Fuel various fuels

Thermochemical Liquefaction. Most of the research done since 1970 on the direct thermochemical Hquefaction of biomass has been concentrated on the use of various pyrolytic techniques for the production of Hquid fuels and fuel components (96,112,125,166,167). Some of the techniques investigated are entrained-flow pyrolysis, vacuum pyrolysis, rapid and flash pyrolysis, ultrafast pyrolysis in vortex reactors, fluid-bed pyrolysis, low temperature pyrolysis at long reaction times, and updraft fixed-bed pyrolysis. Other research has been done to develop low cost, upgrading methods to convert the complex mixtures formed on pyrolysis of biomass to high quaHty transportation fuels, and to study Hquefaction at high pressures via solvolysis, steam—water treatment, catalytic hydrotreatment, and noncatalytic and catalytic treatment in aqueous systems. 

Fig. 5. Fuel economy vs energy content for various fuels. Each data poiat represents the average of twenty 1989 vehicles. To convert MJ/L to Btu/gal,...

The use and effective costs of various energy alternatives are shown in Table 2. Use or internal costs include production, transportation, and distribution. Effective costs take into account the use costs estimated external costs, which include costs associated with damage to the environment caused by utili2ation of various fossil fuels and fuel utili2ation efficiencies, ie, the efficiency of converting fuels into mechanical, electrical, or thermal energy. The effective costs are expressed as /GJ of fossil fuel equivalent (15). The overall equation for the effective cost is... 

A notable difference between the newer large machines and the somewhat smaller units is the use of multiple, reverse-flow can combustors configured annulady. Because the individual cans are relatively small, they reportedly lend themselves well to laboratory experimentation with various fuel types, including reduced-heat value synfuels (see Fuels, synthetic). A dry, low NO version of the can combustors has been developed for both gas and hquid fuel firing. NO emissions can reportedly be held below 25 ppm when firing gas fuel. By employing water injection, NO emissions can be held below 60 ppm for oil-fired units. 

Refuse-Derived Fuel. Many processing faciUties divert a portion of the material that is not recovered for recycling to waste-to-energy plants, also referred to as resource recovery faciUties, where the material is employed as fuel. The processes involved in the production of refuse-derived fuel (RDF) are outlined in Figure 4 (23). Nine different RDFs have been defined, as Hsted in Table 3 (24). There are several ways to prepare RDF-3, which is perhaps the most popular form and is the feed used in the preparation of densified refuse-derived fuel (d-RDF). AH forms of RDF are part of the broader set of waste-derived fuels (WDF), which includes various waste biomass, eg, from silvaculture or agriculture (see Fuels frombiomass Fuels fromwaste). 

FIG. 27-11 Gomtilstion air requirements for various fuels at zero excess air. To convert from kg air/GJ fired to Ih air/lO Btii fired, multiply hy 2.090. 

Flexibility of service and fuels are criteria, which enhance a turbine system, but they are not necessary for every application. The energy shortage requires turbines to be operated at their maximum efficiency. This flexibility may entail a two-shaft design incorporating a power turbine, which is separate and not connected to the Gasifier unit. Multiple fuel applications are now in greater demand, especially where various fuels may be in shortage at different times of the year. 

Figure 12-1. Effect of various fuels on turbine inlet temperature.

Fuel requirements are defined by various fuel properties. By eoineidenee, the heating-value requirement is also a property and needs no further mention. 

Langford, B., Palmer, K. N., and Tonkin, P. S. 1961. The Performance of Flame Arrestors Against Flame Propagating m Various Fuel/Air Mixtures. Fire Research Station Note No. 486. Fire Research Station, Borehamwood, Herts., England. 

The characteristic magnitudes of detonation cells for various fuel-air mixtures (Table 3.2) show that these restrictive boundary conditions for detonation play only a minor role in full-scale vapor cloud explosion incidents. Only pure methane-air may be an exception in this regard, because its characteristic cell size is so large (approximately 0.3 m) that the restrictive conditions, summarized above, may become significant. In practice, however, methane is often mixed with higher hydrocarbons which substantially augment the reactivity of the mixture and reduce its characteristic-cell size. 

Stewart, F. R. 1964. Linear flame heights for various fuels. Combustion and Flame 8 171-178. 

Although desulfurization is a process, which has been in use in the oil industry for many years, renewed research has recently been started, aimed at improving the efficiency of the process. Envii onmental pressure and legislation to further reduce Sulfur levels in the various fuels has forced process development to place an increased emphasis on hydrodesulfurization (HDS). For a clear comprehension of the process kinetics involved in HDS, a detailed analyses of all the organosulfur compounds clarifying the desulfurization chemistry is a prerequisite. The reactivities of the Sulfur-containing structures present in middle distillates decrease sharply in the sequence thiols sulfides thiophenes benzothiophenes dibenzothio-phenes (32). However, in addition, within the various families the reactivities of the Substituted species are different. 

Figure 30.2 The relationship between oxygen and carbon dioxide in the products of combustion for various fuels...

Table 21.2 Flame temperatures with various fuels...

The influence of metal type on the specific impulse of propints has been described previously in this article (Table 16). The max theoretical specific impulse and density impulses (ISp x p ) for the oxidizers AN, AP and hydrazinium nitrate with 15 weight percent -fCH2)- binder have been calculated for various fuels (Ref 24). These data are in Tables 49-51. The ISp performance of nitronium perchlorate, lithium perchlorate and potassium perchlorate and metallized fuels with 4CH2>- binder are given in Table 52 (Ref 43)... 

Dewpoints and the potential rate of corrosion vary with various fuel sources, their sulfur content, and the type of burners employed. Different fuel sources create differences in fireside (gas-side) corrosion and fouling behavior, and particular fuels may lead to very specific... 

Air is added at different elevations within the boiler to provide various fuel-to-air ratios, depending on combustion requirements. Superheated HP steam is produced and passed to a turbine generator. The resultant LP steam is used for woodchip cooking, furnace air heating, pulp drying, and related processes. 

Clinker treatments are additives designed to reduce the amount of clinkering formations that takes place in boilers fired by bark, bagasse, and similar low-calorific-value fuels. These fuels can give rise to considerable amounts of noncombustible deposits that must be continuously or regularly removed from the furnace area. Clinker treatments are formulated for use with various types of furnace, including slant, pin hole, and chain grate furnaces. 

Frayne, Colin (ANCO). Overview of Combustion and Related Problems Associated with Various Fuels, and Their Technical Solutions. Technical Bulletin. Anderson Chemical Company, Inc., USA, 1992. 

Combustion may be induced by lower pressures by preheating the strand, by providing a sufficient incident radiant flux, by adding certain catalytic agents, and by adding small amounts of various fuels. 

Table 10.6. Composition of various fuels used in power plants. Orimulsion is a very heavy fuel, which is retrieved by pumping steam into the oil-field, thereby giving a mixture of heavy oil and water that is only fluid at elevated temperature.

Owing to the high diffusivity, low viscosity, and unique chemical nature, combustibility of hydrogen is somewhat different than the other fuels. Various combustibility properties are described in the following ... 

Two common examples of the three components of the fire triangle are wood, air, and a match and gasoline, air, and a spark. However, other, less obvious combinations of chemicals can lead to fires and explosions. Various fuels, oxidizers, and ignition sources common in the chemical industry are... 

Values of yields for various fuels are listed in Table 2.3. We see that even burning a pure gaseous fuel as butane in air, the combustion is not complete with some carbon monoxide, soot and other hydrocarbons found in the products of combustion. Due to the incompleteness of combustion the actual heat of combustion (42.6 kJ/g) is less than the ideal value (45.4 kJ/g) for complete combustion to carbon dioxide and water. Note that although the heats of combustion can range from about 10 to 50 kJ/g, the values expressed in terms of oxygen consumed in the reaction (Aho2) are fairly constant at 13.0 0.3 kJ/g O2. For charring materials such as wood, the difference between the actual and ideal heats of combustion are due to distinctions in the combustion of the volatiles and subsequent oxidation of the char, as well as due to incomplete combustion. For example,... 

Table 9.4 Estimates of burning rates for various fuel systems [20]...

Figure 10.12 Relationship between the radiative fraction and pan diameter for various fuel fires...

Although an FC produces electricity, an FC power system requires the integration of many components beyond the fuel cell stack itself, for the FC will produce only DC power and utilize only processed fuel. Various system components are incorporated into a power system to allow operation with conventional fuels, to tie into the AC power grid, and often,... 

---