Potential Dynamics of CO2 Stream Composition and Mass Flow Rates in CCS Clusters

Abstract

Temporal variations in CO₂ stream composition and mass flow rates may occur in a CO₂ transport network, as well as further downstream when CO₂ streams of different compositions and temporally variable mass flow rates are fed in. To assess the potential impacts of such variations on CO₂ transport, injection, and storage, their characteristics must be known. We investigated variation characteristics in a scenario of a regional CO₂ emitter cluster of seven fossil-fired power plants and four industrial plants that feed captured CO₂ streams into a pipeline network. Variations of CO₂ stream composition and mass flow rates in the pipelines were simulated using a network analysis tool. In addition, the potential effects of changes in the energy mix on resulting mass flow rates and CO₂ stream compositions were investigated for two energy mix scenarios that consider higher shares of renewable energy sources or a replacement of lignite by hard coal and natural gas. While resulting maximum mass flow rates in the trunk line were similar in all considered scenarios, minimum flow rates and pipeline capacity utilisation differed substantially between them. Variations in CO₂ stream composition followed the power plants’ operational load patterns resulting e.g., in stronger composition variations in case of higher renewable energy production.