Why it's time to dig through the rocks hiding hydrogen

The Hajar Mountains in Ras al Khaimah. Silvia Razgova / The National

The brown and rust-red mountains that make up the spine of the northern UAE and Oman are more than a site for nature and recreation.

They might also host a key part of these countries’ energy future. Natural hydrogen and carbon mineralisation company Decahydron wants to find subsurface wealth beyond traditional oil and gas.

At the Adipec conference in Abu Dhabi this month, Decahydron unveiled the discovery of natural hydrogen in a well drilled in Sharjah. Chief executive Arnaud Lager announced the company had a strategic investment from global drilling and energy services group Weatherford in place. And it sealed a collaboration with Sharjah National Oil Corporation and Siemens Energy to work on a power station using the clean fuel.

This progress ties together two topics at different stages of the cycle of innovative enthusiasm, disappointment and realism. From 2020, there was a surge of interest into hydrogen, a clean fuel that yields only water when it burns, and that can be made using abundant and increasingly cheap renewable energy.

But it has proved harder than hoped-for to produce “green” hydrogen at competitive costs and to find users willing to pay a substantial premium. The light hydrogen molecule is hard to transport worldwide, while converting it into more convenient forms takes energy and further expenditure.

Geoscientists and oil and gas explorers have for a few years had a different idea. Hydrogen is produced within the Earth by a variety of processes. One famous occurrence of subsurface hydrogen is at the village of Bourakébougou in Mali, where it powers a small local power plant.

Perhaps this natural or geologic hydrogen, sometimes termed “white” or “gold”, is more widespread than previously suspected. Searches for hydrocarbons might have overlooked it.

Hydrogen has been found in various places, including gas wells in the US state of Nebraska and in South Australia, coal mines in eastern France, and a chromite mine in Albania. Companies have sprung up to look for substantial accumulations, with Bill Gates backing a couple of start-ups, US-based Koloma and France’s Mantle8.

But hydrogen is a very small, buoyant and chemically-reactive molecule, which tends to seep through the sealing rocks that hold hydrocarbon accumulations. It may occur dissolved in water, or as a minor constituent of fields containing mostly other gases.

Explorers have yet to demonstrate a large subsurface field of quite pure hydrogen comparable to a traditional oil or gas reservoir, with good permeability to permit wells to flow at commercial rates for years. Their efforts have been viewed with understandable scepticism so far by knowledgeable observers such as my former colleague, ex-Shell geologist Arnout Everts.

Maybe Decahydron can do things differently. The company is exploring “ultramafic” rocks in the Northern Emirates. These rocks, high in iron and magnesium, make up the lower parts of an ophiolite - the remnants of an ancient oceanic plate that was pushed on to the northern edge of the Arabian continental plate about 79 million years ago, during the later part of the dinosaurs’ era.

Olivine minerals abundant in these rocks can react with underground water to produce natural hydrogen. Decahydron said this month that analysis of a well drilled in Sharjah showed the presence of natural hydrogen in ultramafic formations. It plans to drill next year to appraise the resource further.

The questions will be how much hydrogen is trapped, and whether the rocks are permeable enough for it to flow at sustained commercial rates.

Decahydron has not released estimates for its production costs. Natural hydrogen explorers elsewhere suggest they could produce at $0.5 to $1 per kilogram – equivalent to about $4 to $8 per million British thermal units, comparable to current natural gas prices.

The Oman-UAE ophiolite is one of the world’s best examples. But such ultramafic rocks are found in many other global locations, such as Cyprus, Turkey, the Zagros Mountains of Iran and northern Iraq, the Alps, Himalayas, California, Japan, South Korea, Cornwall in the UK, and Newfoundland in Canada.

And Decahydron has another trick in its toolbox. When carbon dioxide is injected into these rocks, it reacts to form solid carbonate minerals, also releasing some hydrogen. This can be used to lock away the main gas responsible for global warming safely and permanently. It would answer one of the objections from the persistent environmentalist opponents of carbon capture and storage.

There is still a long way to go to prove that natural hydrogen exists in large and commercially producible quantities. But if it does, whether in the Northern Emirates or elsewhere, this could be transformational.

Low-cost hydrogen can be used to produce green steel, ammonia, methanol, and synthetic low-carbon fuels for aviation and shipping.

Gas-fired power stations can be converted to burn hydrogen, helping to balance fluctuations in solar and wind output. With some effort, existing natural gas pipelines can be converted to carry hydrogen from production sites. Even if only found in a few places in large quantities, low-cost natural hydrogen could kick-start a bigger industry that includes renewable-derived hydrogen. The lucky locations with good geologic hydrogen resources could become centres of green industry, supplying products worldwide.

The UAE, with its long petroleum experience, is well-suited to explore and develop a different subsurface energy source. The scenic peaks of the Northern Emirates may look down on the next stage of the nation’s energy and decarbonisation journey.