Modeling and Simulation of the Simultaneous Absorption/Stripping of CO with Potassium Glycinate Solution in Membrane Contactor.

Global warming is an environmental problem caused mainly by one of the most serious greenhouse gas, CO emissions. Subsequently, the capture of CO from flue gas and natural gas is essential. Aqueous potassium glycinate (PG) is a promising novelty solvent used in the CO capture compared to traditional solvents; simultaneous solvent regeneration is associated with the absorption step. In present work, a 2D mathematical model where radial and axial diffusion are considered is developed for the simultaneous absorption/stripping process. The model describes the CO/PG absorption/stripping process in a solvent-gas membrane absorption process. Regeneration data of rich potassium glycinate solvent using a varied range of acid gas loading (mol CO per mol PG) were used to predict the reversible reaction rate constant. A comparison of simulation results and experimental data validated the accuracy of the model predictions. The stripping reaction rate constant of rich potassium glycinate was determined experimentally and found to be a function of temperature and PG concentration. Model predictions were in good agreement with the experimental data. The results reveal that the percent removal of CO is directly proportional to CO loading and solvent stripping temperature.