Organised by Tiratsoo Technical, a division of Great Southern Press, and Clarion, on behalf of Newcastle University, the First International Forum on the Transportation of CO₂ for CCS was held in Gateshead, near Newcastle, on 1–2 July. The Forum attracted over 100 delegates from around the world as well as a panel of 19speakers representing both industrial and academic organisations.

Putting the Forum in context

It is clear that if the number of CCS schemes that are being proposed internationally actually go ahead, huge quantities of CO₂ gas will need to be transported – by pipeline or other means – from the capture sites to various forms of so-called ‘geologic’ storage. To the uninitiated, this is an issue mainly concerned with constructing new pipelines or, better still, re-using old ones. But looking a little deeper, it turns out that the CO₂ in question is not the relatively-benign gas that is already being transported in the USA and elsewhere by existing pipeline networks.

The ‘anthropogenic’ captured CO₂ is, technically, a very problematic gas to transport by pipeline, being extremely hot (from its source, which is mainly power station chimneys) and contaminated with a number of other toxic gases. This mixture does not behave like the natural gas that the international pipeline industry is used to transporting, being corrosive to pipeline components and highly toxic. Despite this, conservative estimates suggest that over 100,000 km of new pipeline globally will be needed before 2030 to meet the challenge that CCS presents.

Presentations ranged from overviews of the challenges and potential solutions, from both academic and industrial viewpoints, to detailed considerations of pipeline steel’s material properties and its susceptibility to cracking and fracturing when being used to transport CO₂. Regulation and standards were also considered by speakers from the UK’s Health & Safety Executive and DNV, Norway, respectively.

Future requirements for CO₂ transportation

It is worth summarising some of the findings of a recent report for the International Energy Agency’s Greenhouse Gas Programme, entitled CO₂ pipeline infrastructure: an analysis of global challenges and opportunities. Final Report for the International Energy Agency’s Greenhouse Gas Programme. The report emphasises the scale of the problem – both economic and technical – that the international pipeline industry will have to face.

It is reliably forecast that, by 2030, 1.44 gigatonnes per annum (Gt/a) of captured CO₂ worldwide will need to be transported from around 360 sources to storage. The average distance from source to storage will be around 80 km, although there will be at least nine pipelines needed that will exceed 500 km in length. The median price for the source-storage connection is forecast as being $US1.5 per tonne of CO₂ transported, although the marginal cost, particularly from 2050, will be significantly higher. The net present worldwide combined capital and ongoing costs of the pipelines and compressors (including energy costs) for these networks amounts to $US60 billion, excluding the costs associated with capture, initial compression, storage, or financing.

An examination of the marginal transport cost curve for these pipelines shows that, for projects beginning in 2030, more than 20 Gt/a of CO₂ could be transported with an average cost of less than $US5 per tonne of CO₂, assuming an economic life of 20 years. However, the marginal cost for transport above 20 Gt/a rises steeply to $US30 per tonne, as combinations of sources and storage sites that are less attractive must be used. After 2050, the availability of giant exhausted gas fields will provide new opportunities for cost-effective CO₂ transport, although the overall cost-effectiveness for new pipelines will be significantly lower as more challenging distances and terrains will have to be crossed, and there will be a greater emphasis on smaller sources for which transport is less economic.