Carbon Capture and Storage Technology as a Solution to Global Warming

She Task: How new carbon capture and storage technologies provide sustainable solutions for reducing global warming

Introduction:

There are new technologies in place for the reduction of CO₂ emissions, one of these new methods is known as CCS (Carbon capture and storage), this new technology can capture up to 90% of carbon dioxide emissions produced from the use of fossil fuels In the generation of electricity and other industrial processes.¹ The purpose of CCS technology is to reduce the negative impact of anthropogenic greenhouse gas emissions on the environment.² CO₂ emission is the leading cause of global warming world wide and CCS is a sustainable and attainable solution for reducing global warming.

Chemical background:

When coal, oil or gas plant is burned a major by-product is the greenhouse gas carbon dioxide. ³ A seen approach to keep these carbon emissions under control is through the use of carbon capture and storage technology, that use underground rocks as storage tanks.⁴ When the fossil fuels are burned, they produce a different by products such as oxygen, CO₂ and nitrogen. The focus of CCS is to selectively pull the CO₂ out of the gas mixture and storing it underground. There are three main approaches to this method; pre-combustion, post-combustion and oxyfuel combustion.⁵ Pre-combustion as the name suggests focuses on capturing the CO₂ before the fuels are burnt. An air separator strips the oxygen from the atmosphere, producing an almost pure stream of oxygen gas which is then fed into a gasifier, which bakes the coal to around 700^o C, thus releasing a mixture of gases including hydrogen, carbon monoxide, carbon dioxide and steam, this is collectively known as a syngas.⁶ When water is added to this syngas in a shift reactor it is then converted into hydrogen and CO₂, these gasses are then separated producing a stream of hydrogen which is burned off and a stream of CO₂ which is dehydrated to remove any leftover water and compressed to concentrate the gas into a liquid to prepare for storage.⁷ The next technique is post-combustion which as the name suggests is done after the combustion process has begun. Fuel is injected into a boiler with air and burnt in the same way as it would be done within a powerplant. The heat produced inside this boiler is used to convert the water to steam. The by-product of this burn is once again nitrogen, carbon dioxide and water which are collectively termed as flue gas.⁸ A variety of filtration systems are used that can pluck the CO₂ from the mixture. Some examples that are currently used include ammonia membranes that can selectively bind and release CO₂. After this process is complete the same process of liquification and storage is used.⁹ The final technique of CCS is oxyfuel combustion. This technique burns coal using flue gas and pure oxygen, produced with an air separator. This reaction produces heat, which is used to convert water to steam and a mixture of flue gas and water. This mixture is then used to regulate the temperature of the boiler before passing through a CO₂ purifier, this then removes other pollutants including nitrogen.¹⁰ It then compresses the CO₂ and also separates it from the other non-reactive gases including oxygen, to produce a stream of water that has a high concentration of CO₂ within it.¹¹

Discussion:

The overall basic idea of the CCS techniques were first suggested in the year 1977, but has however been used since the early 1920’s for separating CO₂ sometime found in natural gas reservoirs from saleable methane gas and was created to prevent CO₂ from being released into the atmosphere.¹²  In the early 1970’s the CO₂ captured in this way from gas processing facilities in Texas (USA), was pipelined to a nearby oil field and injected into the field to boost oil recovery.¹³ This process was well known at the time as Enhanced Oil Recovery or EOR. This process proved to be extremely successful and many millions of tonnes of CO₂ that was produced from both natural accumulation of CO₂ in underground rocks and from captured CO₂ from industrial factories.¹⁴These are still currently used and injected into oil fields all around the USA and other countries. In the current state of affair in the world it is unclear how many projects there are worldwide. It is known that is 2012 there were 5 large scale CCS projects in operation around the world, with 3 operational full chain pilot projects also ongoing.¹⁵ There are however 23 large scale projects being developed that have secured funding and if these are to continue to progress to large scale operatorial projects, the future development could rapidly increase in pace.

In the world an overwhelming majority of scientists and governments, agree that climate change is an occurring topic and it is mainly caused using fossil fuels by humans.¹⁶ Storing the CO₂ is a much safer option than emitting it straight into the atmosphere leading to global warming. Carbon capture and storage would allow us to continue to use the ever running out supply of fossil fuel while also reducing the emissions of greenhouse gasses that are produced and emitted into the atmosphere, once again leading to global warming. However, countries that are still developing will continue to use fossil fuel as they are reliant upon it to continue their growth and development.¹⁷ To ensure their maintenance of secure, low carbon electricity, in the future developing countries will be required to harness the flexibility of fossil fuel electricity generation as more intermittent and renewable such as nuclear power come into the equation.¹⁸ While these renewables such as nuclear power and other cause an increase in the efficiency of energy and will help the world to take steps towards a low carbon emission world, it is however not a complete answer to the situation. This is where CCS comes into play. CCS gives humanity an option to deploy other low carbon technologies, thus making our energy supply’s more reliable and secure.¹⁹ The international Energy Agency or IEA have estimated that by the year 2030 it is likely that the demand for electricity could increase by an additional 45%, off which around 25% will be secured by fossil fuels. With the help of CCS, we will be able to decarbonise energy, generating the low carbon power to meet the increasing energy demand. ²⁰ CCS is however not applicable to fossil fuel power plants; however, it can be applied to any large industrial source of carbon dioxide, examples include cement, steel and chemical factories. There are however some sectors in which CCS is the only way to reduce CO₂ emissions to the required level.²¹ If CCS is combined with burning biomass for energy, it could result in a negative carbon dioxide emission. As plants grow, they absorb carbon dioxide from the atmosphere.²² If they are then burned and the carbon dioxide is then captured and store via CCS, there would be a net reduction in the amount of CO₂ that is present in the atmosphere. ²³ The Intergovernmental Panel of Climate Change or IPCC have discovered that to ensure that there is a good chance that the global average temperature does not increase over pre-industrial levels by more than 2^oC.²⁴ It is required that by the year 2050 the global carbon dioxide emission needs to be reduced by between 50-85%, this result is only achievable if the world is to integrate CCS into the world as soon as possible to a massive scale, far higher than what is currently being achieved. ²⁵

CCS is an extremely reliable, secure and sustainable way to ensure that carbon emissions are reduced worldwide, CCS is also extremely cost efficient and easily integrated into factory environments where it completely captures the CO₂ commission that is released.²⁶ This in turn means that no carbon emission reaches the atmosphere meaning that global warming is not increased at an exponential rate.

Conclusion

To conclude, CCS is a sustainable and a cost-efficient solution to reducing global warming to our planet. It is found that CCS can capture up to 90% of the carbon that is emitted from industrial and such sources. Scientists all around the world believe that global warming is an ever-growing issue that needs to be solved as soon as possible. With major countries like the USA, India, UK, it can be determined that CCS can easily be spread to the world to give future generations a cleaner future where global warming would not be an issue.

References:

-          Centre for Climate and Energy Solutions. (2017). Carbon Capture | Center for Climate and Energy Solutions. [online] Available at: https://www.c2es.org/content/carbon-capture/ [Accessed 3 Jul. 2019].

-            Ccsassociation.org. (2019). What is CCS? – The Carbon Capture & Storage Association (CCSA). [online] Available at: http://www.ccsassociation.org/what-is-ccs/ [Accessed 3 Jul. 2019].

-          Cosmosmagazine.com. (2019). How does carbon capture and storage work? | Cosmos. [online] Available at: https://cosmosmagazine.com/technology/how-does-carbon-capture-and-storage-work [Accessed 3 Jul. 2019].

-          Stanger, R., Wall, T., Spörl, R., Paneru, M., Grathwohl, S., Weidmann, M., Scheffknecht, G., McDonald, D., Myöhänen, K., Ritvanen, J., Rahiala, S., Hyppänen, T., Mletzko, J., Kather, A. and Santos, S. (2015). Oxyfuel combustion for CO2 capture in power plants. International Journal of Greenhouse Gas Control, 40, pp.55-125.

-          Fossiltransition.org. (2019). What is Post-Combustion Capture? – Fossil Transition Project. [online] Available at: http://www.fossiltransition.org/pages/post_combustion_capture_/128.php [Accessed 3 Jul. 2019].

-          Ieaghg.org. (2019). [online] Available at: https://ieaghg.org/docs/General_Docs/Publications/Information_Sheets_for_CCS_2.pdf [Accessed 3 Jul. 2019].

-          Ccsassociation.org. (2019). Tackling climate change – The Carbon Capture & Storage Association (CCSA). [online] Available at: http://www.ccsassociation.org/why-ccs/tackling-climate-change/ [Accessed 3 Jul. 2019].

-          Evans, S. and Evans, S. (2018). Carbon capture cost: is it worth incorporating in the energy mix?. [online] Power Technology | Energy News and Market Analysis. Available at: https://www.power-technology.com/features/carbon-capture-cost/ [Accessed 3 Jul. 2019].

-          Shahbazi, A. and Rezaei Nasab, B. (2016). Carbon Capture and Storage (CCS) and its Impacts on Climate Change and Global Warming. Journal of Petroleum & Environmental Biotechnology, 7(4).