We are at the brink of a severe climate crisis caused by rising greenhouse gas emissions (GHG), including carbon dioxide (CO2), methane, and nitrous oxide. Anthropogenic activities such as burning fossil fuels have significantly elevated the carbon dioxide levels in the atmosphere. As a matter of fact, the global CO2 average has hit a new record of 409.8 parts per million in 2019, the highest in about 800,000 years!
According to the Environmental Protection Agency, some of the major sectors contributing to GHG emissions in the United States include energy production and industrial manufacturing. The chemical and petrochemical industry is responsible for about 16% of direct CO2 emissions. To minimize these emissions, industries are devising ways to capture and utilize CO2.
Carbon Capture , Utilization and Storage (CCUS)
Carbon capture, utilization and storage (CCUS) is a process that captures carbon dioxide and either reuses it or stores it to prevent its escape into the atmosphere. According to the Intergovernmental Panel on Climate Change (IPCC), capturing carbon at power plants could reduce CO2 emissions by about 80-90%. By 2017, around 21 commercial carbon capture projects were operating globally with about 22 in progress. One such endeavor, undertaken by the Indian firm Carbonclean, is capturing carbon from its own coal-powered boiler and making baking soda out of it. But how does CCUS work?
The Oakridge National Laboratory has developed a technology that uses compounds known as bis-iminoguanidines to capture CO2 from industrial exhausts and convert it into limestone. When heated, CO2 can be released from limestone, and permanently stored underground as rocks, or utilized to make chemicals, fuels, building materials and plastics. Currently, an electrochemical conversion technique is widely being employed by companies such as Verdox and Haldor Topsoe for utilizing carbon emissions. Their technologies convert CO2 into carbon monoxide, which can be subsequently converted into products such as bioplastics and fuels.
Bioplastics from CO2
Currently, most plastic products like recyclable beverage containers are synthesized from petroleum-derived polyethylene terephthalate (PET). The manufacturing of PET generates over four tons of CO2 per ton of PET produced. However, numerous research groups and companies are working on developing sustainable replacements for petroleum-based plastics. Scientists at Stanford University are working on developing a green alternative called polyethylene furandicarboxylate, generated from CO2 and biomass. In another effort to produce bioplastics from CO2, a California-based company, Newlight Technologies, is using a microorganism-derived biocatalyst to convert CO2 captured from the air into a bioplastic material they have named AirCarbon. Their technology utilizes carbon dioxide from waste-water treatment plants or landfills to produce this bioplastic. AirCarbon has been employed by companies like IKEA to make furniture and Dell and Hewlett Packard for packaging. Several research efforts are also currently being directed towards the synthesis of fuels from CO2.
From Air to Fuels
Companies are now keen on using clean renewable energy like hydro or solar power to facilitate the conversion of CO2 into fuels. The Canadian company Carbon Engineering, in partnership with Harvard University, has come up with an Air to Fuel Technology, currently under operation in Squamish, British Columbia. Their hydro-powered innovation combines CO2 with hydrogen to make gasoline and diesel.
Climeworks, a start-up based in Zurich, has also established a direct air capture facility at the Hellisheidi geothermal power plant that captures 50 metric tons of CO2 annually. In addition, they have collaborated with Lufthansa Group, Synhelion, and ETH Zurich to launch sustainable aviation fuels from CO2 using solar energy. Furthermore, NASA has also developed solar energy -powered devices that can convert CO2 into usable fuels such as methane. In fact, NASA scientists are considering using carbon dioxide to generate rocket propellants for their Mars missions. So it won't be long before automobiles and aircraft are running on CO2-derived green fuels!
Climate change is a global challenge that knows no borders. It's high time we came up with green solutions to decarbonize the economy. CO2 capture could pave the way for a low-carbon economy, build climate resilience, and bring financial benefits to businesses investing in the technology. At present, the U.S. hosts the most large-scale carbon capture and storage facilities globally, with the potential to capture about 27 million tons a year. Although CCUS technologies are currently limited by high costs and technical feasibility, scientists are striving to come up with sustainable and economical solutions to transform this pollutant into a resource. In the near future, you could be sitting on a couch, sipping your favorite beverage from a bottle made right out of thin air!
About the Author
Sarada Sripada is a Ph.D Student in the School of Chemical, Material and Biomedical Engineering, College of Engineering at the University of Georgia. She is interested in synthesizing green catalysts for applications in the production of certain fine chemicals. Apart from being passionate about her research, she enjoys music, dance, writing songs and poems and tries her hand at Indian cooking. She totally loves tea and couldn't do a day without it!
