CCS and transportation of captured CO2: a Government initiative, a new book, and an important Forum
The UK Government’s Department of Energy and Climate Change (DECC) has just issued an important strategy document which, if all its aims come to pass, heralds an equivalent expansion of the UK pipeline high-pressure gas-transportation network to the national transportation system constructed when North Sea gas came ashore in the 1970s. Furthermore, if other European governments, not to mention those further afield, take similar steps, the international pipeline industry will experience an expansion that was previously unimaginable. Those of a cynical disposition might well murmur that they’ve “seen it all before” and, to a certain extent, this may be the case. But the Secretary of State for Energy and Climate Change Edward Davey’s recent announcement that “This is a really exciting time for the fledgling CCS industry: our offer is one of the best anywhere in the world” deserves consideration in the context of this new CCS Roadmap  and its accompanying CCS Commercialization Programme.
In this unusually-lengthy editorial, we summarize the intentions of this important Roadmap using its executive summary as a reference, and go on to introduce an important new book that has been published on engineering aspects of the pipelines that will be needed to achieve some of them. We conclude with a review of the forthcoming Third International Forum on Transportation of CO2 by Pipeline, taking place in Newcastle, UK, on 20-21 June and jointly organized by the co-publishers of the Journal.
The DECC’s Roadmap starts by emphasizing that tackling climate change requires global action and every country needs to play its part. For the UK this will mean a transformation in the way the country generates and uses energy – a long-term transition to secure, affordable, low-carbon energy on the way to an 80% cut in greenhouse-gas emissions by 2050. Carbon capture and storage (CCS) has the potential to be one of the most cost-effective technologies for decarbonisation of the UK’s power and industrial sectors, as well as those of economies worldwide. CCS can remove carbon dioxide (CO2) emissions created by the combustion of fossil fuels in power stations and in a variety of industrial processes and transport it for safe permanent storage deep underground, for example (in the UK’s case) deep under the North and Irish Seas.
The deployment of CCS is at an early stage, so to the extent that UK-based business can take advantage of these local opportunities it should help to establish them as leaders in a developing worldwide market. The Government is committed to helping make CCS a viable option for reducing emissions in the UK and, in doing so, to accelerate the potential for CCS to be deployed in other countries. It is seeking to support the development of a sustainable CCS industry that will capture emissions from clusters of power and industrial plants linked together by a pipeline network transporting CO2 to suitable storage sites offshore. The CO2 thus captured might also be used in enhanced-oil-recovery processes to recover additional amounts of the UK’s hydrocarbon reserves, thereby improving the economics of CCS and accelerating deployment.
The Roadmap goes on to outline how the goal of seeing commercial deployment of CCS in the UK in the 2020s will be met, pointing out that the UK has a number of key advantages that make this country ideally suited for the deployment of CCS, including:
extensive storage capacity under the UK seabed, particularly under the North Sea;
existing clusters of power and industrial plants with the potential to share CCS infrastructure;
expertise in the offshore oil and gas industry which can be transferred to the business of CO2 storage; and
academic excellence in CCS research.
To ensure CCS can contribute to the UK’s low-carbon future, the Government is taking forward a programme of interventions that aims to make the technology cost-competitive and enable the private sector to invest in CCS-equipped fossil-fuel power stations, in the 2020s, without Government capital subsidy. This early deployment on power stations is seen as providing the starting point for the development of CCS clusters with multiple sources of CO2, including industrial sources, benefitting from access to shared transport and storage infrastructure. There are three key challenges which the Government believes must be tackled to enable commercial deployment of CCS in the UK:
reducing the costs and risks associated with CCS so that it is cost-competitive with other low-carbon technologies;
establishing the market frameworks that will enable CCS to be effectively deployed by the private sector cost; and
removing key barriers to the deployment of CCS.
Among the ways that these challenges are to be met are a £1-billion CCS commercialisation programme to support commercial-scale CCS schemes, targeted specifically at “learning by doing” and to share the resulting knowledge. There is also to be a £125-million, four-year, co-ordinated research and development and innovation programme and, among other activities, further work to support the CCS supply chain, and to develop transport and storage networks. A UK CCS Research Centre is also to be established which will bring together around 100 of the UK’s top CCS academics to support core research, development, and innovation activities. In the transportation field, the Centre’s aims will include:
understanding potential hazards and risks to inform decisions on pipeline routes onshore;
developing techniques for leak mitigation and remediation;
identifying novel pipeline materials and sealing and jointing technologies;
developing a performance database for CO2 transportation networks to enable grid optimization.
With an important gesture towards the pipeline industry, the Roadmap later points out that the development of the infrastructure necessary to transport and permanently store CO2 is one of the key challenges to achieving its objectives. The availability of pipelines and storage sites that enable high-emitting industries to contract for the transport and storage of CO2 on similar commercial bases to other utilities, it says, will be one consequence of the widespread deployment of CCS in the UK’s economy. It goes on to say that some supporters of CCS argue that the development of the infrastructure will in fact be a pre-requisite for the widespread deployment of CCS on the scale needed to meet the Government’s low-carbon electricity objectives.
A note of caution is sounded further on in the Roadmap in connection with the engineering skills that will be needed to achieve the targets it proposes. One of the main issues, it says, is the expected decline in the number of UK engineering specialists and experts in the coming decade. Greater demand for these skills following commercial deployment of CCS schemes (alongside other low-carbon technologies) is seen as an opportunity of offset this decline. The Roadmap’s authors say that there is no room for complacency in this regard: ensuring enough skilled workers are available will be crucial in the successful roll-out of commercial CCS schemes.
The DECC says that, while it is not the role of the Government to plan the generation of electricity or the pace and location of CO2 transport and storage infrastructure at the level of detail implied by the Roadmap’s ambitions, there are steps the Government can take that will facilitate the development of CCS infrastructure. It intends to tailor these in order to encourage cost-effective investment in CCS infrastructure where it helps deliver the CCS Commercialisation Programme objectives and offers value for money, without compromising the overall thrust of Government policy for infrastructure to be privately owned and financed.
The economic case for investment in shared infrastructure is considered to be straightforward and unquestionable. Although transportation of CO2 in particular, the DECC says, is dominated by upfront capital investment, the investment does not increase in proportion to the installed capacity. Shared infrastructure therefore reduces the cost of CCS, provided the investment in additional capacity is used to the extent necessary to justify the additional investment. The DECC states firmly that the Government will support the development of CO2 transport and storage infrastructure through this programme, as well as keeping the economic regulation arrangements for pipelines under review and assisting those looking to develop regionally focused CCS activities, including the development of regional clusters of CO2 emitters.
The issue about the cost of shared infrastructure is illustrated in the accompanying Table 1 published by the DECC, in which the figures are based on ‘typical’ circumstances in the UK and compare the cost of a pipeline sized to transport CO2 captured from a 300-MW power station, compared with a pipeline constructed at the largest size typical in the UK. The larger pipeline would cost about 25% more than a pipeline designed solely for the 300-MW source. The additional capital investment will increase capacity between five and seven times, and provided this additional capacity is fully exploited it will reduce the cost of transporting CO2 by a factor of about five. However, if that additional CO2 does not materialise, then increasing the capacity of the pipeline beyond that required for the 300-MW power station will have the opposite effect, increasing the cost of transport by about a quarter on an equivalent basis. The cost-benefit is therefore entirely dependent on the likelihood and timing of the additional CO2 materialising: if that were not the case, then the assessment would change markedly.
As the DECC points out, a number of organisations have undertaken more sophisticated assessments and come to similar conclusions. In particular, it says, excellent work has been carried out in areas of the UK where there are high concentrations of CO2 emissions in order to plan the development of regional networks that would enable industries to tap into the service at the point where this makes business sense. The high level of capital investment required to get these projects off the ground becomes economic even when relatively pessimistic assumptions are made about the amount of additional CO2 being handled by the network and when that becomes available.
In addition to these prospective economic benefits, the DECC identifies other less-tangible benefits that are also likely to emerge from a networked approach. It obviously makes sense in terms of reducing environmental damage and public inconvenience to avoid the construction of multiple pipelines along the same or similar routes within a relatively short period. It is also likely to be the case that businesses would be more likely to capture and permanently store CO2 if transport infrastructure were readily available than if they were required to develop and install an infrastructure from scratch. A readily available CO2 transport and storage network is therefore likely to provide an attractive mitigation option for high-emitting industries looking to reduce emissions. This, in turn, is likely to have implications for the make-up of the economy in those areas of the country with a high concentration of carbon intensive industries.
Recognizing the contribution that reduced CO2 transport and storage costs could make to achieving the objectives of the CCS commercialisation programme, the Government will consider supporting the development of CCS infrastructure on a scale that anticipates future demand and enables the development of local infrastructure networks, provided there is clear value for money justification in doing so.
According to the DECC, its Roadmap is intended to help build confidence in the scale, location, and type of investment in CCS that is likely to take place until 2030, and the steps the Government will take in order to facilitate that. The Roadmap will therefore help inform decisions about investment in CCS that will consequently help provide confidence in the emerging need for CCS infrastructure. As is emphasized, the key to unlocking investment in CCS infrastructure is market confidence that CCS will provide the benefits anticipated, that the demand for transport and storage will materialize, and that commercial arrangements typical for other utility services will emerge. Government action to facilitate the development and deployment of CCS is designed to help address each of these points, and will ultimately create the right conditions for the private sector to invest in the pipeline and storage infrastructure without further Government intervention. Prior to this, the Government will be willing to consider supporting the development of infrastructure through the CCS commercialisation programme that anticipates future demand as well as the development of local networks, provided there is clear value for money justification in so doing.
The UK Government’s long-term strategy is that CCS infrastructure will be funded through private investment, and that it will develop over time, in line with demand. It hopes that the relatively ‘piecemeal’ investments will become integrated into a network as demand and geographical distribution of CO2 capture increases. To enable this, regulatory powers have been adopted to ensure that third parties can access infrastructure on a fair and equitable basis, and also to enable new pipelines to interconnect with existing capacity in order for a network to develop.
This is all unmistakably exciting news on several fronts, but not least for the high-pressure pipeline industry in the UK. The challenges are huge, but the outcomes that are anticipated will be significant in their technical achievements as well as in the environmental benefits. There have been few moments such as this in the history of pipelines, when such a clear outlook has been available. We hope that industry embraces these opportunities, to the benefit of itself, the country’s economy as a whole, and the communities it serves.
The definitive textbook on anthropogenic CO2 transportation by pipeline
In the first single source that encompasses such a comprehensive field, this new book  brings together the entire spectrum of design and operating needs for a pipeline network to transport CO2 containing impurities both safely, and without adverse impact on people and the environment.
As is widely acknowledged, pipeline systems are the safest means of transporting captured CO2. However, the phase diagram for a CO2 stream containing impurities is very sensitive to the level of these impurities, which in turn affects the pipeline design and the boundaries between which CO2 pipelines can be operated without affecting the facilities’ design as well as the delivery conditions. The largest network of CO2 pipelines is in North America, the oldest there being Denbury’s 82-km long Cranfield pipeline from Mississippi to Louisiana, constructed in 1963. However, the majority of these lines (with one exception – see below) transport CO2 which predominantly has originated in underground reservoirs and which has been processed and dehydrated, and for which the main use is in enhanced oil recovery (EOR) schemes. The single exception is the 324-km long, 14- and 12.75-in diameter, Weyburn pipeline that came on-stream in 2000, and which transports captured CO2 from the flue stacks of a coal-gasification plant in North Dakota to oil fields in Weyburn, Saskatchewan for EOR. (Not only is this the only pipeline world-wide transporting industrial quantities of anthropogenic CO2, but it is also one of the few pipelines generally that crosses an international border.)
The 13 chapters of this book have been written with the intent that each could stand alone on the subject matter presented without necessarily referencing other chapters. Both imperial and metric units have been used, justified because the industry continues to use the unit systems interchangeably, and the authors have identified exhaustive lists of references for each chapter.
In one of the Forewords to the book, Charles Fox – vice-president of operations and engineering for Kinder Morgan – writes that until now, the transportation aspects of CCS schemes has been unjustly neglected. He goes on: “The authors, from various different backgrounds and organizations related to pipeline engineering, have assembled the state of the art and science”. Perhaps even more significantly, as one who is responsible for the management of the world’s largest CO2 pipeline system, he continues: “Like all companies, my employer constantly faces staff turnover, and we struggle to pass along the knowledge of CO2 transportation to newcomers. This reference will help assure that experts always operate our pipeline system. I encourage others who plan, design, or operate CO2 pipelines, to obtain this book and use it.” It is hard to see how his remarks or his endorsement, can be improved.
Third international Forum planned for June
As mentioned a the beginning of this Editorial the co-publishers of the Journal are organizing the Third International Forum on Transportation of CO2 by Pipeline, which will be held in Newcastle, UK, on 20-21 June. The event has become an important fixture in the calendar of many who are involved in this subject, testified to by the fact that the programme contains 28 papers from authors from seven countries. As in previous years, the programme is a gallimaufry of the latest state-of-the-art, encompassing research and practical solutions, and ranging from fracture arrest to planning. The full programme and other details can be seen at www.clarion.org: we have space here to highlight a number of papers of particular interest.
COOLTRANS – Integrated analysis of CO2 decompression and near- and far-field dispersion from a pipeline release: case studies, by Russell Cooper, National Grid, Warwick, UK
National Grid is progressing the COOLTRANS (Dense Phase CO2 PipeLine TRANSportation) research programme, which aims to address and resolve the key issues relating to the safe routeing, design, and construction of onshore pipelines for the transportation of anthropogenic, high-pressure, dense-phase CO2 from power stations and other industrial emitters to offshore locations for underground storage by 2014. An overview of the COOLTRANS research programme was given at the 2011 Forum, which explained the integrated analysis strategy combining state-of-the art numerical modelling of the pipeline decompression, and near- and far-field dispersion, studies being conducted by three university groups and use of full-scale experimental tests carried out at the Spadeadam test site of GL Noble Denton. This paper presents the results of further work, and explains how the results of the integrated analysis are being used to assess the performance of pragmatic dispersion models used in pipeline QRA studies in the COOLTRANS research programme.
The paper will provide further details of the COOLTRANS project and report the results of integrated analysis case studies designed to bring together theoretical predictions and experimental measurements of CO2 releases. The results of studies involving venting of dense-phase CO2 through a single, straight, vertical vent pipe of constant diameter and instantaneous horizontal release from a shock tube designed to simulate a full-scale pipeline release will be discussed. The paper will include contributions generated by the group of universities working on the integrated dispersion analysis (UCL, Leeds, and Kingston) and contributions generated by GLND using pragmatic models applied in QRA studies. The paper will demonstrate the value of combining and comparing modelling strategies and explain the improvements planned as part of the COOLTRANS objectives.
Corrosion and solid formation in dense-phase CO2 pipelines with impurities: what do we know, and what do we need to know?, by Arne Dugstad, Chief Scientist – Materials and Corrosion Technology, Institute for Energy Technology, Kjeller, Norway
Following the ‘Blue Map Scenario’ for the abatement of climate change, about 10Gt/yr of CO2 need to be safely transported and stored underground by 2050. This requires the construction of about 3000 12-in diameter, or 1000 20-in diameter, pipelines, assuming a flow velocity of 1.5m/s.
The good experience with CO2 transport in USA is often referenced to argue that CO2 pipeline transport will not be a big challenge for CCS. Therefore, so far, there has been surprisingly little focus on corrosion and impurity reactions in the pipeline. A recent review shows that less than ten published papers actually present new data that are relevant for pipeline transport with small amounts of water and impurities. The justification for this negligence can be questioned as:
Few of the existing pipelines are transporting or have transported anthropogenic CO2. None of the reported CO2 compositions found in the public domain include the flue gas impurities given in the CO2 specifications discussed in the CCS community i.e. the recommendations published from the DYNAMIS project or the table with expected impurities in dried CO2 published by IPCC.
Water content in the 500ppmv range is referred to and assumed acceptable in a number of publications discussing CCS and CO2 transport. The question is whether this apparently safe water level also applies when glycols, amines, and flue-gas contaminants like SOx, NOx, and O2, are present in moderate amounts. These impurities dissolve readily in water and induce an aqueous phase at a much lower water concentration than the solubility limits reported for pure CO2 and CO2 contaminated with hydrocarbons.
The water content in the anthropogenic CO2 that has been transported has been low (<130 ppmv) and it can be questioned if the field experience can justify the much higher water content often referred to.
The paper will discuss (1) the gap and recent results obtained in corrosion and solubility experiments with dense phase CO2 containing small amounts of impurities like SO2, NO2 and O2, (2) the need for more experimental data, and (3) the experimental challenges meet when data are generated in the laboratory.
Design of CO2 transmission pipeline systems, by Michael Istre, Chief Engineer, Project Consulting Services, Inc., Lafayette, LA, USA
One of the technologies that may play a role in reducing emission of carbon dioxide is CCS. The widespread adoption of CCS will require the transportation of the CO2 from where it is captured to where it is to be stored. Pipelines can be expected to play a significant role in the required transportation infrastructure.
This paper will review how the current knowledge base of CO2 pipeline design was implemented in a new transmission pipeline system as part of a new electric power plant in Mississippi. The 16-in diameter pipeline is designed to transport over 10,000t/d of CO2 collected from the power plant’s synthetic gas-from-coal process for enhanced-oil recovery in depleted oil fields. The pipeline includes approximately 98km of pipeline designed to transport CO2 in dense-phase and deliver to two independent CO2 consumers. This paper will discuss the efforts made in designing pipelines for anthropogenic CO2 mixtures, specifically for pipeline hydraulics, running-ductile-fracture mitigation, and pipeline-rupture dispersion modelling. The paper will also include a discussion of the risk measures implemented in the design to control release and protect population centres.
Risk assessment of CO2 pipeline network for CCS: a UK case study, by Chiara Vianello and Giuseppe Maschio, Dipartimento di Ingegneria Industriale, Universita’ di Padova, Italy, and Prof. Sandro Macchietto, Department of Chemical Engineering, Imperial College, London, UK
CCS technology requires transporting large amounts of CO2 over long distances, as capture plants are expected to be situated near power plants and other large industrial sources such as steel and cement works, while storage locations are expected to be in remote geological formations, typically offshore. CO2 can be transported using one or a combination of transport media: truck, train, ship, or pipeline. Transport by pipeline is considered the preferred option for large quantities of CO2 over long distances, and is the subject of this paper.
The CO2 pipeline network most appropriate for a country is clearly a function of the specific location of sources and storage points, their capacity and a number of other factors such as population centres and geographical features (rivers, mountains, railroads, motorways, etc).
The phased roll-out and initial design of the onshore part of a CO2 pipeline network for the UK, suitable to deal with the distribution of forecasted CO2 amounts captured at major sources, was proposed by Lone et al., 2010, based on a techno-economics analysis. The analysis resulted in proposed sizing and location of various pipeline segments in a three-phase rollout, dealing with largest duties first, and details of CO2 flows and pressures for each segment in each roll-out phase.
This paper describes the quantitative risk analysis of this pipeline network, and in particular an assessment of consequences due to the possible CO2 releases. First, the probability of various accidental events is determined. Then, the estimation of consequences is made using PHAST software using its ‘long-pipeline’ release model, for two types of release: (i) from a hole with diameter equal to 20% of section area; and (ii) from a full-bore rupture (catastrophic release).
Accidental events in a CO2 pipeline can produce a spray release followed by a dense gas dispersion, and the high concentration of CO2 can cause fatalities. To determine possible health effects it is important to quantify not only the CO2 concentration but also the duration of the exposure, as the gas cloud evolves. For the calculation of risk, the consequences are associated to the Probit function, which calculates the percentage of the death of the individual.
The network can pass near residential areas: for this situation, the consequences produced by a possible release are calculated and various corridors of risk are identified (in terms of population at risk, using population distribution data). Finally, the tradeoffs achievable between population-risk decrease and additional pipeline costs arising from alternative pipeline pathways are shown by means of a specific example.