The separation of oil from stable oil-in-water emulsions is a challenge. This is especially the case if the permitted limits for oil in water are very low, as is the case for the discharge of produced water. Equally challenging is the separation of oil or grease under more extreme process conditions, the processing of food, dairy, pharmaceuticals and chemicals.
Many separation technologies have been studied and have proved to be technically or economically challenging. However, Silicon Carbide (SiC) membranes do seem to be a viable option. In a new project, the development and performance characteristics of SiC membranes are being explored with a view to using them in new applications.
In previous ISPT projects – such as CombiClear – SiC membranes have been found to deliver a good performance for the treatment of oil in water emulsions. However, what is currently still missing and is needed for their deployment in the industry, is knowledge about the behavior of these membranes in duration tests and, in particular, the possibilities for cleaning them. This will be studied in this project during a pilot trial in a relevant environment, where fouling, cleaning options, cleaning frequency and the consequences for the long term performance and economics will be determined.
KWR will contribute to the determination of the long-term performance of the SiC membrane technology and the setup of the test program for the cleaning tests with the pilot plant (membrane surface 8 m2) at the site of ESD-SiC (project partner). In addition KWR will conduct lab experiments with several types of SiC-membranes in a bench scale pilot on produced waters from Saudi Aramco (project partner) at the KWR facilities in Nieuwegein.
Because SiC membranes are very robust, their applicability could be extended to other domains, such as food, dairy, pharmaceuticals, and chemistry. To do so, the potential of SiC membranes for several of these applications will be studied on a small scale, looking at their performance in terms of flux, separation factor, and other aspects. Because the novel applications require partly different types of separation characteristics of the SiC membranes, the existing UF/MF range of SiC membranes will be extended to the nanofiltration (NF) range by developing more dense coatings.
The project will deliver a good assessment of the feasibility of the SiC membranes. It will extend their feasibility to new applications and sectors, and derisk the technology by means of duration tests of their application in the challenging separation of stable oil-in-water emulsions – thus making SiC membrane technology ready for large-scale deployment in the future.