Science

The UK’s CO2 shortage was entirely predictable

The current CO2 shortage is a perfect storm of stretched supply chains and high prices. The government could have been more prepared
Image may contain Alcohol Beer Beverage Lager Glass and Foam
Getty Images / WIRED

Earlier this week, the UK government announced it was offering £200m to businesses to help them reduce their carbon dioxide (CO2) emissions. At the same time, the government gave an unspecified figure totalling “tens of millions” to a fertiliser manufacturer so it can produce huge volumes of CO2 as soon as possible. So while encouraging us all to cut CO2 emissions, the government has also been desperately worried about exhausting supplies of the gas altogether.

It sounds strange, doesn’t it? But the fertiliser manufacturer won’t be sending that CO2 into the atmosphere. This odourless, colourless gas has a range of niche but essential uses in food packaging, Covid-19 vaccine transportation, and livestock slaughtering. And for the last few weeks, the UK has faced the possibility of running dangerously low on the stuff.

Dwindling CO2 supplies prompted fears of a soft drinks shortage and concerns that abattoirs would not be able to use the gas to stun animals before slaughter. The outlook was so dire that Richard Walker, managing director of supermarket chain Iceland, suggested on Twitter that CO2 supply was a “matter of national security” that should be state-controlled.

If there’s so much CO2 in the atmosphere, how can we be running out of it down here on the ground? For one thing, it is currently pretty expensive to extract the gas from the air. And CO2 for industrial uses is produced at just a handful of sites in the UK: 60 per cent of the country’s supply comes from just two fertiliser factories. These factories, owned by US giant CF Industries, produce CO2 as a mere by-product alongside their main output of ammonia, a key ingredient in fertiliser.

And so the government found itself paying CF to reopen one of its plants and start churning out ammonia, for the sake of a relatively inexpensive by-product. Only a few details about the deal have been disclosed, though the government says the agreed sum is less than £50m and will cover production costs only.

“There are reasonable questions asked about whether it’s good value for money,” says Lilah Howson-Smith at advisory firm Global Counsel. “I think people will be sympathetic that it is [in this case] but it’s not if it’s not causing the sector and government to think about this in a long-term way. I think it’s a missed opportunity if it doesn’t precipitate that.”

In 2019, Global Counsel produced a report for the Food & Drink Federation about the last CO2 shortage – which happened just three years ago, in 2018. The report explained the significance of CO2 and noted a catalogue of vulnerabilities in the UK supply chain such as the fact that there are relatively few producers in the country, and that suppliers store very little CO2 as a backup.

Significantly, the report also pushed back against the idea that what happened in 2018 was a freak event. The authors warned that similar incidents could happen again and recommended that UK authorities take steps to prevent this.

Addressing the supply chain issues might have alleviated the recent near-crisis, says Howson-Smith. And Sharon George, at Keele University, says the government paying CF Industries to secure CO2 stocks was likely preventable. “Here we are, the cost of doing nothing, we’re seeing it play out,” she adds.

Among the causes of the 2018 shortage were extremely high demand due to a hot summer that prompted high sales of carbonated drinks, including beer. This year, supply has been the chief concern. Natural gas is the key ingredient in ammonia and so when gas prices rocketed recently, the owners of various ammonia plants in the UK and further afield decided to halt production. Farmers don’t use lots of fertiliser during the summer, so these firms could afford to down tools for a time.

But an unfortunate side-effect of this was the shortfall in CO2 supplies. As the 2019 report authors pointed out, relying on ammonia plants for CO2 means that supply and demand of the gas can become decoupled. Multiple, more reliable sources were needed, they argued.

The UK could have softened the natural gas price shock and its effects on CO2 production by expanding the country’s natural gas storage facilities, suggests George. “It would have meant that the natural gas price wouldn’t have fluctuated so high and ammonia production may not have been turned off,” she says.

The UK has “very modest amounts of storage”, in terms of natural gas, according to Michael Bradshaw, professor of global energy at Warwick Business School. In a piece for The Conversation, he noted that the UK stores less than six per cent of the nation’s annual demand, compared to the 20 per cent or so held by Germany, France and Italy.

A government report in 2017 on the security of natural gas supplies to the UK stated that the country’s existing storage infrastructure was “sufficient to meet all customer demand in all but the most extreme cases”. It added, “Our analysis finds that the market will adapt to these changes in supply and demand. This means that GB will have enough import capacity to deliver even in high demand scenarios.” The government did not respond to WIRED UK’s questions about any steps it had taken in response to the 2018 CO2 shortage.

You might be wondering why the government decided to pay a company to make ammonia, just to retrieve the CO2 by-product, when it could have shipped the gas in from other countries that had more of it to hand. The answer is partly down to the cost of transportation, says Laurence Harwood, professor emeritus at the University of Reading. CO2 requires specially equipped ships or trucks.

“It’s hard to transport long distances because it’s actually not worth it,” he explains. “It’s a very cheap commodity.” That’s precisely why it’s so favoured for use in many food products, as opposed to alternatives such as nitrogen, which is more expensive.

In the future, the UK might get its CO2 from a diverse range of sources – but what are they? Jon Gluyas, executive director of the Durham Energy Institute, suggests carbon capture technology fitted to CO2-emitting infrastructure, such as fossil fuel power plants, might yield a steady supply of the gas going forward. It would have to be purified for use in food products but this should be achievable at a reasonable cost, he says.

Christopher Carson, managing director of BioCarbonics, says that, while he supports the carbon capture and sequestration approach, there is a risk that the recovered CO2 will end up in giant underground storage facilities because it will be considered too costly to extract smaller amounts for industrial uses.

He argues that his firm’s approach offers a better way forward. It involves capturing CO2 from anaerobic digestion sites, where microorganisms break down plant and animal matter. This makes water, methane and CO2. The methane is already used in the UK’s gas grid but it’s the CO2 Carson’s team is after. Their system is already up and running at two anaerobic digestion plants in the UK.

“We contract with them and we agree to buy all of the CO2 that they produce from their site,” he adds. Increasing the number of such systems in place could help to solve the imbalance in the existing CO2 supply chain, he says.

“We’ve kept our customers supplied through this whole thing,” he notes, referring to the latest shortage. Howson-Smith points out that CO2 is also a by-product in the production of bioethanol, which is used to power some road vehicles in the UK. By boosting bioethanol output, the country could potentially score a double whammy – decarbonise transport and nurture a ready supply of CO2 for industrial uses.

Either way, she argues that more long-term thinking on CO2 is needed: “This supply chain is just too fragile for the things that it’s required to supply.”

More great stories from WIRED

This article was originally published by WIRED UK