12 Mar Capturing CO2 from factory gases can be 20 percent cheaper
A new technique makes storing CO2 underground cheaper and more environmentally friendly, say researchers at the Department of Energy in the United States. They found a new solvent that costs less and works better than the resources companies now use to capture and store CO2.
Despite the greening of energy and chemistry, it seems that CO2 emissions are still unavoidable for decades to come. That’s why companies are increasingly looking at CCS: carbon capture and storage. By capturing CO2 by the chimney and then storing it (underground), you prevent more CO2 from entering the air and thus comply with climate legislation.
But capturing CO2 is not so easy. You need a chemical that only binds the CO2 to it, while the rest of the smoke can still go away. Moreover, this substance must work in such a way that it can continuously absorb CO2, or at least fit into a system to which you do not have to add new absorbents every time – after all, that would become unaffordable.
Storing CO2 in aqueous dust
The solvent, which the researchers call EEMPA, absorbs CO2 from chimney gases. This process has been known for some time, and so-called ‘watery amides’ do the work. But these chemicals have problems: in order to detach the CO2 from the liquid, you have to boil it, and then cool down again in order to absorb CO2. As a result, absorbing CO2 becomes relatively energy intensive (after all, boiling water costs energy) and expensive. Amibes with less water were too firm, so they did not work at certain temperatures and thus became unusable.
The new amide contains relatively little water (so loosening CO2 after absorption costs less energy) but it does not have the problems of the other non-aqueous substances. The best of both worlds, therefore, and therefore the researchers think that EEMPA can make capturing CO2 cheaper and more environmentally friendly.
Cheaper and more energy efficient
They calculated a cost reduction of 19 percent and an energy saving of 17 percent. This would raise the price of absorbing a tonne of CO2 to $47. By comparison, commercial installations now cost $58 per tonne of captured CO2. The technology can therefore ensure that more companies choose to capture CO2.
Yet for the time being, that seems unlikely. Even in Europe, where the emissions trading system causes CO2 emissions to cost money, the price for emitting is many times lower than the price for capture. However, co2 emissions are expected to become increasingly expensive, making alternatives – such as capturing CO2 – more popular. Economies of scale also lower the price. At the same time, discoveries and inventions, such as this new amide, show that innovation can also be saved.