Energy requirement analysis on carbon capture plants satisfying impurity specifications

Abstract

Simulation-based analysis estimating both the energy requirement of the entire carbon capture process and the purity of the recovered CO₂ is scarce. The purity of the captured CO₂ is crucial as it must meet a specification before transportation, preventing phase change and damage to the transportation system. This study conducted 31,104 simulations of a monoethanolamine carbon capture plant treating measured flue gas from an existing cement production plant. After capture, the CO₂ is treated through a deoxygenation unit followed by a compression train to fulfill specific quality specifications. Based on the sensitivity analysis, the energy consumption of the post-treatment process decreased with increased purity downstream. Despite this, the total energy consumption was not affected. Moreover, after the two-step purification the CO₂ stream was able to successfully fulfill the specification for NO_x, O₂, NH₃, Ar, CO, SO₂. However, failing to meet the H₂O concentration requirements of both considered specifications and the N₂ concentration specified for ship transport. Thus, increasing the post-treatment energy cost or standard adjustments is required for future applications.