CO2 Pipelines - Regulatory Gaps

The regulation of CCS is still evolving, and there are challenges associated with ensuring the safe transportation and safe, secure storage of CO2 over long time periods. The lack of price regulation jurisdiction over carbon dioxide (CO2) pipelines has become a point of contention, as neither the Federal Energy Regulatory Commission (FERC) nor the Surface Transportation Board (STB) has exercised such authority. This confusion arises from differing definitions of jurisdictional scope among regulatory bodies.

(Source: INGAA foundation)

While FERC does not claim jurisdiction over CO2, as it is not considered a "natural gas" covered by the Natural Gas Act, the STB also declines authority over it, since it does not regulate the pipeline carriage of gas, despite CO2 being indisputably classified as a gas. The CO2 transportation pipelines are regulated by 49 CFR PART 195 - Transportation of Hazardous Liquids by Pipeline.

There are several issues associated with current regulations. A recent report from the pipeline safety trust identified these issues.

1. CFR Part 195 definition of “Carbon Dioxide means a fluid consisting of more than 90 percent carbon dioxide molecules compressed to a supercritical state” does not really cover the entire scope of CO2 pipelines. The definition needs to be changed to include all supercritical, gas, and liquid CO2 transmission pipelines.

2. Current guidelines to calculate potential impact radius (PIR) may not be applicable for CO2 pipeline ruptures. The unique, and potentially very large impact areas for CO2 pipeline ruptures need to be developed, defined, and included in pipeline regulations. PIR for CO2 pipelines may be substantially larger than for hydrocarbon pipelines of similar diameter.

3. Running ductile fracture is a significant safety concern with CO2 pipelines. Regulations should prescribe pipeline design methods to prevent and arrest fracture propagation.

4. CO2 is colorless, odorless, and not a flammable gas which makes transportation safe. However, failure of a CO2 pipeline will have huge implications due to its being heavier than air and its tendency to accumulate in low-lying areas and potentially act as asphyxiant [reduces or displaces the normal oxygen concentration in breathing air]. It could be a safety concern for people who live around the pipeline right of way, emergency responders, pipeline operator employees, and animals. Asphyxiation of humans and animals can lead to death as well. PHMSA needs to mandate the use of odorant injection into CO2 transmission pipelines to help people identify dangerous releases.

5. Corrosion in CO2 pipelines is another primary concern, and it is impacted by the contaminants in the fluid stream. As the current carbon dioxide definition is not stringent, it is recommended to set a maximum limit on impurities such as water, H2S, and other impurities.

6. Conversion of existing hydrocarbon pipelines to transport CO2 poses a lot of risk and federal regulations are not adequate for mitigating the risks. Stricter guidelines should be provided to the industry.