Mineral Engine Oil Research Articles

Reduction of CO2 Emissions and Cost Analysis of Ultra-Low Viscosity Engine Oil

This study is focused on the reduction of CO2 emissions and costs associated with ultra-low viscosity (ULV) engine oils for passenger vehicles. Specifically, the reduction in life cycle CO2 (LCCO2) emissions from lower-viscosity engine oil and the oil drain interval (ODI) extension were estimated taking into account both mineral engine oil and synthetic engine oil. Furthermore, the cost-effectiveness of ULV engine oils were investigated by performing base-stock cost analysis. When the volatility limit of the Noack test (American Society for testing and materials (ASTM) D5800) was set to 15 wt %, the results indicated that the lower limit of kinematic viscosity at 100 °C (KV100) for mineral engine oil (with Group-III base-stock) and synthetic engine oil (with polyalphaolefin (PAO) base-stock) were approximately 5.3 and 4.5 mm2/s, respectively. Compared to conventional 0W-16 mineral engine oil (KV100 6.2 mm2/s), the effect of reducing LCCO2 emissions on ULV mineral engine oil (ULV-Mineral, KV100 5.3 mm2/s) was estimated at 0.6%, considering 1.5–1.8 L gasoline engines in New European Driving Cycles (NEDC) mode. ULV-Mineral, which continues to use a mineral base-stock, is considered highly cost-effective since its cost is similar to the conventional 0W-16 mineral engine oil. On the other hand, compared with ULV-Mineral, the vehicle fuel efficiency improvement from the use of ULV synthetic engine oil (ULV-PAO, KV100 4.5 mm2/s) was estimated to be 0.5%. However, considering CO2 emissions during engine oil production, the reduction of LCCO2 emission from ULV-PAO compared with ULV-Mineral was estimated to be only 0.1% or less using 2030 standards (assuming a vehicle fuel efficiency of 66.5 g-CO2/km) when ODI is set equivalent (7500 km) to mineral engine oil. As a result, ULV-PAO’s cost-effectiveness, considering the cost increase of PAO base-stock, was found to be nominal. Contrariwise, when the characteristics of PAO base-stock with higher oxidation stability are used comparatively with the mineral base-stock while extending the ODI to 15,000 km, the effect of reducing LCCO2 emissions of ULV-PAO was estimated to be 0.7% in 2030, making ULV-PAO a competitive and cost-effective alternative. In other words, the popularization of synthetic engine oil toward 2030 will require the consideration of both viscosity reduction and ODI extension.

Solubility analysis of elastomers in a bio-based lubricant using Hansen parameters

The solubility of automotive elastomers, namely, silicone rubber (VMQ), flouroelastomer (FKM) and ethylene-propylene-diene monomer (EPDM) in Jatropha bio-based lubricant (bio-oil), an engine mineral oil (EMO) and a blend of the bio-oil with EMO, respectively, was analyzed by using the Hansen solubility method. In addition, an experimental compatibility analysis, consisting on standard immersion tests and measurements of changes in mass, volume, hardness and tensile and tear strengths, was conducted to complement and validate the results obtained using the Hansen method. The Hansen method was found to be in good agreement with the compatibility tests and provided an appropiate description of the dissolution/degradation behavior of the seals upon exposure to the lubricants. Finally, it was found that FKM was the most compatible in the three lubricants, while EPDM was very prone to dissolution/degradation in EMO and B20, and VMQ in the bio-oil.

Investigation of Hazard Potential of Oil Industry Wastes and Products for Better Management Practices

AbstractPolychlorinated biphenyl (PCB), metal, and chlorine contents of samples—including waste mineral oil, engine oil, edible oil, oily waste (industrial/domestic), and number 10 lube (NTL)—were ...

Physical and Tribological Properties Degradation of Silicone Rubber Using Jatropha Biolubricant

ABSTRACT This article aims to investigate the degradation of physical and tribological properties (friction coefficients and wear resistance) of a dynamic sealing material (silicone rubber [VMQ]) exposed to Jatropha oil (JO), engine mineral oil (EMO), and a blend (B20; 80% EMO–20% JO), separately. JO has demonstrated better lubricating properties than EMO in various mechanical applications; however, the degradation of elastomers by using this oil has not been studied yet, nor have its effect on their tribological properties. The physical degradation was evaluated by conducting static immersion tests (670 h at 25 °C) based on ASTM-D471 and ASTM-D7216 methods. Hence, the changes in mass, volume, tensile and tear strengths, and hardness of VMQ were measured. In addition, creep compliance tests were conducted to determine the changes in viscoelastic properties and the changes in morphology and topography were measured by scanning electron microscopy (SEM) and optical profilometry, respectively. In addition, the compositional changes were determined by Fourier transform infrared (FTIR) analyses to complement the degradation examination. Changes in the friction coefficients were determined by ball-on-disk tests and changes in wear resistance were obtained by accelerated wear tests (microabrasion tests). Finally, VMQ exhibited no significant physical and compositional degradation due to immersion in the three lubricants. However, considerable changes in the friction coefficients and wear resistance were observed; the change in the friction coefficients was minimal using JO. In addition, the coefficients using JO were 50% lower than those for EMO and the changes in wear resistance were lowest after immersion in JO.

Compatibility study of common sealing elastomers with a biolubricant (Jatropha oil)

Vegetable oils are potential alternative lubricants for the twofold purpose of achieving good tribological properties while protecting the environment. However, any intended use of bio-lubricants in machinery requires of a previous study of their compatibility with the involved sealing materials. In particular, Jatropha oil (JO) is inexpensive and easy to obtain, which make it a good candidate to be used as bio-lubricant in machinery. In this work, a compatibility study of four commercial sealing elastomers, namely, fluoroelastomer (FKM), silicone rubber (VMQ), neoprene/chloroprene (CR), and ethylene-propylene-diene monomer (EPDM) with JO, engine mineral oil (EMO) and a blend of EMO and JO (80-20%) (B20), for the purpose of comparison, was conducted. The analyses include the basic measurements comprised in the ASTM-D471 and ASTM-D7216 methods, namely, changes in mass, volume, tensile and tear resistance and hardness. In addition, non-standard measurements of creep compliance, surface morphology and topography, and chemical composition were performed to achieve a deeper evaluation of the interaction of JO with the elastomers. In general, good compatibility was found regarding the standard methods for the four elastomers with JO, VMQ being the most compatible sealing material. However, FKM, CR and EPDM showed changes in the creep compliance modulus and surface morphology when in contact with the three lubricants, which may considerably affect their sealing performance and decrease their useful life. Overall, pure JO generated much less physical changes on the elastomers than EMO and B20, which can be ascribed to the concentrations of free fatty acids contained in JO.

Friction and wear response of vegetable oils and their blends with mineral engine oil in a reciprocating sliding contact at severe contact conditions

Although many studies investigating the tribological performance of pure vegetable oils have been conducted, a better understanding of vegetable oil tribological performance at extreme conditions is still needed. Similarly, little work has been carried out to study the influence of the vegetable oils on the performance of a lubricant formed from a blend of vegetable oil and conventional mineral engine oil. This work presents the tribological performance of vegetable oils, and their blends with mineral oil, in a high temperature and contact pressure reciprocating contact. Palm- and soybean-based vegetable oils were mixed with a commercial mineral engine oil at a 1:1 ratio by volume. The conventional mineral oil was also tested to provide a benchmark. The pure palm oil exhibited lower friction than soybean oil, but for the wear performance, this was reversed. The friction performance of the palm oil was competitive to that of the mineral engine oil. The mineral engine oil was far superior in wear resistance over both vegetable oils. When blended with mineral engine oil, both vegetable oils demonstrated a reduction in coefficient of friction when compared to their pure oil states. An improvement in the wear performance was observed for both a blend of palm oil and mineral engine oil (25% improvement) and that of soybean and mineral engine oil (27% improvement). This work shows that for palm oil and soybean oil, the performance of a blended oil is influenced by its vegetable oil component and that tribological characteristics of vegetable oils are dominant. That said, the significant limitation of these vegetable oils is their ability to provide a satisfactory level of wear resistance. It is suggested that any future work in this area should have a greater emphasis on the enhancement of wear resistance.

Application of FTIR Spectrometry Using Multivariate Analysis for Prediction Fuel in Engine Oil

This work presents the potentiality of partial least squares (PLS) regression associated with Fourier transform infrared spectroscopy (FTIR spectrometry) for detecting penetration of diesel fuel into the mineral engine oil SAE 15W‑40 in the concentration range from 0 % to 9.5 % (w/w). As a best practice has proven FTIR‑PLS model, which uses the data file in the spectral range 835 – 688 cm−1.The quality of the model was evaluated using the root mean square error of calibration (RMSEC) and cross validation (RMSECV). A correlation coefficient R = 0.999 and values of RMSEC, RMSECV were obtained 0.11 % and 0.38 % respectively. After the calibration of the FTIR spectrometer, the contamination engine oil with diesel fuel could be obtained in 1 – 2 min per sample.

Friction and Wear Phenomena of Vegetable Oil–Based Lubricants with Additives at Severe Sliding Wear Conditions

ABSTRACTThe tribological responses of palm oil and soybean oil, combined with two commercial antiwear additives (zinc dialkyl dithiophosphate and boron compound), were investigated at a lubricant temperature of 100°C and under severe contact conditions in a reciprocating sliding contact. The friction coefficient of palm oil with zinc dialkyl dithiophosphate was closest to the commercial mineral engine oil, with a 2% difference. The soybean oil with zinc dialkyl dithiophosphate produced a 57% improvement in wear resistance compared to its pure oil state. The existence of boron nitride in vegetable oils was only responsive in reduction of wear rather than friction. The response of commercial antiwear additives with vegetable oils showed a potential for the future improvement in the performance of vegetable oils.

Correlation Study of Physicochemical, Rheological, and Tribological Parameters of Engine Oils

The physicochemical and tribological studies of mineral and synthetic commercial engine oils have been carried out to investigate their performance variability and to propose generalized relationship among different physicochemical and performance parameters. Physicochemical parameters have been determined using standard test procedures proposed in ASTM and Indian Standards (BIS). The rheological parameters of these lubricants have been investigated to identify the flow behavior. The tribological performance in terms of their antifriction and antiwear properties has been studied using four-ball tribotester. Correlation and regression analysis has been performed to ascertain relationship among physicochemical and tribological parameters and the causes of performance variability are highlighted. An empirical relation to calculate coefficient of friction as a function of physicochemical properties has been established using regression analysis. The developed relation has fair degree of reliability, as percentage of deviation is less than 20%.

Tribochemical processes in engine oil with copper nanoparticles and azomethine ligand

The tribochemical processes in SAE 10W40 engine mineral oil with complexing compound and dioctylphtalate have been studied. A tribofilm that reduces the coefficient of friction is found to be formed on the friction surfaces; it is probed via optical and scanning electron microscopy, FTIR infrared spectroscopy, and X-Ray fluorescence and is established to be composed of copper covering the steel surface and a tribopolymer film. The effect of tribochemical processes with involving the steel surface, copper nanopowder, ligands, coordination compounds, and complex ether in the formation of a tribofilm has also been elucidated.

Effect of Addition of Tertiary-Butyl Hydroquinone into Palm Oil to Reduce Wear and Friction Using Four-Ball Tribotester

ABSTRACTReplacing mineral oil with vegetable oils as lubricants continues to attract interest due to their environmentally friendly characteristics and ease of disposal. However, one disadvantage can be low thermal oxidative stability. The purpose of our research is to investigate the ways in which oxidation can be contained by combining palm oil with a phenolic antioxidant. A homogeneous mix of palm oil and tertiary-butyl hydroquinone was found to exhibit satisfactory antioxidant properties and reduce wear and friction. Superior mineral engine oil was used to benchmark the performance.

The Use of Tertiary-Butyl-Hydroquinone (TBHQ) in Minimizing Oxidation Effects on Palm Oil Based Lubricant Using Four Ball Tribotester

The extended uses of mineral oil based lubricant have continuously troubling the global environment issues. The remaining mineral oil resources also being the most debated issues in renewable energy conferences. Vegetable oils are still offering the highest possibility in replacing the mineral oil resources. This research is concerning on how to eliminate one of the disabilities found in palm oil based lubricant which is oxidation. Palm oil possessed unsaturated double bond in which susceptible to oxidation process. The simplest approach is to blend the palm oil based with anti – oxidant agent homogenously. This research was conducted using double fractionated palm oil (SPL) as lubricant and Tertiary-Butyl-Hydroquinone (TBHQ) as anti – oxidant agent to determine the tribology behavior including the coefficient of friction, wear scar diameter and the surface roughness profile. The experiment was also conducted using four-ball tribotester by following ASTM D4172B standard. Superior Mineral Engine Oil (EO) was used as comparison. The results found that SPL+TBHQ was able to reduce the coefficient of friction and provided lower surface roughness value. However it was unable to minimize the mean wear scar diameter compared to EO. The physical appearances of wear worn are also being observed in this research.

The mechanisms of tribological wear in lubricated sliding bearings composed of soft bearing alloys with borided steel

In this study, we investigated the wear behavior of borided ISO C45 carbon steel and SAE-48, SAE-783 soft bearing alloys. Boriding was carried out in powder-pack processes at temperature of 950 ℃ for 8 h. High-lead alloy SAE-48 and aluminum alloy SAE-783 was used on low carbon steel. Sliding pairs under the examination were lubricated with 15 W/40 Lotos mineral engine oil. The wear behaviors of borided steel and SAE-48, SAE-783 alloys were characterized by using block-on-ring tester. The testing loads were 0.5 kN, 1.0 kN, 1.5 kN, 2.0 kN, respectively. The linear speed between the couples was 0.2 m/s. The linear speed between the couples was 0.2 m/s. The distance of friction was 100 m. Examinations performed with X-ray diffractometer revealed Fe2B, FeB phases in the borided layer. Scanning electron microscope equipped with energy-dispersive X-ray spectrometer on the cross section of the borided layer revealed columnar crystals of Fe2B phase. The soft bearing alloy SAE-48 showed from 3.3 to 4.5 greater linear wear than SAE-783 alloy. The examined pairs showed abrasive and adhesive wear. The abrasive wear was dominant in the pair with SAE-783 bearing alloy. The adhesive wear was dominant in the pair with the SAE-48 bearing alloy. At the loads of 1.0 kN, 1.5 kN, and 2.0 kN the temperature of the SAE-48 bearing alloy was about 20 ℃ greater than the temperature of the SAE-783 bearing alloy. After the tribological tests the SAE-48 alloy showed greater roughness as compared with the SAE-783 alloy. When combining borided steel with a soft bearing alloy it is recommended to use aluminum-based alloy.

Distribution of Hydrodynamic Pressure in Slide Bearings Applying Lubricants of Different Viscosity

The paper presents the results of tests on the distribution of hydrodynamic pressure in relation to the viscosity of a lubricant, the rotational speed of a journal and bearing load. Two different lubricants were selected for taking tests: base oil SN-150 and mineral engine oil. The distribution of hydrodynamic pressure was determined employing a device constructed for this particular purpose. It has been proved that the type of the lubricant, bearing load and, to a lesser extent, the rotational speed of the journal affect the distribution of hydrodynamic pressure.

Study of Rheological Properties of Industrial Lubricants

The most important rheological parameter for lubricants is viscosity as it also affects the tribological properties like friction between interacting surfaces and wear. This research intends to study the relationship between viscosity and temperature at different shear rates for multiple grades of three different categories of lubricants used for different applications viz. L1: MG20W50 (engine oil), L2: SAE20W50 (engine oil), L3: MC20W50 (mineral engine oil), L4: EP90 (gear oil), and L5: DXTIII (steering fluid). Constant high dynamic viscosity, shear stress, and low compressibility at different temperatures in multigrade as well as single grade industrial oil will help to maintain the surface film over the period of time and hence the reduction in wear. The dynamic viscosity of these chosen samples has been measured experimentally in temperature range of 20 to 50°C. The measurements have been extended to observe the dependence of shear rate, time, and temperature on the dynamic viscosity. All the samples are observed to behave like Newtonian fluids in the entire temperature range of study. Further, all samples seem to obey the Arrhenius relationship with temperature. Shear stress shows linear variation with shear rate exhibiting uniform viscosity which is substantiated by almost no variation in dynamic viscosity with shear rate for value above 5 per second.

Temperature Dependency of Ceramic Nanofluids Shows Classical Behavior

P RESENTLY, nanofluids are among the most intensively investigated options to enhance heat transfer [1–3]. Here, we understand nanofluids as liquids inwhich particleswith sizes ranging from about 10 to 200 nm are suspended in a base fluid. Particle materials are either pure metals (Au, Ag, Cu, etc.), oxide ceramics (Al2O3, CuO, SiO2, etc.), or nonmetals (e.g., diamond and carbon nanotubes). The base fluid is mainly water, but several studies with ethylene glycol, toluene, mineral engine oil, and others were also carried out (see, e.g., [4,5]). The general expectation of nanofluids is that their thermal conductivity is significantly higher than that of the base fluid. However, two main streams of results are currently reported in the literature. Although a large number of publications (e.g., [1–3,6,7]) support an extraordinary enhancement going beyond the classical theory by Maxwell [8], several more recent papers show an agreement with the classical view [9–11]. The situation is obviously especially difficult because, so far, a satisfactory theory does not exist, and a sufficient number of experiments have not been carried out that could explain all phenomena observed. However, it must be assumed that a nonlinear dependency exists of the thermal conductivity of a nanofluid and the particle size [12], the volume fraction [6], the particle shape [13], and the temperature. Here, we will focus on one given particle size and one given particle shape and investigate the dependency on the temperature alone. This strategy limits the number of relevant parameters and allows to draw firm conclusions. For the practical application of nanofluids, the knowledge of thermophysical properties such as viscosity, density, thermal conductivity, and their variationswith temperature is essential. However, it is still not currently possible to calculate these properties from scratch knowing only the thermodynamic properties of basefluid and particles, volume fraction, and geometry of nanoparticles and other physical and chemical properties that constitute the characteristics of a nanofluid. Therefore, it is still a matter of measurements to provide thermophysical properties as the base for heat transfer and other applications. The scope of the present work is to experimentally determine the thermal conductivity of three water-based nanofluids with ceramic particles in a temperature range between 20 and 60 C. For that purpose, a special static measurement devicewas developed. Numerical simulations and preliminary experiments were undertaken to make sure that no disturbing effects like convection and sedimentation contaminate the measurements and that the probe is properly calibrated. However, the study focuses primarily on the question of whether or not the thermal conductivity over the mentioned temperature range shows classical behavior, as proposed by Eapen et al. [10].

TRIBOLOGICAL PROPERTIES OF SURFACE LAYER WITH BORON IN FRICTION PAIRS

The aim of the present work is to determine the influence of technologically produced boron surface layers on the friction parameters in the sliding pairs under the conditions of mixed friction. The tribological evaluation included ion nitrided, pack borided, laser borided, quenched and tempered surface layers and TiB2 coating deposited on 38CrAlMo5-10 , 46Cr2 and 30MnB4 steels. Modified surface layers of annular samples were matched under test conditions with counter-sample made from AlSn20 bearing alloy. Tested sliding pairs were lubricated with 15 W/40 Lotos mineral engine oil. The tribological tests were conducted on a T-05 block on ring tester. The applied steel surface layer modification with boron allows surface layers to be created with pre-determined tribological characteristics required for the elements of kinematic pairs operating in the conditions of sliding friction. Pack boronizing reduces the friction coefficient during the start-up of the frictional pair and the maximum start-up resistance level is similar to the levels of pairs with nitrided surface layers.

Experimental study of the effect of additive on the tribological properties journal bearing under running‐in and start‐up or shut‐down stages

PurposeThe purpose of this paper is to study the effects of additive on the tribological properties such as friction coefficient and wear loss in the journal bearings during start‐up (or shut‐down) and running‐in periods.Design/methodology/approachIn this study, fully formulated commercial engine mineral oil (SAE 20W50) and commercial oil additives (3 per cent) added into this oil were tested to determine the tribological performances such as friction coefficient, wear loss and the effect of the additive on protective layers formed on the sliding bearing's surfaces.FindingsThis study presents an experimental procedure for obtaining practical results pertaining to the tribological performance of the journal bearing under running‐in and start‐up or shut down stages. Also, in this study, the authors have attempted to show the linkage between the oil additive and the running conditions such as running‐in and start‐up and shut‐down in effecting performance of the journal bearing. It is well known that one of the roles of an additive is to form a protective layer to reduce friction coefficient in lubricated contacts.Originality/valueThe paper is of value in presenting an experimental procedure for obtaining practical results pertaining to the tribological performance of the journal bearing under running‐in and start‐up or shut down stages.

Hydrogen degradation of structural steels in technical hydrocarbon liquids

AbstractHydrogen absorption, mechanical testing under different loading mode and electrochemical measurement were done for 0.3C low alloy steels used in the ship engine parts at immersion in the boiler fuel and in the used engine mineral oil at elevated temperatures corresponding to the operating conditions. The hydrogen charging of steels has been found to reach a level causing their plasticity loss. No effect, a plasticity loss and a significant decrease in the number of cycles have been stated in constant load, slow strain rate and fatigue tests, respectively. The results showed the local active plastic deformation proceeded close to the surface of hydrogen ingress to provide the highest possibility for hydrogen induced metal degradation in hydrocarbon environments. Although the source of hydrogen evolved in the case of technical hydrocarbons has been discussed, the promoting effect of formed H2S should be recognized as the important factor influencing the hydrogen charging from those environments. Some variation in the steel microstructure, chemical composition and hardness of steels, even allowed by the standard may affect their susceptibility to hydrogen degradation in hydrocarbons.

Transition of Friction and Wear by Stick-Slip Phenomenon in Various Environments under Fretting Conditions

The fretting wear arises when contacting surfaces undergo oscillatory tangential displacement of small amplitude. Depending on the degree of stick and slip there are three kinds of the contact motions, such as gross-slip, partial-slip and stick-slip. The fretting damage occurs most severely when the transition from gross-slip to partial-slip happens. In this paper, the transitions of friction and wear under fretting were investigated by ball-on-disk wear tests in various environments, which were dry friction of air and nitrogen, and wet friction of mineral oil and engine oil. The transition from partial-slip to stick-slip firstly occurred in nitrogen environment, and then in air. Later, the transition occurred at higher load in mineral oil, and then lastly in engine oil.