Emission control: Turning carbon trash into treasure

Emission control: Turning carbon trash into treasure - New Scientist

IT'S LIKE standing at the edge of a giant patchwork quilt. Stretching into the distance are broad bands of bright yellow alternated with patches of delicate white, all beneath a vast glass roof. This greenhouse full of flowers is just one of hundreds that dot the Dutch coast, where row after row of chrysanthemums, orchids and roses are fed carbon dioxide-enriched air, helping them to grow up to 30 per cent faster than normal.

While plenty of commercial greenhouses top up their air with extra CO2, what is unusual about this one is where its CO2 comes from. Until a few years ago, the greenhouse's operators used to burn natural gas for the sole purpose of generating CO2. Today it is piped from a nearby oil refinery. Each year, 400,000 tonnes of CO2 are captured and then piped to around 500 greenhouses between Rotterdam and The Hague, where it is absorbed by the growing plants before they are shipped for sale around the world (see "Cash for carbon").

As governments ramp up their efforts to cut carbon emissions, carbon capture is moving closer to the top of the agenda. The current plan to deal with all of our excess CO2 is to just pump the stuff underground - a kind of landfill for gases. Looking at this carpet of flowers, it is hard not to think that we are going about this in the wrong way. Shouldn't we look to pioneering schemes like the Dutch greenhouses to find ways to recycle the captured CO2 instead?

It turns out that a growing number of researchers, start-ups and even industry giants are also beginning to think like this. And not just for growing flowers; they believe whole cities could one day be built and powered with the help of exhaust fumes.

"It's time we stopped thinking of CO2 solely as a pollutant and viewed it as a valuable resource," says Gabriele Centi, a chemist at the University of Messina, Italy. "With carbon capture and sequestration, we'll essentially have a zero-cost feedstock."