CO2 capture in air
Schools were shut across India's capital on Friday as a noxious grey smog engulfed the megacity and made life a misery for its 30 million inhabitants. VIDEOGRAPHIC
Category
🗞
NewsTranscript
00:00 Reducing greenhouse gas emissions will not be enough to limit the rise in temperatures
00:12 to 1.5 degrees, the target of the Paris Agreement.
00:16 According to UN experts, it is necessary to use techniques for the elimination of carbon
00:20 dioxide, or CO2, in the air.
00:24 There are a dozen techniques, such as planting trees that absorb CO2, and ocean fertilization
00:30 to increase the ability of phyoplankton to absorb CO2.
00:33 But the technique attracting the most interest is direct CO2 capture in the air, in order
00:38 to transform it into rot, also known as carbon dioxide removal, or CDR.
00:43 The principle is to suck in air with a fan.
00:46 The air passes through a filter which, thanks to chemical processes, traps the CO2.
00:52 The purified air is then expelled from the rear of the fan.
00:56 The filter is heated to recover the CO2.
00:58 Dissolved in water, the CO2 is then injected deep into rocks between 800 and 2000 metres
01:05 deep.
01:06 In contact with the elements contained in the rock, the gas mineralizes in less than
01:10 two years, a process that when occurring naturally takes hundreds of thousands of years.
01:15 If theoretically CDR can be installed anywhere, this technique has significant limitations
01:20 for the moment.
01:23 It must be located near water resources, it is very energy intensive, and to be non-polluting
01:28 its power supply must come from renewable energy.
01:32 Current capacities are undersized.
01:35 The total amount of CO2 captured with CDR is measured in thousands of tons.
01:40 Billions of tons will have to be captured within 30 years.
01:44 This means an increase of at least five orders of magnitude.
01:48 Finally, the very low concentration of CO2 in the air, 0.041%, requires treating huge
01:56 quantities of air, which increases the cost of this process.
01:59 [Music]
02:01 [Music]
02:03 [Music]
02:05 [Music]
02:07 [Music]
02:09 [BLANK_AUDIO]