Carbon Capture and Storage Advances and Challenges

Carbon Capture and Storage (CCS) technology helps mitigate global warming emissions by extracting CO2 from power plant and industrial exhaust streams before it escapes into the atmosphere, and then either storing it underground or incorporating it into products.

CCS facilities are already operating across the US with another 121 under construction or advanced development, yet CCS technology alone will not bring us close to Net Zero energy efficiency.

Advances

Carbon capture and storage (CCS), a technology capable of permanently storing emissions from power plants and industrial facilities underground, remains only partially used today due to its cost. As researchers continue their work to improve CCS efficiency and implement it more efficiently, costs may eventually decline.

At present, CCS works in three steps. First, carbon dioxide is collected from plant flue gas streams using chemical solvents; this method may be implemented during retrofits for existing power plants. Next step involves transporting it via pipelines or ships before injecting it into geological formations such as former oil and gas reservoirs, deep saline formations or coal beds for long term storage – these sites may include former reservoirs as well as deep saline formations or coal beds for injection into storage sites.

At present, there are 15 commercial CCS projects worldwide operating commercially, capable of capturing around 22 million tons per year or about 0.4 percent of United States annual carbon dioxide emissions.

CCS costs depend heavily on how much energy is necessary to capture and transport carbon dioxide. Some sources, like ammonia and ethanol production, require low capture costs; fossil fuel combustion results in higher costs.

Scientists and engineers are working hard to reduce the costs of carbon capture and storage (CCUS). To do this, they are developing more efficient carbon dioxide capture and transport processes as well as technologies that use less electricity to power these processes.

Carbon capture technology could also represent an innovative development. “Blue hydrogen” production involves splitting natural gas into hydrogen and carbon dioxide via steam methane reforming or auto-thermal reforming; unlike traditional combustion which produces greenhouse gas emissions, blue hydrogen produces near-zero emissions.

Federal funding for research into carbon capture and storage has seen a dramatic surge in recent years, with Congress increasing support annually for this effort. This has greatly accelerated development, though still not widely adopted due to costs related to carbon dioxide capture and transport; availability of other clean energy resources; or state and local regulatory barriers.

Challenges

Carbon capture and storage (CCS) technology could play an essential part in meeting global climate targets, according to experts. But its development and deployment pose unique set of challenges.

CCS technology can reduce CO2 emissions from power stations and industrial processes like steel and cement production. There are various techniques available for doing so; post combustion and oxyfuel technologies may be retrofitted into existing plants while pre-combustion technology would work better with new build power stations.

No matter the method chosen, carbon dioxide will typically be stored underground in geological formations for decades or centuries. While risk of leakage and other environmental impacts associated with CCS remains significant, its environmental impacts should diminish over time as industry matures.

Some CCS facilities also repurpose captured CO2 for use in other industrial processes, including enhanced oil recovery and chemical products; research is currently ongoing to discover additional applications of this technology. Some companies are even taking measures directly to remove carbon from the atmosphere through forestation practices or interventions designed to capture and store it as organic matter.

While cost remains an obstacle for implementing CCS, future improvements should reduce these expenses over time. Bloomberg New Energy Finance reported recently that carbon capture’s learning curve will help bring costs down in coming years.

At present, 51 large-scale carbon capture and storage projects exist worldwide, 19 operating and 4 planned. Of these 51 projects, three of the GCC countries stand out; Qatar boasting its 2.2Mtpa LNG liquefaction plant; Saudi Arabia hosting 800Ktpa Hawiyah NGL CCS project while Abu Dhabi housing 800Ktpa Al Reyadah steel project both of which store over 3.7 Million Tonnes per annum of CO2.

Longer-term, many experts see carbon capture and storage (CCS) deployment as necessary to meet climate targets. This is particularly applicable when discussing fossil fuels as a major energy source – where CCS plays an integral part in helping fossil fuels continue providing power without increasing climate risks.

Costs

Carbon capture and storage (CCS) technologies reduce CO2 emissions by collecting it from the air or industrial processes and storing it underground, acting as an essential part of any future energy mix that helps the world meet climate targets. Leading organizations including International Energy Agency, IRENA and Bloomberg New Energy Finance all depend on an expansion of CCS technologies rapidly in order to meet climate targets.

Estimates of the costs to capture and store one ton of CO2 can vary widely, depending on engineering assumptions and the process being captured. As a rule of thumb, however, generally speaking the higher your exhaust gas volume for capture the lower the per-ton cost will be.

Chemical composition also impacts costs for CO2 capture; researchers from the Pacific Northwest National Laboratory at U.S. Department of Energy in collaboration with Electric Power Research Institute and Fluor Corp conducted a recent study which determined that EEMPA, currently being tested at PNNL, can capture CO2 at significantly lower costs than current commercial technology solutions.

CCS methods currently being developed have the potential to significantly decrease costs, from pre-combustion capture technology that involves gasifying fuel and separating out CO2 prior to combustion, through post-combustion capture using energy efficient membrane filters on flue gases from fossil fuel power plants, to oxy-fuel combustion which combines coal with air in a near pure oxygen environment to produce cleaner fuel than usual.

CCS may only currently make up a minor part of global energy systems, yet its potential to make an impactful statement in future may far outstrip its current role. CCS holds promise as an affordable way of supporting renewable energies while making zero carbon future more accessible by helping us bridge between them and traditional fossil fuels.

Of the 10 methods explored in this report, six are projected to become commercially viable and profitable by 2050: CO2-EOR, cement building materials, bioenergy with carbon capture and storage (BECCS), forestry practices that promote soil carbon sequestration, and biochar. Although each approach poses challenges regarding its scalability and permanence, these approaches can help reduce barriers towards reaching Net Zero.

Policy

Carbon capture and storage technologies hold great promise to reduce emissions from power plants and industrial facilities, by collecting carbon dioxide emissions from exhaust systems at these facilities and storing it underground. However, at present these technologies are used only limitedly within the US; their deployment will depend upon numerous factors which will ultimately determine its success.

Current technologies for CO2 capture can capture 90 percent or more of carbon found in flue gas, and other methods exist for collecting it directly from ambient air; these processes, however, tend to be much more energy intensive.

In order for these technologies to become profitable, costs must be kept as low as possible. To meet this objective, researchers are developing new technologies which reduce carbon capture costs while making them more energy-efficient.

Development of more cost-effective systems for transporting and storing captured CO2 could further decrease costs associated with CCUS. Most CCS projects currently ship their captured CO2 to oilfields for use in enhanced oil recovery, which may be cheaper. Unfortunately, this practice may lead to contamination of groundwater. Furthermore, leakage or ruptures in pipelines or pipes expose it to environmental risks.

At last, there remains the issue of geologic storage capacity to store all the CO2 captured through CCUS. Unfortunately, there is no definitive answer as researchers continue to study long-term geological formation storage capacities.

Regardless of these challenges, interest in carbon capture and storage (CCUS) has grown. In the US alone there are six operating CCUS facilities and 11 in construction or advanced development; estimates by the International Energy Agency show CCUS could provide 14 percent of emissions reductions needed to reach global climate targets.

For this technology to truly contribute significantly towards mitigating climate change, it must be widely adopted. Unfortunately, barriers such as high costs for the process remain; to overcome them federal and other policymakers can take several steps that can increase its use.