Simulation and Model Verification of the Dynamic and Steady State Behavior of the CO2 Capture Plant at TCM.

Abstract

Post-combustion CO2 capture (PCC) with amines is the most mature technology for CO2 capture, and is considered to be an important part of future carbon capture and storage projects. A dynamic model of a PCC amine plant could provide useful information about the dynamic behaviour of the plant and be used for optimization purposes. Several dynamic models of PCC amine pilot plant exist but only few have been validated with experimental dynamic data.

In this thesis, a dynamic model of the PCC amine pilot plant at Technology Centre Mongstad has been validated against both steady state and dynamic experimental data from Aker Solutions test campaign. The flue gas used in the test was from a combined heat and power plant and contained approximately 3.5% CO2. Monoethanolamine (MEA) was used as solvent and tests with both 30 and 40 weight percent MEA were conducted. The model was first validated against data from 8 steady state periods. Two different correlations for mass transfer were compared (Billet and Rocha) and the model results are nearly identical with the use of the two. The model well predicts the CO2 production rate and the deviations between simulated and experimental results are below 8% in all the steady state periods. Some differences in temperature results are seen, especially between experimental and simulated desorber temperature profiles.

Four dynamic cases were simulated, all containing multiple parameter changes. The dynamic cases include operations with both 30 and 40 weight percent MEA, and step-changes in solvent flow rate and flue gas inlet were simulated. The model well predicts the dynamic responses in all the investigated parameters. Some stationary deviations are seen, and these are assumed to be caused by errors in pilot plant data and model correlations that are used in calculations of CO2 mass transfer and hydraulic area.