Carbon recycling a waste of time? Scientists say most CCU tech incompatible with Paris Agreement

NIJMEGEN, Netherlands — Carbon recycling technologies, though viewed as yet another way to slow down climate change, may be steering funding away from more impactful solutions. A review by researchers at Radboud University in the Netherlands finds most of these are not compatible with the Paris Agreement both in the long and short term.

The analysis calls into question the viability of carbon capture and utilization (CCU) technology. Researchers suggest focusing instead on using non-fossil CO2 and storing the greenhouse gas permanently.

“If a technology is not going to reduce emissions by a lot and it is still very far away from commercialization, then maybe it is better to redirect funding to technologies that do have the potential of really drastically reducing emissions,” says lead author Kiane de Kleijne, a PhD student at Radboud University, in a statement.

What is CCU?

CCU involves harnessing the gas from emissions from power plants or industry for repurposing. It is converted into a new product, like the fuel methanol, using electricity, heat, or catalysts.

“It sounds really good, right? It’s taking problematic waste and turning it into a valuable product,” says de Kleijne. “But we assessed and harmonized many previous studies on CCU, and this showed us that CCU doesn’t consistently reduce emissions.”

For a technology to be compatible with the Paris Agreement per the IPCC (Intergovernmental Panel On Climate Change), the agency behind the agreement, it must halve CO2 emissions by 2030 and reach zero by 2050. Of the 74 CCU routes reviewed in the paper, only eight met the 2030 target and just four the 2050 one.

Researchers also evaluated CCU’s maturity – how close the technology is to being ready for widespread use – and found they are still very far away.

Carbon recycling not highly effective

Further analysis shows many are also highly energy intensive. The final step to create something like methanol also generates emissions. “In many cases they don’t really reduce emissions compared to the conventional product, so that is problematic,” adds de Kleijne.

The researchers worry that more effective options, like carbon capture and permanent storage and reducing consumption, could take a backseat to carbon recycling technologies. But they identified a few low-emission CCU systems that store carbon longterm, efforts the authors describe as “promising.”

For example, the carbonization of steel slag to create construction materials can sequester large amounts of carbon which would remain stored indefinitely. In addition, if captured directly from the atmosphere or after combustion of biomass, which has sequestered the gas through photosynthesis, it can lower concentrations of CO2.

“We would love to be able to extend our analysis a bit further, because now we have done this assessment for CCU and it is not looking great,” says de Kleijne. “But it would be good to be able to compare it to other alternatives to replacing fossil fuel-based products or services.”

The study is published in the journal One Earth.

South West News Service writer Mark Waghorn contributed to this report.

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