Research by several US Department of Energy Regional Carbon Sequestration Partnerships has a goal of safe, cost-effective, and long-term carbon management, mitigation, and storage. The RCSPs will be field-testing and validating sequestration through 2009, with deployment involving several large-volume sites starting in 2008 and running through 2017.
Current energy legislation also addresses carbon sequestration, including plans to conduct a large-scale demonstration in the vicinity of the Piceance basin.
These efforts have so far focused on capture technology and the viability of the various types of sequestration sites (depleted oil and gas reservoirs, unminable coalbeds, and deep saline reservoirs), rather than how to transport carbon dioxide from source to storage.
A Congressional Research Service report published Apr. 19, “Carbon Dioxide (CO2) Pipelines for Carbon Sequestration: Emerging Policy Issues,” points out economic and regulatory problems that need to be addressed in terms of CO2 transport before carbon sequestration can occur.
The technology for transporting CO2 via pipeline is mature, having been used since 1972 to carry CO2 from a variety of naturally occurring and man-made sources to oil fields for enhanced oil recovery. CO2 pipelines are also similar in construction and operation to natural gas pipelines.
Technological questions regarding CO2 pipelines, therefore, are minimal. By contrast, the CRS report notes considerable uncertainty regarding the size, complexity, and configuration of the pipeline network required to implement a widespread carbon sequestration program in the US.
Costs uncertain
Many existing, large CO2 point sources in the US are relatively close to potential saline reservoir injection points, making transport relatively straightforward (OGJ, May 14, 2007, p. 20). But US Geological Survey Director Mark Myers is among those who have noted that the behavior of CO2 in saline formations is not fully understood (OGJ, Apr. 23, 2007, p. 37).
The resultant uncertainty over the proximity of sources to storage sites brings with it a wide range of possible pipeline configurations and costs, according to CRS, which also notes the economies of scale that would accrue if a CO2 sequestration network were developed in an integrated manner rather than simply emerging piecemeal as each source found its own way to a sequestration site.
At a time when material and labor resources in the pipeline industry are stretched, issues of cost carry particular weight. Dedicated CO2 pipelines would have to compete for resources with already planned expansions of the US gas and liquids transportation infrastructure, as well as potential new dedicated ethanol pipelines also under consideration.
Regulatory issues
Regulatory difficulties also exist. The US Surface Transportation Board regulates interstate pipelines carrying commodities other than water, oil, and natural gas. Its regulatory authority and oversight, however, are limited compared with the Federal Energy Regulatory Commission’s administration of US natural gas and oil pipelines.
The STB is charged with ensuring that CO2 pipelines fulfill common carrier obligations by charging reasonable rates, but it lacks the authority to begin a rate proceeding on its own initiative. Pipeline operators under its supervision are also under no obligation to notify the board of any rate changes, unlike operators under FERC jurisdiction. The STB further lacks regulatory authority regarding pipeline construction, including eminent domain.
Without federal regulatory authority over construction, the CRS report points out, CO2 pipeline siting is regulated to varying degrees by each state. Without the ability to oversee rates, a varied and potentially unstable pricing environment would emerge. The potentially dampening effect of these factors on growth of an integrated pipeline network for CO2 sequestration is clear.
According to the CRS, however, legislation placing CO2 pipelines under FERC’s jurisdiction might imply that CO2 transport is interstate commerce and that captured CO2 is therefore a commodity as opposed to a pollutant, leading to still broader regulatory issues and implications.
Carbon sequestration is one part of the effort to improve the sustainability and environmental responsibility of the US energy infrastructure. To the degree that other parts of this effort lead to the development of nonfossil fuels, the need for sequestration will be diminished.
Regardless of the twists and turns this process takes, however, the transportation of CO2 should receive attention as urgent and careful as that now given other subjects related to sequestration.