Muriel Andreani, Isabelle Daniel, and Marion Pollet-Villard of University Claude Bernard Lyon 1 have discovered a quick recipe for producing hydrogen. The university press release suggests the breakthrough would be a “better way of producing the hydrogen that propels rockets and energizes fuel cells. In a few decades, it could even help the world meet key energy needs – without carbon emissions contributing to the greenhouse effect and climate change.”
It’s a very interesting find with profound implications for explaining the abundance and distribution of life, helping to show how the astonishingly widespread microbial communities that dine on hydrogen exist deep beneath the continents and seafloor.
The lab duplication of the natural form is use a microscopic high-pressure cooker called a diamond anvil cell (within a tiny space about as wide as a pencil lead). Combine the ingredients made up of aluminum oxide, water, and the mineral olivine. Heat at 200 to 300º Celsius and 2 kilobars pressure for 24 hours. The process is comparable to conditions found at twice the depth of the deepest ocean.
Hydrogen Producing Diamond Anvil Pressure Module. Click image for more info.
The natural process produces hydrogen through “serpentinization.” When water meets the ubiquitous mineral olivine under pressure, the rock absorbs mostly oxygen atoms from H2O, transforming olivine into another mineral, serpentine that is characterized by a scaly green-brown surface appearance like snakeskin.
Lizardite Example of Serpentine. Click image for more info.
The complex network of fracturing and created by the serpentinization also creates the habitat for subsurface microbial communities.
The University Claude Bernard Lyon 1 team’s work will be highlighted among several presentations by Deep Carbon Observatory (DCO) experts at the American Geophysical Union’s (AGU) annual Fall Meeting in San Francisco Dec. 9 to 13. The DCO is a global, 10-year international science collaboration working to unravel the mysteries of Earth’s inner workings – deep life, energy, chemistry, and fluid movements.
Dr. Daniel, a DCO leader, explains that scientists have long known nature’s way of producing hydrogen. When water meets the ubiquitous mineral olivine under pressure, the rock reacts with the oxygen atoms from the H2O, transforming olivine into serpentine with a scaly, green-brown surface appearance like snake skin. The olivine is a common yellow to yellow-green mineral made of magnesium, iron, silicon, and oxygen.
The two processes leaves the hydrogen molecules (in H2 form) divorced from their bonds with oxygen atoms in water.
What is new in the research, which was quietly published in a summer edition of the journal American Mineralogist, is how aluminum profoundly accelerates and impacts the process.
Finding the reaction completed in the diamond-enclosed micro space overnight, instead of over months as expected, left the scientists amazed. The experiments produced H2 some 7 to 50 times faster than the natural “serpentinization” process of olivine.
Dr. Andreani explained that over decades, many teams looking to achieve this same quick hydrogen result focused mainly on the role of iron within the olivine. Introducing aluminum into the hot, high-pressure mix produced the team’s eureka moment.
Dr. Daniel notes that aluminum is Earth’s 5th most abundant element and usually is present, therefore, in the natural serpentinization process. The experiment introduced a quantity of aluminum that is unrealistic in a natural process.
Jesse Ausubel, of The Rockefeller University and a founder of the DCO program, says current methods for commercial hydrogen production, “usually involve the conversion of methane (CH4), a process that produces the greenhouse gas carbon dioxide (CO2) as a byproduct. Alternatively, we can split water molecules at temperatures of 850º Celsius or more – and thus need lots of energy and extra careful engineering.”
Ausubels adds, “Aluminum’s ability to catalyze hydrogen production at a much lower temperature could make an enormous difference. The cost and risk of the process would drop a lot. Scaling this up to meet global energy needs in a carbon-free way would probably require 50 years. But a growing market for hydrogen in fuel cells could help pull the process into the market. We still need to solve problems for a hydrogen economy, such as storing the hydrogen efficiently as a gas in compact containers, or optimizing methods to turn it into a metal, as pioneered by Dr. Russell Hemley of the Carnegie Institution’s Geophysical Laboratory, another co-founder of the DCO.”
Dr. Hemley notes that deep energy is typically thought of in terms of geothermal energy available from heat deep within Earth, as well as subterranean fluids that can be burned for energy, such as methane and petroleum. What may strike some as new is that there is also chemical energy in the form of hydrogen produced by serpentinization.
During the AGU Fall Meetings, Dr. Andreani will be taking a lead role with Javier Escartin of the Centre National de la Recherche Scientifique in a 40-member international scientific exploration of fault lines along the Mid-Atlantic Ridge. The ridge is the place where the African and American continents continue to separate at an annual rate of about 20 mm (1.5 inches) and rock is forced up from the mantle only 4 to 6 km (2.5 to 3.7 miles) below the thin ocean floor crust. The study will advance several DCO goals, including the mapping of world regions where deep life-supporting H2 is released through serpentinization.
The background research is quite widespread with a deep-sea robot from the French Research Institute for Exploitation of the Sea (IFREMER), and a deep-sea vehicle from Germany’s Leibniz Institute of Marine Sciences (GEOMAR) aboard the French vessel Pourquoi Pas. The team also includes researchers from France, Germany, USA, Wales, Spain, Norway and Greece.
The research solved the scientific mystery how the rock + water + pressure formula produces enough hydrogen to support the chemical loving microbial and other forms of life abounding in the hostile environments of the deep. Dr. Daniel said, “for the first time we understand why and how we have H2 produced at such a fast rate. When you take into account aluminum, you are able to explain the amount of life flourishing on hydrogen.” The DCO scientists now hypothesize that hydrogen was what fed the earliest life on primordial planet Earth – first life’s first food.
Dr. Daniel added, “We believe the serpentinization process may be underway on many planetary bodies – notably Mars. The reaction may take one day or one million years but it will occur whenever and wherever there is some water present to react with olivine – one of the most abundant minerals in the solar system.”
Engineers are likely already scratching their heads thinking, “Well this looks doable.” And it is. For those of us hoping for a home generator the wait might be a while. 2 kilobars is a bit over 29,000 psi. That is fairly achievable in a safe way with strictly liquids, but not something ready for home design. The temperatures are more modest in the 480º F range plus or minus 122º, way below dry steam levels.
There is as long way to go on the testing, scaling and commercialization of the discovery. The most likely barrier might be the cost of materials and the recycling expenses. The water is near free, a well-insulated unit wouldn’t need a huge amount of energy and the pressure containment is about materials rather than energy cost – except that the hydrogen is going to affect the units over time.
We’ll be watching for this. The payoff form the research could be huge and deeply gratifying for the team members. Congratulations!