The development of a CO2 value chain for CCS poses a number of decisions relating to the capture technology, storage selection and transportation of CO2. In addition, an appropriate approach to the non-technical aspects and risks needs to be incorporated. This paper will provide an overview of the different options available to projects and discuss the selections that Shell has made in its own CCS project development.
Shell has developed a global portfolio of CCS demonstration projects driven by the recognition that carbon capture and storage is currently the only technology available to mitigate emissions from large scale fossil fuel use. Shell’s projects cover a wide range of technologies and consist of targeted applications that are of relevance to the wider oil and gas industry. The Shell portfolio includes Peterhead, Quest, Technology Centre Mongstad and Gorgon. The development of these projects has demonstrated that there are multiple drivers in the development of a CO2 value chain and these can be very project specific.
In the development of CCS for power plants, one of the key considerations is the ability of power plants to be able to respond flexibly to the normal fluctuating demands of the power market. Therefore, a key driver in technology selection is to limit the impact that the addition of a CCS plant could have on this flexibility. On the other hand, availability may not be the most important factor, because power plants usually use an "end of pipe" CO2 solution, and therefore the unavailability of a post-combustion CCS plant will have minimal technical impact on the power export.
However, for a hydrogen plant where hydrogen demand can be relatively stable e.g. in a refinery, then the capture technology selected will not usually need to follow a varying demand but, because the capture technology could be part of the wider process, it may need to offer high reliability and availability.
Similar considerations need to be made about the dehydration technology and the CO2 compression technology selected. For example, re-use of existing facilities can result in more stringent requirements on CO2 purity and possible pressure limitations that could be designed out in a new facility.
In conclusion, Shell';s experience has shown that development of CCS projects poses some new challenges but through good integration of technology and a structured approach to technical and non-technical risks, these can be overcome for successful project delivery.