Remove CO2 directly from the air.

Plants do it all the time: it’s called photosynthesis [1]. They take in CO2 from the air, combine it with water, and use it to grow and produce oxygen [1]. Could we build a machine to suck CO2 from the air?

Some engineers are doing just that [e.g. 2,3,4,5,6]! They call it ‘Direct Air Capture’ (DAC) [13]. One company [3] claims that they will be able to do it for $94-232 per ton of CO2 [16]. Being optimistic and assuming $100 per ton, it would cost $3.7 trillion to remove the amount of CO2 that humans emitted in 2018 (about 37 billion tons [7]). That’s about 4% of global GDP [15]. Clearly we need to get the price down [8,18].

There are a few different methods of DAC [17]. We will explain the most mature one in simple terms: air is blown across a material that CO2 sticks to, whilst the rest of the air is blown out [16]. The CO2 is then collected and the material is re-used to capture the next load of CO2 [16]. Swipe for a diagram of the chemical reactions!

There are a few challenges [9,18]. For example, capturing CO2 from the air is inherently difficult because the concentration of CO2 is so low: only 400 out of every 1,000,000 molecules in the air are CO2 [18]. This means making the process cost-efficient is difficult [18].

Scientists and engineers have solved problems in the past that seemed previously unsolvable (electricity [20], the structure of DNA [21], the internet [22] etc.). A recent investment of $68 million into a DAC company [14], and partnerships between oil companies and teams working on DAC [10] suggests that people think this technology is promising. This is a sign that DAC will hopefully become more efficient and affordable, and could play a major role in reducing CO2 emissions [12]. However, some scientists argue that other methods of CO2 removal deserve more attention [18,19].

References

[1] http://www.biology4kids.com/files/plants_photosynthesis.html

[2] https://www.climeworks.com/

[3] http://carbonengineering.com

[4] https://www.businessgreen.com/bg/news/3077500/lab-in-heart-of-yorkshire-power-plant-to-turn-co2-into-animal-feed

[5] https://www.prometheusfuels.com/

[6] https://globalthermostat.com/

[7] https://www.scientificamerican.com/article/co2-emissions-reached-an-all-time-high-in-2018/

[8] https://www.sciencedirect.com/science/article/pii/S1876610211003900 See: Abstract

[9] https://www.nature.com/articles/s41467-019-10842-5 See: Discussion

[10] https://www.cnbc.com/2019/06/21/carbon-engineering-co2-capture-backed-by-bill-gates-oil-companies.html

[12] https://www.sciencedirect.com/science/article/pii/S0959652619307772

[13] https://www.ipcc.ch/site/assets/uploads/sites/2/2019/02/SR15_Chapter2_Low_Res.pdf See: 2.3.4.1 CDR technologies and deployment levels in 1.5°C pathways

[14] https://carbonengineering.com/news-updates/carbon-engineering-concludes-usd68-million-private-investment-round/

[15] https://data.worldbank.org/indicator/ny.gdp.mktp.cd

[16] https://www.sciencedirect.com/science/article/pii/S2542435118302253 - diagram inspired by this

[17] https://pubs.acs.org/doi/abs/10.1021/acs.chemrev.6b00173

[18] https://pubs.rsc.org/en/content/articlehtml/2018/ee/c7ee02342a See: 12.2 Direct air capture of CO2

[19] https://www.carbonbrief.org/direct-co2-capture-machines-could-use-quarter-global-energy-in-2100

[20] https://www.britannica.com/technology/history-of-technology/Electricity

[21] https://www.britannica.com/science/DNA

[22] https://www.britannica.com/technology/Internet#ref255529

Join our Newsletter!

Impress

Climate Science Ltd
Company Nr: 12370672
Registered in England & Wales
Mail: [email protected]

address

15 Hope Close
Totnes
TQ9 5YD
United Kingdom

Climate Science is registered as a non-profit company limited by guarantee in England and Wales.

Copyright © 2019-2020 Climate Science Ltd. All rights reserved.

Climate Science uses Cookies to ensure you get the best experience on our website.