Carbon Capture and Sequestration At-a-Glance
For centuries, humans have extracted carbon-based fossil fuels from the ground to power our lives. What if we started injecting that carbon back into the ground where it came from?
This is the basis of carbon capture and sequestration (CCS): the process of capturing and storing carbon dioxide in the ground.
A Brief History of CCS
Storing carbon dioxide underground is not a new technology. In the early 1970s, oil and gas companies discovered they could enhance oil yields by injecting carbon dioxide into their wells. As oil wells began to wane in production, companies would inject carbon dioxide into wells to increase their pressure. The increased pressure creates increased oil production. This process is known as Enhanced Oil Recovery (EOR) and the wells that utilize this technology are classified as Class II wells.
Today, the oil and gas industry still uses EOR to increase well yields and contribute to the production of fossil fuels. However, environmental experts now see an opportunity to take a technology that has perpetuated climate change to fight climate change. What if we use the same gas injection technology to store carbon dioxide emissions? This is the rationale behind a Class VI well, a well that involves the injection of carbon dioxide into underground rock formations for long-term storage. These Class VI wells are the main type of well we can utilize to reduce our atmospheric carbon.
CCS is Key to Combatting Climate Change
For the world to meet its climate change goals by 2050, many green technologies need to work in tandem to reduce our carbon footprint. This is where Class VI wells can provide a large role. A good example is with hydrogen production. The process of creating hydrogen produces a large byproduct of carbon dioxide. By capturing the carbon byproduct and storing it underground, we can create a zero-carbon hydrogen fuel. This logic can be applied to any process that involves carbon dioxide as a byproduct. Powerplants that utilize coal, natural gas, or even woody biomass can all produce carbon neutral or carbon negative energy by capturing and storing their carbon dioxide.
Traditional industrial sectors such as cement, iron, and chemical will greatly benefit from the implementation of CCS technology. These sectors produce approximately eight billion tonnes of direct carbon emissions annually. While some carbon emissions can be solved using a zero-carbon energy source, around 1.9 billion tonnes of industry emissions are from chemical processes that cannot be avoided. For example, 65% of emissions from cement production are created when limestone is converted to calcium oxide. This is a necessary process to produce cement, and therefore emissions cannot be avoided. A possible solution is to utilize CCS to capture the chemical reaction emissions and create a carbon-neutral cement process.
Carbon capture and storage not involving EOR is relatively new. Currently, there are only two active Class VI wells in the United States at the Illinois Industrial Carbon Capture and Storage Facility. These wells store carbon dioxide from ADM’s Decatur, Illinois corn processing facility. There are also four permitted facilities, which will hopefully come online within the next few years. As legislation develops and government entities become more comfortable with Class VI regulations, more companies will begin developing and adopting CCS technology to fight against climate change.