In addition to reducing emissions, can we also ‘capture’ the carbon dioxide that has already been produced? The answer is: Yes! CCUS and DAC technologies are becoming the ‘carbon capture tools’ to combat climate change.
When we talk about addressing climate change, ’emission reduction’ is undoubtedly the core keyword. However, the reality is that some important industrial processes (such as cement and steel production) are difficult to completely eliminate carbon emissions in the short term, and the excess carbon dioxide already present in the atmosphere also needs to be removed. At this point, Carbon Capture, Utilization, and Storage (CCUS) and its important branch—Direct Air Capture (DAC) technology—take center stage.
01CCUS: Finding a ‘Home’ for Carbon Dioxide
Imagine the billowing smoke emitted from a factory chimney, which contains a large amount of carbon dioxide. CCUS technology acts like a large net, aiming to ‘capture’ the carbon dioxide produced by these industrial emission sources.
1. Capture (Capture): This is the first step. Using physical or chemical methods (such as absorption, adsorption, membrane separation, etc.), carbon dioxide is separated and purified from the mixed gases emitted by factories. This usually occurs at the source of emissions (such as power plants, chemical plants, cement plants).
2. Transport (Transport): The captured high-concentration carbon dioxide needs to be transported to a suitable location. This is typically done through pipelines (similar to natural gas pipelines) or by ships and vehicles.
3. Utilization or Storage (Utilization/Storage):
Utilization: Treat carbon dioxide as a resource! It can be injected into oil fields to help increase oil recovery, used to produce plastics, fuels (such as synthetic aviation fuel), fertilizers, carbonated beverages, or even to cultivate algae or produce building materials.
Storage: Safely ‘lock’ carbon dioxide deep underground. It is usually injected into carefully selected geological formations with good sealing properties, such as depleted oil and gas fields, saline aquifers, or unmineable coal seams, isolating it from the atmosphere permanently.
In simple terms, the core idea of CCUS is: do not let the carbon dioxide emitted from industrial processes enter the atmosphere, but rather ‘turn waste into treasure’ or ‘bury it deep underground.’
02DAC: ‘Requesting’ Carbon Directly from the Air
CCUS mainly targets concentrated, high-concentration point sources of emissions (such as chimneys). So, can we ‘capture’ the carbon dioxide that is already dispersed in the air at a very low concentration (about 0.04%)? Direct Air Capture (DAC) technology provides a positive answer!
1. Principle Differences: DAC captures carbon dioxide directly from the ambient air. This is fundamentally different from the source capture of CCUS. The concentration of carbon dioxide in the air is extremely low, making capture much more difficult, akin to finding a needle in a haystack.
2. Core Technology: DAC technology typically relies on special adsorbent materials (such as solid amines or new metal-organic framework materials, MOFs) or absorbent solutions (such as strong alkaline solutions). Air is drawn into the device by large fans, coming into contact with these materials, and carbon dioxide is selectively captured. Subsequently, pure carbon dioxide is released through heating (thermal method) or by changing other conditions (such as humidity).
3. Key Advantages:
(1)Flexible Deployment: DAC devices can theoretically be installed anywhere there is air and energy, without relying on specific industrial emission sources. Urban rooftops, deserts, and abandoned lands can all become ‘carbon capture stations.’
（2）Handling Historical Emissions: It can remove carbon dioxide that already exists in the atmosphere, which is a key means to achieve ‘negative emissions’ and offset emissions that are difficult to eliminate.
（3）Geographical Independence: Capture devices can be built near storage sites or areas rich in renewable energy, optimizing overall efficiency.
In simple terms, DAC is like an ‘air purifier,’ but its core goal is specifically to ‘capture’ carbon dioxide molecules from the air.
03Challenges and Breakthrough Directions for DAC
Although the prospects are broad, DAC technology also faces significant challenges, mainly focused on energy consumption and costs:
1. Energy Consumption Issues: Capturing carbon dioxide from thin air requires enormous energy, especially during the desorption (regeneration) step to release carbon dioxide from the adsorbent/absorbent. This has historically been the biggest bottleneck in DAC development.
2. High Costs: High energy consumption directly leads to high costs. Reducing the cost of capturing each ton of carbon dioxide is the core goal of DAC technology commercialization.
To this end, scientists and engineers are seeking breakthroughs in multiple directions:
1. Material Revolution: Developing new adsorbent materials with greater adsorption capacity, higher selectivity, and lower regeneration energy consumption (such as MOFs).
2. Process Optimization: Improving the way air contacts the materials, regeneration processes (such as utilizing waste heat, low-pressure steam, renewable energy electricity), and designing more efficient modular systems.
3. Energy Integration: Closely integrating DAC facilities with cheap, abundant renewable energy (such as solar and wind), utilizing their ‘excess’ electricity to significantly reduce operational costs and carbon emissions.
4. Scale Effects: As technology matures and factory scales expand, unit costs are expected to decrease significantly.
5. Intelligence: Utilizing artificial intelligence to accelerate the screening of new materials and optimize system operating parameters.
04CCUS and DAC: Complementary Rather Than Substitutes
CCUS and DAC are not in competition; rather, they are complementary tools in the ‘toolbox’ for addressing climate change:
1. CCUS: More suitable for handling large, concentrated, high-concentration industrial emission sources. It can quickly and effectively prevent new carbon dioxide from entering the atmosphere.
2. DAC: Excels at dealing with dispersed source emissions (such as transportation and agriculture) and historical emissions, achieving true ‘negative emissions.’ It provides a pathway for addressing the most challenging areas of emission reduction.
05Application Scenarios: The ‘Rebirth Journey’ of Carbon
Their common goal is: to reduce the net increase of carbon dioxide in the atmosphere, or even achieve a net reduction.
The captured carbon dioxide (whether from CCUS or DAC) is no longer ‘waste,’ but a valuable resource or ‘inventory’ that needs safe disposal:
1. Geological Storage: Permanently stored safely deep underground.
2. Resource Utilization (CCU):
(1) Enhanced Oil Recovery: Injecting carbon dioxide into oil fields to displace more crude oil (but attention must be paid to lifecycle emissions).
(2) Chemical Raw Materials: Synthetic fuels (such as aviation fuel), plastics, chemicals, fertilizers.
(3) Building Materials: Injecting into concrete for curing, or producing calcium carbonate aggregates to achieve permanent carbon fixation.
(4) Food and Beverages: Used for carbonated drinks and food preservation.
(5) Synthetic Fuels: Combined with green hydrogen to produce carbon-neutral e-fuels.
3. Preparation of High-Value Materials: Such as carbon nanotubes, graphene, etc.
06Future Outlook: An Indispensable Climate Map
With rapid technological development, energy consumption and costs are quickly decreasing. CCUS and DAC, especially DAC, are moving from laboratory and demonstration projects to larger-scale commercial deployment.
They are widely regarded as one of the key technologies essential for achieving global net-zero emissions goals. Especially before the complete phase-out of fossil fuels, CCUS can significantly reduce emissions in key industries; while in the future, DAC will be the core means to balance remaining emissions, achieve negative emissions, and ultimately reduce atmospheric carbon dioxide concentrations.
From locking the ‘carbon soot’ in chimneys to capturing ‘carbon molecules’ in the air, humanity’s wisdom in addressing climate change is continuously upgrading. CCUS and DAC technologies are paving a path for us to transform carbon dioxide from a ‘climate burden’ into a ‘usable resource’ or safe ‘inventory.’ Although challenges remain, technological advancements give us reason to believe that the era of actively ‘managing’ atmospheric carbon content is approaching. Perhaps in the near future, the ‘carbon capture stations’ scattered everywhere will become a new landscape of harmony between humanity and the Earth, just like solar panels and wind turbines.
Editor-in-Chief: Zero Carbon Economy Service Center
Reviewed by: Zhao Xinyuan
Edited by: Guo Haizhong
Qinghai Carbon Valley Information Technology Co., Ltd. was established in 2021, and its business covers cutting-edge research on low-carbon technologies, carbon sink development, precise carbon asset trading, green finance innovation practices, and digital deep development across multiple sectors. The core structure is supported by the Zero Carbon Economy Service Center and the Carbon Neutral Technology Laboratory, dedicated to providing comprehensive technical and service solutions for dual carbon goals, based on self-developed digital platforms for zero-carbon big data management, enterprise carbon footprint tracking and operation, park carbon emission monitoring and management, and comprehensive carbon asset operation management, covering aspects such as corporate carbon inventory, carbon footprint, and park carbon emission monitoring, fully empowering the construction and operation of zero-carbon factories and promoting industrial green sustainable development.If you are interested in gaining a deeper understanding or collaborating with us, we welcome your inquiries at any time. Contact: Dong Ping: 15897189181 Pan Junjie: 17697037777 Deng Jifei: 15597026883 Zhao Xinyuan: 13099791112 
Scan the QR code to get
more exciting content
Carbon Valley Technology
Disclaimer: All content published by this public account, including but not limited to text, images, audio, video, charts, logos, identifiers, advertisements, trademarks, trade names, domain names, software, programs, etc., unless otherwise specified, is sourced from the internet or user submissions, and the copyright belongs to the original author or source. We are committed to protecting the copyright of the original authors, and if there are any copyright issues, please contact us in a timely manner for resolution.