Can aluminum ignite the hydrogen economy?
Posted on byBrian Nitz inEnergy
Aluminum could be a source of perfect fuel. This Canada produces aluminum with one of the lowest carbon footprints in the world.
Summers are growing hotter, storms more violent, wildfires more frequent andocean levels are rising. It is becoming increasingly obvious thatburning fossil fuels containing millions of years worth of trapped carbon is altering our atmosphere and climate.
Hydrogen is a promising alternative to fossil fuels. It’s abundant, clean burning and has a high mass energy density. With modification it can be used in heating, vehicle engines or fuel-cells as a replacement for carbon-based fuels such as natural gas (CH4) gasoline (C8H18) or diesel fuel (C12H23).
Hydrogen gas is endless and available and a green energy contributing to a carbon-free future. Storage tanks can be sent like drones.
Hydrogen doesn’t have the long-term environmental flaws of fossil fuels. But it is not yet a simple replacement for hydrocarbons. Extracting green or grey hydrogen takes a considerable amount of energy andgeologic hydrogen hasn’t yet been found in commercial quantities.
Hydrogen also has a low volumetric energy density. This means even though one kilogram of hydrogen can provide two to three times the energy of one kilogram of diesel fuel, at standard atmospheric pressure a hydrogen fuel tank requires about 5000 times the volume of a diesel fuel tank in order to provide the same energy and range.
Pressurizing the hydrogen to about 10,000 pounds per square inch improves this so that hydrogen only requires about 7 times the volume of diesel fuel. This pressure is almost twice as high as that which imploded the Titan submersible underwater earlier this year while hunting for the Titantic wreckage.
So whilehydrogen is a promising fuel, storage and transport is challenging. If only we could efficiently generate hydrogen near where it is used. A Canadian research team may have the answer in aluminium.
It takes up to 63 kilowatt-hours to extract one kilogram of aluminium from its bauxite ore. Much of that energy remains trapped in the chemistry of Aluminium in the same way coal and gasoline trap the energy of ancient sunlight. In fact burning aluminium produces almost twice the energy of burning an equivalent mass of coal.
According to the U.S. Environmental Protection Agency the energy embedded in a single soda can could power a 14 watt light bulb for 60 hours or a television for two hours. By tuning the particle size and chemistry, the energy embedded in this metal can be used to extract hydrogen from water.
Reza Kholghy
Reza Kholghy, PhD, is research chair in Particle Technology and Combustion Engineering at Carlton University in Ottawa Canada. Dr. Kholghy was kind enough to provide Green Prophet with some insight on this promising new technology.
GreenProphet (GP):How do you use aluminium to produce hydrogen?
Dr. Kholghy:Aluminium powder is mixed with water and combusts through a high temperature oxidation process. This way, Aluminium takes the oxygen molecule in water and turns into alumina (aluminium oxide) and releases the hydrogen in water molecules.
GP:What is the efficiency compared to other methods of recycling Aluminium?
A reactor in Carleton’s Energy and Particle Technology Laboratory that informed the construction of Kholghy’s reactor with GH Power.
Dr. Kholghy:This is not a method to recycle aluminium. By combusting it with water, we can get 100% yield, meaning that all of the aluminium will be converted to alumina and for every kg of Aluminium, roughly 1 kg of water is consumed releasing around 111 gr of hydrogen.
GP:What is the volume and mass energy density compared to hydrogen fuel cell technology?
Dr. Kholghy:The reactor is very compact, a 2 MW reactors only need a footprint of around 300 to 400 sq sq ft and cogenerate heat, hydrogen and alumina.
GP:Why weren’t we doing this 100 years ago?
Dr. Kholghy:This reaction has been used in a variety of application including green rocket propellant where Aluminium nanoparticles are used. However, the unique feature of our work is finding a way to burn large Aluminium particles
GP:What is the best scale for an Aluminium hydrogen generator? (car, house, utility…)
Dr. Kholghy:Utility, from 1 MegaWatt and higher.
GP:What would you tell someone who is sceptical?
Canada produces aluminum with one of the lowest carbon footprints in the world.
Dr. Kholghy:This is just a pice of puzzle towards transitioning to zero carbon energy production. This technology offers off grid solutions for cogeneration of heat, hydrogen as well as valuable high purity alumina that is used in batteries.
GP:Are you working with other researchers or corporations?
Dr. Kholghy:We are working with a Company calledGH Power to develop this technology.
GP:What is the next step?
Dr. Kholghy:Our industrial partner is working with us to demonstrate the full scale reactor.
GP:How are impurities removed?
Dr. Kholghy:For hydrogen generation, there is no need to remove impurities. We get similar hydrogen yield no matter if recycled Aluminium with low purity or high purity Aluminium is used. The purity of alumina is similar to the purity of the Aluminium fuel used and we have developed a proprietary process to remove impurities from the produced alumina if needed.
Author:Brian Nitz
Brian remembers when a single tear dredged up a nation's guilt. The tear belonged to an Italian-American actor known as Iron-Eyes Cody, the guilt was displaced from centuries of Native American mistreatment and redirected into a new environmental awareness. A 10-year-old Brian wondered, 'What are they... No, what are we doing to this country?' From a family of engineers, farmers and tinkerers Brian's father was a physics teacher. He remembers the day his father drove up to watch a coal power plant's new scrubbers turn smoke from dirty grey-back to steamy white. Surely technology would solve every problem. But then he noticed that breathing was difficult when the wind blew a certain way. While sailing, he often saw a yellow-brown line on the horizon. The stars were beginning to disappear. Gas mileage peaked when Reagan was still president. Solar panels installed in the 1970s were torn from roofs as they were no longer cost-effective to maintain. Racism, public policy and low oil prices transformed suburban life and cities began to sprawl out and absorb farmland. Brian only began to understand the root causes of "doughnut cities" when he moved to Ireland in 2001 and watched history repeat itself. Brian doesn't...
About Brian Nitz
Brian remembers when a single tear dredged up a nation's guilt. The tear belonged to an Italian-American actor known as Iron-Eyes Cody, the guilt was displaced from centuries of Native American mistreatment and redirected into a new environmental awareness. A 10-year-old Brian wondered, 'What are they... No, what are we doing to this country?'From a family of engineers, farmers and tinkerers Brian's father was a physics teacher. He remembers the day his father drove up to watch a coal power plant's new scrubbers turn smoke from dirty grey-back to steamy white. Surely technology would solve every problem. But then he noticed that breathing was difficult when the wind blew a certain way. While sailing, he often saw a yellow-brown line on the horizon. The stars were beginning to disappear. Gas mileage peaked when Reagan was still president. Solar panels installed in the 1970s were torn from roofs as they were no longer cost-effective to maintain. Racism, public policy and low oil prices transformed suburban life and cities began to sprawl out and absorb farmland. Brian only began to understand the root causes of "doughnut cities" when he moved to Ireland in 2001 and watched history repeat itself.Brian doesn't think environmentalism is 'rocket science', but understanding how to apply it within a society requires wisdom and education. In his travels through Europe, North America, Asia and the Middle East, Brian has learned that great ideas come from everywhere and that sharing mistakes is just as important as sharing ideas.
