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Artificial is a term that we typically take to mean fake. So why is it being used to prefix a vital process? And how does artificial carbon sequestration work?
Indeed, artificial carbon sequestration is cropping up all the more frequently these days. It is a favourite amongst the fossil fuel industry, who are quick to promote the process because of its ability to counteract our emissions.1 Their view is that vehicles and power-plants could continue burning fossil fuels, with the resulting carbon emissions captured and stored before entering the atmosphere.
It certainly paints a pleasant picture. Yet, bear in mind this is the same flawed logic behind the failed idea of “clean coal”.2
So… what is so-called artificial carbon sequestration?
Artificial Carbon Sequestration: an overview
Artificial carbon sequestration (ACS) refers to the anthropogenic (human-induced) enhancement of the earth’s own natural carbon capture and storage process. By bolstering the age-old system of removing carbon dioxide – a greenhouse gas – from the atmosphere, scientists propose ACS as a strategy to prevent catastrophic global warming.3
How does it work?
Consider the process of natural carbon sequestration. Forests are burned, a volcano erupts or an animal exhales. Carbon dioxide (CO2) is released into the air. Plants then absorb this CO2 through a process called photosynthesis. The plant uses the CO2 for growth, until eventually it becomes stored in the soil as organic matter. At the same time, more atmospheric CO2 is mixing with rainwater to create carbonic acid. This dissolves rocks through a process called chemical weathering, and eventually reaches the ocean to be turned into carbonate minerals.1
The problem, however, is that some human activities mean we are now pumping out far more CO2 than can be sequestered at the natural rate. The outcome is rising global temperatures. Might it still be possible to re-establish the planet’s carbon sink? Cue artificial sequestration.
In its most basic form, ACS involves planting more trees (afforestation). Currently, forests store nearly a third of global emissions. Planting even more would increase the rate of CO2 uptake further.4 Therefore, fewer emissions would enter the atmosphere.
Enhanced chemical weathering is another option. This involves speeding up the aforementioned natural process by spreading finely crushed rock on farmland, or over the ocean.5
There are various other forms of artificial sequestration.6 However, all share the same end goal: increase the natural rate of CO2 uptake, and offset global emissions.
Can we put faith in this strategy? There are mixed views within the scientific community as to the overall potential of ACS as a global warming solution. We cannot forget that CO2 is not the only greenhouse gas contributing to our global problem.
But from what evidence is available, in the form of the earth’s age-old carbon cycle, it is a project that is worth pursuing.
- Oeklers, E.H. and Cole, D.R. (2008) Carbon dioxide sequestration: a solution to the global problem. Elements 4, 305-310.
- Pierre-Louis (2017) There’s no such thing as clean coal [Online] Popular Science. [Accessed April 2020]
- IPCC. (2018) Global Warming of 1.5˚C: Summary for policy makers. IPCC Special Report. ISBN 978-92-9169-151-7.
- Bastin, J., Finegold, Y., Garcia, C., Mollicone, D., Rezende, M., Routh, D., Zohner, M. and Crowther, T.W. (2019) The global tree restoration potential. Science, 365(6448), 76-79.
- Strefler, J., Amann, T., Bauer, N., Kriegler, E. and Hartmann, J. (2018) Potential and costs of carbon dioxide removal by enhanced weathering of rocks. Environmental Research, 13(3).
- Nogia, P., Sidhu, G.K., Mehrotra, R. and Mehrotra, S. (2016) Capturing atmospheric carbon: biological and nonbiological methods. International Journal of Low-Carbon Technologies, 11(2), 266-274.
What are CO2 removal technologies?
CO2 removal technologies aim to remove carbon dioxide from the atmosphere.1. They can also be referred to as NETs (negative emissions technologies)2.
The IPCC (Intergovernmental Panel on Climate Change) identified NETs as requisite for limiting global temperature rise to 1.5C without overshooting targets3. The European Academies’ Science Advisory Council have also taken a similar stance. They recognise that CO2 removal technology will be vital for reducing global emissions in the atmosphere4.
Several proposed CO2 removal technologies have been subject to intense research and development. These include the likes of afforestation, biochar, bioenergy, enhanced weathering, (DAC) direct air capture, and ocean fertilisation1.
Afforestation, Reforestation and Habitat Restoration
Firstly, afforestation refers to the planting of new trees where there were previously none. You also have reforestation where trees that have been cut down or degraded are restored 1.
As natural solutions, trees act by removing CO2 from the atmosphere and storing it in the biomass and soils of ecosystems5. On a large scale, it is easy to see the effectiveness with U.S. forests estimated to absorb 13 percent of the nation’s carbon emissions6. With space available for trees greater than previously thought, both afforestation and reforestation are potentially large-scale methods for CO2 removal7.
Moreover, the cheap cost of this solution means tree planting could remove more CO2 from the atmosphere at between $0 to $20 per ton of carbon6. As opposed to other solutions, this makes afforestation and reforestation a viable solution in a wider range of countries8 when compared to other CO2 removal technologies. However, land suitability remains a key challenge1.
Aside from trees, coastal and marine ecosystems can also capture and store CO2 from the atmosphere. This solution, referred to as blue carbon habitat restoration, has the potential to be highly effective as these ecosystems can absorb CO2 even faster than terrestrial forests1.
However, uncertainties over blue carbon projects include substantial variation in the amount of CO2 removed by coastal ecosystems in different locations9. These unknowns raise a question mark over effectiveness on a large scale.
Biochar and CO2 Removal
Biochar is a form of charcoal produced by heating biomass without any oxygen present. This process is known as pyrolysis1. Biochar production consumes more energy than it produces, unlike typical burning processes which would be a major source of CO210. Studies have found that biochar has the potential to sequester up to 4.8bn tonnes of CO2 per year11.
Yet it has drawbacks. Biochar, often used as a soil additive, can lower the reflectivity of the soil surface. This result can potentially exacerbate climate change12.
Bioenergy and CO2 Removal
BECCS (Bioenergy with carbon capture and storage) involves burning biomass, capturing the emissions and locking it away deep underground13. BECCS can draw significant quantities of CO2 out of the atmosphere1. This, along with low costs compared to other solutions, make it favourable.
The criticism levelled at BECS’s suitability by the scientific community includes questions over scalability, potential side effects, and whether it is truly able to deliver any negative emissions at all13.
The weathering of huge amounts of rock is another way of potentially removing CO2 from the atmosphere14. The process sees rocks break down by reacting with CO2 in the air creating bicarbonate, a carbon sink. The bicarbonate eventually runs off into the ocean where it stores the CO2 that derives from the process of weathering6.
This normally slow process absorbs around 3% of global fossil-fuel emissions1, and it produces beneficial by-products too. As part of the process, alkaline bicarbonate runoff washes into the ocean and partially helps neutralize ocean acidification6.
Yet the potential of these enhanced weather CO2 removal technologies is limited14, according to studies14. It would likely work best as a small additional contribution to support climate change mitigation.
DAC (Direct Air Capture)
DAC uses machines to suck CO2 out of the atmosphere and either bury it underground or convert it into something useful15.
There are a number of ways to do this. Firstly, industrial-scale facilities use a solution of hydroxide to capture CO2. There is also the possibility of using amine adsorbents in small, modular reactors16.
One study projected that direct air capture could sequester 0.5 to 5 gigatonnes of CO2 a year by 205017. This gives it significant CO2 removal potential compared to other solutions.
However, it is costly and largely inefficient. For example, research suggests DAC could use a quarter of global energy’ in 210016. DAC solutions often increase local air pollution from the energy required to run them, exacerbating public health issues.
Ocean fertilisation works by injecting nutrients into the ocean to trigger a ‘bloom’ of phytoplankton1. Phytoplankton need iron to be able to photosynthesise, and if it is the only limiting element, it can stimulate huge ‘blooms’. During this process of photosynthesis, phytoplankton also need inorganic carbon. By absorbing CO2 from the atmosphere and helping dissolve it in the sea, the blooms help remove atmospheric CO2 levels18.
However, whilst ocean fertilisation would help decrease atmospheric CO2 the impact would largely be minimal. It also carries risks to the ecosystem with possible side effects including changes to phytoplankton species which will have an effect on the food web18.
Finding the Best Solution for Climate Change
There is no single CO2 removal technology that is the ultimate solution to climate change. One proposed way forward involves using a NETs portfolio19 where solutions can be deployed at a more modest scale to help manage risk.
Of course, each technology is feasible at some level but uncertainties about cost, scalability, technology, implementation, or environmental risks remain. No single location and no technology in isolation will be sufficient to solve this huge problem by itself19. A range of solutions will seemingly have to work together where possible in order to remove atmospheric CO2.
- Carbon Brief. 2016. Explainer: 10 ways ‘negative emissions’ could slow climate change.
- The Conversation. 2018. Why we can’t reverse climate change with ‘negative emissions’ technologies.
- Carbon Brief. 2018. In-depth Q&A: The IPCC’s special report on climate change at 1.5C.
- European Academies’ Science Advisory Council. Forest bioenergy, carbon capture and storage, and carbon dioxide removal: an update.
- Johan Busch et al. 2019. Potential for low-cost carbon dioxide removal through tropical reforestation. Nature Climate Change. 9, pp.463-466.
- Columbia University. 2018. Can Removing Carbon From the Atmosphere Save Us From Climate Catastrophe?
- BBC News. 2019. Climate change: Trees ‘most effective solution’ for warming.
- Cosmos. 2019. Rebuilding forests is a cost-effective way to cut carbon.
- Climate Analytics. 2017. The dangers of Blue Carbon offsets: from hot air to hot water?
- Guardian. 2017. Negative emissions tech: can more trees, carbon capture or biochar solve our CO2 problem?
- Pete Smith. 2016. Soil carbon sequestration and biochar as negative emission technologies. Global Change Biology. 3, pp.1315-324
- Sebastian Mayer et al. 2012. Albedo Impact on the Suitability of Biochar Systems to Mitigate Global Warming. Environmental Science and Technology. 46, pp.12726-12734.
- Grantham Institute. 2019. The ups and downs of BECCS – where do we stand today?
- Science Daily. 2018. Enhanced weathering of rocks can help to pull CO2 out of the air — a little
- Quartz. 2019. A tiny tweak in California law is creating a strange thing: carbon-negative oil
- Carbon Brief. 2019. Direct CO2 capture machines could use ‘a quarter of global energy’ in 2100
- Sabine Fuss et al. 2018. Negative emissions—Part 2: Costs, potentials and side effects. Environmental Research Letters. 13
- University of Southampton. 2014. Ocean fertilization – A viable geoengineering option or a pipe dream?
- Carbon Brief. 2018. Guest post: Seven key things to know about ‘negative emissions’
Carbon capture technology companies are central to meeting the aims of the Paris Agreement. 195 countries signed the Paris Agreement in 2016, committing them to keeping the global temperature rise to below 2 degrees Celsius above pre-industrial levels and to limiting the temperature increase to 1.5 degrees Celsius. Fundamental to curbing the temperature rise is the reduction in emissions of long-lasting greenhouse gases, for example carbon dioxide (CO2).1 The Intergovernmental Panel on Climate Change (IPCC) has demonstrated that carbon capture technology companies are likely to be fundamental for preventing the increase in global temperature and are especially useful in decreasing the cost of mitigating climate change.2
This article examines ten companies at the forefront of carbon capture technology. These carbon capture technology companies use innovative ways to capture waste CO2 – often produced by factories and power plants.3 They either store the waste CO2 to keep it out of the atmosphere, or recycle it for reuse. The following have been included in this list either for their immense contribution to carbon capture and storage or conversion on a global scale, or for their innovative methods to reduce CO2 emissions.
Global Thermostat – direct air carbon capture
Global Thermostat have developed direct air capture technology to pull in air through giant fans and subsequently soak up the CO2 in chambers.4 When attached to power plants, the process uses their leftover heat to grab their CO2 pollution, which can then be sold on to other companies as a further power source.4 Global Thermostat’s facility in Alabama is currently the largest commercial plant of its kind worldwide and it can capture 4,000 tons of CO2 annually – approximately the same amount produced by 870 cars.5 By cogenerating carbon capture and power, Global Thermostat is both removing CO2 from the air and utilising it for practical purposes.
Newlight Technologies – carbon capture and conversion
Newlight Technologies is another company that converts waste carbon into a new and practical product, in their case AirCarbon™. AirCarbon™ is a biodegradable energy material that can be used for creating both fibers and solid parts.6 The everyday uses of AirCarbon™ should not be underestimated, as it is being used to produce packaging, furniture and electronics accessories amongst other products.7 Consequently, Newlight Technologies has won numerous awards for their breakthrough technology, for instance the Innovation Prize for “Biomaterial of the Year 2013″ by the Nova Institute.8
Carbon Upcycling Technologies – carbon capture for profit
Carbon Upcycling Technologies chemically adsorbs CO2 emissions into materials such as polyethylene to create a much stronger product than by traditional methods.9 Not only does this capture and store CO2, the product is produced more quickly, it requires fewer labour and operating costs, and the product lasts longer.9 The success of Carbon Upcycling Technologies’ business model was soon evident. In 2017, they became the youngest CO2 capture and utilization company to begin generating commercial revenue.10
DyeCoo – textiles and carbon capture technology companies
Netherlands-based DyeCoo has developed unique technology that uses CO2 to pressurise powdered dye into fabrics without needing water.11 Their system recycles 95 percent of the CO2 for re-use, thereby utilising the greenhouse gas for a practical purpose whilst reducing water, energy and chemical waste.11 This is important technology for the textiles industry whose current dyeing techniques deposit effluents of unabsorbed dyes, chemicals and heavy salts into rivers and waterways.12 However, the major limitation for DyeCoo is that its process can only be used for dyeing polyester.
Climeworks – carbon capture anywhere
Another direct air capture technology, Climeworks stands out because their carbon removal technology does not require water or arable land and consequently has a small physical footprint.13 By installing their machines on the roofs of power plants, they tap into the plant’s own low-carbon electricity and the heat from its incineration system.14 Using their power, Climeworks’ machines suck air into ducts and over a reusable filter material to chemically bind the CO2. It is then heated to release the high-purity captured gas which can then be repurposed, for instance for beverages or fertiliser.14
Carbicrete – carbon capture technology companies in construction
Cement is a key ingredient when making concrete. However, to produce cement, a great deal of CO2 is also released.15 To overcome this, Carbicrete has patented technology to produce cement-free and carbon-negative concrete.16 They use a by-product of the steel-making process (that is also cheaper than cement) and captured CO2.17 Not only does Carbicrete avoid the usual cement production emissions, it also captures CO2, thus meaning products made in this way are carbon-negative, sequestering CO2 in the process.16 In addition to being a far more environmentally friendly technique, Carbicrete’s products are cheaper to make and are more durable.17
Chevron – Gorgon gas fields project
Energy company Chevron manages one of the world’s largest carbon capture projects in Australia’s Gorgon gas fields. These gas fields have been responsible for a massive amount of CO2 being released into the atmosphere as the natural gas there is extracted.18 But, to reduce Gorgon’s carbon footprint by around 40 percent, Chevron are now injecting compressed CO2 in a sandstone reservoir nearby on Barrow Island. The massive amount of CO2 being captured makes it the third largest carbon capture and storage project in the world.19
However, Chevron’s CO2 capture and storage project only began in 2019 and was beset by delays.18 Indeed, half of Australia’s increase in annual carbon dioxide emissions between 2017 and 2018 have been linked to Chevron and its partner’s failure to initiate the project sooner.18
SaskPower – scaling carbon capture technology companies
In 2014, SaskPower’s Boundary Dam Power Station in Canada became the first power station in the world to successfully deploy carbon capture and storage technology.20 The facility captures CO2 emissions and also removes sulfur and other waste products. Subsequently, the CO2 is either reused for enhanced oil recovery (EOR) or else is injected deep underground to permanently separate it from the atmosphere.21
Nevertheless, the Boundary Dam Power Station’s carbon capture and storage technology has faced frequent and significant obstacles. Issues with the plant have often forced it to shut down and instead of capturing 90 percent of CO2 emissions, around half as much have been captured.22 As such, SaskPower is closing down Boundary Dam units 4 and 5 at the plant, instead of transforming them to use carbon capture and storage technology.23
NRG Energy – carbon capture for coal
NRG Energy is also at the forefront of global carbon capture technology companies. In 2017, their Petra Nova coal-fired power plant was one of only two power plants with carbon capture and storage capabilities.24 Coal-fueled power plants are one of the most environmentally damaging power sources currently in use, therefore mitigating their CO2 emissions is of critical importance. The Petra Nova plant routes part of their emissions to a filtration system to isolate and compress the CO2 for liquidation. It is then pumped 5,000 feet beneath the West Ranch Oil Field where it combines with oil to lower its density. When this oil is extracted, the CO2 is separated from the oil, greatly increasing oil production.25
Nevertheless, NRG Energy’s carbon capture technology has fallen short of expectations at the Petra Nova plant. Despite claiming their techology could capture 90 percent of carbon emissions at the plant, Petra Nova captured between 65 percent and 70 percent of the plant’s CO2.26 These figures also fail to take into account emissions from the natural gas turbine that runs the carbon capture equipment. Once these emissions are considered, the effective capture rate at Petra Nova is reduced to about 50 percent.26
- Summary for Policy Makers. Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. IPCC. https://www.ipcc.ch/sr15/chapter/chapter-1/. Published 2018. Accessed April 29, 2020.
- Cambridge University Press. IPCC Special Report on Carbon Capture and Storage. https://www.ipcc.ch/site/assets/uploads/2018/03/srccs_wholereport-1.pdf. Published 2005. Accessed April 28, 2020.
- Taylor, Matthew and Watts, Jonathan. Revealed: the 20 firms behind a third of all carbon emissions. The Guardian. https://www.theguardian.com/environment/2019/oct/09/revealed-20-firms-third-carbon-emissions Published Oct 9, 2019. Accessed May 13, 2020.
- Home. Global Thermostat. https://globalthermostat.com/ Accessed May 14, 2020.
- Peters, Adele. We have the tech to suck CO2 from the air – but can it suck enough to make a difference? FastCompany. https://www.fastcompany.com/90356326/we-have-the-tech-to-suck-co2-from-the-air-but-can-it-suck-enough-to-make-a-difference Published June 2019. Accessed April 28, 2020.
- Newlight. https://www.newlight.com/. Accessed April 28, 2020.
- Newlight Technologies Signs 15-Year Production License Agreement with Paques Holdings bv. Paques. https://en.paques.nl/news/news/newlight-technologies-signs-15-year-production-license-agreement-with-paques-holdings-bv/2. Published July 2016. Accessed April 28, 2020.
- Innovation Prize for “Biomaterial of the Year 2013″ awarded to PHA producer Newlight Technologies (USA) at the Cologne International Conference 2013 on Industrial Biotechnology and Bio-based Plastics & Composites. Bio-based News. http://news.bio-based.eu/innovation-prize-for-biomaterial-of-the-year-2013-awarded-to-pha-producer-newlight-technologies-usa-at-the-cologne-international-conference-2013-on-industrial-biotechnology-and-bio-based-plastic/. Published May 2013. Accessed April 28, 2020.
- Polyethylene Nucleating Agent. Carbon Upcycling Technologies. https://www.carbonupcycling.com/polyethylene-nucleating-agent Accessed May 14, 2020.
- Member – Carbon Upcycling Technologies. About. Solar Impulse Foundation. https://solarimpulse.com/companies/carbon-upcycling-technologies Accessed May 14, 2020.
- DyeCoo’s water-free and process-chemical free-dyeing technology for textiles. Business Europe. http://www.circulary.eu/project/dyecoo/ Published February 2019. Accessed April 29, 2020.
- Hepburn, Stephanie. Nike and Adidas show cautious support for eco-friendly dye technology. The Guardian. https://www.theguardian.com/sustainable-business/sustainable-fashion-blog/2015/apr/24/nike-and-adidas-show-cautious-support-for-eco-friendly-dye-technology. Published April 2015. Accessed April 28, 2020.
- Climeworks. https://www.climeworks.com/our-technology/. Accessed April 28, 2020.
- Gertner, Jon. https://www.nytimes.com/2019/02/12/magazine/climeworks-business-climate-change.html. New York Times. Published February 2019. Accessed April 28, 2020.
- Rodgers, Lucy. Climate change: The massive CO2 emitter you may not know about. BBC. https://www.bbc.co.uk/news/science-environment-46455844 Published December 17, 2018. Accessed May 14, 2020.
- Genest, Florence. https://solve.mit.edu/challenges/circular-economy/solutions/7560 Solve. Published July 2019. Accessed April 28, 2020.
- Carbicrete. http://carbicrete.com/about/. Accessed April 29, 2020.
- Morton, Adam. Gorgon LNG plant begins long-delayed carbon capture and storage project. The Guardian. https://www.theguardian.com/australia-news/2019/aug/08/gorgon-lng-plant-begins-long-delayed-carbon-capture-and-storage-project Published August 8, 2019. Accessed May 14, 2020.
- Duckett, Adam. https://www.thechemicalengineer.com/news/gorgon-ccs-plant-starts-up-after-two-year-delay/ The Chemical Engineer. Published August 2019. Accessed April 29, 2020.
- Burgess, Molly. SaskPower celebrates carbon capture milestone at Boundary Dam Power Station. https://www.gasworld.com/saskpower-ccs-facility-celebrates-milestone/2018021.article. Published November 2019. Accessed April 28, 2020.
- SaskPower Boundary Dam Carbon Capture Project. PCOR. https://undeerc.org/pcor/CO2SequestrationProjects/SaskPower.aspx. Accessed April 29, 2020.
- Burton, Bob. The fallout from SaskPower’s Boundary Dam CCS debacle. Renew Economy. https://reneweconomy.com.au/the-fallout-from-saskpowers-boundary-dam-ccs-debacle-54803/ Published Nov 12, 2015. Accessed May 14, 2020.
- SaskPower abandons carbon capture at Boundary Dam 4 and 5. CBC. https://www.cbc.ca/news/canada/saskatoon/saskpower-abandons-carbon-capture-at-boundary-dam-4-and-5-1.4739107 Published July 9, 2018. Accessed May 14, 2020.
- Dubin, Kenneth. Petra Nova is one of two carbon capture and sequestration power plants in the world. eia. https://www.eia.gov/todayinenergy/detail.php?id=33552. Published October 2017. Accessed April 28, 2020.
- Williams, Todd. Billion Dollar Petra Nova Coal Carbon Capture Project a Financial Success But Unclear If It Can Be Replicated. Scott Madden. https://www.scottmadden.com/insight/billion-dollar-petra-nova-coal-carbon-capture-project-financial-success-unclear-can-replicated/. Accessed April 29, 2020.
- Schlissel, David. IEEFA op-ed: Reality of carbon capture not even close to proponents’ wishful thinking. IEEFA. https://ieefa.org/reality-of-carbon-capture-not-even-close-to-proponents-wishful-thinking/ Published August 8, 2019. Accessed May 14, 2020.
- NIKE, Inc. Unveils ColorDry Technology and High-Tech Facility to Eliminate Water and Chemicals in Dyeing. December 2, 2013.