How would the synthetic tree remove carbon dioxide from the air?
L: The device itself would look something like goalposts with venetian blinds. It would be equipped to use liquid sodium hydroxide, which converts to sodium carbonate as it pulls CO2 from the wind stream. How much could one tree remove? L: The unit, which has a collection area of 50 meters by 60 meters, could gather 90,000 tons of CO2 a year. That means one synthetic tree could handle an amount equivalent to the annual emissions of 15,000 cars. How many of these synthetic trees worldwide would be needed to soak up the 22 billion tons of CO2 produced annually from fossil fuels? L: About 250,000. To make this process efficient, you need to recycle the sodium hydroxide, which means you need to take the absorbed carbon back out. How do you do that? L: You percolate the liquid sodium carbonate over solid calcium hydroxide, and the calcium catches the carbon. So you have taken the carbon out of your sodium hydroxide, and you can use it again. But then you have to get the carbon out of the ca
