Carbon Removal and Sequestration 101
In order to understand our mission here at the CLP, one must answer one question. What is Carbon Removal and Sequestration? The basic concept is fairly simple. Take Carbon Dioxide that would otherwise be present in the atmosphere, capture and contain it, then place it into long term storage. The most basic example is a tree. As it lives it takes in Carbon Dioxide, using it as an ingredient in energy production. The Oxygen is released back into the atmosphere while the Carbon is stored in the tree. Now the tree could live for decades or even centuries, providing long term storage for the Carbon and reducing the amount of Carbon Dioxide in the atmosphere for the duration of its life.
There are two common types of Carbon Capture: direct air capture and point source capture (Bui et al, 2018). In direct air capture, Carbon Dioxide is taken from the atmosphere at large. There are many direct air capture techniques in various stages of development, but the technology is still fairly novel and experimental, (Sanz-Perez et al, 2016) with the obvious exception of plants. Point capture relies on a single point with high Carbon Dioxide emissions. A power plant or fire, for example. The high concentration of Carbon Dioxide around the emission source makes capture a much easier process (IPCC, 2005). Point capture already sees commercial deployment (Ibid), but it isn’t exactly a negative emissions technology. It can reduce current emissions, but it doesn’t take already emitted CO2 out of the atmosphere. For that, direct air capture is required.
Once all this Carbon is captured, the next challenge is what to do with it. How can it be stored long term? Is there something useful that can be done with it that won’t release it back into the atmosphere? Once again, plants have an advantage over man made technologies as the storage is built into the capture process. But there are technological options for storage or utilization. Both geological formation such as depleted oil and gas reservoirs (Benson & Surles, 2006) and industrial products like some types of cement (Novacem, 2008) (TechEco, 1983) have potential to hold Carbon Dioxide long term. A few large scale ocean based geoengineering projects have some (very theoretical) sequestration potential (Traufetter, 2009). And some naturally abundant materials can react with Carbon Dioxide to form long lasting minerals. Take Calcium Oxide, which is common in the Earth’s crust and reacts with Carbon Dioxide to form limestone (Herzog, 2002). And these are just a few of the options available. With each passing year, new and ingenious methods are being developed to sequester and utilize captured Carbon.
Works Cited
Benson, S.M.; Surles, T. (October 1, 2006). “Carbon Dioxide Capture and Storage: An Overview With Emphasis on Capture and Storage in Deep Geological Formations”. Proceedings of the IEEE. 94 (10): 1795–1805. doi:10.1109/JPROC.2006.883718. ISSN 0018-9219. S2CID 27994746.
Bui, Mai; et al. (2018). “Carbon capture and storage (CCS): the way forward”. Energy & Environmental Science. 11 (5): 1062–1176. doi:10.1039/C7EE02342A.
Herzog, Howard (March 14, 2002). “Carbon Sequestration via Mineral Carbonation: Overview and Assessment” (PDF). Massachusetts Institute of Technology.
“Home”. TecEco. July 1, 1983.
[IPCC, 2005] IPCC special report on Carbon Dioxide Capture and Storage. Prepared by working group III of the Intergovernmental Panel on Climate Change. Metz, B., O. Davidson, H. C. de Coninck, M. Loos, and L.A. Meyer (eds.). Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 442 pp.
“Novacem”. Imperial Innovations. May 6, 2008.
Sanz-Pérez, E. S.; Murdock, C. R.; Didas, S. A.; Jones, C. W. (August 25, 2016). “Direct Capture of CO
2 from Ambient Air”. Chem. Rev. 116 (19): 11840–11876. doi:10.1021/acs.chemrev.6b00173. PMID 27560307 – via ACS Publications.
Traufetter, Gerald (January 2, 2009). “Cold Carbon Sink: Slowing Global Warming with Antarctic Iron”. Spiegel Online.
