||Carbon Dioxide Capture & Storage
||Ghani, Ahmad (Department of Chemical and Biochemical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
Thomsen, Kaj (Department of Chemical and Biochemical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark
||Absorption process using aqueous amine solvents is a suitable methode for carbon capture in power plants, because this technology can easily be retrofitted to existing power stations. Absorption process has a high selectivity, very high capacity, low cost and less harmful to the environment. Finding solvents with better properties is one approach to improving this technology.
Amino acids have a high reaction rate in general, particularly when it reacts with carbon dioxide, resulting in high carbon dioxide loading capacity to the absorption column. The reaction’s product carbamate requires a low heat of decomposition in the desorption section.
The main focus of this thesis is to investigate proline loading capacity. Proline seems to be the best amino acid solvent for the carbon capture process; as it has a higher solubility in water than other amino acids. This means proline do have a highest carbon dioxide loading per unit volume.
Work undertaken a part of this thesis analysed proline loading capacity in a stirred cell reactor at two different operating temperatures. The definition of proline loading capacity is the moles of carbon dioxide absorbed per moles of proline in the solution.
Our experimental results indicated that proline loading capacity is 0.51 [mol carbon dioxide /mol proline] at 50°C and 0.63 [mol carbon dioxide /mol proline] at 25°C without precipitation.
Experimental investigation of the effect of precipitation on carbon dioxide absorption systems has shown a higher loading capacity. The precipitation was observed at high proline solution concentration
≥7 Molal and at temperature 25°C. The precipitation was identified using X-ray diffraction. The chemical composition of the precipitates formed is mainly potassium bicarbonate. Proline loading capacity with the precipitation strongly depends on the concentration of proline solution and can be expressed as follows:
Proline loading capacity with the precipitation = 0.0265 X + 0.495, where x is the molality of proline solution
The examination of temperature effect shows lower solvent loading capacity at higher temperatures. It is also observed that the critical point between the precipitating and non-precipitating is strongly dependent on temperature. This system behavior can be explained by the influence of the temperature on the solubility of carbon dioxide in water.
||Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Creation date: 2010-07-06
Update date: 2010-07-06