Techno-economic modelling and analysis of CO2 pipelines

Abstract

The main focus of this paper is on techno-economic modeling and analysis of CO2 pipelines, as it strives to develop a thorough understanding of the essential fluid-mechanics variables involved in modeling and analysis of such pipelines. The authors investigate and analyze the reasons behind the variations in the techno-economic results generated from seven different techno-economic models which are commonly used for construction and operation of CO2 pipelines. Such variations often translate into tens or, at times, hundreds of millions of dollars in terms of initial financial estimates at the Pre-FEED (Front End Engineering Design) or FEED stages for Carbon Capture and Storage (CCS) projects. Variations of this magnitude can easily bring much unwanted uncertainty to the feasibility of a CO2 pipeline project and they can potentially cause a major over or under estimation of the project’s true costs. The summary of a detailed analysis and assessment for these seven existing techno-economic models for CO2 pipeline transport has been presented in this paper. The analysis conducted indicates that some of these models are essentially identical and are rooted in similar fluid mechanics theories and assumptions. This type of analysis assists with explaining and narrowing down the variability of the models’ results. Based on these analyses, a refined and more accurate model was established and the development process was explained. The refined model uses the Reynolds number, Colebrook-White equation using the Darcy friction factor, and the Darcy-Weisbach pressure drop equation to establish the most accurate measure for the pipe’s diameter. To assess the CO2 pipeline’s total capital cost, total annual cost, and the levelized transport cost, a statistical regression analysis approach was suggested and the adjusted-r2 measure was proposed to assess the goodness-of-the-fit of the generated cost function. The accuracy of the new techno-economic model was validated with the figures of a proposed CO2 infrastructure project in the United Kingdom and also through hydraulic modeling.