Experimental Investigation of the Gas/Liquid Phase Separation Using a Membrane-Based Micro Contactor

Abstract

The gas/liquid phase separation of CO2 from a water-methanol solution at the anode side of a µDirect-Methanol-Fuel-Cell (µDMFC) plays a key role in the overall performance of fuel cells. This point is of particular importance if the µDMFC is based on a “Lab-on-a-Chip” design with transient working behaviour, as well as with a recycling and a recovery system for unused fuel. By integrating a membrane-based micro contactor downstream into the µDMFC, the efficient removal of CO2 from a water-methanol solution is possible. In this work, a systematic study of the separation process regarding gas permeability with and without two-phase flow is presented. By considering the µDMFC working behaviour, an improvement of the overall separation performance is pursued. In general, the gas/liquid phase separation is achieved by (1) using a combination of the pressure gradient as a driving force, and (2) capillary forces in the pores of the membrane acting as a transport barrier depending on the nature of it (hydrophilic/hydrophobic). Additionally, the separation efficiency, pressure gradient, orientation, liquid loss, and active membrane area for different feed inlet temperatures and methanol concentrations are investigated to obtain an insight into the separation process at transient working conditions of the µDMFC.

Prototyping a Microfluidic Sensor for Real-Time Detection of Airborne Formaldehyde

“…4). They have a reference pore diameter of 200 nm and the contact angle is 120° [9]. The polymer chip hosts a network of two overlapping meandering micro-channels, one channel being assigned to the liquid stream and the other one to the gas stream.…”

Methanol–Water Purification Control Using Multi-Loop PI Controllers Based on Linear Set Point and Disturbance Models

“…The conversion from methanol to DME will still produce excess methanol and water, so they would be separated in a distillation column where the purified methanol is recycled to produce more DME [6][7][8]. This is different from what has been studied by Dyrda et al [9], who used a membrane-based separation process to separate methanol and water to improve the performance of the fuel cell. In this research, a distillation column is used for separating methanol and water.…”