Development of A CO2 Specification for Industrial CCS Transport Networks: Methodology, Limitations and Opportunities

Abstract

Abstract Impurities in anthropogenic CO2 affect several aspects of a full-chain industrial CCS hub. The concentration and type of impurities expected from various CO2 sources will differ depending on the technology that is emitting CO2. Rather than provide individual specifications to different customers, a single specification approach is being usually considered. The intent of this specification is to provide a single requirement that all sources of CO2 must abide by. If different specifications were provided to different customers, the transport network might become reliant on acombination of users supplying CO2 at specified rates to meet an overall specification. Several CO2 specifications have been developed over the years. Although these specifications serve as guidance,each project/development will develop its own specification that is appropriate for its owncharacteristics. In this paper, we develop a multi-purpose fluid specification for a CCStransport hub. The specification is flexible as it takes into consideration a wide range of emitters,industry type and capture technology. We describe a development framework that takes intoconsideration: mechanical integrity (corrosion), operational integrity (two-phase zone, hydrateformation, water dropout, ductile fracture), HSE, storage capacity and integrity. The proposed specification contains a wide range ofimpurities but the limits in the specification are as broad as reasonably possible. Moreover, the CO2 specification covers a large range of operating conditions: from low pressure (gas phase) and highpressure (liquid phase). As we considered more than 30 species in the fluid, the proposed specificationhas a wider scope that current known industry standards (or even known projects). A comparison with other publicly available specifications is provided. In addition, the specification is heavily relying on good understanding of thethermodynamics of CO2 fluids with impurities: we assess and provide a comparative framework of themost adequate EoS for the chemical nature of the potential impurities. This paper offers an extended CO2 fluid specification for an industrialCCS transport system where a range of emitters (each of different nature) will tie-in. The proposedspecification offers a starting point for the design of CCS networks. It provides a common basis for thedesign of the components of the CCS system. We provide guidance on the specific issues that shouldbe particular for each project in order to optimize and customize the specification.