With some climate commentators suggesting that current action and targets to reduce global warming may not be enough, we look at how Direct Air Capture Technology (DAC) could help.
The Challenges
The world’s governments have set targets to reduce the amount of CO2 produced by human activities in order to at least slow and, hopefully, make headway in trying reverse the effects of global warming. However, some of the challenges include:
– Simply ending emissions may not even be enough to stabilise the climate.
– The world’s energy consumption is growing at round 2 per cent per year anyway.
– Not all CO2 emissions are from large, controllable sources e.g., power plants where CO2 can be captured as it comes out.
(DAC) Technologies
Direct air capture (DAC) technologies can be used to extract CO2 directly from the atmosphere using liquid and solid DAC systems. Liquid systems pass the air through chemicals (e.g., a hydroxide solution) to remove the CO2, whereas solid DAC technology uses ‘solid sorbent’ filters that chemically bind with CO2. Heating the filters and placing them under a vacuum then releases the concentrated CO2 so it can be captured and stored.
Technology Used At Carbon Capture Facilities
There are already 20 direct air capture (DAC) plants operating worldwide, capturing more than 0.01 Mt CO2/year. New advanced versions may able to capture even more. For example, the DAC 1 facility at Permian Basin in the US is due to go live in 2024 when it will become the world’s largest direct air capture (DAC) facility being able to eventually capture to 1.0 MtCO2 (0ne million tonnes)/year.
The Advantages
Some of the advantages of setting up plants/facilities that use DAC to remove CO2 from the air include:
– They can help tackle the less controllable sources of CO2 emissions e.g., cars, planes, and household emissions.
– CO2 removal plants can be set up close to where the CO2 needs to be stored.
– CO2 mixes quickly in the air so it doesn’t matter where in the world the CO2 is removed – the removal has the same impact.
– DAC helps to close the ’carbon loop’ i.e., CO2 is repeatedly captured and reused to avoid producing more.
Issues
Although DAC looks like being a helpful addition in the fight to stabilise the earth’s climate, some of the current issues in scaling it up include:
– The high cost of building CO2 removal facilities.
– The potential high energy usage by the facilities themselves.
Hope, Breakthroughs, and Alternatives
Despite the issues, progress is being made to address them, and alternative ideas for carbon removal and storage are surfacing regularly. For example:
– Arizona State University Professor Klaus Lackner’s use of ‘mechanical trees’/vertical columns of discs coated with a special chemical resin and the use of moisture in the process could reduce the energy requirements of CO2 removal at scale.
– Mineral sequestration is a method that uses calcium-rich minerals, of which there are large areas around the world, to permanently store large quantities of CO2.
– Underground saline aquifers are being used to store CO2.
– Rewards are now being offered to incentivise innovation in CO2 capture technology. For example, in February 2021, billionaire Tesla founder and SpaceX boss, Elon Musk, pledged to give a $100 (£73 million) prize to whomever comes up with the best technology to remove carbon dioxide (which is produced from fossil fuels) from the air.
What Does This Mean For Your Organisation?
Global warming and the greenhouse gas emissions, such as large quantities of CO2, which are causing the warming are everyone’s problem. It is likely to be the case that not enough is being done to reduce levels quickly enough so, if DAC and similar technologies can be shown to make a real difference, it makes sense that efforts and investments are fed into setting up CO2 extraction and storage plants. Progress is already being made in increasing their effectiveness e.g., the US plant that may be able to capture 0ne million tonnes per year when it goes live in 2024. These technologies should be viewed as one of many tools to be used and measures to be taken to dramatically reduce the amount of CO2 we produce globally, and we may still have some way to go towards motivating some of the biggest CO2 producing countries to take serious steps to cut emissions which is a vital step in the overall strategy of which DAC can also play a role.