Fuel, definition

Thus, according to the definitions, diesel fuel (or gas oil) is not a heating fuel but a motor fuel. Incidentally, heavy fuel can be considered a heating fuel or a motor fuel depending on its application in a burner or in a marine diesel engine. 

In the case of motor fuels, when the content of the material added is relatively high, we will use the term components of the mixture. Thus the ethers, used in the formulation of motor fuels in significant proportions, will not be Included in our definition. 

The term feedstock in this article refers not only to coal, but also to products and coproducts of coal conversion processes used to meet the raw material needs of the chemical industry. This definition distinguishes between use of coal-derived products for fuels and for chemicals, but this distinction is somewhat arbitrary because the products involved in fuel and chemical appHcations are often identical or related by simple transformations. For example, methanol has been widely promoted and used as a component of motor fuel, but it is also used heavily in the chemical industry. Frequendy, some or all of the chemical products of a coal conversion process are not isolated but used as process fuel. This practice is common in the many coke plants that are now burning coal tar and naphtha in the ovens. 

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. 

Prior to the discovery of plentihil suppHes of natural gas, and depending on the definition of the resources (1), there were plans to accommodate any shortfalls in gas supply from soHd fossil fuels and from gaseous resources by the conversion of hydrocarbon (petroleum) Hquids to lower molecular weight gaseous products. 

The difference between RON and MON for a particular fuel is called the sensitivity. By definition, the RON and MON of the primary reference fuels are the same and the sensitivity is 2ero. For all other fuels, the sensitivity is almost always greater than 2ero. Generally, paraffins have low sensitivities whereas olefins and aromatics have sensitivities ranging up to 10 and higher. 

The lower volatihty of JP-8 is a significant factor in the U.S. Air Force conversion from JP-4, since fires and explosions under both combat and ordinary handling conditions have been attributed to the use of JP-4. In examining the safety aspects of fuel usage in aircraft, a definitive study (15) of the accident record of commercial and military jet transports concluded that kerosene-type fuel is safer than wide-cut fuel with respect to survival in crashes, in-flight fires, and ground fueling accidents. However, the difference in the overall accident record is small because most accidents are not fuel-related. 

Chemurgy is defined as that branch of appHed chemistry devoted to industrial utilization of organic raw materials, especially from farm products. A more modem and general definition for chemurgy is the use of renewable resources particularly biomass, usually plant or microbial material, for materials and energy (see Fuels frombiomass Fuels fromwaste). 

Originally confined to the shipment of crude raw materials and fuels, the term transportation of bulk sohds now apphes also to manufactured produc ts, which often become raw materials for other industries. In recent years, increasing tonnages of highly processed, finished chemical products have moved to customers in large bulk units. A useful definition of a bulk shipment is any unit greater than 2000 kg (4000 lb) or 2 m (70 fF). The containers available range from small portable hoppers of 2-m (70-fF) capacity to railroad cars of 255-m (9000-fF) capacity. 

With a solid fuel, such as coal or wood, a series of steps are involved in combustion. These steps occur in a definite order, and the combustion device must be designed with these steps in mind. Figure 6-6 shows what happens to a typical solid fuel during the combustion process. 

Cleanliness of the fuel must be monitored if the fuel is naturally dirty or can pick up contaminants during transportation. The nature of the contaminants depends on the particular fuel. The definition of cleanliness here concerns particulates that can be strained out and is not concerned with soluble contaminants. These contaminants can cause damage or fouling in the fuel system and result in poor combustion. 

Most compounds in which carbon is the key element are classified as organic. Common examples of organic compounds include degreasing solvents, lubricants, and heating and motor fuels. This subsection highlights some of the more common characteristics of organics as they relate to hazards. Various relevant classes of organics are presented in terms of chemical behavior and physical properties. In order to facilitate the discussion to follow, a few basic definitions will be presented first. 

There is a wide range of conversion levels. The term maximum conversion type has no precise definition but is often used to describe a level of conversion, where there is no net fuel oil manufactured. A fuel products refinery with specialities may manufacture lubricating oils, asphalts, greases, solvents, waxes and chemical feed stocks in addition to the primary fuel products. The number and diversity of products will naturally vary from one refinery to another. Refineries produce chemical feed stocks for sale to the chemical affiliates and do not have responsibility for the manufacture of chemical products directly. Both operations may be carried out at the same physical location but the corporate product responsibilities are usually separate. 

B is the heat transfer from Z to the closed cycle within control surface Y, which occurs during the time interval that A/f, the mass of fuel, is supplied and [CV]q is its calorific value per unit mass of fuel for the ambient temperature (Tq) at which the reactants enter. F = A/f[CV]o is equal to the heat (0o) that would be transferred from Z if the products were to leave the control surface at the entry temperature of the reactants, taken as the temperature of the environment, Tq. Fig. 1.7 illustrates the definition of calorific value. 

The shortage of petroleum after World War I induced an intense search for a gasoline substitute in the form of alcohol. The trade press felt alcohol would definitely replace gasoline as a fuel at some point. The advantages ot alcohol cited in the technical press included greater power and elimination of knocking. 

Since the foregoing tests were carried out at -identical conditions of compn and temp, and in a standard test fixture, the burning times serve as a means of checking the relative fineness of thea powdered tungsten fuels. The rapid burning times indicate that both M-10 and M-20 are very fine. Also, the M-10 is definitely finer than M-20, as shown by the difference in burning times... 

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