F. Zannikos

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.

Desulfurization of petroleum fractions by oxidation and solvent extraction

Abstract The known ability of several solvents to extract sulfur compounds selectivity from petroleum fractions can be dramatically improved by oxidizing the sulfur from the divalent state (sulfide) to the hexavalent (sulfone). The oxidation process itself leads to the removal of a substantial portion of the existing sulfur and makes the remaining sulfur compounds amenable to efficient removal even by solvents such as methanol which are not effective in selective extraction of the unoxidized sulfur compounds. Thus this combination process is capable of removing up to 90% of the sulfur compounds in petroleum fractions at acceptable yields. The oxidation process has no deleterious effects on the distillation profile and other characteristics of the middle distillate fractions that were examined.

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.

Fuel adulteration issues in Greece

The fuel adulteration problem is associated with environmental pollution, problems with engine performance, and tax losses. Here, results are presented of a survey in leaded gasoline and automotive diesel, obtained from service stations representative of all the oil companies operating in Greece. For this purpose, 165 samples of gasoline and 420 samples of automotive diesel were collected from various parts of the country during the years 1998, 1999, and 2000. The gasoline samples were subsequently analyzed for their key properties and for any adulteration with cheaper unleaded gasoline. Octane number, benzene, olefins, and total aromatics were determined with the mid-IR method, and the sulfur content with a UVF elemental analyzer. The analysis of the automotive diesel samples concerned some key properties such as the cetane index, density, sulfur content, and the distillation properties of the fuel. The results indicate that there is a large fluctuation of fuel properties among the oil marketers. Examination of the quinizarin content (the tracer of unleaded gasoline) has shown that 11 leaded gasoline samples (8.8%) were mixed with unleaded gasoline, 5 leaded gasoline samples (4%) were mixed with aromatic solvents, whereas about 28% of the automotive diesel samples suffered from some degree of adulteration, mainly with cheaper heating fuel; and one automotive diesel sample was adulterated with a lighter fraction. Fuel misuse is a common problem not only for European countries but for practically every nation in the world. The European Union recently expressed its concern on this issue, mandating that by the year 2002 all the member states will promote the development of a uniform system for fuel quality monitoring.

Biodiesel Emissions from a Diesel Vehicle Operated on a Non-legislative Driving Cycle

Abstract The aim of this work was to evaluate the exhaust emissions from a diesel vehicle fueled with diesel/biodiesel blends running in a specific driving cycle. Methyl ester obtained from used frying oil was used as the blending feedstock into the reference diesel fuel to create blends at proportions of 5, 10, 15, and 20% by volume. The on-board emission measurements showed that the addition of biodiesel into the reference diesel fuel demonstrated an increase in NOx emissions. Emissions of CO and hydrocarbons were decreased with the addition of biodiesel; however, this reduction was not significant. Particulate matter emissions followed a decline trend as the addition of methyl ester increased into the baseline diesel fuel. Fuel consumption invariably increased for the biodiesel blends, when the motor vehicle operated under the specific real-world driving cycle.

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.

Converting Biomass and Waste Plastic to Solid Fuel Briquettes

This work examines the production of briquettes for household use from biomass in combination with plastic materials from different sources. Additionally, the combustion characteristics of the briquettes in a common open fireplace were studied. It is clear that the geometry of the briquettes has no influence on the smoke emissions. When the briquettes have a small amount of polyethylene terephthalate (PET), the behavior in the combustion is steadier because of the increase of oxygen supply. The smoke levels are between the 3rd and 4th grades of the smoke number scale. Measuring the carbon monoxide emission, it was observed that the burning of the plastic in the mixture with biomass increases the carbon monoxide emissions from 10% to 30% as compared to carbon monoxide emission from sawdust biomass emissions which was used as a reference.