Modelling, simulation, and membrane wetting estimation in gas‐liquid contacting processes

Abstract

A set of experiments for CO 2 separation from CO 2 -N 2 mixture by absorption into water by means of a gas-liquid membrane contacting process is modelled using the mass continuity equation by combining process conditions, membrane and fluids properties, and module geometric characteristics. The general case of non-constant concentration of the diffusing component in the shell side (Case B) is used, which entails an integro-differential boundary condition at the lumen-wall. The computational method is compared with existing literature data in terms of the logarithmic averaged overall and lumen Sherwood numbers revalidating the superiority of the counter-current to the co-current mode of operation, while offering a theoretical prediction of the limited behaviour of the latter as a function of the equilibrium coefficient. The elaborate model is then applied in order to assess the extent of membrane wetting due to liquid penetration into the pores in terms of the resistance-in-series model by comparing with the experimental results derived in a commercial cross-flow membrane module under the counter-current mode of operation. It is revealed that the assumption of shell-side constant concentration (Case A) underestimates the wetting leading to a false estimation of the extent of liquid penetration into membrane pores. For Case B, a wetting-pattern appears showing a correlation of an increasing shell-side liquid flow rate with a decreasing wetting parameter and, thus, relatively less contribution of the liquid-filled membrane resistance to the overall membrane resistance with increasing liquid loading.

Modeling, Simulation, and Membrane Wetting Estimation in Gas–Liquid Contacting Processes Including Shell-Side Reaction: Biogas Upgrading Using DEA Solution

“…The authors showed that the computational wetting to match the experimental data decreases with the increase of the fiber-side liquid velocity, which indicates that an inverse relationship may exist between the liquid flow rate and the wetting, as also demonstrated by Pantoleontos et al in a previous study when considering a physical-absorption case. 8 The current study improves upon the previous work by Pantoleontos et al, who presented a CO 2 -in-water physicalabsorption case along with macroscopic mass balance on the shell side, also accounting for process conditions, membrane and fluid properties, and module geometric characteristics. 8 The ubiquitous resistance-in-series approach, as shown in eq 1, is a pertinent prerequisite in the analysis attempting to interpret the underlying wetting phenomena and aspiring to discern any wetting pattern.…”

“…CO 2 removal using membrane-based gas absorption and reaction is gaining attention as an alternative to well-established industrial gas-separation and reaction equipment, such as reactive-absorption columns, because of the high mass transfer area (known a priori ) of the membrane modules per unit volume, their modular design, and easy scale-up of the process. − A membrane bundle containing hundreds of fibers is placed within the membrane module with a customizable length, and it may provide a modular solution for easy lab- and pilot-testing with a specific surface area in the range of 1500–7000 m 2 /m 3 compared to 100–800 m 2 /m 3 for conventional devices …”

Investigation of Mass Transfer Characteristics of SO2 Absorption into NaOH in a Multichannel Ceramic Membrane Contactor

“…The microstructure parameters of the membrane have a significant influence on the desulfurization effect of the membrane contactor . Meanwhile, there is also no validated accurate model for the simulation of mass transfer behavior in a multichannel membrane contactor; therefore, the design and optimization of membrane contactors are hindered. − …”

Experimental and numerical investigation binary mixture mass transfer in a gas – Liquid membrane contactor

“…2D models are typically used for this kind of approaches. They consider the fiber radial direction to describe mass transfer in the different phases and perform a numeric resolution considering a single fiber [20,27,28,[37][38][39][40][41].…”