Tribological behavior of pongamia oil-based biodiesel blended lubricant at different loads

Around the globe there is a demand for the development of bio-based lubricants that are biodegradable, non-toxic, and environmentally friendly. This paper outlines the friction and wear characteristics of pongamia biodiesel contaminated bio-lubricant using a pin-on-disc tribometer. To formulate the bio-lubricants, pongamia oil-based biodiesel was blended in ratios of 5, 10, and 20% by volume with the base lubricant SAE 20W40. The tribological characteristics of these blends were carried out at 2.5 m/s sliding velocity and the loads applied were 50, 100, and 150 N. Experimental results showed that the lubrication regime present during the test was boundary lubrication, while the main wear mechanism was adhesive wear. During testing, the least wear was found with the addition of 5 and 10% pongamia oil-based biodiesel, and above this level of contamination the wear rate increased considerably. The addition of 5 and 10% pongamia oil-based biodiesel with the base lubricant represents a very good lubricant additive which reduced the friction and wear rate during the test. It has been concluded that both PBO 5 and PBO 10 can act as an alternative lubricant to increase mechanical efficiency at 2.5 m/s sliding velocity and contribute to the reduction of dependence on petroleum-based products.     

Tribological behavior of pongamia oil as a lubricant additive

This study assesses the friction and wear characteristics of a pongamia oil-contaminated bio-lubricant by using a pin-on-disc tribometer. To formulate the bio-lubricants, pongamia oil was blended in the ratios of 15, 30, and 50% by volume with the base lubricant SAE 20 W 40. Tribological characteristics of these blends were obtained at 1.3 and 2.5 m/s sliding velocity and the load was 150 N. Experimental results showed that the lubrication regime that occurred during the test was boundary lubrication while the main wear mechanisms were abrasive and the adhesive wear. During testing, the lowest wear was found with the addition of 15% pongamia oil, and above this contamination, the wear rate was increased considerably. With an increase in load, the viscosity of all the bio-lubricants increases and meets the International Standard Organization (ISO) VG 100 requirement at 40°C except PB 50. The addition of pongamia oil 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 the PB 15 can act as an alternative lubricant to increase the mechanical efficiency and contribute to reduction of dependence on the petroleum-based products.     

Comparative tribological investigation on EN31 with pongamia and jatropha as lubricant additives

The friction and wear experiments on EN31 are carried out with blends of pongamia (Pongamia pinnata) and jatropha (Jatropha curcas) with mineral oil and also conventional petroleum oil using a pin-on-disc tribometer at various loads and sliding distances. A significant drop is observed with 15% addition of pongamia and jatropha in comparison to mineral oil, for the complete tested sliding distances and loads, leading to the potential use of vegetable oil in tribological applications. To understand the lubrication regimes, a Stribeck curve is also drawn. Both pongamia and jatropha having 15% addition showed a reduction in the boundary lubrication regimes, contributing to a former start of full film lubrication.     

Development of engine oil using palm oil as a base stock for four-stroke engines

The use of palm oil as a base stock for an environmentally friendly lubricant for small four-stroke motorcycle engines is investigated. Palm oil was blended with mineral oil at different compositions to the viscosity requirement of commercial lubricant. A liquid additive package was added to improve the viscosity of the lubricant. A blend that meets the viscosity requirement was then chosen for physical and chemical property characterization and subjected to an engine test. The blend consists of 50.6% (wt.) palm oil, 41.6% mineral oil, and 7.8% additive package. The properties evaluated include viscosity, viscosity index, flash point, foaming characteristics, and wear scar. The engine performance and emission tests were carried out with a 125-cc motorcycle on a chassis dynamometer using a Bangkok Driving Cycle. Compared to a mineral-based commercial oil, the palm oil-based lubricant exhibits superior tribological properties, but offers no clear advantage on engine and emission performance.     

活塞环-气缸套纳米润滑油强化传热的机理研究

内燃机活塞环-气缸套之间润滑油膜存在流体润滑、薄膜润滑以及干摩擦状态共存的现象。针对其中的流体润滑状态,采用Euler-Lagrange算法考察了加入纳米颗粒后对基础润滑油传热性能的影响。结果表明,由于纳米颗粒的加入对流场产生扰动,表现为速度边界层减薄,加速了润滑油与壁面热量传递过程,显著提高了润滑油的换热能力。以体积分数为0.5%、1.0%和1.5%、粒径为50nm的金刚石纳米润滑油为例,相对于基础润滑油,平均对流传热系数分别提高了2.5%、5.4%和7.3%。     

Tribological behavior of diesel/biodiesel blend from waste cooking oil and ethanol

One kind of novel biodiesel waste cooking oil ethyl ester (WCOEE) was prepared via transesterfication reaction between waste cooking oil and ethanol. The tribological behavior of diesel/WCOEE blend was evaluated with a four-ball tribometer. The wear resistance, extreme pressure, and friction reduction of the blend were improved with increasing WCOEE. The optimal content of WCOEE in the blend was 20 vol%. It was also found that free fatty acids (FFAs) had a positive effect on the wear resistance of blend. The lubrication improvement of the blend was ascribed to the formation of polyester film and high polarity of fatty acid ethyl ester.     

Greenhouse gas emissions and energy balances of jatropha biodiesel as an alternative fuel in Tanzania

This paper evaluates GHG emissions and energy balances (i.e. net energy value (NEV), net renewable energy value (NREV) and net energy ratio (NER)) of jatropha biodiesel as an alternative fuel in Tanzania by using life cycle assessment (LCA) approach. The functional unit (FU) was defined as 1 tonne (t) of combusted jatropha biodiesel. The findings of the study prove wrong the notion that biofuels are carbon neutral, thus can mitigate climate change. A net GHG equivalent emission of about 848 kg t⁻¹ was observed. The processes which account significantly to GHG emissions are the end use of biodiesel (about 82%) followed by farming of jatropha for about 13%. Sensitivity analysis indicates that replacing diesel with biodiesel in irrigation of jatropha farms decreases the net GHG emissions by 7.7% while avoiding irrigation may reduce net GHG emissions by 12%. About 22.0 GJ of energy is consumed to produce 1 t of biodiesel. Biodiesel conversion found to be a major energy consuming process (about 64.7%) followed by jatropha farming for about 30.4% of total energy. The NEV is 19.2 GJ t⁻¹, indicating significant energy gain of jatropha biodiesel. The NREV is 23.1 GJ t⁻¹ while NER is 2.3; the two values indicate that large amount of fossil energy is used to produce biodiesel. The results of the study are meant to inform stakeholders and policy makers in the bioenergy sector.     

Mechanistic study on spraying of blended biodiesel using phase Doppler anemometry

Droplet size and dynamics of blended palm oil-based fatty acid methyl ester (FAME) and diesel oil spray were mechanistically investigated using a phase Doppler anemometry. A two-fluid atomizer was applied for dispersing viscous blends of blended biodiesel oil with designated flow rates. It was experimentally found that the atomizer could generate a spray with large droplets with Sauter mean diameters of ca. 30 μm at low air injection pressure. Such large droplets traveled with a low velocity along their trajectory after emerging from the nozzle tip. The viscosity of blended biodiesel could significantly affect the atomizing process, resulting in the controlled droplet size distribution. Blended biodiesel with a certain fraction of palm oil-based FAME would be consistently atomized owing to its low viscosity. However, the viscosity could exert only a small effect on the droplet velocity profile with the air injection pressure higher than 0.2 MPa.     

Assessment of tree seed oil biodiesel: A comparative review based on biodiesel of a locally available tree seed

The present investigation is undertaken to investigate prospect of seeds of a locally available tree (koroch) for biodiesel production. The middle-size, evergreen koroch tree with spreading branches are available in Assam. The characteristics of koroch biodiesel and engine performance fueled by koroch biodiesel are also analyzed reviewing similar results available in the literature so as to ascertain its status. Twelve number of different tree seed oils, reported earlier, are considered for making the present comparative assessment. Though transesterification has been the common process for converting tree seed oil into biodiesel, as evidenced from the literature consulted in this study, but there have been variations of the chemical processes. Variations of the transesterification are attributed to (i) types of catalysis viz., acid (H₂SO₄) or base (KOH, NaOH, and NaOCH₃), (ii) reaction temperature, (iii) molar ratio, (iv) nature of reaction viz., single stage or multi-stage. The outputs of the reaction have also been found varying in terms of yield as well as quality. Quality of biodiesel, however, was found to influence by the nature of feedstock. The assessment of quality parameters was made either by ASTM D 6751 or EN 14214 standards. The major fuel properties such as calorific value, kinematic viscosity, cetane number and cloud point of the reference biodiesel (koroch biodiesel) are compared with the properties of five biodiesel obtained from non-edible tree seed (karanja, mahua, polonga, jatropha and rubber seed) and then ranked them in order of desirable property. No single biodiesel type could be found at top rank with reference to more than one property. With regards to viscosity, except rubber seed biodiesel, all other biodiesels (karanja, mahua, polonga, jatropha and koroch) fulfilled the ASTM D 6751 (1.9-6 cSt) as well as EN14214 (3.5-5) standards. Koroch biodiesel ranks 3rd, 3rd and 6th in case of kinematic viscosity, cetane number and calorific value amongst the biodiesel types considered for the present study. Cloud point of koroch, polanga, mahua, rubber, karanja and jatropha biodiesels are 4, 13.2, 5, 4, 12 and 4 °C. Further, properties of biodiesel were found to have influencing correlation with the fatty acid characteristics of the feedstock. Therefore, biodiesel with desirable properties could be expected form optimum mixing of different feedstock.Eleven number of different engine performance results pertaining to uses of biodiesel are also reviewed in this paper. Varying test conditions with reference to fuel types and blends, engine size and loading pattern are discussed. Engine performance results of koroch biodiesel were then compared with five similar tree-based biodiesel. It is observed that tree seed oil with more unsaturated fatty acids exhibits lower thermal efficiency compared to biodiesel having more saturated acids.     

Effect of temperature on tribological properties of palm biodiesel

Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75 °C, under a normal load of 40 kg for 1 h at speed 1200 rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature.     

Biodiesel from jatropha: Can India meet the 20% blending target?

The need for biofuels, particularly liquid ones like ethanol and biodiesel, has been felt by most of the countries and their governments have been trying to promote these fuels. Following in line with global trend, India declared its biofuel policy in which biodiesel, primarily from jatropha, would meet 20% of the diesel demand beginning with 2011–2012. In spite of the efforts made by the state, production of biodiesel, however, has not picked up at all. Doubt arises as to whether the country will be able to meet the target. It is felt that the government policy, particularly regarding land utilization, organizing cultivation of jatropha and pricing of jatropha seeds, needs to be more clear. This paper attempts to make an assessment of the state of India’s biofuel programme and to identify the hurdles that policy-maker need to overcome to achieve the goal.     

Risk management for jatropha curcas based biodiesel industry of Panzhihua Prefecture in Southwest China

As one of the most important regions selected for jatropha biodiesel industry in Southwest China, Panzhihua has received very high and optimistic expectations. However, current situation suggests that jatropha in Panzhihua has not changed local energy scenario and the industry has been threatened by many risks. Moreover, the study of risk management on jatropha biodiesel industry is largely absent. Therefore, this study applies the idea of risk management to jatropha biodiesel industry in Panzhihua, covering complete procedures with respect to risk identification, risk assessment, risk response and risk monitoring. By risk identification, this study reveals 14 key risks which have critical influences upon this industry. The risk assessment determines the risks which are ranked as the first status to take risk response: risks of low seed yield, insect pests and diseases, poor implementation for the plans set for establishing jatropha biodiesel refining capacity, low profitability for jatropha biodiesel production, no local gas station selling jatropha biodiesel, low comparative price of biodiesel versus diesel, insufficient subsidy for farmers to conduct cultivation, insufficient subsidy for conducting biodiesel production. Accordingly, the measures for risk reduction have been given. It is a very long way to cover before the jatropha biodiesel to be realized in Panzhihua. The urgent tasks for the local governments in Panzhihua are just to maintain but adjust their ambitious plans, enhance the demonstration effects of industrial projects at an appropriate and economic scale.     

Properties and use of jatropha curcas oil and diesel fuel blends in compression ignition engine

In the present investigation the high viscosity of the jatropha curcas oil which has been considered as a potential alternative fuel for the compression ignition (C.I.) engine was decreased by blending with diesel. The blends of varying proportions of jatropha curcas oil and diesel were prepared, analyzed and compared with diesel fuel. The effect of temperature on the viscosity of biodiesel and jatropha oil was also studied. The performance of the engine using blends and jatropha oil was evaluated in a single cylinder C.I. engine and compared with the performance obtained with diesel. Significant improvement in engine performance was observed compared to vegetable oil alone. The specific fuel consumption and the exhaust gas temperature were reduced due to decrease in viscosity of the vegetable oil. Acceptable thermal efficiencies of the engine were obtained with blends containing up to 50% volume of jatropha oil. From the properties and engine test results it has been established that 40–50% of jatropha oil can be substituted for diesel without any engine modification and preheating of the blends.     

Biodiesel improves lubricity of new low sulphur diesel fuels

In this work, biodiesel from waste vegetable oil was used as an additive in low sulphur diesel fuel in automobile engines. The result was a fuel mixture with high lubricating power. According to the lubrication trials, the experimental mixtures complied with lubricity conditions established by European regulations, even when only a small quantity of biodiesel was used. It was also found that the mixtures were compatible with different engine gaskets and engine lubricant. Lastly, bench tests were performed using an automobile engine with mixtures of diesel fuel without conventional lubricant additive and biodiesel. The results showed that engine performance curves were very similar to those obtained with diesel fuel and that contaminating emissions from the engine decreased substantially by including biodiesel in the fuel, except for nitrogen oxides.     

Property modification of jatropha oil biodiesel by blending with other biodiesels or adding antioxidants

The feasibility of biodiesel production from jatropha (Jatropha curcas) oil was investigated with respect to the biodiesel blending properties and its oxidation stability with antioxidants. The JME (jatropha oil methyl esters) had the cetane number of 54, cold filter plugging point of −2 °C, density of 881 kg/m³ at 15 °C, ester content of 99.4 wt.%, iodine value of 96.55 g I₂/100 g, kinematic viscosity of 4.33 mm²/s at 40 °C, and oxidation stability of 3.86 h. Furthermore, the JME was blended with palm oil biodiesel and soybean oil biodiesel at various weight ratios and evaluated for fuel properties as compared to the relevant specifications. In addition, several antioxidants at concentrations between 100 and 1000 ppm were studied for their potential to improve the oxidation stability of the JME. The relationship between the IP (induction period) in the measurement of the oxidation stability associated with the antioxidant consumption in the JME was described by first-order reaction rate kinetics. Moreover, the ln IP (natural logarithm of the IP) at various concentrations of pyrogallol showed a linear relationship with the test temperature. The oxidation stability at ambient temperatures was predicted on the basis of an extrapolation of the temperature-dependent relationship.     

共轨柴油机燃用麻疯树制生物柴油的环境排放特性

对某共轨柴油机分别燃用不同混合比例麻疯树果实制生物柴油全负荷速度特性、标定转速及最大转矩转速负荷特性的全球变暖、光化学烟雾、酸化、人体毒性、气溶胶环境排放特性进行了试验研究。结果表明:与石化柴油比较,随着生物柴油混合比例的增加,该机全负荷速度特性下所有转速的光化学烟雾、气溶胶环境排放降低,1 600 r/min以上的全球变暖、酸化、人体毒性环境排放降低;标定转速及最大转矩转速负荷特性下,该机所有负荷的光化学烟雾、气溶胶环境排放降低,75%负荷以上的全球变暖、酸化、人体毒性环境排放降低。     

Natural and synthetic antioxidants: Influence on the oxidative stability of biodiesel synthesized from non-edible oil

According to the proposed National Mission on Biodiesel in India, we have undertaken studies on the oxidative stability of biodiesel synthesized from tree borne non-edible oil seeds jatropha. Neat jatropha biodiesel exhibited oxidation stability of 3.95 h and research was conducted to investigate the influence of natural and synthetic antioxidants on the oxidation stability of jatropha methyl ester. Antioxidants namely α-tocopherol, tert-butylated hydroxytoluene, tert-butylated phenol derivative, octylated butylated diphenyl amine, and tert-butylhydroxquinone were doped to improve the oxidation stability. It was found that both types of antioxidants showed beneficial effects in increasing the oxidation stability of jatropha methyl ester, but comparatively, the synthetic antioxidants were found to be more effective.     

轴承巴氏合金磨损试验的优化设计

在MG-2000摩擦磨损试验机上采用改进的环环试验方法进行巴氏合金与轴颈材料对磨试验,通过对试样优化设计,确定了试样的最佳尺寸和形状,改进了试验方法。试验结果与工程实际情况相吻合,该试验方法和所确定的试样形式和尺寸适合用于汽轮机大型滑动轴承边界润滑状态下的巴氏合金磨损试验。     

气缸套—活塞环摩擦副材料匹配的研究

作者对国产中小型柴油机缸套一活塞环摩擦副常用的典型材料,进行交替配对组成九种摩擦副,在一定的速度及滴油润滑条件下,以法向载荷及摩擦时间为参变量,考察它们的摩擦磨损性能。试验结果表明,合适的材料组配可以大大提高摩擦副的耐磨性能;摩擦系数随载荷而变化;在一定的载荷作用下,由于材料的塑性变形及石墨的润滑作用可使摩擦系数降低;摩擦系数与磨损量之间不能建立对应的函数关系;在合适的金相组织范围内较硬材质有较高耐磨性;活塞环材质硬度比缸套材质硬度较高时(本试验为40HB)摩擦副的磨损量最小;摩损系数也随载荷而变化。     

Physicochemical and tribological properties of microalgae oil as biolubricant for hydrogen-powered engine

Hydrogen fuel offers a cleaner fuel alternative to fossil fuel due to more efficient burning as well as reduces the environmental and health issues brought by fossil fuel usage. In engine application, regardless of either pure hydrogen or in combination with air or/and other biofuel, all the moving parts are exposed to friction and wear, and lubricant is used to minimize friction and wear for optimum operation. Thus, in this study, the use of microalgae oil as an alternative biolubricant is evaluated from the physicochemical and tribological aspects. It is found that modified microalgae oil (MMO) has demonstrated great anti-friction and anti-wear potential, particularly the 10% modified microalgae oil blend (MMO-10). The coefficient of friction is reduced (up to 10.1%) and significant reductions of wear loss and surface roughness are obtained in comparison to pure poly-alpha-olefin. Lubricant's heat dissipation is also enhanced with MMO addition, demonstrating great prospect for MMO for hydrogen-powered engine utilization.