142,637 research outputs found
Emulsifaction of waste cooking oils and fatty acid distillates as diesel engine fuel
The scope of this paper is to analyze the possibilities and feasibilities, as well as the main experimental results reported about the emulsification method applied to waste cooking oils and fatty acid distillates as diesel engine fuels, compared with other commonly used methods. These waste products are obtained in the refining oil industry, food industry and service sector from the frying process, mainly. However, they are a little used as feedstocks to produce biofuels and constitute a potential source of contamination. From the review of the state of arts, significant decreases in exhaust emissions of nitrogen oxides, cylinder pressure, as well as increases of the ignition delay, brake specific fuel consumption, hydrocarbon, smoke opacity, carbon monoxide, particulate matters to emulsified waste cooking oils and fatty acid distillates compared with diesel fuel are reported. In some experiments the emulsified waste cooking oils achieved better performance than neat fatty acid distillates, neat waste cooking oils and their derivates methyl esters
U.S. Biodiesel Development: New Markets for Conventional and Genetically Modified Agricultural Products
With environmental and energy source concerns on the rise, using agricultural fats and oils as fuel in diesel engines has captured increasing attention. Substituting petroleum diesel with biodiesel may reduce air emissions, increase the domestic supply of fuel, and create new markets for farmers. U.S. agricultural fats and oils could support a large amount of biodiesel, but high production costs and competing uses for biodiesel feedstocks will likely prevent mass adoption of biodiesel fuel. Higher-priced niche markets could develop for biodiesels as a result of environmental regulations. Biodiesel has many environmental advantages relative to petroleum diesel, such as lower CO, CO2, SOx, and particulate matter emissions. Enhancing fuel properties by genetically modifiying oil crops could improve NOx emissions, cold flow, and oxidative stability, which have been identified as potential problems for biodiesel. Research activities need to be directed toward cost reduction, improving fuel properties, and analyzing the economic effects of biodiesel development on U.S. agriculture.biodiesel, biodiesel blends, fatty acid esters, soybean, oil crops, animal fats, plant genetics, diesel engines, alternative fuels, Resource /Energy Economics and Policy,
A note on the combustion of blends of diesel and soya, sunflower and rapeseed vegetable oils in a light boiler
Producción CientíficaThis paper deals with the study of the vegetable oils (VO) used as fuel for heating. The properties of sunflower, rape and soya oils are studied and these are compared with the properties of C-diesel fuel (used for heating domestic purposes in Spain). The mixtures of VO and diesel are studied and characterized and, finally, the results of a series of combustion trials of the mixtures in a conventional heating installation with a mechanical pulverization burner are presented. The results show that viscosity of VO limits the use of blends up to 40% of them, and the oxygen present in their structures contributes to an efficiency gai
Low NO(x) heavy fuel combustor program
The 'low nitrogen oxides heavy fuel combustor' program is described. Main program objectives are to generate and demonstrate the technology required to develop durable gas turbine combustors for utility and industrial applications, which are capable of sustained, environmentally acceptable operation with minimally processed petroleum residual fuels. The program will focus on 'dry' reductions of oxides of nitrogen, improved combustor durability, and satisfactory combustion of minimally processed petroleum residual fuels. Other technology advancements sought include: fuel flexibility for operation with petroleum distillates, blends of petroleum distillates and residual fuels, and synfuels (fuel oils derived from coal or shale); acceptable exhaust emissions of carbon monoxide, unburned hydrocarbons, sulfur oxides and smoke; and retrofit capability to existing engines
Техніко-економічна ефективність екологічнобезпечного знешкодження сивушних масел на дизельних двигунах
Одним из важных аспектов применения сивушных масел в эквивалентном топливе является экономическая эффективность. При расчетах экономической эффективности использования сивушных масел как добавок к дизельным топливом необходимым техническим условием является обеспечение одинаковых цетановых чисел эквивалентного топлива по сравнению с товарным дизельным топливом. Выведена зависимость изменения цены используемого дизельного топлива от процентного содержания в нем сивушных масел. Следовательно, с увеличением процентного содержания сивушных масел в эквивалентном топливе достигается увеличение экономической эффективности за счет использования в эквивалентном топливе дизельного топлива с низким, цетановым числом.One of prominent aspects of application of fusel oils in equivalent fuel is economic efficiency. In calculations of economic efficiency of use of fusel oils as additives to the diesel fuel, the necessary specification takes maintenance identical cetane numbers of equivalent fuel in comparison with commodity diesel fuel. In an end result the author had been calculated dependences oj change of the price of used diesel fuel depending on percentage in it of fusel oils. Hence, for the accepted prices for diesel fuel and fusel oils from the lead calculations it is visible, that with increase in percentage oj fusel oils in equivalent fuel the increase in economic efficiency due to use in equivalent fuel of diesel fuel with low cetane number is reached
On-line monitoring of the transesterification reaction between triglycerides and ethanol using near infrared spectroscopy combined with gas chromatography
Many analytical procedures have been developed to determine the composition of reaction mixtures during transesterification of vegetable oils with alcohols. However, despite their accuracy, these methods are time consuming and cannot be easily used for on-line monitoring. In this work, a fast analytical method was developed to on-line monitor the transesterification reaction of high oleic sunflower oil with ethanol using Near InfraRed spectroscopy and a multivariate approach. The reactions were monitored through sequential scans of the reaction medium with a probe in a one-liter batch reactor without collecting and preparing samples. To calibrate the NIR analytical method, gas chromatography-flame ionization detection was used as a reference method. The method was validated by studying the kinetics of the EtONa-catalyzed transesterification reaction. Activation energy (51.0 kJ/mol) was also determined by considering a pseudo second order kinetics model
The effects of worked examples presentation on sub-cognitive loads
One promising technique for helping students in fulfilling complex problem solving tasks is through learning with worked example. Although worked example approach is the most prominent technique discussed in the literature of cognitive load theory, there is still very little scientific understanding of managing the students’ sub-cognitive load, namely intrinsic, extraneous and germane load on different complexity of worked example approach especially in engineering domain. Thus, this study was conducted to investigate the effects worked examples presentation on sub-cognitive loads among electrical engineering students. In this research, the worked examples were presented in three different sequences: (i) all examples were of same level of difficulty (ii) from difficult to easy example; (iii) from easy to difficult example. Data were collected from 82 students (Condition (i) =27; Condition (ii) = 34; condition (iii) = 21) of Diploma in Electrical Engineering Program at three selected polytechnics. The inventory tool of sub cognitive load were given to students after each teaching and learning session ends. The findings suggested that worked examples presented in easy to difficult format could be one of the approaches that is more efficient to manage students’ cognitive load and effective to be applied in engineering lesson
- …
