Blended E85-diesel fuel droplet heating and evaporation

The multidimensional quasi-discrete (MDQD) model is applied to the analysis of heating and evaporation of mixtures of E85 (85 vol % ethanol and 15 vol % gasoline) with diesel fuel, commonly known as “E85–diesel” blends, using the universal quasi-chemical functional group activity coefficients model for the calculation of vapor pressure. The contribution of 119 components of E85–diesel fuel blends is taken into account, but replaced with smaller number of components/quasi-components, under conditions representative of diesel engines. Our results show that high fractions of E85–diesel fuel blends have a significant impact on the evolutions of droplet radii and surface temperatures. For instance, droplet lifetime and surface temperature for a blend of 50 vol % E85 and 50 vol % diesel are 23.2% and up to 3.4% less than those of pure diesel fuel, respectively. The application of the MDQD model has improved the computational efficiency significantly with minimal sacrifice to accuracy. This approach leads to a saving of up to 86.4% of CPU time when reducing the 119 components to 16 components/quasi-components without a sacrifice to the main features of the model

Engine performance of a single cylinder direct injection diesel engine fuelled with blends of Jatropha Curcas oil and stardard diesel fuel

Blends of Jatropha Curcas oil and standard diesel fuel were evaluated (without pre-heating). The engine tests for the blends were performed in a Petter single cylinder direct injection diesel engine under steady state conditions at high loads. Engine speeds between 1300-1700 rpm were selected for the engine tests. Torque, power output, specific fuel consumption, in cylinder pressure, ignition delay, rate of heat released and exhaust composition were evaluated. The tested blends between 10-20% of oil shown lower effective torque and power output joint to a higher specific fuel consumption related to the lower heating value of Jatropha oil compared to diesel fuel. Lower pressure peaks and rates or pressure rises were observed when Jatropha blends are used. A decrease in the rate of heat released and shorter ignition delay were observed for the blends. Decreases in HC and CO emissions were observed for blends compared to diesel fuel. Both alternatives assessed shown that the differences observed compared to diesel fuel, can be partially restored with engines regulation. The use of Jatropha oil in order to be a partial or full alternative to the use of diesel fuel for energy production was achieved

Characterising the friction and wear between the piston ring and cylinder liner based on acoustic emission analysis

In this paper, an experimental investigation was carried out to evaluate the friction and wear between the cylinder liner and piston ring using acoustic emission (AE) technology. Based on a typical compression ignition (CI) diesel engine, four types of alternative fuels (Fischer-Tropsch fuel, methanol-diesel, emulsified diesel and standard diesel) were tested under dif-ferent operating conditions. AE signals collected from the cylinder block of the testing en-gine. In the meantime, the AE signals in one engine cycle are further segregated into small segments to eliminate the effects of valve events on friction events of cylinder liner. In this way, the resulted AE signals are consistent with the prediction of hydrodynamic lubrication processes. Test results show that there are clear evidences of high AE deviations between dif-ferent fuels. In particular, the methanol-diesel blended fuel produces higher AE energy, which indicates there are more wear between the piston ring and cylinder liner than using standard diesel. On the other hand, the other two alternative fuels have been found little dif-ferences in AE signal from the normal diesel. This paper has shown that AE analysis is an ef-fective technique for on-line assessment of engine friction and wear, which provides a novel approach to support the development of new engine fuels and new lubricants

Bioremediation of biodiesel and diesel contaminated soil by pseudomonas putida

As occurs to the diesel fuel, the commercialization of biodiesel and their diesel blends can cause environmental damages due to accidental spillage. Presence of these contaminants containing polyaromatic hydrocarbons (PAHs) in soil is toxic to humans, plants and soil microorganisms due to their recalcitrant and mutagenic or carcinogenic properties. Therefore, this study was conducted to suggest a new technique of treatment to clean up the biodiesel and diesel contaminated soil by Pseudomonas putida. Spill simulations with biodiesel, diesel and their blends in sandy gravel soil were performed according to previous study with some modification. Briefly, 200 mL of Pseudomonas putida was inoculated into soil samples: B5 (5% biodiesel + 95% diesel), B20 (20% biodiesel + 80% diesel), B50 (50% biodiesel + 50% diesel), B100 (100% biodiesel) and D100 (100% diesel). As a control sample, there is no addition of biodiesel and diesel into the sample. All samples were stored in the incubator at 35 ºC throughout the 24 days of treatment. Samples were analyzed for: soil particle size, moisture content, pH, total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC), soxhlet extraction of PAHs and enumeration of Pseudomonas putida. The measurement of all testing parameters was carried out at interval of three days starting from Day 0 to Day 24 of bioremediation period. Results showed that the highest removal of total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC) and PAHs were observed in the sample B100 with up to 70.43%, 69.47%, 68.08%, 97.66% and 96.28% removal, respectively. The degradation rates of PAHs and survival of Pseudomonas putida were also observed highest in the sample B100 with up to 0.149 mg/kg/day and 60 × 106 cfu/g, respectively. Based on these overall findings, it can be verified that the sample B100 has the higher biodegradability than other samples. According to results, it can conclude that, the capability and effectiveness of Pseudomonas putida as oil-biodegradable agent in soil bioremediation were proved and bioremediation of contaminated samples may be considered as a successful and feasible practice

What drives diesel fuel prices?

Historically, gasoline has commanded a premium over diesel, but that changed in mid-to-late 2007, when diesel rose above gasoline. In 2007 and 2008, however, gasoline traded higher than diesel only 21.1 percent of the time. This deviation from historic norms raises an interesting question--what drives diesel prices? As with virtually all petroleum-derived products, the story begins with oil prices. Seasonal patterns also play a significant role. Demand for a range of oil-based products changes with the weather, and prices fluctuate as refiners adjust their output mix. Government regulations are another source of price variability. Earlier this decade, new standards aimed at reducing diesel fuel's sulfur content required further processing that increased refinery costs and prices for consumers. Finally, short-term changes in supply and demand--including imports--factor into pricing on a day-to-day basis. Our model suggests that spot diesel should rise 25 cents a gallon over the next six months and 41 cents a gallon over the next 18 months.Petroleum products - Prices ; Petroleum industry and trade ; Energy consumption ; Econometric models

Phylogenetic Identification of Petroleum-Degrading Bacteria in Alaska Willow Soils

• Certain plant species may promote growth and activity of pollutant- degrading microbes in the rhizosphere. • Naphthalene is an aromatic component of petroleum fuels, which are common soil contaminants in Alaska. • Willows are known to produce and release salicylate, an intermediate in the naphthalene degradation pathway that induces the expression of microbial naphthalene degradation genes. • A previous pot study (McFarlin et al. in prep) tested the ability of Salix alaxensis (Alaskan willow) to rhizo-remediate diesel-contaminated soil. • Willow growth treatments significantly decreased the concentration of diesel range organics in soil and increased the number of cultured diesel-degrading bacteria in comparison to unplanted controls. • The effects of willow on the identity and diversity of diesel-degrading bacteria in this pot study are unknown

The changes of burning efficiency emission and power output of a diesel engine fueled by bioethanol – biodiesel-diesel oil mixtures

The environmental pollution and the decrease of the oil based fuels are the greatest problems of the automotive-industry at the start of the 21st century. There were and certainly there are a number of experiments to aiming substitute the petrol and the diesel oil with other fuels. One group of these substitutable fuels is the bioethanol – biodiesel – diesel oil mixtures. These mixtures are very similar to the fuels used today, as it can be used in the engines without any structural changes. At the Technical University of Budapest investigations have been made to explore the possibility of using bioethanol – biodiesel – diesel oil mixtures in vehicles and agricultural engines. The main aspects of the researches was find blends that are substitutable for diesel oil consisting of the most renewable part as possible, reaching the same or similar power output and lower the emissions. The experimentations were based on mixing bioethanol and biodiesel with diesel oil. Our idea was, when the biofuels are mixed they supplement each other, cutting the negative effect of each and increasing the renewable component rate in the fuel. During the researches the two main requirements of the fuel were: the maximal possible renewable part with which the engine does not need any changes, yet meets the prerequisites set by diesel oil and to have the same power and better emissions with the blend. The low (up to 20%) biofuel rate was important, while the first step of introduction is possible with low rates. The experiments were maid at engine benches with different engines, one-cylinder measurements, cetin-number determination, viscosity determination, life cycle analysis and cost benefit analysis. In conclusion of the research it could be established that the use of bioethanol-biodiesel-diesel oil emulsion in agricultural engines is in technicality already solved, as no changes are needed on the engine, and it also reduces the emissions and is economically justified

O dilema presentista

The aim of the present paper is to show that presentism cannot answer the truthmaker objection in a satisfactory manner. For such, two main categories of presentist solutions were studied: the first kind states that truthmakers can’t provide any objection to presentism, while the second type tries to ground past truths by postulating new ontological categories, which were rejected, mainly because of their use of ad hoc ontologies. Also, I showed how the presentist should adopt antirealism about the past in case she wants to maintain a simple ontology. Being that said, I conclude that presentism cannot offer satisfactory truthmakers to past truths