Picture a world where today's gas-fueled cars have been replaced by electric cars. Imagine planes operating on low-emission biofuels, and stored hydrogen serving as a significant power source. Visualize energy providers and industrial manufacturers reducing emissions by capturing and injecting CO₂ — the most prevalent greenhouse gas — deep into the earth and under the sea.

Sound futuristic? The change won’t happen overnight. But the transition has begun, and the reality of a net zero emissions world is edging closer. The oil, gas and chemicals industry, power generation providers, and other heavy energy producers are increasingly exploring carbon capture, utilization and storage (CCUS) for decarbonizing their assets and processes.

The process of carbon capture and utilization (CCU) has been used in the oil industry for enhanced oil recovery since the 1970s. CCUS takes the process a step further. The carbon capture and storage (CCS) component involves collecting carbon-containing greenhouse gas emissions (most commonly CO₂) from industrial operations and injecting them deep into a secure geological formation.

Tax credits and other carbon reduction incentives are substantially higher for CO₂ storage versus utilization. But geological storage is a newer technology, and the permitting process and technological barriers are more challenging.

“Without making the most of CO₂ geological storage capabilities, society won’t reach the global temperature rise–capping goal established by the Paris Climate Agreement,” says Doug Cowin, a Burns & McDonnell project manager who works with companies to develop carbon capture, utilization and storage strategies. “If we want to reduce greenhouse gas emissions while maintaining energy reliability and stability, there has to be balance in energy sources. An integrated global effort that relies on multiple components, such as natural gas, renewable energy sources, biofuels, electrification and CCUS, is absolutely necessary.”

The number of storage projects is growing worldwide, with 135 facilities now in the queue — over 70 of which were added to the list in 2021 alone, according to a report from the Global CCS Institute. In order to reach emissions goals, the International Energy Agency predicts 70 to 100 facilities must be built annually through 2050, at a total estimated cost of $655 billion to $1.28 trillion.

In the U.S., there are two permitted Class VI injection wells in Illinois and two in North Dakota for permanent geological storage of CO₂. Four more, located in Louisiana and California, await approval.

The process for obtaining a permit for storage wells in the U.S. is time-intensive and involved. A Class VI underground injection control (UIC) permit is required for the injection and permanent storage of CO₂ in the subsurface. The permitting process is administered by the U.S. Environmental Protection Agency in all states but two, which have primacy designations. North Dakota and Wyoming are allowed to manage their own programs, as long as they comply with federal regulations. Industry insiders suggest more state-regulated programs will speed up Class VI well development.

A variety of projects are being developed in a dozen states: Alabama, California, Florida, Georgia, Kansas, Louisiana, Mississippi, Montana, New Mexico, North Dakota, Texas and Wyoming. “States that have a long history of oil and gas operations and a wealth of subsurface data and technical knowledge are leading the way,” Cowin says. “When a state has regulatory bodies that view utilization and storage projects favorably, and either has or is near ideal geological conditions and/or existing transportation infrastructure, that state is more conducive to this type of development.”

Class VI UIC permitting involves two distinct areas of permitting. Most capital development projects require standard environmental permits that address potential impacts to the environment. Class VI UIC storage requires additional permitting that addresses permanent geologic storage.

A competent seal rock formation must be present to hold the CO₂ in place and prevent migration to shallower underground sources of drinking water (USDWs) or other environmental receptors. The porosity and permeability of the host rock is also important because it determines the permissible injection rate and total volume of CO₂ that can be stored at a location. Several measures are evaluated to confirm CO₂ injection activities won’t endanger drinking water or cause other harmful environmental effects.

Class VI injection well requirements address siting, construction, operation, testing, monitoring and site closure. The regulations focus on the unique nature of CO₂ injection and address relative buoyancy; subsurface mobility; CO₂ corrosivity in the presence of water; pressure, temperature and volume conditions at various depths; and anticipated injection volumes.

During the permitting process, monitoring requirements that address well integrity, CO₂ injection and storage, and groundwater quality (during both the injection operation and post-injection site care period) are reviewed. Financial commitments demonstrating the availability of funds for the life of the project — including emergency response and post-injection site care for up to 50 years — are required. Reporting and record-keeping documents that provide project-specific information are also continually evaluated to confirm USDW protection.

A program designed to protect the public’s drinking water has created many challenges for CO₂ storage deployment. But if done right, it has the potential to create abundant jobs, as well as generate billions of dollars in economic growth and infrastructure investment. As a result, speeding up federal approvals, while securing the most optimal environmental and social outcomes, is critical.

“All the public and private money used for new technology and test programs won’t mean anything if permits can’t be secured in a timely manner,” Cowin says. “Systems need to be put in place that allow more storage wells to be developed quicker. But before that can take place, many issues need to be resolved — such as who owns the rights to the land below ground. Having a uniform way to address concerns like this is key if CO₂ storage is going to really take off at the rate it needs to.”

In anticipation of the industry ramping up, Cowin notes that industrial producers of CO₂ need to have staffers — and/or knowledgeable consultants — who understand the importance of feasibility/design studies; are up to speed on funding sources and incentives; are familiar with environmental regulations; and are knowledgeable about capture and sequestration technology.

To help navigate permitting requirements, reduce costs and speed the process along, hub-and-spoke networks are gaining momentum.

“Hub-and-spoke partnerships are the future,” says John Hesemann, environment department manager at Burns & McDonnell. “High-capital CO₂ producers, considered the spokes, are coming together and joining forces with pipeline providers and storage facility partners, the hubs. This helps minimize financial risks and obligations. It just makes good economic sense and is more cost-effective to bring together multiple entities versus doing solo projects."

What would be the largest hub-and-spoke partnership to date is the Houston Ship Channel CCS Innovation Zone project, proposed in 2021 by ExxonMobil. It’s projected this network would inject more than 100 million metric tons of CO₂ annually — the equivalent of emissions from 44 million light trucks — beneath the Gulf of Mexico.

The U.S. government is another key partner in carbon storage efforts. The bipartisan Infrastructure Investment and Jobs Act allocates roughly $18.6 billion for CCUS projects. This includes establishing the CO₂ Infrastructure Finance and Innovation Act that will provide loans for CO₂ transport infrastructure projects. Industry stakeholders hope future legislation will support storage efforts with additional funding, including increases in incentives such as 45Q tax credits.

CO₂ transportation options, storage site conditions and other engineering considerations are important in determining a project's viability. Also important is an economic assessment of how much CO₂ would need to be stored to break even. This early analysis is a vital part of the overall storage decision-making process.

“There is much enthusiasm surrounding the underground storage of CO₂, and the initial feasibility assessment can be complex, involving several financial and technical risk factors,” Hesemann says. “Policies, carbon capture technologies and storage solutions will continue to evolve as industry leaders innovate and more commercial-scale projects successfully take place.”

Ultimately, Class VI permits need to be processed in a timely, uniform and reliable way to enable CCUS projects to be deployed effectively on a broad scale. Streamlining and speeding up the permitting process is critical to successfully leveraging the technology that will help achieve long-term carbon reduction objectives.