Here, anyone can read, write, and share science.

Try it for free. No registration required.

Carbon dioxide – a pollutant or a resource?

Carbon dioxide – a pollutant or a resource?

Carbon dioxide is a widely found gas around us that comes from several sources. The burning stack of dried leaves, agricultural lands, forest fires, burning of fossil fuels to generate electricity, and more than anything else, the emissions that come out of vehicles, aircraft are all adding the carbon dioxide burden on the earth.

While the experts working hard on climate improvisation on a global level have proposed several scientific methods to stabilize the world climate by 2050, we all have to do more than stop the greenhouse emissions. While one works to keep the carbon dioxide emissions at bay, it is obvious to ask if it could repurpose carbon dioxide?

Several reports and research studies mention the repurposing of carbon dioxide to develop some sustainable solutions that will indirectly help reduce harmful emissions. Before the carbon dioxide can be repurposed, it is necessary to capture it. Once it is captured, we can stop it from polluting the environment. Figure 1 shows a diagrammatic representation of the repurposing of carbon dioxide to create several products.

Figure 1: Illustration of repurposing captured carbon dioxide to produce new goods.

 

  • Carbon dioxide emissions: Burning fossil fuel, automobile emissions, burning agricultural lands, forest fires all result in carbon dioxide emissions.
  • Carbon dioxide capture: This gas needs to be captured and sometimes isolated from the other emissions that accompany it. Carbon dioxide can be captured by several processes such as adsorption, absorption, and further separation using cryogenic separation or separation membranes. This captured carbon dioxide is stored either in the ocean, geological or mineralization storage forms from where it cannot enter the air and pollute it.
  • Transport of carbon dioxide to a production facility: Whenever repurposing is needed, it will be carried to the particular production facility.
  • Reuse: At the production facility the carbon dioxide is used for chemical, industrial or biological processes.

 

Different examples of repurposing carbon dioxide:

The repurposing of carbon dioxide to other industries after being captured from the emissions will benefit if the additional energy spent in capturing, storing, and redirecting is not very high. It is possible to repurpose carbon dioxide in the following ways:

  • Sugar industry: Production of sugar from sugar beet requires a carbonation process. A study shows the use of captured carbon dioxide from the emissions to be used in sugar production.
  • Methane production: Experimental evidence shows that it is possible to produce methane from carbon dioxide and hydrogen using some catalysts. The reaction is possible at low temperature and atmospheric pressure. Similarly, it can produce methanol, ethanol, formic acid, and several other
  • Production of carbon nanotubes: The captured carbon dioxide has been successfully made into multi-walled carbon nanotubes using low-cost scrap metals. These nanotubes have remarkable strength and can be used in effective controlled drug delivery and electronic components.
  • Plastic industry: Captured carbon dioxide is also used in manufacturing polyols, polycarbonates, and other forms of plastics such as polyurethane. Polyurethane foam is widely used to make mattresses, vehicle seats and furniture upholstery. It can also be used as insulation foam for housing.

There is a circular carbon economy for plastic industries. They produce carbon dioxide as a by-product; these emissions are captured and used in the manufacture of plastic. When this plastic is recycled by chemical recycling processes such as pyrolysis, it again emits carbon dioxide, which is captured, continuing the cycle.

Another outstanding example is the synthesis of Polyethylene furan dicarboxylate (PEF), an alternative to its fossil-based counterpart polyethylene terephthalate (PET). PEF has many applications in plastic products.

  • Synthesis of carbon fibers from algae: Carbon fibers are extremely light in weight but have superior strength. Carbon fibers can be effectively used to lower the weight of vehicles and reduce fuel consumption and serve as a green alternative to steel and aluminum. This breakthrough technology from the Technical University of Munich has demonstrated that carbon fibers can be produced from algae, atmospheric carbon dioxide, and direct solar power.

Conclusion:

The rising level of carbon dioxide in the atmosphere is a threat to human beings. Hence to minimize this danger, there is a continuous need for research to keep the carbon dioxide levels low. Capturing carbon dioxide emissions and storing them to be utilized in industries where it is needed is the new technological solution to this problem. Repurposing carbon dioxide is possible; we need to work on economically feasible options to do so.

Sources referred:

Ahmed ME, Adam S, Saha D, Fize J, Artero V, Dey A, Duboc C. Repurposing a bio-inspired NiFe hydrogenase model for CO2 reduction with selective production of methane as the unique C-based product. ACS Energy Letters. 2020 Nov 13;5(12):3837-42.

Andrews R, Jacques D, Qian D, Rantell T. Multiwall carbon nanotubes: synthesis and application. Accounts of chemical research. 2002 Dec 17;35(12):1008-17.

Douglas A, Muralidharan N, Carter R, Pint CL. Sustainable capture and conversion of carbon dioxide into valuable multiwalled carbon nanotubes using metal scrap materials. ACS Sustainable Chemistry & Engineering. 2017 Aug 7;5(8):7104-10.

Duraccio V, Gnoni MG, Elia V. Carbon capture and reuse in an industrial district: A technical and economic feasibility study. Journal of CO2 Utilization. 2015 Jun 1;10:23-9.

Jacquemin M, Beuls A, Ruiz P. Catalytic production of methane from CO2 and H2 at low temperature: Insight on the reaction mechanism. Catalysis Today. 2010 Nov 17;157(1-4):462-6.

Jiang L, Gonzalez-Diaz A, Ling-Chin J, Malik A, Roskilly AP, Smallbone AJ. PEF plastic synthesized from industrial carbon dioxide and biowaste. Nature Sustainability. 2020 Sep;3(9):761-7.

Koo MS, Chung K, Youn JR. Reaction injection molding of polyurethane foam for improved thermal insulation. Polymer Engineering & Science. 2001 Jul;41(7):1177-86.

University of Southern California.  Lucca Henrion, Joe Árvai, Lauren Lutzke, Volker Sick. Using captured CO₂ in everyday products could help fight climate change, but will consumers want them [Internet] [Updated May 14, 2021]. Available at: https://dornsife.usc.edu/news/stories/3480/carbon-dioxide-to-create-products/. Accesssed on Nov 24, 2021]

Source: Lucca Henrion, Joe Árvai, Lauren Lutzke, Volker Sick University of Southern California.  Using captured CO₂ in everyday products could help fight climate change, but will consumers want them [Internet] [Updated May 14, 2021]. https://dornsife.usc.edu/news/stories/3480/carbon-dioxide-to-create-products/. Accessed on Nov 24, 2021]