Analysis of CO2 transport including impurities for the optimization of point-to-point pipeline networks for integration into future solar fuel plants

The present work aims to establish a generic model for calculating point-to-point pipelines transport of CO2 mixtures. This study improves upon highly-detailed existing models by providing further engineering and economics features, such as the rights-of-way portion of the pipeline cost, and the implicit Darcy-Weisbach-Colebrook-White equation for the calculation of the friction and the pressure drop within the pipeline. The model is applied to binary mixtures of CO2 with 2%mol H2 and 4%mol N2 concentrations, roughly resembling oxy-fuel and pre-combustion CO2-capture binary mixtures, respectively. Analytical expressions of the physical properties of CO2 mixtures are combined with engineering and economic aspects of the pipeline facility, in order to determine the optimal pipeline diameter for pipeline capacity within the range of 150-2000 kg/s and for transport distances from 500 to 2000 km. Pure CO2 transport is used as a base-case in order to replicate existing literature data, while the calculated data are interpolated to derive correlations of the minimum levelized cost with respect to transport capacity and distance for all mixtures examined. It is shown that there is a slight impact at the expense of the economics of the process when considering impurities. A breakdown of the cost elements involved in the transportation chain of CO2 is conducted, and the influence of the mass flowrate and the length of the pipeline on the process economics is examined.