Fuels defined

Oppenauer oxidation, 24 506 Opponent theory, of color, 7 304 Opportunistic systematic generation strategy, 22 300 for binary systems, 22 324t flowsheet construction and, 22 307 rules for selecting, 22 313t, 315 Opportunity fuels, defined, 6 828 Opposition patent information searches, 18 235... 

In considering the ignition of vapors, two important concepts are flammability limit and flammability range. Values of the vapor/air ratio below which ignition cannot occur because of insufficient fuel define the lower flammability limit. Similarly, values of the vapor/air ratio above which ignition cannot occur because of insufficient air define the upper flammability limit. The difference between upper and lower flammability limits at a specified temperature is the flammability range. 

The properties of a fuel define its physical and chemical characteristics. A thorough understanding of the properties of a fuel is essential to the design and engineering of engine combustion systems, vehicle fuel systems, fuel storage, and fuel dispensing systems. Fuel properties impact vehicle performance, emissions, fuel efficiency, reliability, and durability. 

Snawder and Butler (2001) collected venous blood and urine from 107 people who worked at six U.S. Air Force bases (AFBs) Davis Monthan AFB, Arizona Seymour Johnson AFB, North Carolina Langley AFB, Virginia Pope, AFB, North Carolina Little Rock AFB, Arkansas and Hurlbert Field, Florida. The exposed workers were fuel tank-entry personnel with persistent exposure to jet fuel (defined as a 1-hr entry twice a week for at least 9 months). The unexposed group consisted of Air Force personnel who had no important occupational exposure to hydrocarbon solvents or fuels. The participants... 

The next big step forward in ERD was the Industrial Revolution. The list of things that get hot and move expanded to include steam engines and house heating, mostly driven by fossil fuels. Defining more complex societies is a more complex calculation, but Chaisson insists that what matters is the flow of energy through the aggregated social network. He estimates that ERD for industrial societies increased to 50 watts/kg. 

Diesel index An empirical measure of the ignition quality of a diesel fuel defined in terms of the API gravity and aniline point of the fuel. The higher the number, the better the ignition quaUty. 

Core U235 Loading (kg) Fuel defined as 9S% dertse U02... 

In practice, for motors, turbines or furnaces, the conditions of combustion are frequently far from those corresponding to stoichiometry and are characterized either by an excess or by an insufficiency of fuel with respect to oxygen. The composition of the fuel-air mixture is expressed by the equivalence ratio, (p, defined by the relation / 5 r)... 

In the expression for heating value, it is useful to define the physical state of the motor fuel for conventional motor fuels such as gasoline, diesei fuel, and jet fuels, the liquid state is chosen most often as the reference. Nevertheless, if the material is already in its vapor state before entering the combustion system because of mechanical action like atomization or thermal effects such as preheating by exhaust gases, an increase of usefui energy resufts that is not previously taken into consideration. 

If one imagine.s that the fuel is used in the liquid state in the form of droplets —as in the case of fuel injection— the specific energy of the motor fuel (SE) is expressed in kilojoules per kilogram of air utilized, under predetermined conditions of equivalence ratio (stoichiometry for example). The SE is none other than the NHY /r quotient where r represents the previously defined stoichiometric ratio. 

Tests on vehicles have shown that the volatility index as defined expresses satisfactorily the fuel contribution during hot operation of the engine (Le Breton, 1984). In France, specifications stipulate that its value be limited to 900, 1000 and 1150, respectively, according to the season (summer, spring/fall, winter). The automobile manufacturers, being even more demanding, require in their own specifications that the FVI not be exceeded by 850 in summer. 

A motor fuel has an octane number X if it behaves under tightly defined experimental conditions the same as a mixture of X volume % of isooctane and (100 - X)% of n-heptane. The isooctane-heptane binary mixtures are called primary reference fuels. Octane numbers higher than 100 can also be defined the reference material is isooctane with small quantities of tetraethyl lead added the way in which this additive acts will be discussed later. 

The Eurosuper as defined by the European Directive of 16 December 1985, offering a minimum RON of 95 and a minimum MON of 85. Found throughout the European countries, it still is fairly scarce in France with 10% of the total demand for unleaded fuels. 

In the United States, the different categories of motor fuels are not defined as they are in Europe by minimum RON and MON values, but by a combination... 

To evaluate the real behavior of fuels in relation to the segregation effect, the octane numbers of the fuel components can be determined as a function of their distillation intervals In this manner, new characteristics have been defined, the most well-known being the delta R 100 (A7 100) and the Distribution Octane Number (DON). Either term is sometimes called the Front-End Octane Number . 

The cold filter plugging point (CFPP) is the minimum temperature at which a given volume of diesel fuel passes through a well defined filter in a limited time interval (NF M 07-042 and EN 116 standards). For conventional diesel fuels in winter, the CFPP is usually between —15 and —25°C. 

Another characteristic used for some time to measure the propensity of a diesel fuel for auto-ignition, is the Diesel Index (Dl). This is defined by the relation ... 

This justifies all the work undertaken to arrive at fuel denitrification which, as is well known, is difficult and costly. Moreover, technological improvements can bring considerable progress to this field. That is the case with low NO burners developed at IFF. These consist of producing separated flame jets that enable lower combustion temperatures, local oxygen concentrations to be less high and a lowered fuel s nitrogen contribution to NOj. formation. In a well defined industrial installation, the burner said to be of the low NO type can attain a level of 350 mg/Nm, instead of the 600 mg/Nm with a conventional burner. 

The nature of these paraffins and their concentration in diesel fuel affect the three temperatures that characterize the cold behavior. The cloud point is the temperature at which crystals of paraffins appear when the temperature is lowered. The cold filter pluming point is defined as the temperature under which a suspension no ionger flows through a standard filter. Finally, the pour point is the temperature below which the diesel fuel no longer flows by simple gravity in a standard tube. These three temperatures are defined by regulations and the refiner has three types of additives to improve the quality of the diesel fuel of winter. 

In the late 1980s attempts were made in California to shift fuel use to methanol in order to capture the air quaHty benefits of the reduced photochemical reactivity of the emissions from methanol-fueled vehicles. Proposed legislation would mandate that some fraction of the sales of each vehicle manufacturer be capable of using methanol, and that fuel suppHers ensure that methanol was used in these vehicles. The legislation became a study of the California Advisory Board on Air QuaHty and Fuels. The report of the study recommended a broader approach to fuel quaHty and fuel choice that would define environmental objectives and allow the marketplace to determine which vehicle and fuel technologies were adequate to meet environmental objectives at lowest cost and maximum value to consumers. The report directed the California ARB to develop a regulatory approach that would preserve environmental objectives by using emissions standards that reflected the best potential of the cleanest fuels. 

Physical Properties. Physical properties of waste as fuels are defined in accordance with the specific materials under consideration. The greatest degree of definition exists for wood and related biofuels. The least degree of definition exists for MSW, related RDF products, and the broad array of ha2ardous wastes. Table 3 compares the physical property data of some representative combustible wastes with the traditional fossil fuel bituminous coal. The soHd organic wastes typically have specific gravities or bulk densities much lower than those associated with coal and lignite. 

Where T)is flame temperature in K MC is moisture content of the waste, expressed on a total weight basis SR is defined as stoichiometric ratio or moles O2 avadable/moles O2 required for complete oxidation of the carbon, hydrogen, and sulfur in the fuel, ie, 1/SR = equivalence ratio and is temperature of the combustion air, expressed in K. In Fnglish units, this equation is as follows ... 

Partial Oxidation. It is often desirable to augment the supply of naturally occurring or by-product gaseous fuels or to produce gaseous fuels of well-defined composition and combustion characteristics (5). This is particularly tme in areas where the refinery fuel (natural gas) is in poor supply and/or where the manufacture of fuel gases, originally from coal and more recently from petroleum, has become well estabHshed. 

Indirect Hquefaction of coal and conversion of natural gas to synthetic Hquid fuels is defined by technology that involves an intermediate step to generate synthesis gas, CO +. The main reactions involved in the generation of synthesis gas are the coal gasification m2LC ions Combustion... 

Although ASTM specifies certain quaUty levels, there are a number of factors that contribute to other quaUty levels in the marketplace. At times, government regulations are more restrictive than ASTM specifications, especiaHy with respect to environmental issues. Secondly, competitive forces may encourage companies to provide fuel quaUty that is better than that defined by ASTM. Thirdly, ASTM specifications do not have the force of law, and certain companies may decide to exceed or not meet their recommended values. In response to this last factor, some states have adopted ASTM fuel quahty specifications as state regulations, thus forcing a minimum quaUty level in the field. 

The octane number requirement (ONR) of a car is the octane number which causes barely audible, ie, trace knock when driven by a trained rater. The Coordinating Research Council (CRC), a research organi2ation funded joindy by the American Petroleum Institute (API) and the American Automobile Manufacturers Association (AAMA), has defined test procedures for measuring ONR. Each car is driven under a set of light and heavy accelerations until the most sensitive driving mode is determined. Then a series of fuels is mn in the car until trace knock is determined. Each year, CRC members measure ONR of more than 100 cars and pubHsh the results. 

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