Global Warming and Carbon Capture and Utilizations
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Introduction
Typically, the solar radiation would escape into space easily because the atmosphere doesn’t block them. However, when global warming is occurred, the Earth’s atmosphere collects carbon dioxide and other air pollutants, which results in the absorption of sunlight and the reflection from the earth’s surface on the atmosphere. As you can see, this is a simplified diagram showing how Earth transforms sunlight into infrared energy.
Infrared energy can be absorbed by greenhouse gases such as carbon dioxide and methane. Then, these gases re-emitting some of infrared energy back toward Earth and some of it out into space. So that the Earth’s atmosphere that collects these pollutants increases the absorption of sunlight and the reflection from the earth’s surface and results in global warming. To exemplify, there are many causes which contribute to global warming since the pre-industrial period between 1850 and 1900 because of human activities, primarily fossil fuel burning. This picture shows steam billows from the Intermountain Power Plant in Delta, Utah. This coal-fired plant is operated by the Los Angeles Department of Water and Power.
Carbon Capture and Storage called CCS involves the capture of carbon dioxide emissions from industrial processes such as steel or cement production, petrochemical processes, and from the burning of fossil fuels in power generation. And then this carbon is transported from where it was produced, via ship or in a pipeline, and stored deep underground in geological formations.
Although the use of alternative energy sources, which can reduce the rate carbon dioxide emissions effectively. The cumulative quantity of carbon dioxide should be reduced in order to mitigate the impact of climate change. As a result, Carbon Capture Utilization and Storage or CCUS, these concept need to be implemented.
What is the difference between CCUS and CCS?
Compared to CCS, CCUS provides that carbon dioxide could be re-used in industrial processes by converting it into plastics, concrete or biofuel instead of storing it.
Global Warming
The influence of carbon dioxide results in climate change. Carbon dioxide absorbs infrared energy that has wavelengths between 2,000 and 15,000 nanometers. After that it vibrates and re-emits the infrared energy back in all directions, which contributing to the greenhouse effect. As you can see on this diagram, energy from the Sun reaches Earth as mostly visible light. Earth reflects that energy as infrared energy, which has a longer, slower wavelength. Whereas oxygen and nitrogen do not respond to infrared waves, greenhouse gases such carbon dioxide do.
Carbon dioxide still account for only 0.04% of the atmosphere, that still adds up to billions upon billions of tons of heat-trapping gas. In 2019, there are 36.44 billion tonnes of carbon dioxide in the atmosphere, which provide heat-trapping blanket across the entire atmosphere. According to the graph down below, the amount of carbon dioxide in the atmosphere (raspberry line) has increased along with human emissions (blue line) since the start of the Industrial Revolution in 1750.
Carbon Capture and Utilization
Carbon Dioxide Capture
For carbon dioxide capture, accelerating deployment of carbon capture technology is essential to reduce emissions from these power plants, and from industrial plants like cement and steel manufacturing, including petrochemical plants. This technology has 2 approaches. The first one is bioenergy with carbon capture and storage, and the second one is direct air capture.
1.Bioenergy with carbon capture and storage (BECCS)
Bioenergy with carbon capture and storage is a carbon-negative technology that combines sustainable bioenergy conversion with carbon dioxide capture and storage.
BECCS is a process that begins with growing biomass, which is organic matter. Commonly used biomass for this process is wood and compost. The biomass is then converted to bioenergy, which is renewable energy. The biomass is burned and converted to bioenergy — electricity, liquid or gas fuels, or heat. While burning biomass is considered to be carbon neutral, the carbon emitted in BECCS is captured and sequestered, or stored, underground in mountains, valleys, and other geological formations, for later usage. Thus, BECCS is considered to be carbon negative. The carbon dioxide can also be stored in products that last a long time, such as harvested wood or landfills.
It is a possible global warming solutions due to the low price of BECCS. Per ton of carbon dioxide captured via BECCS, the cost may be between $20 and $100. Currently, BECCS is included in integrated assessment models’ pathways for mitigating climate impacts, so the Paris Agreement does consider it to be a key technology for helping reduce impacts of climate change.
2.Direct air capture (DAC)
For direct air capture technique, two technology approaches are being used to capture carbon dioxide from the air nowadays.
- Liquid systems pass air through chemical solutions such as a hydroxide solution, which removes the carbon dioxide. The system reintegrates the chemicals back into the process by applying high-temperature heat while returning the rest of the air to the environment.
- Solid DAC technology makes use of solid sorbent filters that chemically bind with carbon dioxide. When the filters are heated and placed under a vacuum, they release the concentrated carbon dioxide, which is then captured for storage or use.
For DAC process, it starts with a large structure modelled off industrial cooling towers which called air contactor. A giant fan pulls air into this structure, where it passes over thin plastic surfaces that have potassium hydroxide solution flowing over them. This non-toxic solution chemically binds with the carbon dioxide molecules, removing them from the air and trapping them in the liquid solution as a carbonate salt. The carbon dioxide contained in this carbonate solution is then put through a series of chemical processes to increase its concentration, purify and compress it, so it can be delivered in gas form ready for use or storage. This involves separating by using a pellet reactor, which was adapted from water treatment technology. The salt out from solution into small pellets in this structure. These pellets are then heated in third step, a calciner, in order to release the carbon dioxide in pure gas form. The calciner is similar to equipment that’s used at very large scale in mining for ore processing. This step also leaves behind processed pellets that are hydrated in a slaker and recycled back into the system to reproduce the original capture chemical.
There are currently 19 direct air capture (DAC) plants operating worldwide, capturing more than 0.01 Mt CO2/year. In the Net Zero Emissions by 2050 Scenario, DAC is scaled up to capture more than 0.085 Gt CO2/year by 2030 and 0.98 Gt CO2/year by 2050. This level of deployment will require several more large-scale demonstrations to refine the technology and reduce capture costs.
Carbon Dioxide Utilization Pathways
The capture and use of carbon dioxide to create valuable products might lower the net costs of reducing emissions or removing carbon dioxide from the atmosphere. carbon dioxide utilization is receiving increasing interest from the scientific community. This is partly due to climate change considerations and partly because using carbon dioxide as a feedstock can result in a cheaper or cleaner production process compared with using conventional hydrocarbons.
There are 10 pathways of carbon dioxide utilization.
- Carbon dioxide-based chemicals—Carbon dioxide can be transformed efficiently into a range of chemicals, but only a few of the technologies are economically viable and scalable. Some are commercialized, such as the production of urea and polycarbonate polyols. The estimated utilization potential for carbon dioxide in chemicals is around 0.3 to 0.6 Gt CO2 yr−1 in 2050.
- Carbon dioxide-based Fuels — Fuels derived from carbon dioxide are an attractive option in the decarbonization process because of the deployment in existing transport infrastructure. The estimated potential for the scale of carbon dioxide utilization in fuels varies widely, from 1 to 4.2 Gt CO2 yr−1.
- Microalgae Fuels and Products — The algal pathways require photobioreactors and the fuel synthesis pathways require electrolyzers. Their high carbon dioxide fixation efficiencies are interested in research topics as well as their potential to produce a range of products. The estimated carbon dioxide utilization potential for microalgae in 2050 ranges from 0.2 to 0.9 Gt CO2 yr−1.
- Concrete Building Materials — Carbon dioxide is used as a cement curing agent in the precast concrete market and in 70% of the pourable cement markets. Concrete building materials are estimated to remove, utilize and store between 0.1 and 1.4 Gt CO2 yr−1.
- Carbon Dioxide Enhanced Oil Recovery (CO2-EOR) — Conventionally, operators aim to maximize both the amount of oil recovered and carbon dioxide recovered per tonne of carbon dioxide injected; between 1.1 and 3.3 barrels of oil can be produced per tonne of carbon dioxide. The estimation of 2050 utilization rate is 0.1 to 1.8 Gt CO2 yr−1.
- Bio-energy with Carbon Capture and Storage (BECCS) — This technology involves the biological capture of atmospheric carbon by photosynthetic processes, producing biomass used for the generation of electricity or fuel. BECCS are estimated to remove, utilize and store between 0.5 and 5.0 Gt CO2 yr−1.
- Enhanced Weathering — The use of terrestrial enhanced weathering on croplands could increase crop yields. This yield enhancement is from nutrient uptake that is facilitated by pH effects. However, there may still be an as-yet-unquantified carbon dioxide utilization potential of this pathway.
- Forestry Techniques — Atmospheric carbon dioxide is removed via photosynthesis and the carbon is stored in standing forests. The estimation of 2050 utilization rate is 0.01 to 1.1 Gt CO2 yr−1.
- Land Management — The carbon dioxide taken up by land ultimately becomes either carbon dioxide utilized, or carbon dioxide removed, but not both. Land management are estimated between 0.9 and 1.9 Gt CO2 yr−1.
- Biochar — It is a carbon-enriched biomaterial generated in the combustion of biomass through a process called pyrolysis. The estimation of 2050 utilization rate is 0.17 to 1.0 Gt CO2 yr−1.
Conclusions
Firstly, carbon dioxide utilization is obviously more consistent with this principle than carbon capture and sequestration.
Secondly, carbon dioxide utilization pathways might reduce emissions of carbon dioxide but have limited potential for its removal, whereas some pathways can both utilize and remove carbon dioxide.
Finally, current strategies to reduce carbon dioxide emissions are necessary, but probably insufficient.
References
Alper, E., Orhan, O., CO2 Utilization: Developments In Conversion Processes, Petroleum, Volume 3, Issue 1, 2017, Pages 109–126, ISSN 2405–6561, https://doi.org/10.1016/j.petlm.2016.11.003.
American Institute of Chemical Engineers, What is CCUS?, Source: https://www.aiche.org/ccusnetwork/what-ccus, Retrieved 14 January 2022.
CO2 Sciences and The Global CO2 Initiative, Global Roadmap for Implementing CO2 Utilization, Source: https://deepblue.lib.umich.edu/bitstream/handle/2027.42/150624/CO2U_Roadmap_FINAL_2016_12_07%28GCI%29.pdf?sequence=1&isAllowed=y, Retrieved 12 January 2022.
Fecht, S., Columbia Climate School, How Exactly Does Carbon Dioxide Cause Global Warming?, Source: https://news.climate.columbia.edu/2021/02/25/carbon-dioxide-cause-global-warming/, Retrieved 13 January 2022.
Hepburn, C., Adlen, E., Beddington, J. et al., The technological and economic prospects for CO2 utilization and removal, Nature, Volume 575, 2019, Pages 87–97, https://doi.org/10.1038/s41586-019-1681-6.
International Energy Agency, Direct Air Capture, Source: https://www.iea.org/reports/direct-air-capture, Retrieved 14 January 2022.
International Energy Agency, Global Energy Review: CO2 Emissions in 2020, Source: https://www.iea.org/articles/global-energy-review-co2-emissions-in-2020, Retrieved 12 January 2022.
M.A. Quader, S. Ahmed, Chapter Four — Bioenergy With Carbon Capture and Storage (BECCS): Future Prospects of Carbon-Negative Technologies,, Clean Energy for Sustainable Development, Academic Press, 2017, Pages 91–140, ISBN 9780128054239, https://doi.org/10.1016/B978-0-12-805423-9.00004-1.
Meylan, F., Moreau, V., Erkman, S., CO2 Utilization In The Perspective Of Industrial Ecology, An Overview, Journal of CO2 Utilization, Volume 12, 2015, Pages 101–108, ISSN 2212–9820, https://doi.org/10.1016/j.jcou.2015.05.003.
NASA’s Jet Propulsion Laboratory, Overview: Weather, Global Warming and Climate Change, Source: https://climate.nasa.gov/resources/global-warming-vs-climate-change/, Retrieved 12 January 2022.
Steen, M., Joint Research Centre (European Commission), Greenhouse Gas Emissions From Fossil Fuel Fired Power Generation Systems, Source: https://op.europa.eu/en/publication-detail/-/publication/221658dd-9556-4591-86ea-51544346a8f7, Retrieved 12 January 2022.
Vandermal, J., Preventing Climate Change With BECCS: Bioenergy With Carbon Capture And Storage, Source: https://psci.princeton.edu/tips/2020/11/15/preventing-climate-change-with-beccs-bioenergy-with-carbon-capture-and-storage, Retrieved 17 January 2022.
