Harnessing nature to store CO2

Project in the Middle East shows how rocks could store greenhouse gas

BY: AMENA H. SAIYID

FUJAIRAH, United Arab Emirates — Among the rocky outcrops of the Hajar Mountain range on the Gulf of Oman, under blazing sun, a startup is quietly tapping nature to store carbon dioxide.

An hour’s drive from the city of Fujairah in the United Arab Emirates brings you to Project Hajar, where 44.01 is storing carbon dioxide by injecting a dissolved form of the gas into the particular rock that dominates the arid landscape here. In this demonstration project, the gas is forced through natural fissures, where it reacts with specific minerals to form part of the rock’s fabric.

Company engineers say this mineralization process, which normally would take years to unfold thanks in part to the region’s sparse rainfall, is now taking place in a matter of months, enhanced by water injected under high pressure. Water is a critical part of accelerating 44.01’s use of this natural mechanism.

The United Nations Intergovernmental Panel on Climate Change, a leading authority on climate science, has identified the capture and storage of CO2 as a viable cleantech solution for tackling climate change. Since CO2 cannot be entirely eliminated from industrial processes or power generation, some will have to be captured and utilized or stored permanently in some form.

Between the various approaches for carbon capture and storage, “we will likely need tens of gigatons of storage per year,” Jack Andreasen Cavanaugh, global energy fellow at Columbia University’s Carbon Management Research Initiative, told Cipher. “Luckily, we have a global embarrassment of riches for mineral and saline storage. If we can capture or remove it, we can store it.”

This is where 44.01 comes in. Named after the molecular mass of CO2, the Oman-based startup is offering a permanent mineralization storage solution that could potentially be used on every continent. The challenge of this technology, as with all novel approaches to solving climate change, is the substantial investment required to build a first-of-a-kind plant and the costs associated with scaling up for commercial use.

The promise, though — true of so many climate-focused startups — is that if commercially successful, it could play a significant role in tackling climate change.

From greenhouse gas to rock

Mineral storage is still in its infancy.

44.01 is one of only a handful of firms globally attempting to mineralize CO2 emissions into rock instead of either injecting the gas into underground storage wells that require constant monitoring for leaks, or using the captured CO2 in some way, including to extract oil from deep underground wells (a common practice that has drawn criticism).

“Once you’ve proved it’s turned into a rock you don’t need to keep monitoring the carbon dioxide because you know it’s not going anywhere,” Charlie Booth, spokesman for 44.01, told Cipher.

The mineralization approach is a developing technology; engineers and geologists are still studying which rock formations are most suitable, Cavanaugh said.

Such efforts are underway in disparate locations. Canadian firm CO2 Lock is piloting storage in brucite rocks, commonly found in limestone-rich regions of British Columbia. Iceland-based Carbfix received a permit from the European Union in May to store carbon in basalt formations near Reykjavik. And New York-based Cella aims to store carbon in Kenya’s basalt formations.

According to Cavanaugh, 44.01 is the only one targeting peridotite rocks — a form of coarse-grained volcanic rocks rich in magnesium — for which it won a $1 million XPRIZE earlier this spring. Its demonstration used Berkeley, CA.-based AirCapture’s modular direct air capture technology to complement its mineral storage.

XPRIZE judges said 44.01’s approach provided “a compelling example” of a scalable carbon-removal solution with “potential to make a meaningful difference in the fight against climate change.”

Experiment visit

Reaching 44.01’s peridotite project involves a scenic drive along the Gulf of Oman’s coast, then a road winding through jagged terrain dotted with native Sidr trees and the occasional orchard of mangoes, figs and almonds.

Located just miles from the border with Oman, Project Hajar has turned out to be the perfect spot for carbon storage, as Oman and the UAE are home to the world’s largest formation of peridotite.

The mountains of rock are veined in white. “Those white veins are CO2 that has naturally mineralized,” says Booth, who conducted a tour for Cipher. “Our technology simply recreates that natural process deep in the subsurface.”

The project looks like a run-of-the-mill construction site, with bulldozers, drilling equipment and makeshift trailers. But there’s also a white storage tank housing the captured gas and an array of shimmering solar panels at the entrance.

The company draws a parallel between its technology and oil and gas drilling and extraction, common in this fossil-fuel rich Gulf State. The difference is oil firms pull hydrocarbons out of the ground, while 44.01 uses a similar technology to put carbon back.

As it stands now, though, the project is a bit like a large-scale demonstration of a high-school chemistry experiment.

How it works

Here are the steps it takes to dissolve Earth-warming carbon dioxide in these jagged, otherworldly rock formations.

• First, CO2 is captured from air or nearby industries and dissolved in treated wastewater or seawater.

• That water is injected under extremely high pressure through boreholes drilled into the mountains nearly 3,000 feet deep, or more than twice the height of the Empire State Building.

• The carbon-infused water spreads through naturally occurring fissures in the peridotite rocks and reacts with magnesium-rich minerals to form white carbonate deposits, where the carbon is trapped for good.

For the demonstration, 44.01 used the gas collected by AirCapture’s onsite technology, which has the potential to capture up to 800 metric tons of carbon dioxide per year. But down the road, Booth said the goal is to take emissions from nearby industrial facilities in Fujairah, a deep-sea port and major hub for oil and gas.

The project is powered by an array of solar panels supplied by UAE renewables firm Masdar. AirCapture CEO Matt Atwood told Cipher it may move its capture operations offsite to a location supplied by natural gas-fired grid power to meet the needs of scaled-up operations.

What’s next

44.01 hopes that by scaling up operations to commercial levels at the UAE site, it can reduce storage costs.

Reducing costs is a major challenge in the carbon capture industry writ large and 44.01’s solution will have to compete economically with other types of carbon storage. The fact that mineral storage requires less long-term monitoring could eventually translate into lower costs, Cavanaugh said.

Currently, the costs of mineralizing CO2 are mostly theoretical as most projects are still in the pilot stage. Estimates range from $30 a metric ton to $150 a metric ton, depending on the scale of the project and the underlying geology, Cavanaugh said.

Booth said the firm’s goal is to lower costs to roughly $30 per metric ton through scale and efficiencies in the process, including how it gets and uses water.

Transporting water, whether through a pipeline or trucks, is always an additional cost burden for injection operations, according to Carolyn Seto, S&P Global Commodity Insights’ executive director of Energy Technology and Innovation. As of now, 44.01 is trucking in treated wastewater, but “to begin commercial-scale operations, investment in infrastructure, like pipelines, would be required,” Seto said.

In the UAE, 44.01 has the backing of Abu Dhabi National Oil Company, Masdar and the Fujairah Natural Resources Corporation. Recently it announced investments from Norwegian oil major Equinor and Japanese investment firm Sumitomo Corporation.

Looking ahead, Cavanaugh sees 44.01’s mineral storage as a viable and promising climate solution, but more studies are needed to fully understand the potential of mineral storage compared to other solutions, like storing CO2 in subterranean saline aquifers or depleted oil and gas reservoirs.

“As yet, we don’t have a clear view of mineral storage of carbon dioxide globally,” he added. “The work 44.01 and others are doing will enhance that understanding.”

Editor’s note: 44.01’s investors include Breakthrough Energy Ventures, a program of Breakthrough Energy, which also supports Cipher.