What is Carbon Capture Usage and Storage and its role in circular economy?

In November 2020, the U.K. announced its 10 point plan for a Green Industrial Revolution where one aspect was Carbon Capture, Usage, and, Storage (CCUS). Since April 2020, the USA has announced more than 9 new CCUS plants. Globally, CCUS has been gaining popularity when it comes to climate change mitigation measures. Intergovernmental Panel on Climate Change (IPCC) has used CCUS in their future scenarios multiple times as it is only of the few technologies that have negative emissions. Understandably, governments have started to consider the technology in their journey to net-zero emissions. But what is CCUS and its contribution towards a circular economy? Let’s find out.

What is CCUS?

Carbon capture, usage and storage (CCUS) refers to technologies which capture carbon dioxide (CO₂) emissions from sources such as industrial processes and fuel combustion to prevent them from entering the atmosphere. The captured CO₂ is then transported via ship or pipeline, and either it is used as a resource to create valuable products or services or it is permanently stored deep underground in geological formations. CCUS technologies also provide the foundation for carbon removal or “negative emissions” when the CO₂ comes from bio-based processes or directly from the atmosphere.

As of 2020, there are only two large scale CCUS power projects in operation. Despite the having a combined capture capacity of 2.4 million tons of CO2 (MtCO₂) per year, CCUS in power remains well off track to reach the 2030 SDS level of 350 MtCO₂ per year. Figure 1 shows the two operating projects (in yellow)- Boundary Dam CCUS project in Saskatchewan (Canada) and Petra Nova Carbon Capture in Texas (USA). There are 20 CCUS projects in power in early development (in red) as well out of which 11 are in the USA, 3 in China and the UK, and one each in Ireland, Korea and the Netherlands. However, there are in total 51 CCS facilities globally– 19 in operation, four under construction and 28 in various stages of development focusing on power, industry and other sectors.

What are the applications of CCUS?

Many CCUS technologies are currently in either a pre-commercial stage such as for power or in a pilot stage such as for iron, steel and cement. But for some industries such as natural gas processing, CCUS is already operating at full commercial scale. According to the International Energy Agency’s (IEA) Energy Technology Perspectives (2012), around 45% of the total CO₂ captured between 2015 and 2050 will be in industrial applications. Some important industrial sectors which are suitable for CCUS applications include the following:

• Natural gas processing: Many sources of natural gas contain high levels of CO₂ that must be removed before the gas is sold. There were 10 projects in this sector as of 2015.
• Food and drink: CO₂ is used primarily for the carbonation of drinks, although the brewing industry generates substantial volumes of CO₂ from the fermentation processes that convert sugars to alcohol. Clime Works provides services in using CO₂ as a carrier gas in bars, inert gas for packing meat and vegetables as well as for dry ice.
• Chemicals: The manufacture of ammonia, methanol and olefins, which rely on fossil fuel feedstocks process CO₂ emissions. SACROC and Crossett in West Texas are two large scale projects dealing with ethanol production.
• Cement: CO₂ is generated from the calcination of lime (process emissions), which also relies on fossil fuels.
• Iron and steel: Manufacturing process generates CO₂ due to the dominance of coal as a reducing agent and a fuel, as well as the process emissions that cannot be avoided. The Abu Dhabi CCS Project (Emirates Steel Industries) has implemented large scale CCS facility for steel production.
• Non-ferrous metals: Includes the manufacture of aluminium.
• Biofuels: BECCS for energy generation is an integral part of the future energy markets in the UK as suggested by the National Grid. The Illinois Industrial CCS Project captures CO₂ from ADM’s Decatur corn processing and stores it underground.
• Hydrogen Production: Three projects were working in this sector with the use of methane reforming as of 2015 including the Sleipner gas field in the North Sea, Valero Port Arthur Refinery and the Weyburn oil fields in Canada.
• Agriculture: The captured CO₂ can be used in greenhouses. Clime Works has been undertaking these projects for a few years in Zurich where they make aubergines and tomatoes.
• Fertilizer Production: Three projects have been working on capturing the CO₂ during fertilizer production as of 2015.

What are the types of CCUS?

There are three categories where all the different CO₂ capture approaches/systems can be classified into:

• Pre-Combustion: Pre-combustion CO₂ capture related to a gasification plant involves the process of partial oxidation which leads to by-products such as CO₂ and Hydrogen (Syngas).
• Oxy-Combustion: The process of pulverized coal oxygen-fired combustion is used in this category.
• Post-Combustion: This category applies to conventional natural gas and pulverized coalfired power generation. Unlike the other two, this doesn’t utilize air separation (NETL, 2020). These three process of CCUS can then be combined with other technologies in the power and industry sectors such as those used for producing natural gas, hydrogen, and BECCS. Combining the CO₂ capture methods with fossil fuel such as natural gas keeps the emissions from the production process significantly low.

What are the benefits of CCUS?

Of the various forms of energy production known to mankind, CCUS has shown promising results for carbon reduction in production of natural gas, hydrogen and bio-fuels as described next.

• Natural Gas:

Gas power generation produces around 350 kg CO₂/megawatt hour (MWh) for the most efficient combined cycle gas plant which though is half the CO₂ emissions of coal, cannot be considered a low emissions technology. It is estimated that more than 700 Megatons per annum (Mtpa) of indirect CO­₂ emissions could be eliminated from oil and gas operations through the application of CCS. The cost of applying CCS at gas processing facilities is around USD20-25 per tonne CO₂. This is one of the lowest cost CCS-applications and is already capturing 25 Mtpa at ten of 19 operating large-scale CCS facilities. Even so, roughly 150 Mtpa of effectively pure CO₂ is still being vented from facilities around the globe. The liquified natural gas trade is predicted to grow by a quarter to 2024 globally, which indicates that there is an opportunity to build the new plants made with the CCUS technology from the beginning. As of now, there are two projects which have to utilize CCUS technology:

• The Gordon CCS project which started storing CO₂ in August 2019. It is expected to store 80% of reservoir CO₂ (3.4 to 4 Mtpa), reducing the facility’s total emissions by 40%. Global CCS Institute (2019) predicts that when operating at full capacity, it will be the world’s largest dedicated geological storage project.
• The CCS project at the Snohvit LNG plant in Norway which has been operating since 2008. It is storing about 0.7 Mtpa in a depleted natural gas field, under the seabed.

Apart from these two, the UK has been planning CCUS projects for natural gas as well which includes the Acron CCS and the Clean Gas Project. The Clean Gas Project is planned to store up to 6Mt of CO₂ each year. The Acron CCS and Acron Hydrogen are planning to use hydrogen to reform the North Sea natural gas and to decarbonize heating in UK’s houses and industries.

• Hydrogen:

There are five low-carbon hydrogen production facilities with CCS operating globally and three under construction, with a total production capacity of 1.5 million tonnes. Despite this, 98% of global hydrogen production is from unabated fossil fuels, around three quarters stemming from natural gas. CO₂ emissions from its production are approximately 830 Mtpa, equivalent to the annual emissions of the UK in 2018. There are three main technologies used to produce low carbon hydrogen- gas reforming with CCS; coal gasification with CCS; and electrolysis powered by renewables. The benefits of low-carbon hydrogen production through gas reforming and coal gasification with CCS are the maturity of the technologies, scale and commercial viability. The Great Plains Synfuel Plant in North Dakota, US, has been in operation since 2000 and produces approximately 1300 tonnes of hydrogen per day, form brown coal. This signifies the maturity of the technology. When we look at the scale, there are commercial-scale hydrogen production facilities with CCS that each produce around 1000 tonnes of hydrogen per day similar to the North Dakota plant. Hydrogen produced using coal or methane with CCS costs USD1.70-2.40 per kilogram compared to USD7.45 for hydrogen produced via electrolysis. CCS hydrogen costs two thirds less, signifying the commercial viability of the technology.

• Bioenergy with Carbon Capture and Storage (BECCS):

The production of sustainable biomass is considered to be renewable energy, so integrating its combustion or fermentation with CCS technology, achieves negative emissions. This has made BECCS very significant and popular when considering emissions reduction. Private sector companies particularly have seen BECCS to decarbonise and shelter themselves from carbon prices, or to meet regulatory requirements. The Drax power station converted the first of its six boilers to fire using biomass in 2013 as a response to UK’s regulation to phase out coal. Drax initiated a CCS pilot project in 2018 which now captures 1 tonne of CO₂ per day.

The three above mentioned applications are the most popular and developed ways to utilize CCUS. Technologies such as Direct Air Capture do exist, but they are not advanced, developed or cost-effective enough to be considered acquiring large portions of the future energy mix.

The most unique advantage of CCUS is its ability to generate negative emissions. Apart from trees, there are a very limited number of ways to achieve negative emissions. When done correctly it can complement and make other technologies and energy generation have a significantly low carbon footprint. Looking at the power sector CCUS projects sown in Figure 2, the benefits of investment, research and development of CCUS is evident. The Levelized Cost of Capture (LCOC) is decreasing with newer projects through knowledge and experience.

Another advantage of CCUS is to build it in industry hubs and clusters. The Latrobe Valley of Australia has shown how such clusters can be developed in dying coal-fired plants where there are suitable storage options. It also helps the local economy through a shift in labour skills. The Tees Valley project is planning on such a cluster development.

When we consider the benefits of specific technologies of CCUS, the integrated Hydrogen production with CCUS has several advantages over all the others. Firstly, the two ways to produce low carbon hydrogen include coal gasification with CCUS and gas reforming with CCUS. Secondly, the by-products of the process, hydrogen and CO₂ both can be utilized for energy and industrial products respectively.

What are the barriers to deployment?

Despite all the above mentioned benefits of deploying CCUS for environmental conservation, there are a few barriers to deployment that prevent the use of CCUS at scale. Budinis et al. (2018) analysed the barriers to the deployment of CCUS and concluded that there are no barriers exclusively technical, with the cost being the most significant hurdle. Aside from the financial aspect, other barriers to deployment include:

• International acceptance: There needs to be an implementation of CCUS in developing countries and inclusion of CCUS in the Construction, Design and Management (CDM).
• Regulatory development: There are issues regarding the pace of regulatory development, developing regulations in developing countries and international standards.
• Storage options: There are several options such as saline aquifers and enhanced oil recovery. Factors in choosing the correct one are the size of the project, the geology of the location, regulations and available data.
• Safety/permanence: There is huge concern over leakage and a lot of planning and research needs to be done to ensure it does not happen. In case it does, there is a high cost in repair, re-seal of well and removal of accumulated CO₂.
• CCUS market creation: A long term CO₂ market needs to be created along with an emissions trading scheme. Costs of projects can be reduced by 20-40% with replication.
• Infrastructure development: A substantial pipeline system all over Europe can help significantly with CCUS supply and cost reduction. But the question of financing and controlling such a system also remains.

When considering specific technologies such as BECC, the hurdles in development are- producing crops specifically for BECCS involve land clearing, which may reduce or even reverse its carbon removal potential; wide-scale deployment of BECCS could compete or overlap with land available for forest creation or food production, leading to significant changes in ecosystems; producing biomass at the scale required demands large amounts of water and fertilizer. Apart from these, educating the public and building capacity are also a major challenge for CCUS development. Globally, there is a substantial lack of university courses and students interested in CCUS currently. This needs to be addressed for capacity building.

CCUS cannot be relied on for more than 10% of the future energy markets. But it needs to be used as a means to reduce emissions from fossil fuels and reach the net zero emissions target. CCUS provides a unique opportunity to be built in industry clusters and hubs such as the Latrobe Valley. This can be achieved by utilizing CCUS with hydrogen production. For example, the Acron CCS Project has been vey efficient for the development of both technologies. Despite CCUS being in the early stage of development, high cost and other above-mentioned barriers, it needs to be considered in all mitigation measures. Achieving net-zero emissions is not viable without CCUS for any economy.