Hydrodynamics study of the modified rotating disc contactor for CO2 absorption from natural gas using emulsion liquid membrane

Abstract

A c c e p t e d M a n u s c r i p t Highlights:Emulsion liquid membrane in rotating disc contactor was used for CO2/CH4 separation A stable emulsion liquid membrane was formulated by high-speed homogenization The characteristics of emulsion liquid membrane system were evaluated The process parameters for CO 2 separation from natural gas were analyzed ABSTRACT This study modified the rotating disc contactor (RDC) structure to optimize its performance for CO 2 separation from natural gas feed using stable emulsion liquid membrane (ELM).Based on parametric study of absorption of CO 2 from natural gas feed into ELM, the mass transfer behaviour in the RDC system was optimized. Rotor diameter, stator inner diameter and minimum free area of RDC were modified to achieve maximum contact between dispersed liquid phase and gas feed phase which was necessary to achieve maximum mass transfer. The problem of rupture the emulsion droplet due to pressure created by direct dispersing of gas at the bottom of conventional RDC extraction system was addressed by Page 3 of 44 A c c e p t e d M a n u s c r i p t adding an impeller at the bottom compartment of RDC. Impeller provided continuous mixing of emulsion and a gas sparger was fitted along the impeller side which maintained the dispersed aqueous phase miscible in system. The hydrodynamic behavior of a modified RDC was optimized for CO 2 absorption from natural gas in ELM which indicated that modified design dimensions can provide a maximum liquid-gas contact. Beside the concentration CO 2 in natural gas feed, it was observed that the speed of RDC and run time significantly influences CO 2 absorption from natural gas using ELM. If all the parameters optimized absorption from natural gas feed. This study is also useful in extending the application of RDC in liquid-gas system. In this study are applied in proper conditions, the use of ELM in RDC can be effective for CO 2 .

The Effect of Cosurfactant in Co2 Absorption in Water – In – Oil Emulsion

“…Based on Figure 1, the stability of emulsion was at lowest which at 9.6% when DOPC acted as the only surfactant for sample 3. This finding agreed with paper published by Kim et al, where the researcher reported that DOPC is typically unstable because of its molecular structure whose HLB value is moderate (7), therefore resulting in the poor stability of W/O emulsion [6].…”

“…Two different types of aqueous phase were used, there were the combination of MDEA/AMP and MDEA only. For MDEA/AMP, 8% v/v MDEA and 88% NaOH and 4% v/v AMP and for MDEA, 8% v/v MDEA was the best for CO2 absorption [7]. Despite the appealing features of emulsion, this technique used in absorption is not widespread used due to the instability of emulsion [8].…”

“…In addition, a cone shape molecular geometry possibly induced a better packed interface with phospholipids, preventing coalescence between dispersed droplets in the emulsion [6]. Increasing viscosity is one of methods to increase the stability of emulsion globules [7]. Viscosity of emulsion increase as SPAN 80 used as cosurfactant complementary to DOPC, however increase in viscosity may inhibit the absorption process as it can reduce the solubility of CO2 [13].…”