G. Anastopoulos

AN INVESTIGATION OF USING BIODIESEL/MARINE DIESEL BLENDS ON THE PERFORMANCE OF A STATIONARY DIESEL ENGINE

Vegetable oils are produced from numerous oil seed crops. While all vegetable oils have high-energy content, most require some processing to assure safe use in internal combustion engines. Some of these oils already have been evaluated as substitutes for diesel fuels. With the exception of rape seed oil which is the principal raw material for biodiesel fatty acid methyl esters, sunflower oil, corn oil and olive oil, which are abundant in Southern Europe, along with some wastes, such as used frying oils, appear to be attractive candidates for biodiesel production. In this paper, fuel consumption and exhaust emissions measurements from a single cylinder, stationary diesel engine are described. The engine was fueled with pure marine diesel fuel and blends containing two types of biodiesel, at proportions up to 50%. The two types of biodiesel appeared to have equal performance, and irrespective of the raw material used for their production, their addition to the marine diesel fuel improved the particulate matter, unburned hydrocarbons, nitrogen oxide and carbon monoxide emissions.

Tobacco seed oil as an alternative diesel fuel: physical and chemical properties

Abstract Tobacco seed is a byproduct of tobacco leaves production in Greece. This oil seed was evaluated in the present study, as a renewable and potential source of energy. Successive tobacco seed oil extraction indicated that almost 38% of the seed was oil. The major constituents observed by GC analysis were linoleic acid (18:2), oleic acid (18:1) and palmitic acid (16:0). The physical, chemical and fuel related properties of tobacco seed oil were investigated in this work. These properties were comparable to those of other vegetable oils and to current European specifications for automotive diesel fuel. This study suggests that this non edible oil may be an appropriate substitute for diesel fuel. The environmental advantages of tobacco seed oil as a fuel can be exploited for specific niche markets such as inner city vehicles or tractors. On the other hand, tobacco seed oil as a fuel represents one possible hope for the future of EU tobacco agriculture.

Study of using JP-8 aviation fuel and biodiesel in CI engines

Abstract The first jet fuels were aviation gasoline (avgas), and the characteristics of subsequent jet fuels have evolved from this original choice, the available supply infrastructure, and the refiners’ capabilities. Earlier on, it was evident that avgas would have to be altered to operate satisfactorily in jet powered aircraft. The present contribution outlines the various requirements that led to development of various operational jet fuels, including United States Jet A (European Jet A-1), JP-4 (NATO code, F-40), JP-5 (NATO code, F-44), JP-7 (US only), JP-8 (F-34), JP-TS (US only), and JP-8+100. To reduce this fuel logistic burden, the NATO Armed Forces are advancing the use of a single fuel for both aircraft and ground equipment. To this end, F-34 is replacing distillate Diesel fuel in many applications. In order to make this type of fuel compatible with direct injection compression engines, the Fuels and Lubricants Laboratory of the National Technical University of Athens, used a stationary Diesel engine fueled with fuel blends containing two different types of biodiesel, at proportions up to 50%. In this paper, fuel consumption and exhaust emission measurements from a single cylinder, stationary, Diesel engine are described. The two types of biodiesel appeared to have equal performance, and irrespective of the raw material used for their production, their addition to the JP-8 aviation fuel improved the particulate matter emissions.

Influence of aceto acetic esters and di-carboxylic acid esters on diesel fuel lubricity

This paper presents the impact of acetoacetic esters and di-carboxylic acid esters on the lubrication properties of automotive diesel. Three alkyl acetoacetates and seven di-carboxylic esters were used as lubricating additives on two low sulfur diesel fuels, at seven different concentrations of 50, 100, 500, 750, 1000, 1500 and 2000 ppm. Tribological experiments carried out on the high frequency reciprocating rig (HFRR) showed that only two of the three acetoacetic esters used, provide satisfactory mean wear scar diameter (WS 1.4) of less than 460 μm, at the concentration level of 750 ppm. In the case of di-carboxylic acid esters, the effective concentration was 500 ppm or higher.

Hfrr lubricity response of an additized aviation kerosene for use in CI engines

Abstract To reduce their fuel related logistic burden, NATO Armed Forces are advancing the use of a single fuel for both aircraft and ground equipment. To this end, F-34 is replacing distillate diesel fuel in many applications. However, tests conducted with kerosene on High Frequency Reciprocating Rig, showed that it causes unacceptable wear due to the poor lubricity of aviation fuel. In order to make this type of fuel compatible with direct injection compression engines, tests were carried out with ten mono–carboxylic acid esters to improve the lubricity of kerosene. Tribological results showed that all esters tested, were suitable for increasing the kerosene lubricity to a satisfactory level. Among the esters of the same molecular type, those having the ester group around the middle of the molecule appear to have better lubrication performance.

Biodiesel production by ethanolysis of various vegetable oils using calcium ethoxide as a solid base catalyst.

In this study, fatty acid ethyl esters (FAEE) were produced from four different vegetable oils (sunflower, cotton seed, olive oil, and used frying oil) using calcium ethoxide as a heterogeneous solid base catalyst. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. The optimal conditions for first stage transterification were an ethanol/oil molar ratio of 12:1, catalyst amount (3.5%), and 80°C temperature, whereas the maximum yield of ethyl esters reached 80.5%. In the second stage, the yield of ethyl esters showed signs of improvement of 16% in relation with the one-stage transesterification, which was obtained under the following optimal conditions: catalyst concentration 0.75% and ethanol/oil molar ratio 6:1. Property analysis of prepared ethyl ester samples was done, in order to examine their quality parameters. The results obtained showed that the density, viscosity, and calorific value of the produced ethyl esters had values close to those of a no. 2 diesel. On the contrary, the cold filter plugging points were higher than the conventional diesel fuel.

Methanolysis of sunflower oil and used frying oil using LiNO3/CaO as a solid base catalyst

The conversion of sunflower oil and used frying oil to methyl esters (biodiesel) was studied using lithium nitrate loaded on calcium oxide as heterogeneous catalyst. Reaction parameters such as catalyst concentration, methanol to oil ratio, reaction time and agitation speed on the conversion of sunflower and used frying oil were investigated. The catalyst loaded LiNO3 of 35% m/m on CaO, after being calcined at 750°C for 6 h, was found to be the optimum catalyst. The quality of the methyl esters was tested according to the European Standard ELOT EN 14214. The two types of biodiesel produced, seemed to meet all the parameters of the European Standard except the oxidation stability, acid value and the glycerol content for the used frying oil methyl ester only.

Synthesis of biodiesel from tobacco and waste frying oil using heterogeneous KHCO3/Al2O3 catalyst.

The transesterification of tobacco seed oil and used frying oil to methyl esters (biodiesel) was studied using potassium bicarbonate loaded on alumina as heterogeneous catalyst. Reaction parameters such as catalyst concentration, methanol to oil ratio, reaction time, and agitation speed on the conversion of tobacco seed and used frying oil were investigated. The catalyst loaded KHCO3 of 30 % m/m on Al2O3, after being calcined at 700°C for 6 h, was found to be the optimum catalyst. The quality of the methyl esters was tested according to the European standard EN 14214. The two types of biodiesel produced seemed to meet all the parameters of the European standard except the oxidation stability. In the case of used frying oil biodiesel, not only the oxidation stability was not met, but this biodiesel did not also meet the acid value and water content specifications.

Investigating “De Minimis” Level of Fatty Acid Methyl Esters (FAME) in Distillate Marine Gas Oil

According to the existing maritime regulation, the marine diesel equipment will be necessary to operate with low sulfur marine fuels. Low Sulfur Middle Gas Oils (MGOs) often have a viscosity that is lower than that of Heavy Fuel Oil (HFO). The problems in diesel engines are mainly related to high pressure fuel pumps that depend on the fuel oil for their lubrication. A solution to that problem probably will be the addition of Fatty Acid Methyl Esters (FAME) as an additive to the fuel. On the other hand, for the purposes of International Standard ISO 8217:2012 in the case of distillate fuels it is recommended that “de minimis” level of FAME is recommended. “De minimis” level is determined approximately as the 0.1% volume of the fuel. In this study, Distillate Marine Diesel Oil with good lubricity performance was used blended with FAME fuel, according to national and European Standard (ELOT EN 14214), was used as an additive. The FAME was stored for three months period in a plastic container. Then mixture with concentrations of 0.5%, 1.0%, 2.0%, 3.0%, 4.0% and 5.0% by volume were used. The obtained results shown that all the mixtures are within the specification limits but the tribological measurements, which were carried out with an applied load of 600 g using the High Frequency Reciprocating Rig (HFRR) with test duration for each test 150 min., revealed an increased wear. This happened because after the storage period the water content of the FAME increased significant.

Fuel quality assessment of ethyl esters produced from vegetable oils and their blends with petroleum diesel.

Ethanolysis of four different vegetable oils (sunflower, soybean, cotton seed, and used frying oil) was studied using sodium ethoxide as a catalyst. The ester preparation involved a two-step transesterification reaction, followed by purification. The effects of the mass ratio of catalyst to oil, the molar ratio of ethanol to oil, and the reaction temperature were studied on conversion of sunflower oil to optimize the reaction conditions in both stages. The rest of the vegetable oils were converted to ethyl esters under optimum reaction parameters. Ethyl esters of four different types of vegetable oils were blended with the diesel fuel at 2 %, 5 %, 10 %, and 20 %, on a volume basis. The experimental results showed that the densities and viscosities of the blends increased with the increase of biodiesel concentration in the fuel blend. Cold flow properties were negatively affected as ethyl ester content was increasing. Distillation characteristics and cetane indexes were not significantly altered. These results are promising, and ethyl esters can be seen as a viable fully renewable alternative to petroleum diesel.