Major step forward in the production of 'green' hydrogen

Credit: CC0 Public Domain

The first thermodynamically-reversible chemical reactor capable of producing hydrogen as a pure product stream represents a "transformational" step forward in the chemical industry, the authors of a new study claim.

The novel , described today in the prestigious academic journal Nature Chemistry, avoids mixing reactant gases by transferring oxygen between reactant streams via a solid state oxygen reservoir.

This reservoir is designed to remain close to equilibrium with the reacting gas streams as they follow their reaction trajectory and thus retains a ' memory' of the conditions to which it has been exposed.

The result is that is produced as a pure product stream, removing the need for costly separation of the final products.

Led by Newcastle University, UK, the research involved experts from the universities of Durham and Edinburgh and the European Synchrotron Radiation Facility in France, and was funded by the Engineering and Physical Sciences Research Council (EPSRC).

Professor Ian Metcalfe, lead author and Professor of Chemical Engineering at Newcastle University said:

"Chemical changes are usually performed via mixed reactions whereby multiple reactants are mixed together and heated. But this leads to losses, incomplete conversion of reactants and a final mixture of products that need to be separated.

"With our Hydrogen Memory Reactor we can produce pure, separated products. You could call it the perfect reactor."

Most abundant element in the universe

Hydrogen is the most abundant element in the universe. Produced through the splitting of water molecules, the shift towards has led to a rise in so-called 'green hydrogen'.

Hydrogen is a clean and useful energy store and can be used as a fuel, to generate electricity and can be stored and transported via the gas networks.

All processes—be they chemical, mechanical or electrical—are thermodynamically irreversible, and are less efficient that they otherwise could be.

This means that in traditional chemical reactors when hydrogen is produced it needs to be separated from other products, a process which is both costly and often energy intensive.

Describing their new system, the team demonstrate a chemical reactor capable for the first time of approaching thermodynamically-reversible operation.

Reacting water and carbon monoxide to generate hydrogen and , the system also prevents carbon being carried into the hydrogen produce stream as or carbon dioxide, thus avoiding contamination of the product.

'Flipping' the reservoir a bit like a switch, the team showed it is possible to reach high conversion in the system so that carbon dioxide and hydrogen are produced at either end of the reactor as pure products.

"Whereas conventional hydrogen production requires two reactors and a separation, our reactor accomplishes all the steps in one unit," adds Professor Metcalfe.

"And while we demonstrate the concept with hydrogen, the memory reactor concept may also be applied to other processes."

Explore further

Chemical hydrogen storage system

More information: Overcoming chemical equilibrium limitations using a thermodynamically reversible chemical reactor, Nature Chemistry (2019). DOI: 10.1038/s41557-019-0273-2 ,
Journal information: Nature Chemistry

Citation: Major step forward in the production of 'green' hydrogen (2019, May 27) retrieved 16 October 2019 from
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

Feedback to editors

User comments

May 27, 2019
100 1000 mega watt fission power plants would be so much superior to any "green" idea it is beyond belief the Greens haven't been run from polite society much like their cousins the Reds were.

May 27, 2019
We do not need costly and dangerous nuclear power. The last forecasts of the cost of power from the Vogtle nukes in Georgia was 15 cents/kWh, and that was before two increases in construction costs. By comparison, actual bids for continuous power in Colorado had wind plus battery storage at 2.1 cents/kWh, one-seventh the cost of Vogtle power.

Wind and storage do not produce high-level nuclear waste and cannot melt down to threaten entire continents. Whose power do you want to buy?

May 27, 2019
And in Ohio, conservatives are ramming through a bill that would bail out two nukes and some coal powered plants while marginalizing renewable energy. Once more the GOP is leading us backwards.

May 27, 2019
Hmm.... a "green" combustible. Maybe the ICE isn't done yet?

May 27, 2019
@Shootie you seem to have forgotten what you're going to do with the electric current. It's not going to make everything work by magic.

May 28, 2019
fission power plants would be so much superior to any "green" idea

You're right, if you're referring to Thorium Molten Salt Fission reactors. SAFE fission, never talked about by the Greens. Developed at Oak Ridge. It doesn't produce neuk weapons grade waste. Why this method wasn't used!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more