While meaningful progress demands a committed transition from non-renewable energy, developments in carbon capture technologies promise to be a comprehensive solution. However, it’s imperative to balance this potential against its many limitations and hindrances.
Human activities and their associated greenhouse gas emissions are the leading factors driving global climate change. According to Climate Watch, 10 countries are responsible for 60% of these emissions, with the energy sector accounting for three-quarters.
Carbon capture and storage technologies seek to address these emissions by directly extracting carbon dioxide from the atmosphere or another source and storing it underground or diverting it for future use, such as concrete or fuel production.
Modern CO2 capture methods include the following.
Pre-combustion: Instead of fully combusting the fuel, the reformation or gasification process converts it to a carbon-and-water mixture.
Post-combustion: This process removes CO2 from flue gas after cleansing it to eliminate pollutants.
Oxy-combustion: This simpler, more cost-effective technique involves burning fuel in at least 95% pure oxygen to create a concentrated CO2 stream.
Choosing a carbon capture strategy depends on the fuel type, desired CO2 purity and available infrastructure. Industries must consider the technological and economic feasibility and specific project constraints to select the most efficient approach.
Carbon capture technologies include use and storage. For example, it’s possible to sequester CO2 from large industrial facilities like coal-fired power plants, refineries and factories, or even extract emissions directly from the air. Carbon capture storage stores CO2 underground in empty oil and gas reservoirs, deep saline formations, basalt formations and coal beds unsuitable for mining. The goal is to prevent CO2 from leaking back into the atmosphere.
Currently, the U.S. Department of Energy, Office of Fossil Energy and Carbon Management and National Energy Technology Laboratory support several research initiatives studying the viability of CO2 storage. Researchers have completed several large-scale studies involving injecting CO2 deep into the ground. Similar projects are underway in Canada, Norway, China and Australia.
The International Energy Agency says 45 countries have CCU and CCS projects in development. With the completion of all projects, these technologies will be able to capture 400 metric tons of CO2 annually by 2030 — more than eight times what they do now. However, as of June 2023, only 20 carbon capture projects were under construction, far from achieving net-zero emissions.
Industries might also use sequestered CO2 for secondary applications, such as increasing oil production by injecting it into oil wells or carbonating food and beverages. Some may even gear it toward producing fuels, chemicals and building materials. According to researcher Mengwei Zhao, CO2 well injections could extend a pool’s lifespan by up to 84 years during oil recovery.
The renewable energy sector is among the fastest-growing global markets, with experts estimating it will reach $259 billion by 2025 and $1.8 trillion by 2027. Renewable-based electricity supply increased from 20% in 2011 to 29% in 2021, and fossil fuel consumption declined from 68% to 62%, validating this trend.
Industries can apply clean energy to carbon capture and storage technologies to decrease their carbon footprint. Despite the challenge of intermittency in renewable production, energy storage developments may provide steady power for sequestration.
According to one study in which researchers combined renewable energy with CCU for sustainable fuels, the findings showed a 60% high energy efficiency and almost zero CO2 emissions at the plant, resulting in negative greenhouse gases. Scaling up may pose challenges, but the study demonstrated the potential for this approach.
The economic feasibility of CO2 capture technologies hinges on the cost of building each facility, operating expenses and the cost per ton of CO2 removed from the atmosphere. For instance, CCS outlays are between $15 and $130 per metric ton of CO2, while direct air CCS costs between $100 and $345.
Nations recognize the need for decarbonization, fostering collaboration to advance CCU and CCS solutions. For instance, the European Union’s Industrial Carbon Management Strategy outlines widespread planning and investment in CO2 sequestration infrastructure. Bilateral agreements also position CO2 capture as a critical climate objective and energy security.
Additionally, governments can implement domestic regulations and incentives, forcing industries to take financial accountability for CO2 emissions and offering tax credits and carbon pricing to make this approach more attractive.
Though carbon capture technologies aim to benefit the environment, scientists can still improve their sustainability. For example, integrating CCS into a coal plant would increase water consumption by 55% and reduce plant efficiency by 45%.
The capture and transport stages also create harmful fossil fuel emissions, while there is always the risk of CO2 leakage. Studies show that these uncertainties could cause a 16% increase in global warming in a worst-case scenario.
Mitigating these impacts requires learning from projects early and enhancing the technology to manage future risks.
Carbon capture technologies are not a silver bullet, but it would be much harder to fight climate change and protect the future environment without these tools. Researchers must continue improving carbon capture techniques and accelerating the development of these solutions for a promising outlook.
