CFD Analysis of CO2 Sequestration Applying Different Absorbents Inside the Microporous PVDF Hollow Fiber Membrane Contactor

Abstract

The sequestration process of greenhouse contaminants such as CO 2 via hollow fiber membrane contactor (HFMC) is regarded as a promising technology to manage the deleterious impressions of CO 2 on environment such as global warming and air pollution.This investigational paper renders a wide-ranging 2D simulation in order to assess the removal performance of CO 2 from CO 2 /CH 4 gaseous stream (containing 80 % CH 4 and 20 % CO 2 ) in the HFMC. As the novelty, the evaluation of CO 2 acid gas removal from gaseous mixture applying four novel absorbing agents (potassium threonate (PT), piperazine (PZ), pure water (H 2 O) and methyldiethanolamine (MDEA)) is implemented in the HFMC with the aim of introducing a more efficient liquid absorbent for CO 2 sequestration.Model validation is done based on the comparison of mathematical model outcomes and experimental data in a wide range of H 2 O velocity and confirms a desirable agreement with an average relative deviation (ARD) of approximately 3 % for CO 2 flux. It is perceived from the results that PZ is introduced as the most efficient liquid absorbent for CO 2 sequestration and MDEA, PT and H 2 O are in the next category (100 % removal using PZ > 96 % removal using MDEA > 89 % removal using PT > 57 % removal using H 2 O). The results corroborate that increase in membrane tortuosity and gas velocity negatively affects the sequestration process while increment of module length and porosity improve the separation of CO 2 .

Molecular investigation into the effect of carbon nanotubes interaction with CO2 in molecular separation using microporous polymeric membranes

“…Indeed, the CFD-based results of CO 2 sequestration percentage using CNTs water-based nanofluid are compared with measured data provided by Peyravi et al in various gas flow rates (Q g ) 16 . The sequestration yield of CO 2 molecules applying distilled water and CNTs water-based nanofluid is presented in the following equation, where C and Q are respectively expressed as the concentration of CO 2 in the gas phase and volumetric gas flow rate 44,48,54 : Figure 3 implies the presence of a great agreement between the measured data and modeling/simulation results for CO 2 molecular separation percentage using CNTs water-based nanofluid with an average deviation (AD) of about 6%. Figure 4a,b demonstrate the modeled surface plots of CO 2 concentration distribution in all main domains of PMC applying distilled water and CNTs water-based nanofluid as absorbents, respectively.…”

“…The boundary conditions employed in the tube section are interpreted as below: (6) at r = r 3 : ∂C CO 2 ,shell /∂r = 0 (7) at z = 0: Convective flux www.nature.com/scientificreports/ The continuity equation based on steady state and non-wetted operating modes inside the PMC's membrane segment is given by Eq. 20 28,38,42,43,48 . Non-wetting assumption caused that the fiber pores are only filled with the gas molecules.…”

Theoretical investigations on the effect of absorbent type on carbon dioxide capture in hollow-fiber membrane contactors

“…Carbon dioxide chemical absorption by chemical absorbents in packed or tray columns is one of the commercial and conventional methods for reduction of CO 2 emission into the atmosphere. However, these techniques have some critical issues including high energy consumption, flooding, foaming, channelling and entrainment, which reduce the process efficiency [9,10]. Membrane contactor concept was introduced for CO 2 absorption in order to overcome the technical problems associated with conventional methods.…”

Molecular separation of ibuprofen and 4-isobutylacetophenone using octanol organic solution by porous polymeric membranes

“…The hollow fiber membrane systems, as an innovative device for separating trace concentration of contaminants, have great advantages including independent controllable flow rates of aqueous/organic phases, membrane high surface area, low analysis cost, easy handling, low consumption of organic solvent, and high analyte capacity [17][18][19][20][21].…”