On Earth day, the world always talks of zero emissions and a greener world, which always gains significance. In a world where electric vehicles and renewable energy are among those helping stopping carbon emission, a new world of technology and approach is no doubt going to have its positive impacts on mother earth. And this is sucking CO2 emitted by us from the atmosphere and storing it.
The Direct Air Capture (DAC) could be a solution for combating carbon emissions. Let us look at what DAC IS.
WHAT IS DIRECT AIR CAPTURE?
DAC involves capturing carbon dioxide directly from the air and then permanently storing it. This means that there is no further emission of the stored CO2. A DAC plant in Iceland captures 4,000 tonnes of carbon dioxide a year and stores it in basalt, a type of volcanic rock. The CO2 then mineralizes over around 20 years, turning into stone in a natural reaction with the rock.
The captured CO2 can also be reused in other industries. In food processing, it can be used to carbonate drinks. And in aviation, it is being combined with hydrogen to create synthetic low-carbon fuel.
The DAC involves two technologies – liquid and solid. Liquid systems pass air through chemical solutions (e.g. a hydroxide solution), which removes the CO2. The system reintegrates the chemicals back into the process by applying high-temperature heat while returning the rest of the air to the environment. Solid DAC technology makes use of solid sorbent filters that chemically bind with CO2. When the filters are heated and placed under a vacuum, they release the concentrated CO2, which is then captured for storage or use.
WHERE ARE DAC FACILITIES NOW PRESENT?
As per the date from the International Energy Agency (IEA), 19 Direct Air Capture facilities are in operation across the world. Of these, 18 are in Canada, Europe and the United States. The world’s first large-scale plant is in development in the US. It will be able to capture up to one million tonnes of CO2 a year.
Big companies such as Microsoft, e-commerce company Shopily and reinsurance firm Swiss Re are starting to invest in DAC removal as a way to offset their carbon emissions
DAC’S POTENTIAL?
The IEA says that DAC technologies need to be capturing more than 85 million tonnes of CO2 in 2030, and then 980 million tonnes in 2050 to help the world reach net zero emissions by 2050. Though a uphill task, there is good news that governments all over are for this technology. The IEA says that governments have committed almost four billion dollars to develop and deploy DAC plants since the start of 2020. Australia, Canada, Japan and the United Kingdom are among the countries investing in DAC research and development.
OTHER CARBON REMOVAL OPTIONS
Other carbon removal options include nature-based solutions (e.g. afforestation, reforestation, and restoration of coastal and marine habitats), measures to enhance naturally occurring processes (e.g. land management approaches to increase the carbon content in soil, biochar) and other technology-based solutions such as bioenergy with carbon capture and storage (BECCS).
