||Thermodynamic modeling of sour water strippers
||Krüger, Thomas Christian (Department of Chemical and Biochemical Engineering, Technical University of Denmark, DTU, DK-2800 Kgs. Lyngby, Denmark)
||Thomsen, Kaj (CERE – Center for Energy Ressources Engineering, 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
||Combustion of fossil fuels like oil and gas is still the primary energy source in our society. Due to the tightening of environmental legislation, treatment
of waste material has become an important scientic issue. The processing of hydrocarbons leads to big amounts of waste water. The waste water contains carbon dioxide, ammonia and hydrogen sulde. The waste water is stripped
for contaminants in a collumn. In order to optimize the process it is necessary to be able to simulate it. For this matter, the extended UNIQUAC model is used.
In total 948 points of measured data have been obtained from the litterature.
All of the data contains information on the vapor-liquid equilibrium for the quartenary H2S-NH3-CO2-H2O system and its subsystems containing H2S. The data represents a broad range of temperatures (203-453 K), pressures (0,40 mbar - 89 bar) and concentrations of H2S (0,027-14 molal), NH3 (0,28-52 molal) and CO2 (0,027-3,0 molal).
The modelling is based on estimation of parameters for the extended UNIQUAC model. The parameters are the volume and surface parameters ri and qi, and the interaction parameters u0 ij og ut ij . In order to determine these a Bjerrum diagram has been constructed. Hence, it is possible to determine which species that can co-exist.
A number of graphs have been made in order to illustrate the t of the model to the experimental data. Furthermore, the results of the models have been compared to results obtained from models made by van Krevelen et al., 1949,
Edwards et al., 1978, Beutier & Renon, 1978 and Wilson, 1978.
It is shown, that the model is able to reproduce the experimental values with a good correlation. Furthermore, the comparison with other models show that
the extended UNIQUAC model is superior. The extended UNIQUAC model is a suitable solution for the simulation of the stripping process of sour water.
||Technical University of Denmark (DTU) : Kgs. Lyngby, Denmark
Creation date: 2011-02-16
Update date: 2011-02-16