Science Speaks: Carbon Dioxide Use

TheScience speaksthe blog series offers a deep dive into the topics of science, technology and innovation in the public mind. The series explains key themes through relatable analogies and asks readers to consider key possibilities, explore pathways for advancing gender equity and equality, and answer the ultimate question: Why should we care?

In the 2009 animated comedy Cloudy with meatballs, fictional inventor Flint Lockwood creates a machine to turn water vapor into food. The machine accidentally crashes into the stratosphere and causes cheeseburgers to fall from the sky. The justification as Flint’s fantastical invention is reminiscent of a far more realistic but equally exciting technology: using carbon dioxide.

As part of the larger category of technologies called carbon capture, use and storage (CCUS), carbon dioxide utilization is the concept of reuse the greenhouse gas carbon dioxide after it has been collected through carbon capture. Like Flint’s invention, the use of carbon dioxide seeks to turn an abundant atmospheric gas into a practical, value-added product. By finding alternative uses for captured carbon dioxide, the use offers exciting research and entrepreneurial opportunities, meaning it can also provide opportunities for economic empowerment for women.

Women and girls face systemic and cultural barriers to pursuing science, technology and engineering careers.

But in Cloudy with meatballs, character Sam Sparks, a reporter covering Flint’s invention, explains how women and girls regularly struggle with harmful stereotypes that threaten their leadership in climate innovation. In Sam’s case, this includes being ridiculed for her interest in meteorology, and in the real world, systemic and cultural barriers prevent women and girls from studying science, technology, and engineering disciplines that are critical to the development of the use of carbon dioxide and other important technologies.

Within these disciplines—seemingly inspired by the range of foods produced by Flint’s invention—researchers are expanding the range of marketable products that can be made from carbon dioxide. These include chemical raw materials (needed to synthesize pharmaceuticals, plastics, and more) and carbon-neutral fuels (so-called because burning them results in no new carbon dioxide reaching the atmosphere). If carbon dioxide-derived fuels are used in conjunction with a second round of carbon capture, the entire process could theoretically be carbon negative.

One of the most widely studied methods of using carbon dioxide is catalysis, often through a process called electroreduction. A voltage is applied to drive a chemical reaction that turns carbon dioxide into a different carbon-containing molecule, such as the alternative fuel methanol. When carried out in water, electroreduction can even be tailored to generate “synthesis gas”, which is further reacted to produce fuels. But the field of electrochemistry (where much of this research takes place) consists of disproportionately few women scientists.

Non-catalytic methods also exist. For example, captured carbon dioxide can be injected into concrete mixes where it chemically reacts with calcium ions to form solid calcium carbonate. This not only captures carbon dioxide, but also strengthens the concrete, potentially reducing the amount needed for a given project. This has many advantages, as concrete accounts for 8% of global greenhouse gas emissions by 2020. As in the case of electrochemistry, women are underrepresented in construction fields, including concrete production.

Carbon dioxide can be used to strengthen concrete.

Nature-based utilization methods include photosynthetic processes. Plants and plant-like organisms (eg microalgae) consume carbon dioxide and can be used as a basis for carbon-neutral biofuels. Plus, just like Flint’s invention produces an abundance of food in the air Cloudy with meatballsagricultural yields (albeit on the ground) can be increased by treating fields with biochar, a by-product of biofuel synthesis.

Although the researchers suggest that different utilization methods will offer different degrees of emission reduction, an effective strategy is likely to use multiple tools in the carbon dioxide utilization toolkit, selected based on the needs and resources of a given location. Pieces of this puzzle are increasingly coming to light, such as a led by women a startup that demonstrates the generation of jet fuel from carbon dioxide.

The use of carbon dioxide poses no risk of spaghetti tornadoes or other food-related weather events, but there are challenges to its application. Electroreduction (and other catalytic methods) require significant energy inputs because carbon dioxide is extremely stable and therefore does not tend to undergo chemical reactions. As a result, it is extremely important that the energy used in these processes is obtained from renewable sources, especially as utilization efforts increase.

The United States recognizes the need to explore a myriad of solutions to meet our goal of limiting global temperature rise to 1.5 degrees Celsius and reaching net zero emissions by 2050. The State Department is working with allies and partners to advance technology solutions for climate, such as carbon capture and use, and the Interdepartmental is conducting and financing research that seeks to transform carbon waste streams into value-added products. Diplomatic and programmatic efforts support women and girls as they pursue opportunities in science, technology, engineering and mathematics and help women gain access to climate-related sectors, including renewable energy and construction .

Flint Lockwood should consider transforming a different greenhouse gas the next time he creates a physics-defying invention. Where might the use of carbon dioxide appear in your life?

About the Author: Aubrey R. Parris, Ph.D., is the Contract Advisor for Policy on Gender, Climate, and Innovation in the Secretary’s Office on Global Women’s Issues (S/GWI). Dr. Paris received his Ph.D. in Chemistry and Materials Science from Princeton University and a BS in Chemistry and Biology from Ursinus College.

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