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Fuels Combining with Oxygen

Most of the natural fuels we use are what are called fossil fuels - they are the remains of organisms which were alive millions of years ago. All living things contain carbon. When anything bums, the elements in it combine with oxygen from the air. When these fuels bum, the carbon in them is oxidised to carbon dioxide. They all contain hydrogen as well, and when they bum the hydrogen is oxidised to water. For example, when methane (in natural gas) is burned, the equation for the reaction is  [Pg.95]


Because of the price diffferential between low- and high-efficiency condensing furnaces, only 22 percent of gas furnaces sold in the mid-1990 s were high-effi-ciency condensing-type furnaces. Condensate is water that forms as a result of the combustion process. When the hydrogen in the fuel combines with oxygen from the combustion air, it forms water... [Pg.542]

Reactions in which a fuel combines with oxygen to produce water and carbon dioxide are called combustion reactions. Because natural gas consists primarily of methane, it is expected that reaction (1) will liberate heat. Reactions that liberate heat are termed exothermic reactions, and reactions that absorb heat are termed endothermic reactions. [Pg.1244]

The role of oxygen in combustion was recognized instead by the French chemist Antoine Lavoisier, who said that during combustion, a fuel combines with oxygen from the atmosphere (instead of giving off phlogiston), producing carbon dioxide and water. Lavoisier also discovered the law of conservation of mass in chemical reactions. [Pg.18]

Combustion reactions are among our most important chemical reactions. Our technological, energy-intensive society relies heavily on the combustion of fossil fuels as a source of energy. In the combustion of hydrocarbons, such as the substances found in natural gas or petroleum, the fuel combines with oxygen gas (O ) from the atmosphere to make carbon dioxide (CO ) and water (H O). [Pg.108]

Prevention of fires requires a knowledge of the basic elements and conditions which must coexist for a fire to occur. The fire triangle is a convenient schematic representation of the conditions under which combustion reactions occur, and therefore the key to preventing such reactions. Fire is a chemical reaction in which a substance (the fuel) combines with oxygen in the evolution of heat. Under normal circumstances fuels and... [Pg.102]

Another source of NO, usually unwanted, is in high-temperature combustion processes, such as those that occur in automobile engines and in electric power plants. At the same time that the fuel combines with oxygen from air to produce a high temperature, N2(g) and 02(g) in the hot air combine to a limited extent to form NO(g). [Pg.1072]

When fuels combust, it is always the carbon, hydrogen, or sulfur that produces the heat energy chemical reaction by combining with oxygen. [Pg.690]

This proton exchange membrane is used in both hydrogen and methanol fuel cells, in which a catalyst at the anode produces hydrogen from the methanol. Because the membrane allows the protons, but not the electrons, to travel through it, the protons flow through the porous membrane to the cathode, where they combine with oxygen to form water, while the electrons flow through an external circuit. [Pg.639]

Acid rain is caused primarily by sulfur dioxide emissions from burning fossil fuels such as coal, oil, and natural gas. Sulfur is an impurity in these fuels for example, coal typically contains 2-3% by weight sulfur.1M Other sources of sulfur include the industrial smelting of metal sulfide ores to produce the elemental metal and, in some parts of the world, volcanic eruptions. When fossils fuels are burned, sulfur is oxidized to sulfur dioxide (SO2) and trace amounts of sulfur trioxide (SC>3)J21 The release of sulfur dioxide and sulfur trioxide emissions to the atmosphere is the major source of acid rain. These gases combine with oxygen and water vapor to form a fine mist of sulfuric acid that settles on land, on vegetation, and in the ocean. [Pg.47]

Now, whatever purpose water gas may be required r, its use for this purpose depends on the fact that the IS will combine with oxygen with the evolution of ia.t, consequently the plant should be worked to make e product with the highest calorific power for the west fuel consumption. This requirement is reached ore closely if the plant is operated so that the first nation represents the chemical reaction which takes ice , consequently, in the practical manufacture of water s the coke or other fuel in the gas producer should at a temperature of about 1000° C. [Pg.73]

Acetylene, C2H2, and ethylene, C2H4, are both used as fuels. They combine with oxygen gas to produce carbon dioxide and water in an exothermic reaction. Acetylene also reacts with hydrogen to produce ethylene, as shown. [Pg.265]

Most fuels contain carbon. Charred wood, or charcoal, is almost pure carbon. When this burns in air, it combines with oxygen to make another gas, called carbon dioxide, and gives out heat energy. [Pg.6]

When the hydrogen is combined with oxygen in a fuel cell, a chemical reaction creates electricity. Between 150 and 200 fuel cells are stacked together to accumulate enough electricity to power the car. [Pg.162]

It is well known that U.S. space vehicles obtain their auxiliaiy power in space by the use of fuel cells (Chapter 13), electrochemical devices in which the spontaneous tendency of hydrogen to combine with oxygen drives the cell and produces electricity, with water as a by-product (pure enough to drink). It stands to reason then, that one might think of producing substances more economically valuable than water in this electrogenerative way. Such work is into its first decade and Fig. 7.190 shows an example benzene is oxidized to phenol with electricity as a by-product Clearly, the economics of such a process depend on the cost of the H2 and whether one can sell the electricity. This gives rise to a speculation. [Pg.660]

Natural gas, which was previously the predominant feedstock for the production of channel blacks and furnace blacks in the United States, has lost its importance for economic reasons. Currently, only thermal blacks are produced with natural gas. However, natural gas is still the most important fuel in the furnace black process, even though the use of other gases and oils is also possible. In several patents recycled tail gas in combination with oxygen or oxygen-enriched air, has also been proposed as a fuel, but has not reached any commercial importance. [Pg.149]

That carbon may enter into these two combinations with oxygen is of utmost importance in the design of combustion equipment. Firing methods must assure complete mixture of fuel and oxygen, to be certain that all of the carbon bums to CO and not to CO. Failure to meet this requirement will result in appreciable losses in combustion efficiency and in the amount of heal released by the fuel, since only about 28% of the available heat in the carbon is released if CO is formed instead of CO . [Pg.425]

Electrons are necessary for electricity to form because electricity is the result of electrons in motion. Inside a fuel cell, electrons are stripped of hydrogen atoms that enter the cell. These electrons are now free to travel through a circuit and provide electricity. Remember that hydrogens atomic number is 1, so it has 1 proton. A neutral hydrogen atom, then, must also contain 1 electron so that the charges balance. In a fuel cell, the stripped-off electrons and the other part of the hydrogen atom—the proton—are eventually combined with oxygen. This combination makes water. Because water is the only byproduct of this reaction, fuel cells produce very little pollution, unlike other methods used to produce electricity. [Pg.8]

Figure 23 Air-breathing microfluidic fuel cells showing the colaminar flow principle, in combination with oxygen capture via gas diffusion through a porous cathode A three-phase interface is established between gas, electrolyte, and catalyst/solid electrode (reprinted with permission from Jayashree et al., 2005. Copyright 2005 American Chemical Society). Figure 23 Air-breathing microfluidic fuel cells showing the colaminar flow principle, in combination with oxygen capture via gas diffusion through a porous cathode A three-phase interface is established between gas, electrolyte, and catalyst/solid electrode (reprinted with permission from Jayashree et al., 2005. Copyright 2005 American Chemical Society).
Results Whenever the yellow part of a flame came in contact with a cool dish, a black substance was deposited. This substance is carbon. When carbon burns incompletely, which is usually the case, it glows with a yellow color. A flame is made of tiny particles of very hot carbon. When they cool quickly, as they did on striking the cool dish, they were deposited there as black carbon. When they cool more slowly, as above an open flame, they join with atoms of oxygen from the air and become carbon dioxide (C02), a colorless invisible gas. You found the bottom of the saucers damp. Every flame gives off water vapor also. This is because the fuel contains hydrogen, which combines with oxygen in the air to form water vapor. Wherever there is a fire then, there is carbon in the flame, and there are two by-products—carbon dioxide and water vapor. [Pg.63]


See other pages where Fuels Combining with Oxygen is mentioned: [Pg.495]    [Pg.34]    [Pg.96]    [Pg.95]    [Pg.473]    [Pg.46]    [Pg.495]    [Pg.34]    [Pg.96]    [Pg.95]    [Pg.473]    [Pg.46]    [Pg.347]    [Pg.2313]    [Pg.2367]    [Pg.807]    [Pg.65]    [Pg.340]    [Pg.527]    [Pg.44]    [Pg.12]    [Pg.145]    [Pg.315]    [Pg.23]    [Pg.189]    [Pg.161]    [Pg.175]    [Pg.48]    [Pg.84]    [Pg.209]    [Pg.101]    [Pg.44]    [Pg.2068]    [Pg.2122]    [Pg.387]    [Pg.121]   


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