Mass Transfer Analysis of CO₂ Capture by PVDF Membrane Contactor and Ionic Liquid

Abstract

Post-combustion processes based on ionic liquids (ILs) and membrane contactors are attractive alternatives to traditional systems. Here, a gas stream composed of 15 % CO 2 and 85 % N 2 flowed through the lumen side of a hollow-fiber membrane contactor containing poly(vinylidene fluoride)-IL (PVDF-IL) fibers. The IL 1-ethyl-3-methylimidazolium acetate [emim][Ac] served as an absorbent due to its high chemical absorption and CO 2 solubility. The overall mass transfer coefficient (K overall ), activation energy (E a ), and resistances of the hollow-fiber membrane were quantified. The K overall value was one order of magnitude higher than those reported in previous works with conventional solvents, and the E a was lower than formerly stated values for other solvents. A theoretical simulation was conducted to estimate the operational parameters required for 90 % CO 2 capture and to quantify intensification effects related to CO 2 absorption in a packed column.

Selective Removal of H2S from Gas Streams with High CO2 Concentration Using Hollow‐Fiber Membrane Contractors

“…According to , in the absence of CO 2 , an increase in H 2 S feed concentration does not lead to a significantly negative effect on removal efficiency, while in the presence of CO 2 an increase in concentrations of acid gases strongly decreases the removal efficiency. It should be noted that the negative impact of CO 2 feed concentration is more effective on CO 2 removal efficiency compared to that of H 2 S. So, it can enhance the H 2 S selectivity despite of reducing its removal efficiency.…”

“…In the absence of CO 2 , no reduction in removal efficiency of H 2 S was observed as a result of increasing its feed concentration , but as can be seen in Figs. and , in the presence of CO 2 , an increase in H 2 S or CO 2 concentrations strongly reduced removal efficiencies.…”

“…The topic of membrane wetting has been widely discussed in literature , . A large number of studies , dealing with H 2 S and CO 2 absorption by membrane contactors involving hydrophobic microporous hollow fibers have been published. The common chemical absorbents used in those studies were alkanolamine solutions, metal hydroxides, and water.…”

Mathematical modeling of CO2 absorption with ionic liquids in a membrane contactor, study of absorption kinetics and influence of temperature

“…Values of Henry's law constant are presented in Table . Gómez‐Coma et al . transformed the value of overall mass transfer coefficient for [emim][OAc] to a reaction constant.…”

Experimental and Numerical Investigation of CO2 Absorption Using Nanofluids in a Hollow‐Fiber Membrane Contactor

“…In recent years, increasing greenhouse gas emissions have resulted in climate change and led to wide concern in scientific, environmental, political, and economic fields. CO 2 causes roughly two‐thirds of greenhouse effects and is responsible for 55 % of global warming . Currently, fossil fuels are the major CO 2 emission source and it is estimated that they will remain the main energy generation source for more than the next two decades .…”