blended at the ratios 4, 12, and 20% by volume with the base lubricant SAE 20 W 40. Tribological characteristics of these blends were carried out at 3.8 m/s sliding velocity and loads applied were 50, 100, and 160 N. Experimental results showed that the lubrication regime that occurred during the test was boundary lubrication while the main wear mechanism was adhesive wear. During testing, the lowest wear was found with the addition of 4 and 12% jatropha oil-based biodiesel, and above this contamination, the wear rate was increased considerably. The addition of 4 and 12% jatropha oil-based biodiesel with the base lubricant acted as a very good lubricant additive, which reduced the friction and wear rate diameter during the test. It has been concluded that JBO 4 and JBO 12 can act as an alternative lubricant to increase the mechanical efficiency at 3.8 m/s sliding velocity and contribute to reducing the dependence on petroleum-based products.

Antioxidants from Slow Pyrolysis Bio-Oil of Birch Wood: Application for Biodiesel and Biobased Lubricants

Birch wood was slowly pyrolyzed to produce bio-oil and biochar. Slow pyrolysis conditions including reaction temperature, residence time, and particle size of the feed were optimized to maximize bio-oil yield. Particle size had an insignificant effect, whereas yields of up to 56% were achieved using an optimized reaction temperature of 450 °C and a residence time of 2 h. Bio-oil was also produced from commercial Kraft lignin and was compared to the bio-oil obtained from birch wood. These bio-oils were characterized for elemental composition, phenolic compound identification using GC-MS, boiling point distribution using GC-FID, and molecular weight distribution using GPC. Simulated distillation indicated that a majority of the bio-oil compounds were found in the fraction between 200 and 300 °C, followed by fractions <200 °C and 300–400 °C. Phenolic fractions extracted from bio-oil using an alkali method were evaluated as antioxidant additives in soy biodiesel using Mihaljevic, Rancimat and PDSC test method...

Development of passenger tire treads: reduction in zinc content and utilization of a bio-based lubricant

The present study aimed to characterize and determine the technical viability of using vegetable oil as a lubricant and vulcanization activator with low zinc content in a natural rubber tire tread as additives. These additives were used to replace traditionally used components in the rubber industry. The chemical and thermal characterizations of each alternative additive were performed using thermogravimetric analysis, Fourier transform infrared spectroscopy, and atomic absorption spectrometry. Nine samples were prepared with various vegetable oil contents (3, 4, 6, and 8 parts per hundred of rubber – phr) and vulcanization activators with lower zinc content (2, 3, 4, and 5 phr). The compositions were characterized using rheometry and physico-mechanical analyses. The obtained results were compared to the standard formulation of tire treads using naphthenic oil and zinc oxide. The thermal and chemical characteristics suggest that the vegetable oil has the typical structure of a phenol. The low-zinc-content vulcanization activator has the typical structure of an aromatic zinc carboxylate. The physico-mechanical properties of the samples indicate that the best performance was achieved with 3 phr of the low-zinc-content vulcanization activator and 3 phr of vegetable oil, which reduced the lubricant content by 50% and zinc content by 75% without unfavorably affecting the properties of the final product.

The Effect of Tribology Behavior on Machining Performances When Using Bio-based Lubricant as a Sustainable Metalworking Fluid

Metalworking fluid (MWF) is commonly used to reduce wear and friction, thus improve the machining productivity and quality. However, the usage of conventional MWF made from mineral oil causes negative effects to the ecology and human health. Therefore, it is desirable to formulate a sustainable MWFs as an alternative to petroleum-based oils. The crude jatropha oil was chemically altered via transesterification process of jatropha methyl ester and trimethylolpropane to develop various compositions of modified jatropha oils (MJOs). The orthogonal cutting process was carried out and the lubricants were supplied by using minimum quantity lubrication (MQL) technique. It was observed that the MJO5 exhibits an outstanding performance in terms of wear and friction as well as cutting force and maximum cutting temperature when compared to commercial synthetic ester (SE). This works shows that MJO5 is a viable candidate to replace SE as a machining lubricant.

Tribological Study of a Tetrahedral Diamond-Like Carbon Coating under Vegetable Oil–Based Lubricated Condition

Maintaining a clean environment is the major concern of industries that produce fuel and lubricants for automotive applications. Thus, vegetable-based oils are being explored for the preparation of biobased lubricants because of their biodegradability and nontoxicity. Despite their low thermal stability, vegetable oils show better tribological characteristics than mineral oils. Nonetheless, the thermal stability of vegetable oils could be improved by transesterification. In this study, three vegetable-based oils (sunflower, palm, and coconut) were used to investigate the tribological properties of ta-C diamond-like carbon (DLC) coating under DLC–steel contact condition. A BICERI ball-on-a plate tribotesting machine was used to conduct experiments. During the experiment, test contacts of tribopairs lubricated with sunflower oil exhibited better tribological characteristics than those using coconut oil as a lubricant.

Studies on biodegradability of bio-based lubricants

Vegetable or synthetic lubricants, also called biolubricants, are less harmful to the environment. In order to quantify their biodegradability, some tests are able to predict how long oil/lubricants will take to be degraded in the environment. This study proposes to evaluate the biodegradability of bio-based lubricants using a bio-kinetic model (without microorganisms), comparing their performances with fresh vegetable oil and mineral oil. The results are presented through an Effective Composition for Biodegradation (ECB), half-lives and biodegradation time profile. The synthesized biolubricants showed ECB values closer to vegetable oil than mineral oil. Half-life times are approximately 12 days for fresh vegetable oil, around 20–30 days for the biolubricants, and over 200 days for the mineral oil.