Carbon fuels definition

First, we will refer to the direct use of hydrocarbon fuels in an SOFC as direct utilization rather than direct oxidation. Second, we recognize that the broadest definition of direct utilization, exclusive from mechanistic considerations, should include rather conventional use of fuel by internal reforming, with steam being cofed to the fuel cell with the hydrocarbon. Indeed, this nomenclature has been used for many years with molten-carbonate fuel cells. However, because internal reforming is essentially limited to methane and because the addition of steam with the fuel adds significant system complexity, we will focus primarily on systems and materials in which the hydrocarbons are fed to the fuel cell directly without significant amounts of water or oxygen. 

The role of biomass in the natural carbon cycle is not well understood, and in the light of predictions of a future atmospheric energy balance crisis caused by carbon dioxide accumulation, in turn the result of an exponential increase in the consumption of carbon fuel, the apparent lack of concern by scientists and policy makers is most troubling. Yet there is no other single issue before us in energy supply which will require action long before the worst effects of excess production will be apparent. The only satisfactory model is the action taken by the R D community with respect to the SST in nitric oxide potential and chloro-halocarbon emissions, when it was realised that the stratospheric ozone layer was vulnerable to interference. Almost all other responses to pollution" have been after definitive effects have become apparent. 

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. 

A petrochemical is any chemical (as distinct from fuels and petroleum products) manufactured from petroleum (and natural gas) and used for a variety of commercial purposes (Table 3.8). The definition, however, has been broadened to include the entire range of aliphatic, aromatic, and naphthenic organic chemicals, as well as carbon black and inorganic materials such as sulfur and anunonia. Petroleum and natural gas are made up of hydrocarbon molecules, which comprise one or more carbon atoms to which hydrogen atoms are attached. Currently,... 

As for similar additives for jet and gas-turbine fuels, the literature is sparse on those distillate fuel-oil additives reported to have definite beneficial influence on actual combustion and is confined largely to claims that certain stability improvers also reduce carbon deposits in preheaters and on burner tips. However, a recent report indicates that ferrocene has recently been groomed for a job as combustion catalyst in home heaters (15). As mentioned previously, this substance is reported to have excellent properties for prevention of carbon formation (2). 

Synthesis gas may be prepared from any feedstock containing any ratio of carbon and hydrogen and oxygen and not extreme levels of sulphur and nitrogen. Such a definition covers feedstocks ranging from wood, biomass, coal and heavy fuel oils, to naphtha and natural gas. 

Combustion of Solid Carbon.—Owing to their importance as fuel, eaibonaceous materials have for centuries been the subject of scientific consideration. For some time prior to the discovery of oxygen, carbon or charcoal was regarded as composed mainly of the essence of combustibility, and Stahl (c. 1697) considered it to be almost pure phlogiston (see p. 11). On this theory, the fact that only a certain quantity of charcoal could bum m a limited supply of air was readily explained on the assumption that phlogiston could not leave a substance unless it had somewhere to go. The air could only absorb a definite amount, and when once fully phlogistieated behaved like a saturated body and refused to take up any more. 

The storage of methane as hydrates offers a potentially vast natural gas resource. As to the question of how much hydrate there is right now, there is no definitive answer. However, the worldwide amount of carbon bound in gas hydrates has been estimated to total twice the amount of carbon to be found in all known fossil fuels originally on Earth. Additionally, conventional gas resources appear to be trapped beneath methane hydrate layers in ocean sediments.22... 

Max. lb fluegas = (LHV/lb fuel/(carbon fraction X 745).) The important consideration is the definition of the C fraction. CO. is not combustible carbon and should be treated as an inert. CO is not combustible carbon but an entity unto itself. CO will burn when the fluegas enthalpy per pound of... 

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