Given that fossil fuel requirements will continue well into the future, and the worldwide desire for cuts to ultimate emissions, is CO2 recycling a valid tactic for emissions reductions? A new study from Columbia University’s Center on Global Energy Policy – Opportunities and Limits of CO2 Recycling in a Circular Carbon Economy: Techno-economics, Critical Infrastructure Needs, and Policy Priorities – looks at the upsides and downsides of CO2 recycling.
While it may be possible to dramatically cut CO2 emissions from power generation and vehicle uses, carbon-intensive fossil fuels will remain necessary for uses such as aviation fuels and cement production. The report, with lead author Amar Bhardwaj of the University of Edinburgh, concludes “Recycling CO2 into valuable chemicals, fuels, and materials has emerged as an opportunity to reduce the emissions of these products. In this way, CO2 recycling is a potential cornerstone of a circular carbon economy that can support a net-zero future. However, CO2 recycling processes have largely remained costly and difficult to deploy, underscoring the need for supportive policies informed by analysis of the current state and future challenges of CO2 recycling.”
Key findings:
* CO2 recycling could yield deep emissions reductions. “When supplied by low-carbon electricity and chemical feedstocks, CO2 recycling pathways have the combined potential to abate 6.8 gigatonnes of CO2 per year (GtCO2/yr) when displacing conventional production methods.”
* Some recycling technologies are cost effective today, but other remain doubtful. Electrochemical carbon monoxide (CO) production, ethanol from lignocellulosic biomass, concrete carbonation curing, and the CarbonCure concrete process all have an estimated cost of production (ECOP) lower than the product selling price. These pathways have a combined carbon abatement potential of 1.6 GtCO2/yr. Most remaining pathways have an ECOP of 2.5 to 7.5 times greater than the product selling price.”
Carbon Cure, according to its developer, is a “technology retrofitted into concrete plants and enables concrete producers to inject captured CO₂ into fresh concrete during mixing. Once injected, the CO₂ reacts with the concrete mix and becomes a mineral that is permanently embedded. Best of all, the CO₂ mineralization also increases the concrete’s strength, resulting in economic and climate benefits—truly a win-win solution.”
* How catalysts perform and electric input prices are the “main cost drivers.” The costs of electricity and of chemical feedstocks drive the recycling costs.
* CO2 recycling to meet the needs of current markets requires “enormous new capacity of critical infrastructure. Each pathway at global scale would consume thousands of terawatt hours of electricity, 30–100 million metric tons (Mt) of hydrogen, and up to 2,000 Mt of CO2 annually. This would require trillions of dollars of infrastructure per pathway to generate and deliver these inputs, including a combined 8,400 gigawatts (GW) of renewable energy capacity and 8,000 GW of electrolyzer capacity across all pathways.”
— Kennedy Maize
(kenmaize@gmail.com)