The Steps to Carbon capture and sequestration (CCS)
Written By: Lauren Rosenthal
Edited By: Vanessa Lu Langley
Carbon capture and sequestration (CCS) refers to the process of capturing carbon that was destined to be emitted into and/or remain in the atmosphere and storing it in secure reservoirs for long periods of time (Herzog & Golomb, 2004). Like afforestation, it is among the climate change mitigation strategies that attempt to address carbon dioxide after it has been produced as opposed to reducing directly at the source. Since fossil fuels are expected to remain the dominant energy source for the foreseeable future (Scott et al., 2013), technology that promises the ability to counteract the resulting emissions is very appealing in an increasingly climatically-turbulent world.
CCS is designed to target large, stationary, industrial sources of carbon dioxide that produce highly concentrated streams at a given time. This includes structures like oil refineries, ammonia production, and, most notably, power plants, which are responsible for a quarter of greenhouse gas emissions worldwide (Herzog & Golomb, 2004;“Global Greenhouse Gas Emissions Data”, 2021).
There are three steps in the CCS process: capture, transportation, and storage (“Capture”, 2018).
Step 1: Capture
Normally, the aforementioned industrial sources release energy via the combustion of fuels such as coal, oil, and natural gas, emitting CO2 as a byproduct. How and when the capturing of this carbon occurs depends on the type of technology used: pre-combustion, post-combustion, or oxy-fuel combustion systems. Pre-combustion, which is mainly used for industries such as natural gas processing, involves separating the fuel into hydrogen and carbon dioxide. The hydrogen is then safely burned and the carbon dioxide is sectioned away. Post-combustion, which is used mainly in the food and beverage industry, separates carbon dioxide from combustion exhaust gases. Oxy-fuel combustion uses oxygen to combust the fuel instead of air, which produces water vapour and carbon dioxide. The latter is captured and separated into its own stream (“Capture”, 2018).
CCS Step 2: Transportation
The carbon dioxide is liquified and transported mainly via pipeline to the storage location. It can also be transported by truck or rail in small quantities (“Capture”, 2018).
CCS Step 3: Storage
There are several carbon dioxide storage options available. It is important for the storage space to be long-lasting, relatively inexpensive, and minimally environmentally impactful. The main two storage options are geologic sinks and the deep ocean. Geologic sinks involve injecting the carbon dioxide into sites such as depleted oil and gas fields, abandoned coal seams, and deep saline formations that can accommodate it. Storage in the deep ocean involves adding the carbon dioxide to the natural reservoir that already exists at the bottom of the ocean (Herzog & Golomb, 2004).
The CCS industry is still relatively small, but is rapidly growing. The market is set to grow from 2.01 billion USD as of 2021 to 7.00 Billion USD in 2028 as new production facilities are built and the technology becomes more commercialized (Fortune Business Insights, 2021). However, there are still numerous barriers standing in the way of widespread CCS adoption. The most evident issue is cost, as the cost of the equipment and facilities is extremely high. Further, investment in CCS is still risky given how new the technology(Gonzalez et al., 2020). Between USD$655 billion and USD$1,280 billion in capital investment is still needed in order to limit global warming to 2ºC (Global CCS Institute, 2021). Transportation is also still very costly given the large amount of energy required to compress the carbon dioxide and the need for special pipelines to accommodate it. There are also questions related to long-term carbon storage, both in terms of availability and in terms of environmental risks that must be accounted for. For example, there is the possibility of seismic activity caused by carbon dioxide inputs (Gonzalez et al., 2020).
Outstanding details aside, carbon capture is increasingly playing a role in government climate change strategies around the world (“Governments in race”, 2021). Furthermore, in their landmark 2018 special report, the Intergovernmental Panel on Climate Change states that carbon capture is becoming increasingly necessary to limit global warming to 1.5ºC as achieving net-zero emissions is taking longer than anticipated That said, the IPCC also cautions against relying upon it alone as a way to engate emissions as opposed to working towards a conventional energy transition given that its effectiveness on a large scale remains unproven (Rogelj et al., 2018). Any green innovation is not itself a solution to the energy transition, but if its funding and prominence continue to rise, carbon capture is definitely one to watch as a potential major player.
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Fortune Business Insights. (2021). Carbon Capture and Sequestration Market Worth USD 7.00 Billion by 2028; Rising Need to Lower Carbon Emission will Favor Growth: Fortune Business Insights™. Global Newswire. Retrieved Mar 12, 2022, from https://www.globenewswire.com/news-release/2021/12/22/2356587/0/en/Carbon-Capture-and-Sequestration-Market-Worth-USD-7-00-Billion-by-2028-Rising-Need-to-Lower-Carbon-Emission-will-Favor-Growth-Fortune-Business-Insights.html
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