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Carbon Capture Technology: A Step towards Combatting Climate
Carbon Capture Technology: A Step towards Combatting Climate

Carbon capture technology, a vital tool in the fight against climate change, encompasses two main approaches: biological and artificial/geological carbon capture and storage (CCS). Biological CCS involves natural environments like forests and oceans absorbing CO2 from the atmosphere, while artificial / geological CCS extracts emissions from human processes and stores them underground. These methods, once considered expensive, are evolving due to increased investment and research. The concentration of CO2 in the Earth's atmosphere is approximately 0.04%. Despite this seemingly small proportion, the capacity of CO2 to trap heat makes its increasing concentration a matter of significant concern. As reported by the Scripps Institution of Oceanography, the peak CO2 level was recorded at 417.1 ppm in May 2020. This marked the highest seasonal peak in the 61-year span of recorded observations.

Natural carbon sinks, such as forests, oceans, grasslands, and wetlands, capture CO2 from the atmosphere, with grasslands and wetlands being particularly efficient. Preserving and cultivating these sinks can rapidly reduce atmospheric carbon. For instance, specific trees like birch or willow are effective at land-based carbon capture

One project involves preserving an ancient peat bog in South Wales, storing the equivalent of 32,000 tonnes of CO2 and benefiting local biodiversity. Deep saline aquifers, vast underground rock formations filled with salt water, have substantial storage potential for injected CO2. The 'Endurance' aquifer in the UK's North Sea and projects like the Citronelle Project in the US showcase this technique's efficacy.

Innovative approaches like massive air filters and ionic liquids show promise for carbon capture. China employs giant air-purifier towers, while ionic liquids offer efficient CO2 absorption and environmentally friendly chemistry.

Growing biological CCS involves tree planting and wetland development, requiring collaboration among governments, landowners, and communities. Financial incentives and offsetting emissions through carbon capture schemes are also becoming prevalent. For example, Microsoft invested in Climeworks’ Orca CCS facility, aiming to capture thousands of metric tonnes of CO2 annually.

These evolving carbon capture methods hold significant potential in mitigating climate change while driving sustainable practices and innovation. There are several carbon capture technologies aimed at mitigating carbon dioxide emissions from various sources. Carbon capture technology, a vital tool in the fight against climate change, encompasses two main approaches: biological and artificial/geological carbon capture and storage (CCS). Biological CCS involves natural environments like forests and oceans absorbing CO2 from the atmosphere, while artificial/geological CCS extracts emissions from human processes and stores them underground. These methods, once considered expensive, are evolving due to increased investment and research.

Tubular Algae Bioreactors Fixing CO2 To Produce Biofuel As An Alternative Fuel

Supporting Carbon Dioxide Recovery with Purification and Liquefaction

Once captured, the CO2 can be purified to the level required by various use cases in industry. Many industrial applications such as methanization only require a low level of CO2 in the gas, whereas food and beverage or electronics applications require very high or ultra-pure levels of CO2. The CO2-enriched gas stream can be liquefied for delivery or supplied as pressurized gas to the end-user. Alternatively, the CO2 can be sequestered to mitigate the climate impact of industrial processes that rely on the combustion of carbon-based fuels. Looking at post-combustion CO2 capture (PCC), use cases include capturing carbon from the flue gases of SMR units as well as in power, cement, iron and steel plants, and many more. This adsorption-based technology supports all CO2 product aggregate states (gaseous, liquid and supercritical form) and product purities meeting all industrial applications. As a one-stop shop, Linde provides an all-inclusive CO2 solution bundle.

Coal and steam. Mae Moh, Lampang, Thailand.

Post-combustion capture

This involves capturing CO2 after combustion processes, like in power plants. Solvent-based methods are commonly used to capture CO2 from flue gases.

Pre-combustion capture

Here, carbon is removed from fuels before combustion. This is often used in integrated gasification combined cycle (IGCC) power plants, where syngas is produced and CO2 is separated before combustion.

Oxy-fuel combustion

In this method, fuels are burned in an oxygen-rich environment, resulting in a flue gas primarily composed of CO2 and water vapor, making it easier to capture CO2.

Direct air capture (DAC)

DAC technologies directly capture CO2 from the ambient air, often using chemical reactions or absorbent materials.Direct Air Capture (DAC) is a technology that removes carbon dioxide (CO₂) from the atmosphere.

Using high-powered fans, air is drawn into a processing facility where the CO₂ is separated through a series of chemical reactions. Then the CO₂ is either permanently stored in underground reservoirs through secure geologic sequestration, or is used to make new products such as building materials and low-carbon fuels.

Bioenergy with carbon capture and storage (BECCS)

This combines biomass energy production with carbon capture and storage (CCS), where the CO2 released during combustion is captured and stored underground.

Mineralization

CO2 can be captured and converted into solid carbonate minerals through a process known as mineralization.

Industrial processes

Certain industrial processes can capture CO2 emissions before they are released into the atmosphere. For instance, cement and steel production can incorporate carbon capture.

Enhanced oil recovery (EOR)

This involves injecting captured CO2 into oil reservoirs to increase oil extraction, while simultaneously storing the CO2 underground.

Ocean-based solutions

While controversial due to environmental concerns, some concepts propose capturing and storing CO2 in deep ocean waters or converting it into solid carbonate minerals.

Ionic liquids

A capturing carbon technology of the future?

The most recent advancements in CCS technology includes new types of liquids, which are highly effective at absorbing CO2. Two dimensional ‘ionic’ liquids have a molecular structure that allow for higher rates of CO2 to be absorbed. Scientists believe ‘editing’ liquids can offer more precise control in the chemical engineering process and are considered environmentally friendly.

Helping to 'grow' biological CCS

Planting trees or developing wetland areas are two of the simplest ways of stimulating CCS on huge scales, but there are often issues around land ownership and space. Governments, landowners and local communities all have a role to play in identifying opportunities for projects and collaboration.

In the UK, financial incentives in the form of Environmental Land Management schemes are offered to landowners and land managers who commit to managing their land in an environmentally sustainable way.

In the US, land reclamation for environmental purposes is similarly incentivised by the Department of Agricultural Farm Service Agency (FSA). Farmers can receive rental payments if they no longer develop on land or use it for agricultural purposes; allowing grasslands, uplands, wetlands and forests to flourish instead.

Businesses in the private sector are increasingly ‘offsetting’ the emissions they produce by funding carbon capture schemes. This is also known becoming carbon neutral through the purchase of ‘carbon credits’.

Microsoft has made its initial offset purchase through a $1 billion investment in Climeworks’ Orca CCS facility, located in Reykjavik. Climeworks opened the first commercial CCS facility in Switzerland in 2017, before opening the larger Orca site in 2021. It’s estimated that the Icelandic plant can capture up to 4,000 metric tonnes from the atmosphere annually.

Scientists from the Scripps Institution of Oceanography at the University of California, San Diego, have been meticulously measuring the levels of CO2 in the Earth's atmosphere at the Mauna Loa observatory in Hawaii since 1958. Back then, the atmospheric CO2 levels were below 320 parts per million (ppm), with an annual increase of around 0.8 ppm. However, over the last decade, this rate of increase has surged to a troubling 2.4 ppm per year.

Future Prospects and Conclusion

Potential for Mitigation

Discuss the potential of evolving carbon capture methods in mitigating climate change and driving sustainable practices.

Collective Effort

Emphasize the need for continued investment, research, and collaboration across sectors to achieve meaningful impact in combatting climate change through carbon capture technology.

Conclusion

Carbon capture technology has evolved from being considered expensive to becoming a crucial tool in addressing climate change. With diverse approaches such as biological and artificial/geological methods, natural carbon sinks, innovative technologies, and collaborative efforts, the fight against rising CO2 levels is gaining momentum. By harnessing these advancements, we have the potential to mitigate the effects of climate change and work towards a more sustainable future.

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