If the latest university hydrogen research and development breakthroughs prove commercial, they may radically impact the way the gas is produced industrially.
Currently, there are not just one but three processes in the pipeline that could achieve this.
Scientists from the Skolkovo Institute of Science and Technology in Russia have proposed a method of extracting hydrogen from natural gas formations that shows “incredible” potential.
- University of Illinois, Chicago is working on a process that uses agricultural waste as feedstock.
- The RIKEN Center for Sustainable Resource Science (CSRS) in Japan reports a new method that reduces the amount of iridium needed to produce hydrogen from water by 95%, without altering the rate of hydrogen production.
- Scientists from the Skolkovo Institute of Science and Technology have proposed a method of extracting hydrogen from natural gas formations that shows “incredible” potential.
Natural gas to H2 downhole
In research funded by the Russian Science Research Council, a team of scientists at the Skolkovo Institute of Science and Technology say they have come up with a promising alternative to steam reforming of methane, which is currently the main method of producing hydrogen.
The new method makes it possible to produce hydrogen downhole in four key stages.
First, water vapour and a catalyst are pumped into a candidate gas well, followed by air or pure oxygen, thanks to which natural gas is combusted right inside the formation.
During the combustion process, natural gas turns into a mixture of carbon monoxide and hydrogen: carbon monoxide produces carbon dioxide, which remains inside the formation. Hydrogen is extracted from the well using a membrane that does not allow other reaction products to pass through.
As a result, all emerging gases except hydrogen, including carbon monoxide and carbon dioxide, remain forever preserved underground, making it possible to minimise the carbon footprint.
The Global Energy Association reports that the new technology underwent testing in a reactor, which made it possible to recreate gas formation conditions, including pressure 80 times higher than atmospheric pressure.
The team loaded crushed rocks into the reactor and then used pumps to inject methane (the main component of natural gas), water vapour, catalyst and oxygen into the reactor.
An analysis of the gas composition in the reactor showed that a high amount of hydrogen – 45% of the total volume of gases – was formed at a temperature of 800 degrees Celsius with large volumes of water vapour supplied to the reactor (in a ratio of four-to-one to the volume of natural gas).
The yield of hydrogen during the experiment also depended on the composition of the rocks.
If aluminium oxide was used, which did not react with the substances surrounding it, hydrogen yield was at 55%.
In turn, the use of natural rocks saturated with chemically active minerals that entered into side reactions with the components of the gas mixture led to a lower hydrogen yield.
All stages of the proposed process are based on well-proven technologies that had not previously been adapted to extract hydrogen from a real gas formation.
Seventeen tests using custom-designed and manufactured reactors were carried out.
In their research paper, the team say: “Our findings suggest the incredible potential for underground hydrogen generation in natural gas reservoirs.
“This approach holds great promise as a leading candidate for the foreseeable future, benefiting from the synergy of the fossil fuel industry and an innovative hydrogen production technology.”
They point out: “All four stages of the proposed process rely on well-established and widely used technologies, indicating the potential for this process to emerge as a highly promising technology for hydrogen production in future.”
The next step is to run trials in a real gas reservoir.
H2 from muck
University of Illinois Chicago (UIC) engineers have helped design a new method to make hydrogen gas from water using only solar power and agricultural waste, such as manure or husks.
The method reduces the energy needed to extract hydrogen from water by 600%, creating new opportunities for sustainable, climate-friendly chemical production.
Hydrogen-based fuels are one of the most promising sources of clean energy. But producing hydrogen is an energy-intensive process.
In a paper for Cell Reports Physical Science, a multi-institutional team led by UIC engineer Meenesh Singh unveils the new process for green hydrogen production.
The method uses a carbon-rich substance called biochar to decrease the amount of electricity needed to convert water to hydrogen. By using renewable energy sources such as solar power or wind and capturing byproducts for other uses, the process can reduce greenhouse gas emissions to net zero.
“We are the first group to show that you can produce hydrogen utilizing biomass at a fraction of a volt,” says Singh, associate professor in the Department of Chemical Engineering. “This is a transformative technology.”
Electrolysis, the process of splitting water into hydrogen and oxygen, requires an electric current. At an industrial scale, fossil fuels are typically required to generate this electricity.
Recently, scientists have decreased the voltage required for water splitting by introducing a carbon source to the reaction. But this process also uses coal or expensive chemicals and releases carbon dioxide (CO2) as a byproduct.
Singh and colleagues modified this process to instead use biomass from common waste products. By mixing sulphuric acid with agricultural waste, animal waste or sewage, they create a slurry-like substance called biochar, which is rich in carbon.
The team experimented with different kinds of biochar made from sugarcane husks, hemp waste, paper waste and cow manure.
The best performer, cow dung, decreased the electrical requirement sixfold to roughly a fifth of a volt.
The energy requirements were low enough that the researchers could power the reaction with one standard silicon solar cell generating roughly 15 milliamps of current at 0.5 volt. That’s less than the amount of power produced by an AA battery.
“It’s very efficient, with almost 35% conversion of the biochar and solar energy into hydrogen” says Rohit Chauhan, a co-author and postdoctoral scholar in Singh’s lab.
“These are world record numbers; it’s the highest anyone has demonstrated.”
To make the process net-zero, it must capture the carbon dioxide generated by the reaction. But Singh suggests this too could have environmental and economic benefits, such as producing pure CO2 to carbonate beverages or converting it into ethylene and other chemicals used in plastic manufacturing.
UIC graduate Nishithan Kani, co-lead author on the paper, adds: “This cheap way of making hydrogen could allow farmers to become self-sustainable for their energy needs or create new streams of revenue.”
Orochem Technologies Inc., which sponsored the research, has filed for patents on their processes for producing biochar and hydrogen, and the UIC team plans to test the methods on a large scale.
Just a sprinkle of Iridium
In Japan, researchers led by Ryuhei Nakamura at the RIKEN Center for Sustainable Resource Science (CSRS) in Japan report a new method that reduces the amount of iridium needed for the reaction by 95%, without altering the rate of hydrogen production.
This breakthrough could revolutionize our ability to produce ecologically friendly hydrogen and help usher in a carbon-neutral hydrogen economy.
The green way to extract hydrogen from water is an electrochemical reaction that requires a catalyst. The best catalysts for this reaction – the ones that yield the highest rate and the most stable hydrogen production – are rare metals, with iridium being the best of the best.
But the scarcity of iridium is a big problem.
“Iridium is so rare that scaling up global hydrogen production to the terawatt scale is estimated to require 40 years’ worth of iridium,” says team member Shuang Kong.
The Biofunctional Catalyst Research Team at RIKEN CSRS (RIKEN is a Japanese National Research and Development Agency) is trying to get around the iridium bottleneck and find other ways of producing hydrogen at high rates for long periods of time.
In the long run, they hope to develop new catalysts based on common earth metals, which will be highly sustainable. The team recently succeeded in stabilising green hydrogen production at a relatively high level using a form of manganese oxide as a catalyst.
“We need a way to bridge the gap between rare metal- and common metal-based electrolysers, so that we can make a gradual transition over many years to completely sustainable green hydrogen,” says Nakamura.
The current study does just that by combining manganese with iridium. The researchers found that when they spread out individual iridium atoms on a piece of manganese oxide so that they didn’t touch or clump with each other, hydrogen production in a proton exchange membrane (PEM) electrolyser was sustained at the same rate as when using iridium alone, but with 95% less iridium.
With the new catalyst, continuous hydrogen production was possible for over 3,000 hours (about 4 months) at 82% efficiency without degradation.
“The unexpected interaction between manganese oxide and iridium was key to our success,” says researcher Ailong Li. “This is because the iridium resulting from this interaction was in the rare and highly active +6 (CORRECT) oxidation state.”
The expectation is that the use of the catalyst will “immediately increase the capacity of current PEM electrolysers”.
The team has begun collaborating with partners in industry.
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