CARBON CAPTURE & UTILISATION

Carbon capture and Utilisation technology may make economic sense

Carbon capture and utilisation (CCU)could be one of the best ways of combating climate change.

Passing carbon dioxide through slag left over from steel-making turns the waste product into a strong material that can be used for construction. Pumped into greenhouses, it provides a growing boost for crops. Put into tanks of algae, it can be used to make biofuels. Waste carbon dioxide can even be cleaned up to “food grade” and injected into fizzy drinks.

But these processes are rare — instead, carbon dioxide from power generation is normally simply vented into the atmosphere, where it contributes to global warming. When the gas is needed for an industrial process, it is manufactured from scratch.
The Carbon capture and utilisation (CCU) could be one of the best ways of combating climate change, by turning carbon dioxide from a waste gas into an integral part of industrial processes.

There are a few examples of the development of processes to use CO -2 to make synthetic diesel from carbon dioxide,  to manufacture cement using the carbon dioxide from power plants, and in several places around the world, algae is being cultivated that would absorb the gas and could itself then be used to make biofuels.

In  UK  where the carbon from power stations is liquefied and stored in depleted oilfields under the North Sea — but nothing into recycling carbon dioxide.

The group of researchers have developed a new class of catalysts for the conversion of CO -2 into commercially important cyclic carbonates, which can be used as electrolytes for lithium ion batteries; additives for petrol, diesel and aviation fuel; solvents; and in the production of polycarbonates and polyurethanes, and other commercial chemical processes.

Many of the processes envisaged for CCU require some energy input — but the report's authors note that this could be provided by renewable energy, especially when wind or solar plants are producing energy at times of low demand. In this way, producing fuels from CO -2 could effectively be a way of storing renewable energy in another form.

However, the costs are still high for many of the potential applications of waste CO -2— about 10 times too expensive in the case of algae, for example. Much more investment is needed to bring down the costs, and putting a sizeable price on carbon dioxide emissions would also help.