Iranian Journal of Oil and Gas Science and Technology

Abstract Hot potassium carbonate (PC) solution in comparison with amine solution had a decreased energy of regeneration and a high chemical solubility of . To present vapor and liquid equation (VLE) of this system and predict  solubility, the ion specific non-electrolyte Wilson-NRF local composition model (isNWN) was used in this study; the framework of this model was molecular. Therefore, it was suitable for both electrolyte and non-electrolyte solutions. The present research employed the NWN model and the Pitzer-Debye-Hückel theory in order to assess the contribution of the excess Gibbs energy of electrolyte solutions in a short and long range. The data of  solubility in water and the system of aqueous  were correlated in the model considering a temperature range of  and a pressure range of and . The average absolute error of ( ) and ( ) systems were  and  respectively. The results and comparisons with other models proved that the experimental data were exactly correlated in the model.

Abstract Abstract
In this study, a mathematical model is proposed for CO₂ separation from N₂/CO₂ mixtureusing a hollow fiber membrane contactor by various absorbents. The contactor assumed as non-wetted membrane; radial and axial diffusions were also considered in the model development. The governing equations of the model are solved via the finite element method (FEM). To ensure the accuracy of the developed model, the simulation results were validated using the reported experimental data for potassium glycinate (PG), monoethanol amine (MEA), and methyldiethanol amine (MDEA). The results of the proposed model indicated that PG absorbent has the highest removal efficiency of CO₂, followed by potassium threonate (PT), MEA, amino-2-methyl-1-propanol (AMP), diethanol amine (DEA), and MDEA in sequence. In addition, the results revealed that the CO₂ removal efficiency was favored by absorbent flow rate and liquid temperature, while the gas flow rate has a reverse effect. The simulation results proved that the hollow fiber membrane contactors have a good potential in the area of CO₂ capture.

Abstract In this paper, the development of a new potassium carbonateon alumina support sorbent prepared by impregnating K2CO3 with an industrial grade of Al2O3 support was investigated. The CO2 capture capacity was measured using real flue gas with 8% CO2 and 12% H2O in a fixed-bed reactor at a temperature of 65 °C using breakthrough curves. The developed sorbent showed an adsorption capacity of 66.2 mgCO2/(gr sorbent). The stability of sorbent capture capacity was higher than the reference sorbent. The SO2 impurity decreased sorbent capacity about 10%. The free carbon had a small effect on sorbent capacity after 5 cycles. After 5 cycles of adsorption and regeneration, the changes in the pore volume and surface area were 0.020 cm3/gr and 5.5 m2/gr respectively. Small changes occurred in the pore size distribution and surface area of sorbent after 5 cycles.