Underwater Vehicle Can Go Forever

A Photocatalytic Water Dissociation System

Gasoline’s replacement does not have to be invented. It’s here, waiting to be developed, in the form of two hydrogen molecules bound to one molecule of oxygen. Water split into hydrogen and oxygen on board a motor vehicle is possible right now, using the current technology of photocatalysis. Photocatalysts in the presence of water and light—either natural or electric light—dissociate water into hydrogen and oxygen.

Water, of course, is the only portable non-carbon source of renewable fuel available in the huge quantities needed to supplant gasoline. Water requires no investment in exploration, drilling, refining, mining, transportation, service stations, or disposal of nuclear waste. Unlike carbon-based fuels, water is recyclable.

The hydrogen and oxygen yield from this water dissociation system can be used in internal combustion engines that are designed to burn hydrogen. Hydrogen and oxygen fed into a fuel cell will create electricity for electric motors to propel motor vehicles.

The gases, of course, can be burned to heat boilers to create steam to drive turbines connected to electric generators in large electric generating plants, or the hydrogen can be used in large stationary fuel cells to generate electricity for individual businesses or homes.

Thanks to Dr. Bjorn Winther-Jensen of Monash University in Australia, (bjorn.wintherjensen@eng.monash.edu.au) platinum electrodes [$1,000/troy ounce] can be replaced in fuel cells by his polymer electrodes, thus substantially lowering the cost of fuel cells.

Titanium dioxide is a cheap and plentiful photocatalyst. Dr. Chris Sorrell at the University of New South Wales is working on water dissociation systems using titanium dioxide. (c.sorrell@unsw.edu.au) Australia has 40% of the world’s supply of titanium dioxide.

In February, 2007, Dr. Manoranjan Misra of the University of Nevada/Reno, (misra@unr.edu) announced that he had developed nanotubes that dissociate water in the presence of light. He reported that: “The new power source is extremely cost-effective…”

Expensive tris bipyridine ruthenium1 (TBR), reacting in combination with dioctadecyl or dihydrochlolesteryl esters, also dissociates water in the presence of light, according to research done by Professor David G. Whitten et al, Department of Chemistry, U. of North Carolina. [G. Sprintschnik, H. Sprintschnik, P. Kirsch, and D. Whitten, Journal of the American Chemistry Society, 1976, 98, 2337-2338]

An article in the April 29, 2010 issue of Nature magazine by lead author Hemamala Karunadasa of the DOE’s Lawrence Berkeley National Laboratory discusses “A molecular molybdenum-oxo catalyst for generating hydrogen from water.” The catalyst can be used with clean or dirty water, or salt water, at ambient temperatures. Apparently, light is not needed to power the water dissociation.

The photocatalytic system consists of a water dissociation chamber connected to a light chamber by optical fibers. The light chamber receives sunlight from a vehicle’s top surfaces. Sunlight is supplemented by powerful electric lights for both overcast daylight and night driving. The dissociation chamber contains photocatalysts and a gas separation system. The temperature of the dissociation chamber must be kept below 1130о F. to prevent pre-ignition of the hydrogen/oxygen mixture. Solid gas-permeable membranes in the dissociation chamber can be used in a gas-separation system.

The light chamber contains one or more golf-ball-size light bulbs, developed many years ago by Fusion Lighting of Rockville, Maryland under a U.S. D.O.E. grant, and it should be available for licensing. It emits 450,000 lumens when excited by microwaves. A 100-watt incandescent light bulb output is 1,690 lumens.

The Fusion light bulb contains argon gas and a small amount of sulfur. The presence of microwaves makes it necessary to shield the dissociation chamber from the light chamber.

Microwaves are supplied by micro-power impulse radar (MIR), a short-range system small enough to be put on a $10 computer chip, using very little electricity. MIR was developed years ago at the U.S. Lawrence Livermore National Laboratory by Tom McEwan, and is available for licensing.

An alternative to the Fusion light bulb is a light-emitting diode [LED] light bulb, which is 70% more efficient than an incandescent light bulb. using much less electric power while developing the same amount of lumens that incandescent bulbs of the same rating develop. LEDs can be tailored to emit specific ranges of wavelengths that are most efficiently compatible with whatever photocatalyst is used. Extreme ultraviolet wavelengths of 1236 Angstroms and shorter, are effective.

Another lighting alternative would involve the use of mercury vapor lights into which scandium iodide has been added. The resulting light is very close to natural sunlight.

Heat from the light bulb(s), as well as heat from any fuel cell, internal combustion engine, or steam engine in the system, may be converted to electricity, which is stored in batteries. Heat may be conducted by insulated heat pipes to a chamber equipped with thermoacoustic electric generators developed at the U.S. Los Alamos Lab. The chamber may also be equipped with photovoltaic cells that use both infrared and visible light to make electricity, such as the 35% efficient solar cells developed by JX Crystals Inc. of Issaquah, Washington, U.S.A.

The more light and area of catalyst to which water is exposed, the greater the quantity of water that can be dissociated within a given time period. This is the key to the whole system. When daylight is directed by optical fibers to power a large area of catalyst, hydrogen and oxygen are produced in quantities sufficient to meet the demands of the vehicle’s fuel cell, internal combustion engine, or steam engine.

An auxiliary fuel cell, smaller than that used for the vehicle’s electric motors, is to be part of the dissociation system. It would function much like an alternator in a motor vehicle, which supplies electric power to the engine as well as all of the vehicle’s electric systems and accessories. The auxiliary fuel cell would perform all of the existing functions of an alternator and battery in a motor vehicle, plus it would be used to power all of the needs of the dissociation process. In addition to solar cells, the auxiliary fuel cell would function to keep the vehicle’s batteries charged; it would supply electric power to the microwave that excites the Fusion light bulb, or power the optional sources of light for the photocatalysts. It would be used also to power a compression pump that stores a modest amount of hydrogen in a storage tank.

Since motor vehicles spend much time parked outdoors, solar cells will continually charge batteries for night driving, taking advantage of free solar light and infrared energy.

A honeycombed and well-lighted catalyst can expose water to an acre of area within a volume of a couple of cubic feet. One cubic foot of charcoal, for example, has a surface area of 12.4 square miles. A stable foam such as that developed by Dr. Eric Beckman at the University of Pittsburgh, may be used to contain and support the titanium dioxide catalyst.

The photocatalyst is fused or otherwise attached to the surface of a rigid foam support. Water circulated throughout such foams is simultaneously exposed to the photocatalyst and light. Natural light and electric lighting are combined, and is carried throughout the foam structure by glass or plastic fibers. A rigid foam or a woven fabric providing water passages can be made entirely of joined pairs of glass or plastic fibers, of which half of the pair conducts light, and half are coated with the chosen photocatalyst. The electric lighting depends on car batteries being recharged by regenerative braking, household plug-in battery chargers, or by solar cells responding to natural daylight—all of which means are external sources of energy.

An alternate method of getting the maximum exposure if titanium dioxide is used as the photocatalyst is to keep it continually in a colloidal-like suspension in water in a baffled tank that is equipped with thousands of strands of glass fiber, through which fibers intense light is conducted from the light source.

A gas separation system is essential for separating the hydrogen from the oxygen. Both gases are collected and are fed into the fuel cells or into small storage tanks. The storage tanks are used to supply hydrogen and oxygen when extra power is needed for acceleration, or to start the fuel cell if the system has been shut down entirely. Since the byproduct of the fuel cells is water, it can be filtered if necessary, and returned to the water dissociation tank. An extra water replenishment tank is provided, filled with three gallons, for example, of distilled water, since 100% recovery of water from the dissociation process is not practical.

Insulation is provided where needed throughout the system to prevent the system water from freezing in cold weather. Surrounding each item needing freeze protection is an insulating jacket filled with millions of hollow, vacuum ceramic microspheres with very low thermal conductivity—a NASA development. Each microsphere is smaller than a grain of talcum powder, has a compressive strength of 60,000 psi, and a softening point of about 3,272о F. (1,800о C.). These microspheres are so efficient at insulating that the flame of a Bunsen burner will not melt ice cream placed above the flame if there is a solid layer of the microspheres on a suitable support between the flame and the ice cream. A standby system, described below, will also aid in preventing water freezing.

Catalysts can become contaminated. Since titanium dioxide is inexpensive—it’s the stuff that makes paint and toothpaste white—provision is made for changing the catalyst and its support structure, much like changing a vehicle’s oil filter. Contaminated catalysts can be recycled and used again.

Electric power for night driving comes from multiple high-capacity car batteries kept charged by solar cells, regenerative braking; by excess electricity developed by fuel cells, and by utilization of waste heat. Batteries sometimes require recharging during periods of prolonged absence of sunlight caused by clouds, or caused by the parking of vehicles in enclosed garages during daylight hours. The batteries, of course, supply power for the electric lights—the LEDs, or the mercury vapor lights, or the Fusion lights, and the MIR radar, which excites the argon gas and sulfur in the Fusion light bulbs to produce their intense light.

A standby system is recommended to operate the dissociation cycle on a minimum demand basis when vehicles are not in use, using solar power during daylight hours, and battery power at night. The standby system will eliminate the warm-up time required by current fuel cells, and, in cold weather, keep the system water from freezing.

Honda stated a few years ago that their FCX-V3 concept car had a range of 270 miles, using 8.8 pounds of compressed hydrogen. That is 30.7 miles per pound of hydrogen. Adjust that down to 30 miles per pound of hydrogen. Eight pounds of oxygen will combine with one pound of hydrogen to make nine pounds of water. Nine pounds of water, containing that one pound of hydrogen, equals 137.83 liquid ounces (adjust that figure up to 138 liquid ounces), or slightly more than a U.S gallon which contains 128 liquid ounces and weighs 8.36 pounds. At 30 miles per pound of hydrogen, each mile traveled would consume 1/30th of the pound of hydrogen contained in those 138 liquid ounces of water, or 4.6 liquid ounces per mile—slightly more than half an 8-ounce glass of water. This proposed water dissociation system can catalytically dissociate 4.6 ounces of water per mile of travel, using either titanium dioxide or Dr. Misra’s nanotubes as a photocatalyst.

Large, stationary versions of the portable system in conjunction with fuel cells can be built to provide on-site generation of electricity for individual businesses and homes, thus eliminating the need for large electric generating plants [which now are possible terrorist targets] and the millions of miles of transmission wires. Those who can generate their own power will say goodbye forever to high electricity prices and electric power outages caused by grid overloads, downed power lines, or sabotage.

“expand when the outside water temperature goes above 10oC and contract when the temperature goes below.”

so how constant is ocean temp? i would imagine you need to be at a very specific depth for this to work…?