Typically perceived as pollution, CO2 is slowly but surely turning into a resource. CO2 reuse can be defined as any process making use of captured carbon dioxide. An increasing number of companies have been working on different forms and ways to reuse it. Although repurposing CO2 is not new, as it has been used for Enhanced Oil Recovery for decades, it is only until recently that the development of a variety of utilizations took off.
Dr Stephen Pacala, professor of ecology and evolutionary biology at Princeton University and chair of the US National Academies panel on CO2 says: “If you’re a young person and you want to save the planet, while also becoming the richest person on it, then this is the problem to solve. Using captured carbon dioxide, how do you make, say, a fuel?”
However, according to Dr Pacala, “there’s a long development road ahead” for CCUS. Carbon removal is also not the silver bullet in the fight against tackling climate change emissions as perceived by many. It can’t be denied though that a new industry growing out of CO2 reuse, would also help countries recover their economies from the investments those new technologies offer.
CO2 Reuse Methods
Several utilization developments have already been embraced. According to Dr Edward Sargent, professor of electrical and computer engineering at the University of Toronto, CO2 could be used to make new plastics. His view comes strictly from an economic sense, as storing emissions underground is expensive and the business hasn’t taken off.
His team is combining the reactant CO2, water and electricity to create ethylene – used to make plastics. Since ethylene is already a $60-billion-a-year market, it’s considered a beneficial option for the overall CO2 utilization idea.
Another reuse method is turning CO2 into rock. The construction industry has an opportunity now to use concrete partially built with CO2 emissions. Terminal One of San Francisco International Airport is actually made with such concrete. It uses aggregate coated with artificial limestone and is developed by California-based Blue Planet.
The company’s ambitious plan is to turn the world’s construction projects into a massive carbon sink. Everything from roads and bridges to office buildings and regular homes could be made of rock that sequesters carbon emissions.
Startups in the food industry claim they are able to make a protein out of CO2 combined with other elements. The idea is to create “air-based” meat, made from carbon dioxide, oxygen, and nitrogen found in the air.
A company called Air Protein uses single-cell microorganisms, known as hydrogenotrophs that act like plants in the way that they can convert CO2 into protein. The idea for air protein was originally inspired by NASA in the 1960s. The agency wanted to produce food for long space missions with limited resources. It decided to look into the idea of microbes converting exhaled air into food.
A catalytic converter developed by chemical and biomolecular engineers from Rice University, Texas, uses CO2 as a chemical feedstock to produce high concentrations of formic acid. Using CO2 in the process makes it much more purified and so less expensive than other methods to date.
There are good reasons to develop CO2 utilization processes to reduce emissions, mainly to develop cost-competitive processes. In practice, there are numerous different technologies that utilize carbon dioxide in one way or another. The impact of the CO2 utilization for cutting emissions is very different and more research needs to be done to determine its efficiency.