Viability of a Hydrogen Fuel Based Economy

Some “alternates within alternates” are studied and possible improvement of our energy policies are explored. The viability of a hydrogen fuel economy is reviewed. Methanol, ethanol or ammonia versus hydrogen is one area of interest. Others include liquid hydrogen versus jet fuels, the use of geothermal, solar, wind or water energy for production of hydrogen gas versus development of deep earth supplies of natural gas is another. Energy enhancement as opposed to energy conservation is investigated with regard to polar climate and what might be done to improve natural energy balances, particularly in the northern hemisphere. Pumping Arctic Ocean water out into the Pacific Ocean via the Bering Strait would be an energy debit as opposed to energy gains such as biomass conversion of future plant growth throughout the Siberian and Canadian tundra regions and presently very arid desert regions, improved access to northern region fuel, metal ore and mineral resources, year-round shipping and fishing fleet operations in the Arctic Ocean and development of the tremendous Greenland hydroelectric power potential. VIABILITY OF A HYDROGEN FUEL BASED ECONOMY Impending energy problems were foreseen at least since World War II but some 12 years ago people everywhere were forcefully reminded as to what happens when fuel for a worldwide energy systems economy becomes scarce. This happened when the price of crude rose in frequent spasmodic jumps from $2 per barrel to $34 a barrel and more during the 1970’s. It was held that natural gas was in even shorter supply and official USA policies accepted the end of natural gas as dogma. Many people believed nuclear fission plants would be our salvation even though nuclear fuel was scarcer than oil and its costs rose whenever the cost of oil rose. Also fission plants generate electricity which furnishes l/3 of our energy but not liquid or gaseous fuels needed for the other 2/3 of our energy consumption. Others said not to worry we would go back to coal which can be fired in thermalelectric plants and also converted to fuel oil and/or combustible gases. Coal is more plentiful than crude oil and its price increases did not keep up with rising costs of crude oil and uranium during this period. On the other hand air pollution is a major problem in burning coal and flue gas scrubbers are expensive. Up to 2 pounds of coal are needed to obtain either 1 pound of fuel oil or 1 pound of combustible gas. These considerations led to mass reviews of alternate energy sources. Hydro-electric power had languished with the advent of cheap thermal fuels and nuclear fission. Most sites close to load centers were well utilized or quite small. Extraction of energy from tidal eagres, wave action, thermal gradients or saline gradients at sea remains in its infancy. Many large hydropower sites even at maximum distances from load points are being developed. Many more such as in Alaska and Greenland are still too far from load points. Many older *Work supported by the Department of Energy, DEAC03-76SF00515. Presented at the 7th Annual International Conference on Alternate Energy Sources, Miami, Florida, December 411, 1985 hydro-electric plants have been revitalized using newer more efficient turbine-generators and there has been realistic interest in small hydro-plants despite legal difficulties with reluctant utility system customers and a host of government regulatory agencies. Interest in windmills was bought back from the grave but such power plants are small and do not generate electricity when wind velocity is too high or too low. Intense interest was focussed on solar power but large plants are very expensive and much development work is needed if costs are to be tamed. In solar power the technology exists but the ideal of photo-voltaic direct conversion of heat into electricity remains much more costly than thermal-electric cycles and the sun does not shine at night. Fusion reactor power plants in principle could very well be an energy problem panacea but so far the technology does not yet exist, development programs are being cut back and prognostications have become gloomy. In view of the dwindling of fossil fuels, the growing problems of nuclear fueled plants and apparent demise of natural gas it became clear to many that what was really needed was an alternate energy fuel economy. Attention increasingly focussed on hydrogen as the answer. It is plentiful, can be burned in existing equipment with minor changes, burns to water vapor in air, has an energy content per pound that is 3 times that of petrofuels and 4 times that of the best grades of coal, is as safe as other fuels presently in use, burns cleaner than any other fuel and can be produced economically using free energy sources provided other fuels continue to cost more and more [l]. Proponents of hydrogen energy should not be purists. A prime example of the drawbacks of a purist approach is our languishing nuclear fission industry. These plants were designed to be 100% nuclear and most of these plants use either the pressurized water or boiling water design. This approach required use of expensive enriched uranium fuel and precluded use of standard 2 pole (3,600 RPM) generators driven by steam turbines using superheated, dry throttle steam. This led to the development of 4 pole(1800 RPM) generators driven by steam turbines using wet throttle steam with condensate extracted between each row of rotary blading and are about 25% less efficient than AIEEE-ASME preferred standard units. A major factor causing frequent shutdowns of nuclear fission plants is not the nuclear side but the steam turbines in which all blading is subject to erosion damage. A separate oil or gas fired superheater could have been used at each reactor to permit use of more efficient and trouble-free turbines. One U.S.A. reactor uses very high temperature helium gas turbine drives at high efficiency and on-line ratings and it is claimed that reactor melt down cannot happen in such a cycle. The Canadian design uses heavy water as a moderator-coolant so that natural uranium-oxide fuel elements can be used in an arrangement which allows on-line fuel replacement, obviating extensive shutdowns for fuel bundle replacement. The punch line of Reference 1 was “There is such a fuel-it is hydrogen.” I am indebted to a gentleman from Italy who followed the text closely but with changes so that his punch line reads “There is such a fuel-it is methane.” (21. Hydrogen proponents should be the first to agree that an alternate fuel system should be based on a fuel that is normally gaseous, can be easily liquified using pressure or by means of refrigeration for storing, is as safe as contemporary fuels, burns cleaner than most contemporary fuels, has a reasonable energy content per pound of fuel, is easy to synthesize and can be sold in competition with fossil fuels or natural gas. Whether the fuel for such a system is hydrogen, ethanol, ammonia, methanol or deep earth natural gas [3] or some of all of these is not important and should be decided in the marketplace anyway. Hydrogen as the only fuel faces a lot of problems. First there is storage. Hydrogen is fluffy. Practical methods of storage include as a gas at hundreds of bars of pressure in thickwalled pipe tanks, as a liquid in cryogenic Dewars at a temperature of 20°K or as a hydride in conjunction with certain metals or alloys. Next hydrogen gas has to have an admixture to prevent embrittlement failure of steel pipe or tanks, allow leaks to be detected by smell and allow flames to be visible. Finally there is safety. All combustible gasses and volatile liquid fuels can leak and, if triggered, detonate and burn. This is also true of very fine dust suspended in air such as grain dust or pulverized coal. Hydrogen mixed with