International Journal of Greenhouse Gas Control 31 (2014) 165–174 Contents lists available at ScienceDirect International Journal of Greenhouse Gas Control j ourna l h o mepage: www.elsevier.com/locate/ijggc Optimal pipeline design for CCS projects with anticipated increasing CO 2 flow rates Z. Wang, G.A. Fimbres Weihs, G.I. Cardenas, D.E. Wiley ∗ Cooperative Research Centre for Greenhouse Gas Technologies (CO2CRC), School of Chemical Engineering, UNSW Australia, UNSW, Sydney 2052, NSW, Australia a r t i c l e i n f o Article history: Received 4 July 2014 Received in revised form 7 October 2014 Accepted 16 October 2014 Keywords: CSS economics Pipeline optimisation Pipeline sizing Pipeline diameter a b s t r a c t Large-scale CCS projects with multiple CO 2 sources will require large investments. Optimising the pipeline network design for cost reduction has been proposed as a potential way to reduce overall CCS costs. This paper presents a two-step methodology for the optimal design of on-shore pipelines with a projected increase in CO 2 flow rate. The first step involves determining whether an oversized design is preferable over a duplicate pipeline design, on the basis of the levelised CO 2 transport cost. This is performed through a simple correlation that depends on key parameters including the length of the pipeline, the timing and magnitude of the flow increase. If the oversized design is preferred, the second step of the proposed method determines the optimal diameter for the oversized pipeline. The approach, based on modelling of a wide range of generic cases, provides a two-step method to quickly verify whether an oversized pipeline is necessary, to assess the costs of using an oversized design against those of building duplicate pipelines, and to identify the pipeline design that minimises levelised cost of CO 2 transport. A sensitivity analysis shows that the correlations are applicable for a wide-range of values for flow rate, transport distance, discount rate, steel price, booster pump and electricity costs. In addition, the correlations for pipeline cost and optimal diameter developed in this paper can be integrated into and accelerate the existing large scale, staged CO 2 pipeline network optimisation models. © 2014 Elsevier Ltd. All rights reserved. 1. Introduction 1.1. Background Large pipeline infrastructure will be one of the options avail- able for CO 2 transport in Carbon Capture and Storage (CCS) projects (Calvo and Gvirtzman, 2013; Roussanaly et al., 2013). Several regions around the world are developing ideas for CO 2 networks which can accommodate CO 2 emissions from industrial facilities as well as from power stations (Fimbres Weihs et al., 2011; Mikunda et al., 2011). It is relatively simple to model and optimise a single pipeline connecting a steady source and a CO 2 sink by determining the minimum diameter required to achieve a fixed pressure drop while keeping the CO 2 in a dense phase throughout the length of the pipeline (NETL, 2013), by minimising the unit cost of CO 2 trans- ported (Knoope et al., 2014; Zhang et al., 2006), or by optimising a trunk pipeline (Chandel et al., 2010; Knoope et al., 2013). ∗ Corresponding author. Tel.: +61 2 9385 4755; fax: +61 2 9385 5966. E-mail address: d.wiley@unsw.edu.au (D.E. Wiley). Most of the existing literature on CCS transport networks in dif- ferent regions around the world assumes that the CO 2 flows within the network are static for the life of the network. For example, steady-state optimisation of CCS networks has been investigated in Australia (Fimbres Weihs et al., 2011, 2012; Fimbres Weihs and Wiley, 2012) and in the United States (Ambrose et al., 2009; Kuby et al., 2011; Middleton et al., 2012a) Several large-scale models have also been applied to the economic analysis of CO 2 networks in Euro- pean countries (Chandel et al., 2010; Klokk et al., 2010; McCoy and Rubin, 2008; Mikunda et al., 2011; Morbee et al., 2012). One of the major drawbacks of using a static network model is that it assumes all the CO 2 sources are connected to the network at the same time and that CO 2 flow rates stay constant for the entire project life. The substantial CO 2 infrastructure proposed in these studies would require significant upfront financial investment in order to achieve the predicted economies of scale in levelised CO 2 transport and avoidance costs. It is also possible that CO 2 transport requirements may not be static but expand due to the gradual uptake of CCS over time. The CO 2 pipeline network used for EOR in the U.S. is an example of this type of infrastructure expansion (Dooley et al., 2009). In the early 1980s CO 2 —EOR comprised approximately 5% of total U.S. http://dx.doi.org/10.1016/j.ijggc.2014.10.010 1750-5836/© 2014 Elsevier Ltd. All rights reserved.