Capturing and using carbon dioxide, the great pending challenge

“It is not enough to reduce emissions of carbon dioxide (_CO2) – the main gas that causes global warming – we must capture the carbon we have already emitted if we want to curb climate change,” warns Mariano Marzo, director of the UB-Fundación Repsol Energy Transition Chair.

A recent report by the UN Economic Commission for Europe (UNECE) stresses that carbon capture, use and storage (CCUS) is “crucial” to get closer to the goal of limiting global warming and urges the large-scale deployment of these technologies. The reason: the gas we emit today into the atmosphere is in addition to the one that humanity has been emitting since the time of the industrial revolution (see complementary text).

Urgency

UN report calls on EU for rapid large-scale deployment

It is about developing technology capable of doing what nature (with its forests, wetlands and posidonia meadows) did naturally and in balance before humanity began to change the climate. The same hand that has broken this balance must now find a way to regulate planet Earth’s thermostat again.

“There is already technology capable of capturing _CO2 directly from the air. The problem is its high price,” says Joan Ramon Morante, director of the Institut de Recerca en Energia de Catalunya (IREC). Lowering these costs requires large economic investments. “For Europe alone, it is estimated that €320 billion will be needed for the ccUS deployment planned for 2050, plus another €50 billion for the required transport infrastructure,” the UN estimates in its report.

March points out that there are many research projects in this line that have been submitted to European aid for the recovery of the covid crisis, but warns that it will not be enough. “All this will end up having an impact on the pocket of the final consumer, who sooner or later will have to pay for the emissions that derive from their daily activities,” he explains.

With the necessary investment, Marzo affirms that the technologies for the capture, use and storage of carbon “are in the phase in which renewable energies were ten or fifteen years ago.” Less optimistic is Paco Ramos, of Ecologists in Action, who sees “fanciful” the option of capturing CO2 directly from the air. “It’s going to be very small amounts,” he says. “They are selling us an illusion,” adds the spokesman for the environmental entity.

Beyond the economic viability of this technology and its suitability or not, the second part is: what do we do with carbon once we have captured it? Currently, the _CO2 that some industries manage to capture in their combustion processes is injected into oil exploitations to obtain more fossil fuels. When there is no longer any oil or gas to extract, these deposits are also used as warehouses.

Paco Ramos warns of the risk of leaks due to seismic movements. “It’s not a very high risk, but you have to take it into account,” he says. Víctor Vilarrasa, a researcher at the Institute of Environmental Diagnosis and Water Studies (Idaea-Csic), agrees: “It is a fairly safe system, which does not mean that it should not be controlled so that there are no leaks.” “In Norway they have been doing it for 25 years and have offered to store _CO2 from Europe,” adds the researcher. Vilarrasa also points out that in Spain there are very few research projects in this line “because a few years ago money was stopped for this type of projects”.

However, Mariano Marzo points out that the great challenge is not to store the captured carbon, but to ensure that it ceases to be considered a waste and becomes a resource for the manufacture of a multitude of products: from food, plastics, concrete, through more specific issues such as the cultivation of microalgae to the manufacture of beer, among many other options that are under study.

Source: The Vanguard