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.     

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.     

Experimental investigations of performance,emission and combustion characteristics of Karanja oil blends fuelled DICI engine

Vegetables oils are simplest route of biofuel utilization in direct injection compression ignition (DICI) engines however several operational and durability problems are encountered while using straight vegetable oils in CI engines due to their high viscosity and low volatility. Reduction of viscosity by blending or exhaust gas heating leads to savings in chemical processing cost incurred on transesterification. In this experimental study, performance, emission and combustion characteristics of Karanja oil blends (K10, K20, K50 and K100) with mineral diesel were investigated in unheated conditions in a direct injection CI engine at different engine loads and constant engine speed (1500 rpm) vis-à-vis baseline data from mineral diesel. Analysis of performance parameters such as brake specific fuel consumption (BSFC), thermal efficiency, and exhaust gas temperature; mass emissions of various gaseous pollutant species; combustion parameters such as in-cylinder pressure rise, instantaneous heat release and cumulative heat release etc. were carried out. Detailed combustion analysis revealed that the combustion duration increased significantly even with smaller concentration of Karanja oil in the fuel blend. HC, CO and Smoke emissions were found to decrease for 20–50% (v/v) Karanja oil content in the fuel blends.     

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

Around 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.     

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.     

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.     

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.     

A study on performance and exhaust emissions of the steam injected DI diesel engine running with different diesel- conola oil methyl ester blends

Although biodiesels have low emission profiles, the main drawback of using biodiesel in diesel engines is higher NOx. Nowadays, the electronic controlled steam injection is a promising method for NOx control. This study investigates the effects of steam injection with diesel fuel-canola oil methyl ester (COME) blends on the performance and emissions characteristics of a direct injection (DI) single cylinder diesel engine. Steam is injected into the inlet manifold during inlet period. The combustion of diesel-COME blends has been modeled using two zone combustion model. The results have been compared with each other in terms of performance and emissions. The maximum increments in engine torque and power were measured as 2.5% for 10% COME (B10) at 1200 rpm, 2.8% for 20% COME (B20) at 2200 rpm. The effects of steam injection on performance and emissions of the diesel engine running with B10 and B20 COME blends were also investigated. Satisfaction improvements have been obtained with the combination of steam injection and COME blends. The maximum torque of the engine running with B10 and 10% steam ratio combination (B10 + S10) and B20 and 10% steam ratio combinations (B20 + S10) were found as 2.4% at 1400 rpm and 0.6% at 1400 rpm, respectively. Significant reduction has been observed in NOx emission with B10-S10 combination. The reduction rate in NOx emissions were 22% with B10-S10 and 18% with B20-S10 at 1200 rpm. The study showed that steam injection is an effective tool for controlling NOx emissions without performance degradation in the diesel engines fueled with COME blends.     

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.     

Assessment of basic properties and thermal analysis of hybrid biofuel blend

Among the alternative fuels, vegetable oil is seen as a potential source of energy due to its readily available variety of sources and its certain physical properties that are comparable to those of diesel fuels. However, higher contents of triglyceride in vegetable oil contribute to higher viscosity and density that is affecting the inferior engine performance and emissions. The key properties, such as viscosity, density, and calorific value (CV), have a significant effect on fuel atomization, fuel combustion, and exhaust emissions. In this study, refined palm oil (RPO) was blended with a newly introduced novel biofuel, Melaleuca cajuputi oil (MCO), in order to reduce the viscosity and density and enhance blend properties. This blend is analyzed and compared with RPO–diesel and RPO–ethanol blends in terms of viscosity, CV, and density. These hybrid binary biofuel (HBB) blends were prepared on the volumetric basis of 10%, 20%, 30%, and 50% of MCO, ethanol, and diesel with RPO. The basic fuel properties and the correlation of temperature–viscosity–blend ratio were analyzed. The results showed that the MCO has comparable key properties to those of diesel fuels. The viscosity and density of HBB decrease as the fraction of MCO/ethanol/diesel increases in the blend. The higher the fraction of MCO/diesel in the blend, the higher is the CV observed. Notably, the viscosity of neat RPO and its blends is strongly influenced by temperature variations. The combination of blend technique and preheating had a substantial effect in reducing the viscosity and density of the HBB. Remarkably, the blend of MCO–RPO has the potential to highly considered as a new source of biofuel.     

Biodiesel production from waste cooking oil using heterogeneous catalysts and its operational characteristics on variable compression ratio CI engine

In the present work, the optimum biodiesel conversion from waste cooking oil to biodiesel through transesterification method was investigated. The base catalyzed transesterification under different reactant proportions such as the molar ratio of alcohol to oil and mass ratio of catalyst to oil was studied for optimum production of biodiesel. The optimum condition for base catalyzed transesterification of waste cooking oil was determined to be 12:1 and 5 wt% of zinc doped calcium oxide. The fuel properties of the produced biodiesel such as the calorific value, flash point and density were examined and compared to conventional diesel. The properties of produced biodiesel and their blend for different ratios (B20, B40, B60, B80 and B100) were comparable with properties of diesel oil and ASTM biodiesel standards. Tests have been conducted on CI engine which runs at a constant speed of 1500 rpm, injection pressure of 200 bar, compression ratio 15:1 and 17.5, and varying engine load. The performance parameters include brake thermal efficiency, brake specific energy consumption and emissions parameters such as Carbon monoxide (CO), Hydrocarbon (HC), Oxides of Nitrogen (NOx) and smoke opacity varying with engine load (BP). Diesel engine's thermal performance and emission parameters such as CO, HC, and NOx on different biodiesel blends demonstrate that biodiesel produced from waste cooking oil using heterogeneous catalyst was suitable to be used as diesel oil blends and had lesser emissions as compared to conventional diesel.     

Performance and emissions characteristics of Jatropha oil (preheated and blends) in a direct injection compression ignition engine

The scarce and rapidly depleting conventional petroleum resources have promoted research for alternative fuels for internal combustion engines. Among various possible options, fuels derived from triglycerides (vegetable oils/animal fats) present promising “greener” substitutes for fossil fuels. Vegetable oils, due to their agricultural origin, are able to reduce net CO₂ emissions to the atmosphere along with import substitution of petroleum products. However, several operational and durability problems of using straight vegetable oils in diesel engines reported in the literature, which are because of their higher viscosity and low volatility compared to mineral diesel fuel.In the present research, experiments were designed to study the effect of reducing Jatropha oil’s viscosity by increasing the fuel temperature (using waste heat of the exhaust gases) and thereby eliminating its effect on combustion and emission characteristics of the engine. Experiments were also conducted using various blends of Jatropha oil with mineral diesel to study the effect of reduced blend viscosity on emissions and performance of diesel engine. A single cylinder, four stroke, constant speed, water cooled, direct injection diesel engine typically used in agricultural sector was used for the experiments. The acquired data were analyzed for various parameters such as thermal efficiency, brake specific fuel consumption (BSFC), smoke opacity, CO₂, CO and HC emissions. While operating the engine on Jatropha oil (preheated and blends), performance and emission parameters were found to be very close to mineral diesel for lower blend concentrations. However, for higher blend concentrations, performance and emissions were observed to be marginally inferior.     

Performance evaluation of a diesel engine fueled with methyl ester of castor seed oil

In this investigation, castor methyl ester (CME) was prepared by transesterification using potassium hydroxide (KOH) as catalyst and was used in four stroke, single cylinder variable compression ratio type diesel engine. Tests were carried out at a rated speed of 1500 rpm at different loads. Straight vegetable oils pose operational and durability problems when subjected to long term usages in diesel engines. These problems are attributed to high viscosity, low volatility and polyunsaturated character of vegetable oils. The process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. The important properties of methyl ester of castor seed oil are compared with diesel fuel. The engine performance was analysed with different blends of biodiesel and was compared with mineral diesel. It was concluded that the lower blends of biodiesel increased the break thermal efficiency and reduced the fuel consumption. The exhaust gas temperature increased with increasing biodiesel concentration. The results proved that the use of biodiesel (produced from castor seed oil) in compression ignition engine is a viable alternative to diesel.     

Performance,emission and combustion characteristics of a variable compression ratio engine using methyl esters of waste cooking oil and diesel blends

The performance, emission and combustion characteristics of a single cylinder four stroke variable compression ratio multi fuel engine when fueled with waste cooking oil methyl ester and its 20%, 40%, 60% and 80% blends with diesel (on a volume basis) are investigated and compared with standard diesel. The suitability of waste cooking oil methyl ester as a biofuel has been established in this study. Bio diesel produced from waste sun flower oil by transesterification process has been used in this study. Experiment has been conducted at a fixed engine speed of 1500 rpm, 50% load and at compression ratios of 18:1, 19:1, 20:1, 21:1 and 22:1. The impact of compression ratio on fuel consumption, combustion pressures and exhaust gas emissions has been investigated and presented. Optimum compression ratio which gives best performance has been identified. The results indicate longer ignition delay, maximum rate of pressure rise, lower heat release rate and higher mass fraction burnt at higher compression ratio for waste cooking oil methyl ester when compared to that of diesel. The brake thermal efficiency at 50% load for waste cooking oil methyl ester blends and diesel has been calculated and the blend B40 is found to give maximum thermal efficiency. The blends when used as fuel results in reduction of carbon monoxide, hydrocarbon and increase in nitrogen oxides emissions.     

Characterization and effect of using rubber seed oil as fuel in the compression ignition engines

Vegetable oils pose some problems when subjected to prolonged usage in compression ignition engines because of their high viscosity and low volatility. The common problems are poor atomization, carbon deposits, ring sticking, fuel pump failure, etc. Converting the high viscosity vegetable oil into its blends or esters can minimize these problems. The various blends of rubber seed oil and diesel were prepared and its important properties such as viscosity, calorific value, flash point, fire point, etc. were evaluated and compared with that of diesel. The blends were then subjected to engine performance and emission tests and compared with that for diesel. It was found that 50–80% of rubber seed oil blends gave the best performance. Long run tests were conducted using optimized blend and diesel. It was found that blend fueled engine has higher carbon deposits inside combustion chamber than diesel-fueled engine. Utilization of blends requires frequent cleaning of fuel filter, pump and the combustion chamber. Hence, it is recommended that rubber seed oil–diesel blend fuel is more suitable for rural power generation.     

An environmental effect of Vitis vinifera biofuel blends in a marine engine

In this study, grape seed oil was transesterified with methanol using sodium hydroxide as a catalyst to obtain grape seed oil methyl ester (GSOME). It was basically identified through Fourier transform infrared (FTIR) spectrum. The blends such as B10, B15, B20, and D100 were tested in a compression ignition diesel engine. The fuel properties were determined using American Society of Testing and Materials (ASTM) and the engine emission parameters were analyzed for those test fuels for different load at constant engine speed of 1,500 rpm. The experimental results show that all the blends provided significant reductions in NOx than D100.     

Strategies to improve the performance of a spark ignition engine using fuel blends of biogas with natural gas,propane and hydrogen

This work presents the strategies applied to improve the performance of a spark ignition (SI) biogas engine. A diesel engine with a high compression ratio (CR) was converted to SI to be fueled with gaseous fuels. Biogas was used as the main fuel to increase knocking resistance of the blends. Biogas was blended with natural gas, propane, and hydrogen to improve fuel combustion properties. The spark timing (ST) was adjusted for optimum generating efficiencies close to the knocking threshold. The engine was operated on each blend at the maximum output power under stable combustion conditions. The maximum output power was measured at partial throttle limited by engine knocking threshold. The use of biogas in the engine resulted in a power derating of 6.25% compared with the original diesel engine (8 kW @ 1800 rpm). 50% biogas + 50% natural gas was the blend with the highest output power (8.66 kW @1800 rpm) and the highest generating efficiency (29.8%); this blend indeed got better results than the blends enriched with propane and hydrogen. Tests conditions were selected to achieve an average knocking peak pressure between 0.3 and 0.5 bar and COV of IMEP lower than 4% using 200 consecutive cycles as reference. With the blends of biogas, propane, and hydrogen, the output power obtained was just over 8 kW whereas the blends of biogas, natural gas, and hydrogen the output power were close to 8.6 kW. Moreover, a new approach to evaluate the maximum output power in gas engines is proposed, which does not depend on the engine % throttle but on the limit defined by the knocking threshold and cyclic variations.     

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。     

Performance evaluation of a vegetable oil fuelled compression ignition engine

Fuel crisis because of dramatic increase in vehicular population and environmental concerns have renewed interest of scientific community to look for alternative fuels of bio-origin such as vegetable oils. Vegetable oils can be produced from forests, vegetable oil crops, and oil bearing biomass materials. Non-edible vegetable oils such as linseed oil, mahua oil, rice bran oil, etc. are potentially effective diesel substitute. Vegetable oils have high-energy content. This study was carried out to investigate the performance and emission characteristics of linseed oil, mahua oil, rice bran oil and linseed oil methyl ester (LOME), in a stationary single cylinder, four-stroke diesel engine and compare it with mineral diesel. The linseed oil, mahua oil, rice bran oil and LOME were blended with diesel in different proportions. Baseline data for diesel fuel was collected. Engine tests were performed using all these blends of linseed, mahua, rice bran, and LOME. Straight vegetable oils posed operational and durability problems when subjected to long-term usage in CI engine. These problems are attributed to high viscosity, low volatility and polyunsaturated character of vegetable oils. However, these problems were not observed for LOME blends. Hence, process of transesterification is found to be an effective method of reducing vegetable oil viscosity and eliminating operational and durability problems. Economic analysis was also done in this study and it is found that use of vegetable oil and its derivative as diesel fuel substitutes has almost similar cost as that of mineral diesel.