Mustafa Ertunc Tat

A high‐oleic‐acid and low‐palmitic‐acid soybean: agronomic performance and evaluation as a feedstock for biodiesel

Phenotypic characterization of soybean event 335-13, which possesses oil with an increased oleic acid content (> 85%) and reduced palmitic acid content (< 5%), was conducted across multiple environments during 2004 and 2005. Under these conditions, the stability of the novel fatty acid profile of the oil was not influenced by environment. Importantly, the novel soybean event 335-13 was not compromised in yield in both irrigated and non-irrigated production schemes. Moreover, seed characteristics, including total oil and protein, as well as amino acid profile, were not altered as a result of the large shift in the fatty acid profile. The novel oil trait was inherited in a simple Mendelian fashion. The event 335-13 was also evaluated as a feedstock for biodiesel. Extruded oil from event 335-13 produced a biodiesel with improved cold flow and enhanced oxidative stability, two critical fuel parameters that can limit the utility of this renewable transportation fuel.

Exergy analysis of engines fuelled with biodiesel from high oleic soybeans based on experimental values

This study dealt with energy and exergy analyses of a John Deere 4045T diesel engine run with no. 2 diesel fuel, Soybean oil Methyl Ester (SME) and High-Oleic soybean oil Methyl Ester (HOME) at 1400 1/min. It was aimed at determining energy and exergy efficiencies, energy losses and exergy destructions of the combustion process and comparing exergetically the fuels used. The specific exergy of the fuels was calculated to be efuel,No.2 Diesel > efuel,HOME > efuel,SME, while energy (thermal) and exergy efficiencies were 40.5% and 37.8%, respectively. There were no statistically significant differences between the fuels based on the Tukey method.

Physical Properties and Composition Detection of Biodiesel-diesel Fuel Blends

Biodiesel is an oxygenated, sulfur-free, biodegradable, non-toxic, and environmentally friendly alternative diesel fuel. Biodiesel can be derived from renewable resources, such as vegetable oils, animal fats, and waste restaurant greases. One of the attractive characteristics of biodiesel is that its use does not require any significant modifications to the diesel engine, so the engine does not have to be dedicated for biodiesel. However, due to its different properties, biodiesel will cause some changes in the engine performance and emissions including lower power and higher oxides of nitrogen. Biodiesel can be blended in any proportion with petroleum-based diesel fuel and the impact of the changes is usually proportional to the fraction of biodiesel being used. If the biodiesel-diesel fuel blend level were known, these changes could be eliminated by the engines electronic control system. The objective of this study was the investigation of the effect of biodiesel blend level on density, speed of sound, and isentropic bulk modulus at higher pressures, and at 20 °C and 40 °C. Also, blend detection with a commercial fuel composition sensor, and the effect of temperature, water, and alcohol on this detection was investigated.

Biodiesel Blend Detection Using a Fuel Composition Sensor

Biodiesel is an alternative diesel fuel consisting of the alkyl monoesters of fatty acids from vegetable oils and animal fats. Biodiesel can be used in diesel engines as a pure fuel or in blends with petroleum-based diesel fuel. To maintain optimum performance and meet emission regulations, it may be necessary to measure the composition of blended fuels and adjust the fuel injection timing and other injection parameters during operation. The objective of this study was to investigate the suitability of using a commercial Flexible Fuel Composition Sensor for the detection of biodiesel composition in biodiesel/diesel fuel blends. Twelve different biodiesel fuel samples were tested including pure esters and esters from soybean oil, tallow, lard, canola oil, and yellow grease. The sensor produced a frequency output between 58.75 and 60.23 Hz for all of the biodiesel samples. Six different diesel fuel samples were also tested including commercial No.1 diesel fuel and EPA emission certification fuel. All of the diesel fuel samples gave frequencies between 51.84 and 52.62 Hz. The frequency output of the sensor was observed to be linearly proportional to the percentage of biodiesel in blend. The 7.14 Hz average difference from diesel fuel to biodiesel is sufficient to use this fuel composition sensor for blend detection of biodiesel blended fuels.

A review on exergetic analysis and assessment of various types of engines

This study presents a review on energy and exergy analysis of Otto and Diesel engines. Calculation methods of the analysis are discussed in detail. Previous studies, from 1963 to 2008, are chronologically listed and studied. The test engines had different cylinder numbers, speeds and rated powers. Engine specifications and test bench schematics are given in tables and figures. The best exergetic efficiency is achieved with four-stroke, four-cylinder, turbocharged Diesel engines at about 30% excepting to stationary Diesel engine. It is considered that exergetic efficiency can be higher at lower speeds between 1140 1/min and 2200 1/min.

Fuel Property Effects on Biodiesel

Biodiesel is an environmentally friendly alternative diesel fuel obtained from renewable resources, such as vegetable oils, animal fats, and recycled restaurant greases. It is described in ASTM standard D 6751-02 as: a fuel comprised of mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats. Biodiesel is oxygenated, sulfur-free, biodegradable, and nontoxic. One of the attractive characteristics of biodiesel is that it does not require any significant modifications to the diesel engine, so the engine does not have to be dedicated for biodiesel. However, due to its different properties, such as a higher cetane number, lower volatility, and lower energy content, biodiesel may cause some changes in the engine performance and emissions. These different properties can effect the injection timing and the diesel combustion process causing lower power and higher oxides of nitrogen. The objective of this study was the investigation of biodiesel fuel properties such as cetane number, fuel volatility, and energy content on biodiesel combustion. The results of heat release analysis are presented from measured cylinder pressure data on a turbocharged diesel engine fueled with biodiesel from soybean oil, biodiesel from animal grease, and No. 2 diesel fuel.

Fuel Property Effects on Injection Timing, Ignition Timing and Oxides of Nitrogen Emissions from Biodiesel-Fueled Engines

Biodiesel is an environmentally friendly alternative diesel fuel consisting of the alkyl monoesters of fatty acids. It is obtained from triglycerides through the transesterfication process. Biodiesel has been observed to reduce most engine exhaust pollutants with the exception of oxides of nitrogen (NOx), which generally increase by 5 to 15%. The objective of this research was to determine the reason for the higher levels of NOx emissions. A concept map was developed to show the interrelationships between the fuel and engine variables that affect NOx production. It was determined that a change in combustion timing caused by changes in the fuel properties between diesel fuel and biodiesel is an important source of the NOx increase. The properties investigated in this research included the lower heating value, volatility, density, speed of sound, bulk modulus, and cetane number of biodiesel. It was found that half of the start of combustion advance associated with biodiesel originated from a start of injection advance that was split approximately evenly between the automatic timing advance of the pump as it injects more fuel to compensate for the lower heating value of biodiesel and the effect of the bulk modulus, viscosity, and density of the fuel. At the same temperature, the fuel delivery of biodiesel was higher than for petroleum-based diesel fuel because of the higher viscosity of biodiesel. At the same viscosity level, it was found that the fuel delivery of petroleum-based diesel fuel was higher than for biodiesel. This was attributed to the metering orifices in the fuel injection pumps restricting the amount of fuel flow for more dense fuels. The other half of the start of combustion timing advance was due to the higher cetane number of the biodiesel.