Carbon capture and storage (CCS) technologies have long been recognized for their ability to significantly lower emissions from fossil fuel power plants as well as industrial processes like steel production, cement manufacture and ammonia/ethanol production. CCS also complements renewable sources like wind and solar by producing low-carbon electricity on demand when winds are less prevalent or the sun doesn’t shine as brightly.
Capture
Burning fossil fuels (such as coal, oil and natural gas) and running certain industrial processes ( such as cement and steel making) emits carbon dioxide into the air – leading to global warming over time. CCS offers an effective means of significantly reducing these emissions as well as decarbonising “hard-to-decarbonise” sectors like heavy industry which do not yet have an ideal alternative.
CCS (or CCUS as it is sometimes known) involves extracting CO2 from industrial exhaust gases or directly from the atmosphere before its release into the atmosphere. Once captured, this CO2 is transported and stored deep underground. At present there are 77 commercial CCS projects worldwide operating which capture and store around 50 million tonnes annually (which would equal the annual emissions from Greece or Peru), supported by over 600 projects for development and research.
Separation
CO2 that’s captured from power plants or industrial processes such as steel and cement production is separated from other gases using various technologies. These include:
Liquified carbon dioxide is then transported to storage sites – typically saline aquifers or depleted oil and gas fields, depending on its form – usually 0.62 miles (1km).
Once stored safely, scientists are working hard on developing uses for captured CO2. Current applications include enhanced oil recovery and greenhouses for plant cultivation.
Captured CO2 can also be used to produce building materials, plastics and futuristic materials like graphene. Companies are working on developing these technologies; however, in order for CCS to become widespread deployment it needs to become economically feasible due to adding CCS systems onto existing power plants incurring substantial additional costs which has delayed widespread deployment so far – yet CCS may play a pivotal role in helping us meet climate goals more quickly than previously believed.
Transport
At power plants and industrial processes, CO2 must be transported and stored at its final destination. However, transporting CO2 presents many unique challenges; compression and chilling of CO2 require considerable energy; special pipelines must also be built to carry this highly pressurized fluid at low pressures and temperatures.
carbon dioxide is then injected into underground geological formations for long-term storage, similar to how oil and gas reservoirs are drilled and managed. Storage sites include saline aquifers, depleted oil fields, unmineable coal beds or basalt formations.
CCS remains an effective technology, but its costs continue to make it unsuitable for many projects that could significantly lower CO2 emissions. Furthermore, its use increases the costs associated with producing clean electricity generated from fossil fuels (like coal or natural gas with CCS) when compared with renewable wind or solar power generation technologies. To be effective over time CCS must be combined with other mature technologies like renewables or nuclear in order to meet significant portions of our energy requirements.
Storage
Carbon capture and storage (CCS) technology works by diverting carbon dioxide emissions from smokestacks, compressing it, transporting it underground for storage permanently, then returning it. CCS plays a central role in energy systems designed to lower greenhouse gas emissions while being applicable across power generation, industrial production, transportation technologies as well as other industries.
CO2 captured from power plants and other facilities is stored permanently by injecting it into deep rock formations such as saline aquifers or depleted oil and natural gas reservoirs for permanent storage. Alternatively, EOR may be utilized, or converted to low-carbon products such as concrete additives and fuels for low carbon emission reductions.
CCS could play an essential part in mitigating CO2 emissions from fossil fuels and hard-to-decarbonise sectors such as steel production, cement manufacturing and chemical manufacturing. But it must be used alongside other measures to limit global temperature rises; CCS could enable such drastic cuts under the Paris Agreement.