In 2005, the Intergovernmental Panel on Climate Change's Special Report on CCS concluded that “there is no indication that the problems for CO2 pipelines are any more challenging than those set by hydrocarbon pipelines in similar areas or that cannot be resolved”. Furthermore, a recent report published by the Global CCS Institute suggests that the existing experience with CO2 transportation in the US, where 36 CO2 pipelines are currently transporting around 65Mt CO2 per year for enhanced oil recovery (EOR), may have contributed to a general perception among the CCS community that CO2 transport is not considered a barrier to the deployment of CCS.
CO2-EOR pipelines are a growing industry. Proposals for new CO2-EOR pipelines exist to link the St John’s CO2 dome on the border of New Mexico and Arizona to West Texas and to extend the recently constructed 373km Greencore pipeline further south to access additional CO2 supplies, and north into Montana to provide CO2 for additional CO2-EOR projects. There are also a number of large-scale integrated CCS projects that could be considered extensions or components of existing CO2-EOR pipeline networks in the US. They are driven mainly by opportunities to increase oil production based on access to new sources of CO2. An overview of these projects can be found here.
While it may be generally true that CO2 distribution networks present fewer hurdles to the wide-scale deployment of CCS than capture processes and storage solutions, this component is far from simple. It is unlikely that you will hear the engineers who designed the 145km offshore pipeline for the Snøhvit CO2 Injection project telling anyone that it is just a matter of ‘laying a pipe’! Since 2008, this pipeline in northern Norway carries around 700,000 tonnes of CO2 per year from an LNG production plant close to Hammerfest, to an aquifer under the ice cold Barents Sea.
Pipeline engineering may be a mature profession, but there are significant differences between the US experience with CO2-EOR pipelines (mainly dealing with naturally occurring CO2), and the expertise needed to design transport systems for CO2 that is captured from power plants. For example, impurities or by-products that may exist in the CO2 stream coming from the plant, such as nitrogen, argon and methane, could influence the hydraulics calculations that are needed to design these pipelines. The Global Status of CCS: 2012 chapter on CO2 transport discusses the main design challenges identified by project engineers and CO2pipeline operators.
In her recent blog Kirsty Anderson, the Institute's Public Engagement Manager talked about 'overall-clad' challenges, when referring to the technical problems engineers may face when developing CCS projects. She then went on to highlight the equally challenging roles held by public engagement officers tasked with communicating the solutions to these problems to the public in order to obtain a social license to operate. The latter is of particular relevance when a CO2 pipeline route is passing urban areas. A recent report from the South West Hub in Western Australia cites the long lead times associated with obtaining a range of licenses, environmental permits, and approvals for land access rights associated with constructing CO2 pipelines.
The South West Hub is one of several proposals worldwide for new CCS networks that are based mainly on direct storage, or at least a combination of both permanent storage and CO2 utilisation. Even though the initial demand for additional CO2 transportation capacity will likely unfold in an incremental and geographically dispersed manner, large-scale deployment of CCS is likely to result in the linking of proximate CO2 sources, through a hub, to clusters of sinks, either by ship or so-called ‘back bone’ pipelines. For example, the 240km Alberta Carbon Trunkline in Canada is designed to accommodate about 14 Mtpa of CO2. An overview of other CCS network examples in Australia, Europe and the Middle East can be found here.
Given the economies of scale that can be achieved, the benefits of integrated CO2 transportation networks are apparent, but a network approach can also entail additional challenges, in particular from commercial, financial, and legal perspectives. Ever thought about how to design a multi-user charging framework that reflects the separate infrastructure development, operation, and decommissioning costs and is also linked to the allocation of capacity in the system? I can tell you that it is not easy to obtain financing for pipeline assets that will initially be ‘oversized’ in anticipation of future volumes of CO2 being added to the transportation infrastructure; and this is not only because of the current status of the global financial markets.
Challenges most definitely remain for those developing CO2 transportation systems, but to end on a positive note, most of the challenges relating to the development of CO2 transport infrastructure have already been tackled by other major transport infrastructure programs. Notably, integrated transport networks have been financed and constructed in virtually every country to move fluids, solids, or waste materials safely.