Carbon Capture Technology 101: A Critical Solution to Climate Change

Anthropogenic greenhouse gas emissions, mainly CO₂, have led to significant and lasting effects on the planet, prompting governments and industries to set ambitious goals to reduce CO₂ emissions and achieve net-zero carbon emissions by 2050. The Intergovernmental Panel on Climate Change (IPCC) has found that 78% of greenhouse gas emissions are caused by carbon dioxide released from fossil fuel combustion and industrial processes (Guo et al., 2023).

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Carbon capture technology is one of the leading solutions to battle CO₂ emissions, but its implementation has been slow due to its high cost and energy requirements. The race against time to combat the climate crisis is urgent, and implementing carbon capture technology is critical in achieving our net-zero carbon goals. Recent innovations in carbon capture technology have shown promising results in producing syngas with net-zero CO₂ emissions through direct electrochemical CO₂ reduction (Langie et al., 2022).

Before delving into the present state of carbon capture technology and the possibilities of nascent technologies, let us examine the statistics on which industries are accountable for the most significant carbon dioxide emissions.

Carbon Dioxide Emission Figures and Data

The global emissions of greenhouse gases can be categorized into four main sectors: energy (electricity, heat, and transport), direct industrial processes, waste, agriculture, forestry, and land use (Ritchie et al., 2020). Direct industrial processes contribute to 5.2% of emissions, while waste management is responsible for 3.2%. The agriculture, forestry, and land use sector are responsible for 18.4% of global emissions.

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The energy sector is responsible for the largest share of global emissions, accounting for 73.2%. Industry accounts for 24.2% of energy use and contributes to energy-related emissions. The top industries with the highest energy-related emissions are iron and steel manufacturing (7.2%), chemical and petrochemical manufacturing (3.6%), and food and tobacco processing (1%). Other industries, such as non-ferrous metals, paper and pulp, machinery, and others, make up the remaining 12.6% of energy-related emissions.

Figure 1. Carbon Dioxide Emission Statistics (Ritchie et al., 2020)

Figure 1 emphasizes the urgency of a collaborative approach to curbing emissions from the energy industry, the primary driver of climate change. In order to attain a sustainable, low-carbon future, it is essential to tackle emissions from other sectors. Industrial activity is significant in carbon dioxide emissions, accounting for approximately 29% of global emissions. As such, industries must begin adopting carbon capture technologies.

The Basics of Carbon Capture Technology

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Carbon capture methods have benefits such as low waste production, stability, and efficient CO₂ capture (Khurana et al., 2021), and combustion techniques can aid CO₂ separation. Storage of captured carbon has potential benefits, but proper monitoring techniques are crucial for safe storage. Further research can focus on new crop strains and location-specific techniques to bridge the carbon capture, utilization, and storage gap. Carbon capture methods can be classified into three broad categories:

1. Pre-combustion capture technologies use advanced solvents, membrane systems, and solid sorbents to convert natural gas or solid waste into gaseous fuel (e.g., hydrogen, carbon monoxide) for electricity generation after carbon capture. Methods like water gas shift reactions increase hydrogen production and convert carbon monoxide to carbon dioxide. Ongoing efforts aim to improve efficiency and effectiveness, including developing sorbents with high adsorption capacity and resistance to regeneration cycles and researching membrane systems with high CO₂ selectivity.
2. Post-combustion capture removes carbon dioxide (CO₂) from flue gases emitted from power plants and other sources. Chemical solvents like Monoethanolamine (MEA) are commonly used to bond with CO₂ in a counter-current contact process chemically. The CO₂ -free gas is released into the atmosphere, while the CO₂-enriched absorbent is exposed to high temperatures to break the bond and collect the CO₂ for transportation. This method can remove up to 90% of CO₂, and MEA in water is a commonly used absorbent system.
3. Oxy-fuel combustion is used in coal-fired power plants to produce flue gas with high concentrations of CO₂ and water vapor for easier separation of CO₂ at low temperatures. It involves using 95% pure oxygen and recycled flue gas for combustion, resulting in a gas stream of mainly CO₂ and water, eliminating the need for costly capture methods. The recycled flue gas can be reused, creating a closed-loop system for CO₂ capture.

As we can see, carbon capture technologies, including pre-combustion capture, post-combustion capture, and oxy-fuel combustion, each have their own set of advantages and disadvantages. Pre-combustion capture has the potential for hydrogen production but requires high temperature and pressure conditions. Post-combustion capture can be retrofitted to existing plants but has higher energy consumption. Oxy-fuel combustion produces flue gas with high CO₂ concentrations, eliminating the need for costly capture methods, but requiring oxygen handling.

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Choosing the most suitable method for carbon capture depends on various factors, such as the type of plant, the availability of resources, and the desired end-use of the captured CO₂. Continued research and development in these technologies aim to improve their efficiency, effectiveness, and economic viability in mitigating greenhouse gas emissions.

Upon successful carbon capture, CO₂ can be stored or utilized in a variety of ways, including through advanced methods such as Carbon Capture Sequestration (CCS) and Carbon Capture and Utilization (CCU), as highlighted by Gueddari-Aourir et al. (2022). While CCS stores CO₂ as waste, CCU uses it to create value-added products. Concerns about leakage and limited storage capacity raise questions about the viability of CCS, although it is cost-effective in the long run. In contrast, CCU technologies are gaining popularity due to their potential applications in various industries and alignment with circular economy strategies.

All in all…

As mentioned earlier, anthropogenic greenhouse gas emissions, particularly carbon dioxide, have had lasting effects on the planet. Ambitious targets have been established to attain net-zero carbon emissions by 2050 to solve this problem. Carbon capture technology is an effective strategy to reduce CO₂ emissions, and recent advancements offer promise. The selection of the most suitable carbon capture method will depend on several factors. Further research and development are required to enhance carbon capture technologies’ efficiency, effectiveness, and economic viability in mitigating greenhouse gas emissions. Continued efforts towards sustainable solutions and a transition to a low-carbon economy are critical to combatting climate change and preserving the planet for future generations.

Keep an eye out for upcoming articles if you want to learn more about carbon capture technology, its storage, and utilization.

References

Gueddari-Aourir, A., García-Alaminos, A., García-Yuste, S., Alonso-Moreno, C., Canales-Vázquez, J., & Zafrilla, J. E. (2022). The carbon footprint balance of a real-case wine fermentation CO₂ capture and utilization strategy. Renewable and Sustainable Energy Reviews, 157. https://doi.org/10.1016/j.rser.2021.112058

Guo, Z., Bian, X., Du, Y., Zhang, W., Yao, D., & Yang, H. (2023). Recent advances in integrated carbon dioxide capture and methanation technology. Journal of Fuel Chemistry and Technology, 51(3), 293–302. https://doi.org/10.1016/S1872-5813(22)60048-3

Khurana, N., Goswami, N., Sarmah, R., & Devanshi. (2021). Carbon Capture: Innovation for a Green Environment. In Advances in Carbon Capture and Utilization. Springer. https://www.springer.com/us/authors-editors/journal-author/journal-author-hel

Langie, K. M. G., Tak, K., Kim, C., Lee, H. W., Park, K., Kim, D., Jung, W., Lee, C. W., Oh, H. S., Lee, D. K., Koh, J. H., Min, B. K., Won, D. H., & Lee, U. (2022). Toward economical application of carbon capture and utilization technology with near-zero carbon emission. Nature Communications, 13(1). https://doi.org/10.1038/s41467-022-35239-9

Ritchie, H., Roser, M., & Rosado, P. (2020). CO₂ and Greenhouse Gas Emissions. Our World in Data. https://ourworldindata.org/CO₂-and-greenhouse-gas-emissions