Carbon capture options

Because the alternative is deep and rapid emissions cuts which countries are unwilling to implement, the IPCC now assumes that stabilizing the climate will involve heavy use of negative emission technologies: “between 100bn and 1trn tonnes of CO2 to be removed from the atmosphere by the end of the century if the Paris goals were to be reached; the median value was 730bn tonnes–that is, more than ten years of global emissions.”

There are numerous possible options. CO2 could be separated from flue gasses from power plants, compressed, and injected underground. If those power plants burn biomass which recently took CO2 out of the atmosphere, that could help draw down the stock of carbon in the atmosphere. That approach is called bioenergy with carbon capture and storage or BECCS. It’s also possible to separate CO2 directly from the air and bury it (direct capture). It’s also worth bearing in mind that sometimes CO2 is injected underground to push up oil to be sold (enhanced oil recovery or EOR). In that case, it likely creates more emissions than it avoids since the same volume of oil is pushed out and then likely burned in a vehicle where it cannot be captured.

All this may be highly questionable as a climate change solution and, indeed, the main push for CCS is from corporations and states that don’t want to give up fossil fuel production. The notion the technology will eventually exist at scale helps justify today’s fossil fuel burning, even though right now we’re buying about 40 million tonnes of CO2 while emitting 43.1 billion tonnes. Burying any substantial fraction of global CO2 emissions would mean compressing and burying many times the total quantity of oil we take out of the ground — with everything that implies about costs, deployment times, and capital requirements — and this whole infrastructure would require energy to run instead of producing it, either requiring us to deploy yet-more climate-safe energy to build and power the equipment or putting us in the self-defeating position of burning more fossil fuels to generate energy to bury the CO2 from the fossil fuels we already burned.

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8 thoughts on “Carbon capture options”

  2. $1.2 billion CO2 pipeline from Industrial Heartland to depleted oilfields in central Alberta comes online

    After 11 years, the province’s largest carbon capture and storage project is fully operational, allowing millions of tonnes of emissions to move from facilities near Edmonton to a storage site in central Alberta.

    The Alberta Carbon Trunk Line (ACTL) has been in the works since 2009 when then-premier Ed Stelmach’s government funded the project with $495 million to help tackle emissions and gain more oil revenues from depleted wells.

    …

    The roughly $1.2-billion project will transport liquified CO2 from Alberta’s Industrial Heartland area northeast of Edmonton to a site near Clive, about 120 kilometres south of Edmonton. The CO2 will then be pumped into Enhance Energy’s depleted oil reservoirs allowing for up to 20 per cent more oil to be taken out of the ground because it will flow more easily.

    The system is designed to store about two million tonnes of CO2 underground at the site per year.

    The first to use the pipeline will be the Agrium fertilizer plant and the NWR Sturgeon Refinery. The cost of processing CO2 will then be recouped from Enhance Energy as part of a commercial agreement.

  6. The policy implications of an uncertain carbon dioxide removal potential

    https://www.sciencedirect.com/science/article/abs/pii/S2542435121004323

    • Experts are surveyed on the feasible CDR potential from BECCS, DACCS, and afforestation

    • Results highlight a potentially large but highly uncertain CDR potential

    • Uncertainty in future CDR potential drives greater climate action in the 2020s

    • High uncertainty in CDR leads to an extra 10 GtCO2e of emissions reductions by 2030

  7. Carbfix pipes the gas to nearby wells, mixes it with water and pumps the resulting carbonated water into the bedrock. In Iceland that consists almost entirely of volcanic basalts, which contain minerals that react with carbon dioxide to form calcium carbonate, a white crystal that is the main ingredient in limestone. Thus, the full operation extracts CO2 from air and turns it to rock. Trials have shown that Icelandic basalts can sequester CO2 in solid rock within two years. Power comes from a nearby geothermal power station.

    One catch is volume. Orca will capture 4,000 tonnes of carbon dioxide a year, out of around 35bn tonnes produced by burning fossil fuels. Climeworks is “confident” it can reach millions of tonnes before the decade is out. (A previous, eye-popping ambition to grab 1% of emissions by 2025 is no longer on the cards.)

    Another is cost. It costs Orca somewhere between $600-800 to sequester one tonne of carbon dioxide, and the firm sells offset packages online for around $1,200 per tonne. The company thinks it can cut costs ten-fold through economies of scale. But there appears to be no shortage of customers willing to pay the current, elevated price. Even as Orca’s fans revved up, roughly two-thirds of its lifetime offering of carbon removals had already been sold. Clients include corporations seeking to offset a portion of their emissions, such as Microsoft, Swiss Re (and The Economist), as well as over 8,000 private individuals.

    https://www.economist.com/science-and-technology/2021/09/18/the-worlds-biggest-carbon-removal-plant-switches-on

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