Repurposing Coal: Carbon GeoCapture’s Unique Approach

By Mark Northam, retired Executive Director of the School of Energy Resources at the University of Wyoming

In November 2021, world leaders, scientists, CEOs, and activists met in Glasgow, Scotland for the 26^th United Nations Climate Change Conference of the Parties (COP26) to discuss progress in the fight against climate change, and to negotiate how to move more quickly to achieve the challenging goals of limiting the impacts of global warming. If we are going to be serious about limiting climate change, we must start now. The world is not ready to eliminate fossil fuels, so technologies to manage the emissions of carbon dioxide are required. They must be safe, affordable, effective, and widespread.

Key observations from the meeting included:

• Countries agreed at the conclusion of the conference to accelerate action to cut global emissions in half.
• Countries signaled the need to accelerate a shift away from fossil fuels towards renewable energy.
• Though there was a call to phase-down coal power, it is still not feasible to eliminate it in the near-term.
• Carbon capture and storage (CCS; more below) is a viable tool in the mix for reducing emissions.
• There is still no formal treaty that would legally bind countries to reduce their emissions.

Ironically, the world is focused on eliminating the climate-changing impact of burning the fuels that created the society in which we live today. First coal, then oil and natural gas, enabled the Industrial Revolution that began in the 1800s. Though society has benefited immeasurably from fossil fuels, the negative impacts of their broad use on air and water have grown. Global communities now face the crisis of a warming earth because of increasing concentration of heat-trapping carbon dioxide in the atmosphere.

The International Energy Agency (IEA) reports that global energy-related carbon dioxide emissions are greater than 30 billion tons per year and are at the highest level they have ever been. Scientists and most governments have adopted the recommendation of the Intergovernmental Panel on Climate Change (IPCC), that to hold global temperature increase to 1.5 degrees Celsius, we must reduce emissions of carbon dioxide in the atmosphere to net-zero by 2050. Reducing and eliminating these emissions in that timeframe is a challenge of epic proportions.

Importantly, participants at COP26 seemed unanimous in their resolve that the fight against climate change will only be won through elimination of fossil fuels as an energy source. That pathway to success is a difficult one in this 30-year window, and promises hardship for rich, and especially, poor nations. There will be a transitional period for fossil fuels as economical and reliable alternative energy sources are developed and implemented on a global scale. To achieve the goal of limiting average global temperature to 1.5 degrees Celsius, we need technologies today that keep new greenhouse gas (GHG) emissions out of the atmosphere. Furthermore, as it becomes more likely that the world will overshoot the 1.5-degree target, we will need technologies that will allow us to reduce the atmospheric concentrations of GHGs. Currently, the most attainable technology for achieving that goal is carbon capture and storage (CCS), and we need implementation now.

CCS is a series of processes that start with the removal of carbon dioxide from an emissions stream or from the atmosphere. The carbon dioxide is transported to a disposal site. Then, ideally, the carbon dioxide is pumped down into geologic storage facilities (various types of rock and mineral formations) in the earth through a series of wells. The goal is to effect permanent storage of the carbon dioxide to ensure it never reaches the atmosphere.  

Carbon GeoCapture Approach

Carbon GeoCapture (CGC) is moving towards commercialization of its proprietary low-cost sequestration method that is the result of 20 years of research and development, and investments of $35 million. The focus is on storing carbon dioxide in unconventional rocks – specifically organic shales and coal beds. These formations are widely distributed and underlie much of the world’s landmass but have not previously been considered as targets for storing significant volumes of carbon dioxide. Proving their viability will enable more flexible implementation of CCS projects.

CGC has developed a unique process of co-injecting carbon dioxide mixed with water into shale and coal beds.  The water will be sourced from these formations, an important aspect that will limit impacts on communities that rely on existing water resources. As the mixture flows through the formation, the carbon dioxide is preferentially absorbed, and the water continues to flow where it is eventually recovered and reused. Additional carbon dioxide can be injected and sequestered in the rock.

There are several advantages to sequestering carbon dioxide with this method. Shale and coal beds are shallower than conventional formations, an important factor in reducing operational costs. Co-injection with water reduces the requirement for high compression of the carbon dioxide, further reducing cost. It also avoids a major issue of coal swelling at the injection site that significantly reduces flow, an issue previously experienced with direct injection of carbon dioxide into coal seams. The CGC method promises to be suitable for use around the world, and is easily controlled and monitored, safe, and long-lasting.

Carbon GeoCapture’s Demonstration Plans

CGC is currently in final planning stages for two important pilot demonstrations in Wyoming in the Powder River Basin (PRB), which has been a prolific coal, oil, and natural gas-producing region for over a century. The pilot tests will be conducted in fields that were initially developed to produce fossil fuels. The same fields will now be used to demonstrate the viability of safely storing carbon dioxide in the earth.

The first pilot test will be conducted in the western PRB in existing, but abandoned, coalbed methane wells. The injection water will be sourced from un-mineable coalbeds, mixed with carbon dioxide at the surface, and then injected directly into the coalbed through a dedicated injection well. The carbon dioxide will be absorbed by the coal. Some methane may be released from the coalbed and flow toward the water production well. If so, it will be captured at the surface for use to generate clean electricity (through a process that likewise captures any carbon dioxide generated) that powers additional injection of carbon dioxide.

The second pilot test will be conducted in the PRB by recompleting old oil wells into shallow coal seams, separate from the oil reservoirs that provided the production for the field. The process will be the same as described above and will validate the repurposing of numerous existing, but declining, oil fields in the area into sequestration wells.

The goal of each of these tests is, first, to demonstrate the viability of un-mineable coal seams for safely sequestering significant volumes of carbon dioxide. Furthermore, the tests will allow CGC to evaluate the economics of the process. The company believes the results of these pilot tests will inform future, scaled-up projects to further improve the process and operations, and will demonstrate a path to economic viability. Though success is certainly not assured, all indications are optimistic for commercialization to be possible in the near future.

Demonstrating the viability of coalbeds as storage facilities will be a game changer for global CCS opportunities. Repurposing coal from an energy resource to a carbon dioxide “sponge” will greatly increase the scale and distribution of storage potential. It will also benefit communities that have relied on production of coal by providing opportunities to retrain and retain a skilled workforce as well as create good jobs operating storage projects.

The Future Starts Now, and CGC is Leading the Way

If we are going to be serious about limiting climate change, we must start now. The world is not ready to eliminate fossil fuels, so technologies to manage the emissions of carbon dioxide are required. They must be safe, affordable, effective, and widespread.

Storage of carbon dioxide in coalbeds makes sense, and CGC is showing that it is safe, affordable, and effective. 2050 is coming quickly, and it is almost a certainty that managing carbon dioxide will continue for a long time thereafter. Proving we can do it has never been more important. Carbon GeoCapture is ready to do just that and plans to be a significant player in spreading the technology globally.

About the author: Mark Northam

Mark Northam retired in June 2020 from his appointment as the Executive Director of the School of Energy Resources at the University of Wyoming, where he was selected by the University in 2007 to be the school’s Founding Director. Mark is a Mobil and ExxonMobil veteran, with twenty years of carbon capture and sequestration projects. He also oversaw carbon management operations at Saudi Aramco in the Research and Development Center. Prior, Mark was a principal contributor to the technology program for one of the most significant and longest-running carbon dioxide storage projects to date, the Sleipner CO2 Storage Project in the offshore of Norway. That project began operating in 1996 and continues to store one million tons of CO2 annually.