Writer: Jana Chan
Current Solutions and Their Insufficiencies
Although many countries have recently taken steps to reduce their carbon emissions, a plethora of industrial and electrical generating sources continue to burn fossil fuels that produce carbon dioxide, all of which eventually flow into the atmosphere. It simply isn’t enough to offset the sheer amount of emission. Even with all the climate awareness raised and rules being set, scientists estimate that the burning of fossil fuels will remain a major source of energy for decades to come (Center for Climate and Energy Solutions [C2ES], n.d.). Therefore, while preventing future emissions is certainly important, it is also just as vital that we study and invest in the potential solutions to treat the increasing levels of carbon dioxide that will be released over the next couple of decades. One such solution lies in carbon capture and storage (CCS) technology, which seems to have a very promising future with “almost two dozen commercial-scale carbon projects operating around the world” (C2ES, n.d.).
Carbon capture and storage technology, also known as carbon capture and sequestration, works to reduce carbon emissions in three steps: capture the carbon dioxide, transport the carbon dioxide, and then securely store the carbon dioxide (Carbon Capture and Storage Association [CCSA], n.d.) as seen in the flowchart in Figure 1.
Figure 1. Schematic of the overall process of carbon capture and sequestration. Those in italics are not yet
available or have not been used on a large scale. Retrieved September 30, 2020 from Elsevier: https://doi.org/10.1016/j.pecs.2012.03.003
In the first step of capturing carbon dioxide, there are also three potential capture techniques, all of which separate the carbon dioxide from the gases that are produced during industrial and electrical generating processes. One technique, called pre-combustion capture, can capture carbon dioxide during the gasification process (Environmental and Energy Study Institute [EESI], n.d.). Completed before the burning of fossil fuels, the fuel used in these processes is gasified to produce a synthesis gas (also called syngas) which consists of a mixture of mainly carbon dioxide (CO) and hydrogen (H2). Following this is a shift reaction that converts the CO to CO2 while a physical solvent separates the CO2 from the H2 (C2ES, n.d.). Another technique, called post-combustion capture, uses chemical solvents to extract carbon dioxide from the flue gases that arise from fossil fuel combustion (C2ES, n.d.; The London School of Economics and Political Science [LSE], 2018). The final technique, oxyfuel carbon capture, burns fossil fuels in pure oxygen instead of air to produce CO2-rich gas and steam, thus assisting in a quicker and more efficient capture process (C2ES, n.d.; LSE, 2018).
Next, the carbon dioxide that was previously captured gets transported from its source to its storage site. To do this, the carbon dioxide is compressed into a liquid or a near-liquid state and transported by pipelines, ships, or road tankers (LSE, 2018).
Finally, the transported carbon dioxide is stored in places that are the most environmentally suitable in preventing it from escaping back into the atmosphere. Most commonly, it is stored in geological formations or deep underground. For example, depleted gas and oil reservoirs are great options because the carbon can be injected into these reservoirs and cause a process called “Enhanced Oil Recovery with Carbon Dioxide” (or CO2-EOR). In this way, there are two beneficial outcomes: Carbon is safely stored and can be put to good use by forcing any extra oil or gas to the surface of the reservoirs (C2ES, n.d.; EESI, n.d.). These reservoirs currently seem to be the most suitable solution because there is evidence that they could hold oil and gas underneath the surface for millions of years, with the potential for it to be a permanent storage solution as well. Alternatively, deep saline aquifer formations can be used to dissolve carbon dioxide in its briny waters (EESI, n.d.). Lastly, sandstone formations are also useful as the near-liquid carbon dioxide can flow into the sandstone’s tiny pores and become trapped in a dense rock layer just above the sandstone ( C2ES, n.d.; EESI, n.d.).
One of the biggest benefits of this method is that the captured carbon dioxide can be reused. Instead of simply keeping it stored away, carbon dioxide can be put to productive use and utilized for the production of commercially marketable products. This has already been seen through the “Enhanced Oil Recovery with Carbon Dioxide” process but is not just limited to that. There is also a huge possibility for the stored carbon dioxide to be used in creating concrete and plastic materials or in converting it into biomass (LSE, 2018). Moreover, these technologies will be essential in addressing climate change. CCS is currently the only technology that can reduce emissions from large-scale industrial plants (LSE, 2018). It’s potential to create “negative emissions,” that is, remove carbon from the atmosphere is monumental (LSE, 2018). However, there are some drawbacks. CCS technology may not be economically feasible as it is extremely expensive due to high maintenance and energy costs, thus potentially making it harder to implement on a large-scale for long periods (LSE, 2018). Furthermore, if carbon dioxide storage sites are not adequately maintained, then leakages can appear. This would not only waste the time, effort, and money spent on storing the carbon dioxide but also damage the environment, specifically entire ecosystems, even more (Climate Vision, 2015).
Even though CSS seems to be a very suitable solution for climate change, this technique has still yet to be proven to be safe and effective in the long-term (EESI, n.d.). However, CSS still serves as the perfect jumping point for more advancements and interactions to redesign the ideal tool for fighting climate change. Thus, I propose the following redesigns to the CSS system and its technologies to overcome these high costs and potential carbon dioxide leakage.
The author of this example starts by providing a brief explanation for why this solution is needed in the first place, which in this case is as a result of increasing carbon dioxide emissions. She then thoroughly and clearly explains how the solution works and what it was designed to accomplish. This part is expertly supported by her inclusion of a diagram that further illustrates the effectiveness of carbon capture and sequestration technology in an orderly manner. It provides excellent support for her justification that this tool has the potential to and highlights the many routes that could be taken from this technology. However, she also understands that almost no techniques are without faults and makes sure to acknowledge any insufficiencies with the current solution. This provides the perfect transition into the next section of the proposal where she will explain her solution to the problem and how it overcomes the insufficiencies presented before.
Moreover, one way that the author could’ve improved is by keeping the terms consistent throughout her proposal. For example, while the terms “carbon capture and storage technology,” “carbon capture and sequestration,” and “CCS” are all interchangeable, she does not just choose one but uses them all in various places. This may be very confusing to the reader, so it may be helpful stylistically to stick with one version of the term.
Carbon Capture and Storage Association. (n.d.). What is CSS?.
Center for Climate and Energy Solutions. (n.d.). Carbon Capture. C2ES.
Climate Vision. (2015, July 6). The Negatives of Carbon Capture and Storage.
Energy and Environmental Studies Institute. (n.d.). Carbon Capture and Storage (CSS). EESI.
Rubin, E. S., Mantripragada, H., Marks, A., Versteeg, P., & Kitchin, J. (2012). The outlook for carbon
capture technology. Elsevier Journal of Progress in Energy and Combustion Science, 38(5),
The London School of Economics and Political Science. (2018, May 1). What is Carbon Capture Storage
and what role can it play in tackling climate change?. LSE.
[Photograph of a brown coal power plant emissions for cover image]. Retrieved from Mother Jones.