What is Direct Air Capture? (Part 2: Climeworks Launch)

This is the second post of the #WhatIsDAC series. My goal for this series is to unpack some of the nuances around technologies (Direct Air Capture – DAC) that can remove CO2 from the atmosphere. Click here to read the first one.

View of the 37,632 sq M Meier Greenhouse using Climeworks CO2

As I walked up to the Meier Greenhouse in Hinwil, I got a strong whiff of fresh manure. Indeed, I was in Swiss farming country. Later that day, the Climeworks team would unveil the world’s first plant to extract CO2 from the atmosphere for commercial use. After eight years of hard work, the team grew from two PhD students, Jan Wurzbacher and Christoph Gebald, completing their theses in a lab at ETH Zurich under Aldo Steinfeld, to almost fifty at the commissioning of the new plant. They went from finding optimal materials to capture a few micrograms of CO2 to developing a system that delivers over 900 tons a year.

Please enjoy this three-minute film I put together to capture the event. Highlights: Noah Deich from the Center for Carbon Removal, drone footage of the plant’s commissioning, and an up-close viewing and explanation of the system.

How does it work?

The company builds units to provide on-demand beverage grade CO (over 99% purity). At any one time, there are units with filter materials which are adsorbing (capturing) and desorbing (releasing) CO2­. The units swing back and forth between capturing and releasing every few hours. They are activated by low-grade heat at around 100 degrees Celsius which causes the material to release the CO2. Each module has the capacity to capture and deliver around 135 kilograms of CO2 per day. After Gebald and Wurzbacher hit the start button, I saw the CO2 levels drop on the egress side of the units to below 80 parts per million, meaning that their process captures at least 80% of the CO2 from the atmosphere. Of course, since CO2 mixes rapidly in the atmosphere, the CO2 depleted air is not a major concern for plants which want to naturally photosynthesize, but it is notable that unlike post combustion capture with carbon capture at centralized fossil emissions, which must strive to capture as much as possible to stop the waste from accumulating in the atmosphere, DAC plants only need to go for the optimum.

Climeworks also produces ancillary equipment for process control for heating and cooling, and post-processing treatments. These could include aspects like gas buffers to control the the volume flow of CO2, CO2 conditioning modules for compression or compression or liquification of the CO2 or storage modules. The entire process is automated and can be controlled from wherever.

Because CO2 exists everywhere in the air, Climeworks can operate independently of any emission source. They become the CO2 provider to customers who want to use the gas for feeding it to greenhouses to enhance their yield, carbonating beverages, making fuels, providing for carbon negative materials, or permanently sequestering it underground.

A Spirit of Collaboration

Inside the Kezo waste incineration plant

The success of this company to date embodies the spirit of collaboration. The “Climeworkers” pulled together the many pieces of integration that are required to make direct air capture work at a commercial scale. They found customers who had problems – like a need for CO2 and excess heat – and partners who had an aligned interest in seeing the technology come to fruition. With a highly methodical and multidisciplinary approach, the team grew out from the technical university, benefited from strong government support with the Swiss Federal Office of Energy, and secured the right strategic partners who could suspend disbelief that the Climeworks process would become affordable. The location of Climeworks’ first commercial demonstration was chosen with careful attention to synergies. The Meier Greenhouse prides itself on being a CO2 neutral company. They are agnostic as to where the CO2 comes from – but can enhance their yield of tomatoes, cucumbers and eggplant by up to 20% with higher CO2 concentrations and therefore are willing to pay. They were already co-located next to the Kezo waste incineration plant which provides heating to the greenhouse so that they can run through the winter. Through using CO2 from the atmosphere, Meier could take their climate commitments one step further. Climeworks can immediately utilize Kezo’s waste heat, therefore making the plant more efficient, while simultaneously drawing from a carbon neutral source of energy.

It is notable that when Climeworks began their entrepreneurial journey, the notion of direct air capture was still viewed as an abstract last resort for addressing climate change. This thinking of the past follows the lines of:

  • If we can’t decarbonize quickly enough or reduce emissions, we might need to rely on this process
  • Only until after we can capture CO2 from all industrial sources of emissions does it make sense to capture CO2 from the atmosphere
  • This process is still a science experiment and will never come down in cost

With the increasing acknowledgement of the need for negative carbon emissions, the argument is changing from the question of “either/or.” We need all. And being able to clean up after yourself doesn’t give you the license to keep making a mess. It motivates you not to make a mess in the first place and allows you to pay for your past messes.

What is next for Climeworks?

Some of the Climeworks team

Climeworks is at base camp. They are at the beginning of an ambitious plan to be part of playing a role in reversing climate change. The company has a production facility on track to create modules to capture 7,500 tons per year – or 150 modules this year. They have seven commercial demonstrations that will roll out over the next twenty-four months. By 2025, Climeworks’ goal is to capture 1% of global annual CO2 emissions. As Dr. Julio Friedman of Lawrence Livermore National Laboratory noted at the event, 1% of global emissions is about 400 million tons of CO2. The carbon capture and storage industry has spent hundreds of billions of dollars in research and demonstration plants, and has projected plans to capture and store a similar amount by 2025. Even if Climeworks does not reach this goal, the fact that they can make the claim shows the disruptive potential of direct air capture. Modular and mass produced technologies can scale substantially more quickly than centralized power plants. Climeworks’ aim would come from They will face significantly fewer headwinds relative to carbon capture at centralized emissions in terms of site selection, resistance from the “keep it in the ground” faction, and questions about impact on the carbon balance – i.e. where does the carbon come from and ultimately end up, and to what extent does this technology lock the world in to fossil fuel technologies. While at the event they publicly announced that they can estimate the cost of capture at around $600/ton today, they already have a pathway to cut this down by at least a factor of 3. At first glance, $600/ton is far off the McKinsey cost curve in terms other CO2 abatement options which cost significantly less in $/ton of CO2 reduced, or not emitted, there are a couple of aspects to keep in mind about this number:

  • Unlike conventional carbon capture and storage, who build power plants with a high capital expenditure – over $1 billion – and might be locked into a process for 40 years with minimal efficiency improvements and cost reductions, DAC plants will enjoy capital expenditures in the single digit millions, and can be replaced quickly allowing for significantly more rapid cost reductions.
  • Because the units are modular, cost curves can more closely follow the solar photovoltaic costing trend, which has come down more than 100 times since the first of a kind technologies.
  • This is but one way to extract CO2 from the atmosphere, there are many different ideas and companies with processes that may prove to be more efficient and less costly (more on this in a future post). As the industry advances – and collaborates – optimal approaches will be identified.
  • If the cost of capturing and storing the CO2 comes down below the social cost of carbon, high costs may not matter. Let’s assume that the world begins to count the excess damage of a ton of CO2 to the atmosphere and agrees that we need to pay for it. If the cost of an unambiguous method to capture and permanently remove CO2 from the atmosphere with a theoretically limitless scale is lower than this cost – which in some cases exceeds $100/ton, then Climeworks will be in a profitable business of disposing CO2 It is highly likely that the social cost of carbon is only going to go up as the world attributes more pain to climate change. It could be that we truly do not have a choice but to support those technologies which aid in pulling back greenhouse gases as quickly as possible.

I hope you enjoyed! Please share your comments below, join the conversation on twitter with #WhatIsDAC, and look forward to future posts in this series where I will expand on other methods and companies that pull CO2 out of the atmosphere, how direct air capture compares to carbon capture and storage, and more!

Also published on Medium.

1 thought on “What is Direct Air Capture? (Part 2: Climeworks Launch)”

  1. Excellent piece. A few nuances from the view of Climate Restoration:
    -We are doing this in order to give our children a healthy climate. It does not matter how the CO2 got into the atmosphere, we want to get the level back to 280-300 ppm.
    -The only way to get back to 300 ppm is with CDR, and on land, DAC is the main option.

    Carry on!

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