How does Carbon Capture Work?

A very effective way of curbing climate change caused by carbon dioxide (CO2) released into the atmosphere is to capture and store it through a process called carbon capture.

The technique can absorb up to 90% of the CO2 produced while burning fossil fuels to produce power and in industrial activities like making cement.

What is Carbon Capture?

Carbon capture is a method of lowering carbon emissions, which may be essential in the fight against global warming.

It entails a three-step procedure that includes catching the carbon dioxide released during the production of electricity or other industrial processes, such as the production of steel or cement, transporting it, and then burying it deep underground.

Typically, CO2 is removed from sizable point sources like chemical plants or biomass power plants and then stored in subterranean geological formations.

To lessen the effects of climate change, it is important to stop the heavy industry from releasing CO2.

Long-term storage of CO2 is a relatively recent idea, even though it has been injected into geological formations for several decades for various purposes, including better oil recovery.

Before we discuss how does carbon capture work? Let’s look a little more at carbon capture and storage.

About Carbon Capture and Storage (CCS)

A significant byproduct of burning fuel in a coal, oil, or gas plant to produce electricity is the greenhouse gas carbon dioxide (CO2).

Using carbon capture and storage (CCS) technology, which uses subterranean rocks as “storage tanks,” is one way to keep carbon emissions in check.

How do these technologies function, though?

When fossil fuels are burned, a variety of gases are produced, including oxygen, nitrogen, and carbon dioxide (CO2).

The main goal of CCS is to prepare this CO2 for underground storage by selectively removing it from the gas mixture.

Read also: 6 Types of Solar Energy Storage Systems

How does Carbon Capture Work?

Three fundamental steps are commonly involved in carbon capture and storage:

  • Capture: The CO2 is removed from other gases produced during industrial operations, such as those at cement or steel plants, or coal- and gas-fired power plants.
  • Transport: Before being transported to a storage site, CO2 can be compressed into a liquid or maintained as a gas.
  • Storage: After arriving at the storage site, CO2 is then stored permanently by being injected into underground rock formations or another suitable location.

Here, we’ll look into these actions:

1. Capture

Carbon dioxide can be extracted either directly from the air or an industrial source (like a power plant).

For carbon capture, several technologies can be used, including membrane gas separation, adsorption, chemical looping, gas hydrate technologies, and absorption.

The best place to capture CO2 is right at the source, which includes industries that generate large amounts of CO2 emissions, biomass or fossil fuel energy plants, natural gas electric power stations, natural gas processing facilities, synthetic fuel plants, and fossil fuel-based hydrogen production facilities.

As was already noted, CO2 can be extracted directly from the air, although this method is less efficient and more challenging than extraction at the source.

Carbon can also be captured from organisms that digest sugars to make ethanol, among other sources.

This produces pure CO2, which can be poured into the ground in amounts slightly less than ethanol by weight.

The three main technologies for carbon capture are,

  • Pre-Combustion
  • Post-Combustion
  • Oxyfuel Combustion

1. Pre-Combustion

Following the combustion of fossil fuel, CO2 must be eliminated.

This procedure, which is typically utilized at power plants, involves capturing carbon dioxide from flue gases emitted by power plants or other places that produce carbon emissions.

This capture method’s technology can be integrated into newly constructed plants as well as retrofitted to existing power plants.

2. Post-Combustion

This is frequently applied in the chemical, gaseous fuel, fertilizer, and power generation industries.

The approach involves employing a gasifier, for instance, to partially oxidize the fossil fuel.

As a result, syngas is produced (CO and H2), which interacts with steam (H2O) to produce CO2 and H2.

The CO2 can then be recovered from an exhaust stream that is quite clean, and the H2 can be used as fuel without emitting any carbon dioxide (CO2).

It is ideal to include this method in brand-new constructions.

3. Oxyfuel Combustion

Oxyfuel combustion calls for burning the fuel in oxygen as opposed to air.

To avoid high flame temperatures, cooled flue gas is recirculated and pumped back into the combustion chamber.

The major components of this flue gas are carbon dioxide and water vapor.

Cooling allows the water vapor to condense, leaving almost entirely pure carbon dioxide steam that may be collected.

While the enormous amount of carbon dioxide that is caught makes this process characterized as “zero emission,” some of it still enters the condensed water, which must be properly treated or disposed of to prevent it from entering the environment.

There are several different types of carbon capture technology, including:

  • Absorption
  • Adsorption
  • Calcium Looping
  • Chemical Looping Combustion
  • Cryogenic
  • Membrane
  • Multiphase Absorption
  • Oxyfuel Combustion

The most expensive component of CCS is capture, which makes up about two-thirds of the whole cost.

This is mainly because the technologies for the transport and storage procedures have already been established, whereas there is still room for improvement in the capture operations.

2. Transport

The CO2 must be delivered to a storage location after it has been caught.

While ships can occasionally be a more affordable option, especially for long-distance transportation, pipelines are typically the most cost-effective way to move significant amounts of CO2.

Rail and tanker trucks are other methods for moving CO2, but they are about twice as expensive as pipelines or shipping.

3. Storage

For the long-term storage of CO2, a variety of techniques have been investigated, including geological storage (as a gas or a liquid), mineral-based solid storage through a reaction with metal oxides to produce stable carbonates, using carbon dioxide-degrading bacteria or algae to break down the CO2, and even ocean-based storage.

However, because this kind of storage could significantly worsen ocean acidification, it has been rendered banned under the London and OSPAR agreements.

Read also: Geothermal Energy Advantages and Disadvantages

Carbon Capture Methods

The potential size and expense of several CO2 usage methods are shown here.

All things considered, CO2 utilization has the potential to function at a huge scale and at a low cost, indicating that it could be a major business in the future.

The scale assessments for 2050 result from a procedure involving structured estimations, professional advice, and extensive scoping reviews.

Our costs are presented as the interquartile ranges from techno-economic studies gathered via scoping reviews and are breakeven costs, which means they take into consideration revenue.

This indicates that the costs are outdated and are likely to undervalue the paths’ capacity for achieving economies of scale.

Under the assumptions of today, processes with negative costs are profitable.

  • CO2 Chemicals
  • CO2 fuels
  • Microalgae
  • Concrete Construction Materials
  • Enhanced Oil Recovery using CO2 (EOR)
  • Bioenergy with Carbon Capture and Storage (BECCS)
  • Enhanced Weathering
  • Forestry
  • Soil Carbon Sequestration
  • Biochar

1. CO2 Chemicals

In 2050, 0.3 to 0.6 GtCO2 could be used annually for the production of methanol, urea (for use as fertilizer), or polymers (as durable products) at costs ranging from -$80 to $300 per tonne of CO2.

This would be accomplished by reducing CO2 to its parts using catalysts and using chemical reactions.

2. CO2 fuels

Hydrogen and CO2 may be combined to create hydrocarbon fuels like methanol, synfuels, and syngas, which can be used in existing transportation infrastructure.

However, the costs at this time are significant.

In 2050, CO2 fuels might use 1 to 4.2 GtCO2 annually, but costs could reach $670 per tonne.

3. Microalgae

The focus of research efforts has long been on using microalgae to fix CO2 at high rates and then processing the biomass to produce goods like fuels and high-value compounds.

Costs for producing a tonne of CO2 range from $230 to $920, while utilization rates in 2050 may range from 0.2 to 0.9 GtCO2 annually.

4. Concrete Construction Materials

CO2 can be utilized in the production of aggregates or to “cure” cement.

By doing this, ordinary cement that emits heavily could be replaced while storing some CO2 over the long term.

We project that in 2050, with current costs ranging between -$30 and $70 per tonne of CO2, there will be a potential for utilization and storage of between 0.1 and 1.4 GtCO2 due to rising global urbanization and a difficult regulatory environment.

5. Enhanced Oil Recovery using CO2 (EOR)

Oil production may be increased by adding CO2 to oil wells.

However, crucially, it is feasible to operate EOR so that more CO2 is injected and stored than is produced when the ultimate oil product is consumed.

Normally, operators maximize the amount of oil and CO2 recovered from the well.

We project that, in 2050, 0.1 to 1.8 GtCO2 might be used and stored in this manner for prices between -$60 and -$40 per tonne of CO2.

6. Bioenergy with Carbon Capture and Storage (BECCS)

In the case of bioenergy with carbon capture, the operator grows trees to absorb CO2, uses bioenergy to generate electricity, and then sequesters the emissions that arise.

We calculate utilization costs of between $60 and $160 per tonne of CO2 using a reasonable estimate of energy income.

In 2050, this method might be used to store and use between 0.5 and 5GtCO2 annually.

This deployment level considers other sustainability goals and is lower than certain BECCS estimations that were previously published.

7. Enhanced Weathering

Rocks like basalt may quickly create stable carbonate from atmospheric CO2 when they are crushed and spread out on land.

On agricultural lands, doing this is probably going to increase yields.

We haven’t provided 2050 projections for this pathway because it is still in its very early stages.

8. Forestry

A commercially useful product that can store CO2 in buildings and replace cement use is timber, which can come from both new and old forests.

We predict that, at costs of between -$40 and $10 per tonne of CO2, up to 1.5GtCO2 might be used in this way in 2050.

9. Soil Carbon Sequestration

Techniques for managing land that sequesters carbon in the soil can increase agricultural output while simultaneously storing CO2 in the soil.

At costs of between $90 and $20 per tonne of CO2, we predict that the CO2 used in the form of that enhanced output might range from 0.9 to 1.9GtCO2 annually in 2050.

10. Biochar

Biochar is biomass that has been burned at high temperatures with little oxygen, or “pyrolyzed” biomass.

Adding biochar to agricultural soils has the potential to boost crop yields by 10%, however, it is extremely difficult to produce a consistent product or foresee how soil will react.

We predict that biochar might use between 0.2 and 1GtCO2 in 2050, with costs of about -$65 per tonne of CO2.

Read also: How Does Hydroelectric Energy Work

Best Carbon Capture Companies

The struggle to minimize carbon emissions from current sources of emissions and address the issue of past carbon emissions that are already present in our atmosphere is being led by these carbon capture firms.

According to MindsetEco, the 7 Leading Carbon Capture Companies are:

  • Carbfix
  • Global Thermostat
  • CO2 Solutions by SAIPEM
  • Net Power
  • Quest Carbon Capture and Storage by Shell
  • Climeworks
  • Carbon Engineering

1. Carbfix

Carbfix is headquartered in Iceland, and since 2014, they have operated at the Hellisheii Power Plant.

They were founded as a Reykjavik Energy (OR) subsidiary in 2019 and have been functioning independently since January 2020.

Their goal is to quickly accumulate one billion tons of permanently stored CO2 (1 GtCO2) to become a “key instrument in tackling the climate issue.”

Location: Reykjavik, Iceland

Established: 2012-2014 Pilot Project, 2014 to Current – operational plant at the Hellisheiði Power Plant and taking on new projects from 2020.

2. Global Thermostat

In 2010, Global Thermostat was founded in the US.

Their proprietary process directly extracts carbon from the atmosphere or industrial emissions and concentrates it.

Then it can be sold to different industries so they can utilize it again during production.

With this strategy, carbon capture becomes a lucrative undertaking rather than a cost to the emitting entity.

Additionally, it opens up the possibility of running a business for those who want to collect atmospheric carbon and sell it to sectors of the economy that want it.

Their modular design eliminates the geological restrictions that carbon storage systems must contend with and enables the construction of individual plants in any location.

Location: New York, United States

Established: 2010

3. CO2 Solutions by SAIPEM

In Quebec, Canada, CO2 Solutions by SAIPEM is headquartered.

Since their founding in 1997, they have created a special carbon capture technique that was motivated by the human lung.

All animals and plants include the natural enzyme carbonic anhydrase (CA), which is used in their technologies in an industrial form.

By controlling the carbon we breathe in, the enzyme enables us to breathe.

They have developed and copyrighted their technique over the past 20 years to enable the capture of up to 99.95 percent of carbon from industrial smokestacks and power plant emissions.

After that, the carbon is moved to nearby businesses that require it, such as agricultural greenhouses.

Location: Quebec, Canada

Established: 1997 (first commercial application in 2016)

4. Net Power

The headquarters of Net Power is in Durham, North Carolina, in the US.

Their technological advancements started in 2008 with a project to create inexpensive, carbon-free power.

The Allam-Fetvedt Cycle, which they created, led to the creation of NET Power in 2010.

Through natural gas power facilities that are semi-closed loops and CO2-powered with the Allam-Fetvedt Cycle, NET Power hopes to achieve all of the 2050 power goals.

Location: Durham, North Carolina, United States

Established: 2010

5. Quest Carbon Capture and Storage by Shell

In Canada’s Alberta, at the Scotford Upgrader power plant, Shell has a carbon capture facility called Quest.

Shell, which owns and operates it, uses it to reduce the carbon emissions from the power plant that transforms bitumen from sand into oil.

After being piped to a different place, the carbon is then injected 2 kilometers below into porous geologic formations, where it remains indefinitely.

Location: Edmonton, Alberta, Canada

Established: 2015

6. Climeworks

Founded in 2009, Climeworks is a carbon capture business with headquarters in Zurich, Switzerland.

But since 2007, their technology has been under development.

Climeworks is the biggest provider of direct air capture services for carbon capture, and they are currently constructing a new direct air capture facility in Iceland named Orca.

They are capturing CO2 with their method and storing it underground with Carbfix’s technology.

The facility will be the largest climate-positive facility in the world when it can capture 4000 tons of CO2 annually.

Additionally, they operate around 6500 smaller plants with different partners.

Location: Zurich, Switzerland

Established: 2009

7. Carbon Engineering

In 2009, Carbon Engineering was founded in Calgary, Canada.

In 2015, they relocated to Squamish, where they set up a pilot plant to directly capture carbon from the atmosphere and either safely store it underground or turn it into synthetic fuel.

Since then, Carbon Engineering has collaborated with businesses in the US and the UK as well as businesses worldwide to collect and store atmospheric carbon and to create clean fuel from the carbon they sequester.

Location: Squamish, British Colombia, Canada

Established: 2009

Read also: Pros and Cons of Electric Cars on the Environment

Conclusion

Can carbon capture reduce climate change?

This is the main question, but CCS is unquestionably a crucial instrument in combating climate change as it is now the best choice for lowering emissions from significant industrial uses.

CCS can produce “negative emissions” and remove CO2 from the environment when used in conjunction with bioenergy technologies for power production, such as bioenergy with carbon capture and storage (BECCS).

To keep temperature increases to a minimum and begin reversing climate change, carbon must be removed from the atmosphere.

To reach the capacity predicted by the Global CCS Institute, which states that we will need 2,500 CCS systems by 2040, with each one absorbing about 1.5 million tonnes of CO2 annually, there is still a lot of work to be done.

Before we can reach that stage, we get more familiar with environmentally friendly sources are prevention is better than cure.

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A passion-driven environmentalist by heart. Lead content writer at EnvironmentGo to educate the public on the environment and her concerns.
It has always been about nature, we ought to protect not destroy.

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