Towards defining reasonable minimum composition thresholds – Impacts of variable CO2 stream compositions on transport, injection and storage
Heike Rütters, Sebastian Fischer, Le Quynh Hoa, Dirk Bettge, Ralph Bäßler, Jobst Maßmann, Christian Ostertag-Henning, Jan Lennard Wolf, Martin Pumpa, Udo Lubenau, Sandra Knauer, Philip Jaeger, A. Neumann, Kristoff Svensson, Herbert Pöllmann, Christof Lempp, Flora Feitosa Menezes, B. Hagemann
Abstract
To set up recommendations on how to define “reasonable minimum composition thresholds” for CO 2 streams to access CO 2 pipeline networks, we investigated potential impacts of CO 2 streams with different and temporally variable compositions and mass flow rates along the CCS chain. All investigations were based on a generic “CCS cluster scenario” in which CO 2 streams captured from a spatial cluster of eleven emitters (seven fossil-fired power plants, two cement plants, one refinery and one steel mill) are collected in a regional pipeline network. The resulting CO 2 stream (19.78 Mio t impure CO 2 per year) is transported in a trunk line (onshore and offshore) and injected into five generic replicate storage structures (Buntsandstein saline aquifers) offshore. Experimental investigations and modeling of selected impacts revealed beneficial as well as adverse impacts of different impurities and their combinations. Overall, no fundamental technical obstacles for transporting, injecting and storing CO 2 streams of the considered variable compositions and mass flow rates were observed. We recommend to define minimum composition thresholds for each specific CCS project through limiting i) the overall CO 2 content, ii) maximum contents of relevant impurities or elements, iii) acceptable variability of concentrations of critical impurities, and defining impurity combinations to be avoided.