One of the major issues encountered in the Post Combustion CO₂ Capture processes is the degradation of the solvent which can be in great part attributed to the presence of oxygen in the solution. The present report focuses on the demonstration of DORA (Dissolved Oxygen Removal Apparatus), a technology developed by TNO as a counter-measure of oxidative degradation. The DORA was first operated in combination with TNO's mobile bench-scale CO₂ capture pilot (5 Nm³/h flue gas capacity) with artificial flue gas, showing an instant drop of 15% and an overall reduction of approximately 70% in the ammonia emissions from the absorber, which is an indication of reduced degradation. The technology was also demonstrated using the same pilot in an industrial environment in collaboration with the facility PlantOne bringing DORA from TRL5 to TRL6. This campaign proved that DORA contributed to the deacceleration of solvent degradation. The tests were executed with a porous membrane, and it was observed that exposure to degraded solvents led to solvent leakage through this membrane. Therefore, the use of a coated membrane was proposed to optimize the operation and increase oxygen removal. The use of this membrane is demonstrated at TRL3. Along with that, a model was developed to determine mass transfer resistances and the membrane area required to remove different levels of dissolved oxygen.

This work aims to understand oxygen solubility in pure and aqueous amine solvents for CO₂ capture. Commercially available dissolved oxygen sensors were studied to evaluate whether these can be used for measuring oxygen solubility in the carbon capture processes. It also aims to understand the possible discrepancies from realistic concentrations of oxygen when using a dissolved oxygen sensor. Two independent measurement principles were used for this purpose, both electrochemical and optical. Furthermore, a Winkler titration method was used to aid the validation of the sensors as well as understanding salting-out effects. A simple model for predicting oxygen solubility in CO₂-loaded ethanolamine solutions was made, which also has potential for predicting oxygen solubility in other loaded amine solutions. The results of the study show that dissolved oxygen sensors may be applied for measurement of oxygen concentrations in amine solutions and that different amines and different concentrations in water only show small variations in oxygen solubility. The sensors may also be used in CO₂-loaded amine solutions, but here the increased conductivity of the solution may give a higher measured concentration of oxygen, than it is in reality. In ethanolamine, the consumption of oxygen is faster than the mass transfer of oxygen from gas to liquid phase, giving lower concentrations of oxygen than it should be in absence of a chemical reaction between oxygen and amine.

Knowledge on the solubility of gases, especially carbon dioxide (CO2), in monoethylene glycol (MEG) is relevant for a number of industrial applications such as separation processes and gas hydrate prevention. In this study, the solubility of CO2 in MEG was measured experimentally at temperatures of 333.15, 353.15, and 373.15 K. Experimental data were used to validate Monte Carlo (MC) simulations. Continuous fractional component MC simulations in the osmotic ensemble were performed to compute the solubility of CO2 in MEG at the same temperatures and at pressures up to 10 bar. MC simulations were also used to study the solubility of methane (CH4), hydrogen sulfide (H2S), and nitrogen (N2) in MEG at 373.15 K. Solubilities from experiments and simulations are in good agreement at low pressures, but deviations were observed at high pressures. Henry coefficients were also computed using MC simulations and compared to experimental values. The order of solubilities of the gases in MEG at 373.15 K was computed as H2S > CO2 > CH4 > N2. Force field modifications may be required to improve the prediction of solubilities of gases in MEG at high pressures and low temperatures.

Calorimetric study of a precipitating solvent system of Potassium-Taurate (KTAU) was performed in the CPA202 calorimeter. Two different experiments were conducted, i.e. heat of absorption of CO2 in KTAU solvent at different conditions (concentration = 1.5 M and 3.0 M), loading up to ∼ 0.8 mol CO2/ mol Taurine and temperature = 25 °C, 40 °C, 80 °C). Moreover, dissolution heats of Taurine/solid were also measured. The result agrees well with the reported data. The procedure developed for the heat of dissolution measurements was verified by measuring heat of dissolution of solid Taurine in water and comparing results with data in literature. The solid formation occurs during the absorption of CO2 in 3.0 M KTAU at low temperatures (25 °C and 40 °C) and at loadings (∼ 0.3 mol CO2/ mol Taurine). The heat of dissolution of the formed solid in pure water is slightly higher than that of Taurine in pure water but less heat is required to dissolve the same solids in unloaded 3.0 M KTAU solution. Published by Elsevier Ltd.