The world’s largest plant designed to suck carbon dioxide out of the air and turn it into rock has started running, the companies behind the project said on Wednesday. …Constructed by Switzerland’s Climeworks and Iceland’s Carbfix, when operating at capacity the plant will draw 4,000 tonnes of carbon dioxide out of the air every year, according to the companies. …The plant cost between US$10 and 15m to build. To collect the carbon dioxide, the plant uses fans to draw air into a collector, which has a filter material inside. Once the filter material is filled with CO2, the collector is closed and the temperature is raised to release the CO2 from the material, after which the highly concentrated gas can be collected. The CO2 is then mixed with the water before being injected at a depth of 1,000 metres into the nearby basalt rock where it is mineralised.