Pressure resistant liquid membranes

Introduction

The increasing energy consumption and decreasing amount of fossil fuels available requires efficient use of fossil fuels, exploration of sustainable energy sources and a reduction in the energy consumption. The (petro)chemical industry contributes to a significant amount of the world total energy consumption and approximately 40% of it is applied for separation processes (e.g. distillation, ad- and absorption). The separation of olefins and paraffins by cryogenic distillation is currently one of the most energy intensive separation processes in the petrochemical industry due to the close boiling points and similarities between the components. Therefore, the energy savings obtainable in this area with membrane technology are significant.

Research

Liquid membranes are promising for the separation of olefins and paraffins. By filling porous membranes with ionic liquids mixed with silver salts, high olefin/paraffin selectivities can be obtained, often in combination with enhanced olefin permeances because of the liquid state of the selective layer. However, one of the main drawbacks of liquid membranes is the limited pressure they can sustain which is crucial for practical applications where process conditions are typically above 0.5 MPa. This project aims at developing pressure resistant liquid membranes by sealing liquid membranes with a dense layer, only permeable to gasses. This layer should be highly permeable to gasses to prevent losing the advantage of liquid membranes as a selective layer. After preparation of the liquid membranes a thin dense membrane will be coated on one or both sides of the liquid membrane. Several different coating techniques will be investigated as well as different polymer coatings to optimize the sealing layer. Afterwards, the membrane properties will be evaluated using several techniques (e.g. pycnometry, DSC, TGA, SEM and high pressure gas permeation experiments).

Main activities during the project

M-Committee