Separasjons- og miljøteknikk

Membranes for gas and liquid separations

The Memfo group

The group has extensive activities both on basic membrane material development, as well as membrane gas separation processes, modelling and simulations. The main focus for the research is CO2 capture by membranes (from flue gas, natural gas sweetening, biogas upgrading) and hydrogen recovery from various mixed gas streams. In addition to these energy focused applications, the research on membranes for chlorine separation continues. The membrane materials in focus are various types of polymers, nanocomposites, carbon membranes, and modified glass membranes. The international network is extensive, with co-operation both within EU-projects, USA, Japan, the Nordic countries and Russia.

Reverse osmosis is today one of the major methods for desalting ocean water into freshwater. Osmotic effects demands that a high pressure on the saltwater side of the membrane modules must be applied to override the osmotic pressure difference between sea water and freshwater. If the applied pressure in the cells is lower than the osmotic pressure the water flow is reversed and freshwater flows into the saltwater compartment, thus increasing the volume of moderately pressurized saltwater. This is the principle of Pressure Retarded Osmosis (PRO), which may be used to produce electric energy as the surplus water on the saltwater side may be run through turbines for power production. The potential for power production at the outlet of every river that flows into the ocean is very large. The experiments are done in cooperation with SINTEF and others, and are partly financed by Statkraft.

Crystallization

In the crystallization group we study kinetics of nucleation, crystal growth, and agglomeration in order to predict and control the particle size distribution and shape of crystalline particles related to scaling behaviour and down-stream processes like solid-liquid separation and powder characteristics. The research is financed through collaboration projects with international and domestic industry and the Norwegian research council. The main areas of the research are:

• Precipitation of scaling minerals in gas and oil processing. Induction time and growth rate measurements.
• Fundamental investigations of crystal growth mechanisms and agglomeration.
• The link between filtration behaviour and particle shape and growth kinetics.