Carbon capture utilisation and storage (CCUS)
Across the globe, many countries have committed to reducing greenhouse gas emissions. One-hundred-and-ninety-six parties signed The Paris Agreement, a legally-binding international treaty on climate change adopted in 2015.
Its central aim is to limit the global temperature increase to no more than 2 degrees Celsius, and preferably no more than 1.5 degrees Celsius, above pre-industrial levels. It also aims to achieve a climate neutral world, i.e., net zero, by 2050.
Capturing and storing carbon is a vital part of meeting these goals.
According to the CCUS Market Update for Q2 2022 from research and consultancy business Wood Mackenzie, the current global carbon storage capacity is about 63 million tonnes per annum (Mtpa). Global CCUS capacity is planned to reach 905 Mtpa, with more than fifty new projects announced in Q2 2022. However, the report predicts the need for a CCUS capacity of over 5,000 Mtpa to keep the global temperature rise to no more than the 1.5 degrees called for in the Paris Agreement.
Although the US is the global leader in CCUS, with over 65% of the current global storage capacity, the number and scale of CCUS storage projects proceeding globally is accelerating. For example, multiple storage sites are being developed in the North Sea. Earlier this year, the NTSA (North Sea Transition Authority), launched the UK’s first-ever carbon storage licensing round for 13 storage sites; the first of many, as up to 100 CO2 stores could be needed for the UK alone.
Global patent activity
The demand for CCUS is reflected in technical innovation with global patent filings related to CCUS from all jurisdictions increasing over the past 20 years shown in Figure 1.
There was a large peak in priority filings in 2011/2012, after which filing numbers decreased slightly until 2015. Since 2015, filing numbers have continued to trend upwards with over 140 new filings in 2020. The number is expected to continue rising in 2021/2022.
Figure 1: Twenty-year trend: priority filings - CCUS
Figure 2 shows the patent activity over the same 20-year period, split into the top five filing jurisdictions (with the largest activity from the US, Europe, and South Korea).
The US has filed the most applications continuously over the past twenty years – unsurprising, given its dominance as the current global leader in CCUS storage.
The US is also almost entirely responsible for the peak in filings between 2009-2012 (Figure 1) – potentially a direct response to the US 45Q tax credit incentive for carbon sequestration launched in 2008. US patent filings for CCUS decreased slightly after the peak in 2012, but since 2015 have generally trended upwards.
On 16 August 2022, Present Biden signed the Inflation Reduction Act which enhances and extends the 45Q tax incentive. This could potentially accelerate the planned carbon storage capacity in the US as well as incentivising further innovation in CCUS via smaller-scale projects. It will be interesting to see if this is reflected in the number of patent filings.
Figure 2: Twenty-year trend: top five filing jurisdictions - CCUS
Filings peaked in Europe between 2008 and 2011 and have been much slower to recover from a subsequent decline than the US, increasing again only since 2017. Interestingly, South Korea has shown significant filing numbers over the past ten years despite an upturn in filing numbers happening later than the in US and Europe. It is now in the top three filing jurisdictions for CCUS.
Capture technologies
Currently, most carbon captured comes directly from industrial activity. The main method of carbon capture uses amine-based solvents where the flue gas is exposed to the solvent that selectively removes the CO2. The CO2-rich solvent is then separated and heated to release CO2 which is captured before sending for storage or onward use.
There are various upcoming projects transforming industrial zones into carbon capture hubs with the aim of achieving net zero. For example, the C4 consortium project (Carbon Capture Cluster Copenhagen) aims to reduce CO2 emissions by approximately 3 Mtpa from large power plants in the Copenhagen metropolitan area, as well as using communal CO2 transport and geological storage options in the Danish North Sea. Similarly, the Net Zero Teeside (NZT) is a collection of industrial, power and hydrogen businesses which aim to decarbonise the industrial cluster with a unique, fully integrated commercial scale gas-fired power station with carbon capture in the North Sea.
Direct air capture - capturing carbon dioxide directly from the air - is a newer area of innovation. It is thought this technology will be required to meet the climate goals in the Paris Agreement.
However, it presents unique challenges: carbon dioxide concentration in the air is much lower than in a gas power station flue, for example. The regeneration process of amine-based systems is highly energy intensive, limiting its use in large, direct air capture systems (because of costs, for example). Therefore, making direct air capture viable for large scale use will need new, or improved, technology.
As shown in Figure 3, priority patent filings relating to direct air capture show a sharp increase from 2017, with over seventy new priority applications filed in 2020. The challenges associated with direct air capture clearly provide scope for innovation and solutions, reflected in the increased number of patent filings.
Figure 3: Filing trend 2017-2020 - direct air capture
Notable companies
ExxonMobil and General Electric have both been key players in the field of CCUS over the past twenty years although, more recently, General Electric has decreased its number of priority filings. Other major players include Fluor Technologies Corporation, Linde plc, Royal Dutch Shell plc, Korea Electric Power Corp, Air Liquide, Mitsubishi Industries, and Aker Solutions.
ExxonMobil advertises its achievements to date as having cumulatively captured more CO2 than any other company. It has pioneered and protected many of the amine-based process technologies used in carbon capture to date. More recently, the company has filed patents relating to metal-organic frameworks (MOFs) for use in gas separation and carbon capture. MOFs are a new class of advanced materials that show potential as a novel capture technology. General Electric was very active around 2010 and has built a large carbon capture patent portfolio for industrial settings, including multiple filings focused on technology to capture carbon from fossil fuel power plants.
Climeworks AG, a Swiss company that specialises in carbon dioxide capture from ambient air, has been dominant in direct air capture patent filings since 2013. It uses filters made of granulated and highly porous materials that contain amines to bind the carbon dioxide from the air. The carbon dioxide is subsequently released into a high CO2 stream for storage. In 2021, Climeworks launched Orca, the world’s largest direct air capture and storage plant. The current plant captures and permanently removes from the air about 4 kTpa of CO2. The company announced in June 2022 that work had begun on constructing Mammoth, its second commercial direct air capture and storage plant, designed to capture 36 kTpa when operational.
Other new players include Carbon Engineering Ltd, which produces synthetic fuel that is almost carbon neutral, using direct air capture. Also, Verdox Inc. use an electrochemical approach to capture CO2 from the air. Giants such as ExxonMobil are also actively filing patents in the area of direct air capture.
Implications for innovation and future patent filings
We expect that new types of technology – either improvements to current technology or new capture technology – will increase with the global interest in improving such processes. For example, if metal-organic frameworks manage to provide the properties required, it could attract major interest. We believe this will be an important growth area in the future, in addition to new technologies associated with the industrialisation of direct air capture.
CCUS is an expensive solution to climate change and, until recently, the financial incentive for CCUS has been driven by the utilisation aspect of the captured carbon. Accordingly, the most successful projects are usually associated with using the captured carbon dioxide with Enhanced Oil Recovery.
However, in the future, harnessing algae for carbon capture on an industrial scale provides a promising alternative to direct carbon capture. Microalgae can capture large amounts of CO2 and it is financially attractive to industry because of emerging uses of algae to produce biofuels, plant/animal food, and plant-based food alternatives. The value of this market is expected to reach USD 8.3 billion by 2028, with interest and investments from large players such as ExxonMobil, Unilever, and Whole Foods.
Several start-up businesses are also progressing innovations in this area. For example, Brilliant Planet has been growing algae in large ponds – which are used to remove carbon from the air and then bury it underground – in the Sahara Desert, effectively acting as a natural direct air capture system. Algae-based systems can capture CO2 at a much lower cost than current direct air capture plants and, as a result, are an interesting area of development.
As innovation in both areas of CCUS progresses, it will be interesting to see how these technologies help achieve the Paris Agreement goals.
Sarah Gibbs Senior Associate
Ashley Wragg Patent Attorney