Fuel cell

“ When a flow of electrons is allowed to do work and move to the oxygen side of the fuel cell, the reaction will proceed. By use and replacement, hydrogen ions flow through the solid electrolyte to the catalytic electrode on the oxygen side of the fuel cell. When electrons are available on this surface, oxygen disassociates and combines with the available hydrogen ions to form water. ”

“ FUEL CELL BATTERIES CONSTRUCTION The fuel cell batteries used in the Gemini Spacecraft are of the solid ion exchange membrane type using hydrogen (H2) for fuel and oxygen (O2) for an oxidizer. The fuel cell battery system is comprised of two separate sections which are sealed in air tight pressure containers. Each section is made up of three interconnected fuel cell stacks with plumbing for transferring hydrogen, oxygen and product water.
Each fuel cell stack consists of 32 individual fuel cells. ”

“ Most of the impetus for developing the fuel cell as a practical device comes from the space program. The cell has admirable properties for space missions that are less than a few months in duration. It is a clean, quiet, vibrationless source of energy. Like the battery it has a high electrical overload capacity for supplying power peaks and is easily controlled. ”

“ One is the fuel cell, which converts fuel directly into electric power without the necessity for machinery or working parts. Much progress has been made on the fuel cell in recent months. In England a 40-cell unit has been used to drive a forklift truck and to do electric welding. It develops up to 5 kilowatts. [31] In the United States a 30-cell portable powerplant developing 200 watts has been delivered to the Army and Marine Corps, [32] while a 1,000-unit cell has been developed in the Midwest which provides 15 kilowatts and drives a tractor. ”

“ For short missions where large fuel supplies are not needed, it is also among the lightest power plants available.
These compelling advantages have led the National Aeronautics and Space Administration to choose the fuel cell for some of the first manned space ventures. Project Apollo, the manned lunar landing mission, is the most notable example. Here the fuel cell will be not only an energy source, but also part of the ecological cycle which keeps the crew alive.
Problem 4
A manned space vehicle requires an average of 2 electrical kilowatts. ”

“ Saturday is Earth Day, and many of you are asking how we can meet our growing energy needs while protecting our environment. The key is technology. So I have proposed the Advanced Energy Initiative to change the way we power our homes, businesses, and cars. I will visit the California Fuel Cell Partnership to take a closer look at hydrogen fuel cells, one of the exciting new technologies supported by my initiative. These fuel cells have the potential to revolutionize the way we power our cars by giving us vehicles that will emit no pollution and will be more efficient than gas-powered cars. ”

“ You can't get compressed hydrogen down at your Exxon station. But the people who build these fuel-cell cars say if there were incentives for energy companies to start doing that, that we could see fuel-cell cars, clean technology on the roads very soon. ”

“ It also conducts research into the technology for the manufacturing of basic and key components of fuel cells, integration of fuel cell stacks, fuel cell power generation and automotive fuel cell power systems, and strives to make breakthroughs in the technology for the end-use energy conversion, storage and combined cooling, heating and power projection of fossil energy-based micro-miniature gas turbine systems. ”

“ The fuel supplied to the engine is combined by chemical forces with the oxygen of the air. The vigour of the oxidation is partly dependent upon temperature, just as it is in any other oxidation process, and is of course dependent upon the presence of fuel to be oxidized, and air to furnish the oxygen. Unless the fuel is supplied and the air has free access to it, the machine stops, the cell dies. The energy liberated in this machine is converted into motion or some other form. ”

“ A wide range of fuels may be used in an internal-combustion engine. They may be either gaseous, liquid, or even solid. In stationary engines hydrogen, coal gas, natural gas, blast-furnace gas, and [156] producer gas are employed to advantage. Volatile fuels, such as alcohol, bensol, gasoline, and kerosene, are turned into a mist or vapor and then burned as a gas. In engines of the Diesel type any liquid fuel ranging down to thick crude oils may be employed, and in one type of engine, which, however, has not proved commercially practicable, coal dust is burned in the cylinder. ”

“ Water-gas, very rich in hydrogen, and made by a very similar process, is therefore not suitable for internal combustion engines.
There are many types of producers, but they fall under two main heads, i.e. the pressure and the suction.
The pressure producer contains the following essential parts:—
The generator, a vertical furnace fed from the top through an air-tight trap, and shut off below from the outside atmosphere by having its foot immersed in water. Any fuel or ashes which fall through the bars into the water can be abstracted without spoiling the draught. ”

“ In the case of a steam-boiler the energy of combustion is transmitted to water inside an air-tight vessel. The fuel does not actually touch the "working fluid." In the gas or oil engine the fuel is brought into contact and mixed with the working fluid, which is air. It combines suddenly with it in the cylinder, and heat energy is developed so rapidly that the act is called an explosion. Coal gas, mineral oils, alcohol, petrol, etc., all contain hydrogen and carbon. If air, which contributes oxygen, be added to any of these in due proportion, the mixture becomes highly explosive. ”

“ A current of air is introduced through the pipe, O, and this traverses the regenerators, B, enters the chamber, T, and the generator, A, through the flue, E. As this air rises through the mass of incandescent fuel, its oxygen combines with an atom of carbon and forms carbonic oxide. This gas that is disengaged from the upper part of the fuel consists chiefly of nitrogen and carbonic oxide, mixed with volatile hydrocarburets derived from the fuel used. ”

“ Other internal-combustion engines, as, for instance, the Priestman, Akroyd, and Knight engines, use common burning oils directly, and act as their own gas generators. Prof. Robinson urges that such dangerous and highly volatile hydrocarbons as benzoline, gasoline, and petroleum spirit should not be used as fuel in gas-engines. ”

“ The air drawn in combines with the carbon during its downward journey, and then passes through a cooling tower surrounded by a water jacket which acts as a boiler. The heat extracted from the gas is therefore used to produce steam, which drives an engine working the pump which aspirates the air. The exhaust steam from this engine passes into the incandescent fuel and is decomposed, forming hydrogen and carbon monoxide. The valves which govern the supplies of air and steam are so arranged that producer gas or water gas, or both at once, may be generated at will. ”

“ Inverted Combustion.—With a few exceptions the pressure-generators which have been described, as well as suction gas-producers which will be later discussed, are fed with anthracite coal or with coke. They cannot be operated with moderately soft or bituminous coal. For this reason they limit the employment of producer-gas engines. Manufacturers have long sought generators in which any fuel whatever can be consumed. ”

“ Turning to Fig. 6, we see a pipe through which the exhaust steam from the locomotive's cylinders is shot upwards into the funnel, in which, and in the smoke-box beneath it, a strong vacuum is formed while the engine is running. Now, "nature abhors a vacuum," so air will get into the smoke-box if there be a way open. There is—through the air-doors at the bottom of the furnace, the furnace itself, and the fire-tubes; and on the way oxygen combines with the carbon of the fuel, to form carbon dioxide. ”

“ It may be well to recall here that coal is not the only fuel which lends itself to the generation of gas suitable for driving engines, but that some generators are able to utilize lignite, peat, and the like. ”

“ In both engine and turbine the real source of power is not the steam but the fuel, such as coal or oil, which converts the water into steam.
180. Gas Engines. Automobiles have been largely responsible for the gas engine. To carry coal for fuel and water for steam would be impracticable for most motor cars. Electricity is used in some cars, but the batteries are heavy, expensive, and short-lived, and are not always easily replaceable. For this reason gasoline is extensively used, and in the average automobile the source of power is the force generated by exploding gases. ”

“ The chemical energy of coal and other fuels cannot be directly converted into electric energy. For power producing purposes, the chemical energy of a fuel is first converted into heat by combustion, and the heat thus obtained converted into mechanical energy by some form of heat engine, and the mechanical energy subsequently transformed into electric energy in an electric generator.
Energy cannot be created or destroyed. This is the law known as the conservation of energy which has been built up by Helmholtz, Thomson, Joule and others. ”

“ Since the carbon and hydrogen elements of a fuel exist in many different proportions and conditions in coal and oil, different amounts of oxygen are required for the consumption of different fuels. It should also be borne in mind that a greater quantity of air is required for the combustion of a fuel than oxygen, as the air is greatly diluted by an inert gas, nitrogen, which will not support combustion. Because of the impossibility of obtaining perfectly homogenous mixtures of air and the fuel, a greater quantity of air is used in practice than is theoretically required. ”

“ In passing into the incandescent fuel that fills the generator, the steam is decomposed, and there forms carbonic oxide, while hydrogen is liberated. The mixture of these two gases with the hydrocarburets furnished by the fuel constitutes water gas. This gas on making its exit from the generator through the pipe, M', passes through the chambers, B, and abandons therein the greater part of its heat, and enters the pipe, R, whence it passes through Q into the purifiers, and then into the gasometer. ”

“ For petroleum as a fuel under boilers in the generation of steam there are numerous substitutes, including wood, charcoal, coal, peat, natural gas, artificial gas, and electricity; as a fuel in internal-combustion engines some demonstrated substitutes are natural gas, artificial gas, benzol, and alcohol, and in the Diesel type of engine certain vegetable and fish oils can be utilized. ”

“ Under the head of fuel he includes not only wood, coal, but also all forms of matter that may be used or burnt up by heat, or dissolved by chemical agencies. Thus zinc and lead, which are used in batteries, are merely forms of fuel. That potential energy resides in such things as wood and coal is a matter of common experience. All our coal-fields are stores of energy, which received their energy when in plant form, ages ago, from the sun, and this energy is now being used to drive our machinery, to warm our houses, and to give light to our homes and our cities. ”

“ The process of making gas, which consists in blowing to incandescence the exterior portion of a body of fuel, forcing fresh fuel into the interior of the body, utilizing the sensible heat of the incandescent fuel in the destructive distillation of the fresh fuel, introducing steam into the interior portion of the body of fuel and causing it to pass, first through the fresh fuel and then through the heated exterior portion of the fuel bed. ”

“ While gas can yield the full fuel value of coal in a more efficient form than solid fuel, as well as all the commodity values, if it is converted into power through the steam engine, at least one-half of its energy value is lost. To conserve its full value, gas must be burned in the internal-combustion engine, the most familiar type of which is the one we know under the hood [Pg 99] of the automobile and the most efficient type is the Diesel engine which has made the by-product system industrially practical. ”

“ He looks beyond either turbine or shaft turned by wind or tide, and, remembering that the zinc dissolved in his battery yields at his will its full content of energy, either as heat or electricity, he asks. Why may not coal and forest tree, which are but other kinds of fuel, be made to do the same? ”

“ Chemical generators are of two kinds, primary and secondary cells. While primary cells are of many forms, that called the dry cell is universally used for the ignition of automobile engines, being adapted to the purpose because there is nothing to spill, and may be used in any position. ”

“ This brings about the necessity for injecting the fuel in a well-atomized condition at the time that combustion is desired and the quantities of fuel injected at this time control the amount of heat generated; that is, an infinitesimally small quantity of fuel will be burned just as efficiently in the Diesel engine as a full charge of fuel, whereas in the gasoline engine the mixture ratio must be kept reasonably constant and, if the supply of fuel is to be cut down for throttling purposes, the supply of air must be correspondingly reduced. ”

“ The automobile may have as the source of power internal-combustion engines using such fuel as gasoline, kerosene, benzol, and alcohol; it may use steam generated by these fuels; or an electric storage battery charged by sources outside the engine may furnish the propelling force. ”