Recovery of energy and raw materials from Flemish waste water

Water treatment company Aquafin is to build a sewage sludge processing installation on the ArcelorMittal site in the port of Ghent, to be operational by 2026.

Both companies will apply the green energy produced there to further reduce their CO2 impact. Aquafin is also planning the large-scale recovery of phosphorus, used among other things in fertiliser. The contract for the design, construction and financing of the installation and its maintenance until 2046 has been awarded to the BESIX/Indaver consortium.

The installation is intended to process the biomass that remains after the purification of domestic waste water. This biomass, created by the growth of the micro-organisms that do the purifying work, contains a wealth of energy and raw materials. Aquafin already produces fully green energy on this basis, in the form of biogas, and right now at one Antwerp location also biomethane, for injection into the natural gas network. The new installation, which should be operational in 2026, will be able to make even more use of the biomass delivered to it. As this is a mono-processor, the sludge will not be diluted with other substances, enabling maximum recovery of energy and raw materials.

Using a European tender procedure with competition-oriented dialogue, Aquafin went in search of a partner for the design, construction, financing and maintenance of the mono-processor. The DBFMO contract was recently awarded to the BESIX-Indaver consortium, which is setting up a Special Purpose Vehicle (SPV) for this purpose.

The location of the new installation has been determined for some time. ArcelorMittal is giving Aquafin a building right on the site and will purchase, 100% of the steam produced by the sludge processor. For the steel company, this is an additional energy source for their internal steam network, further reducing the use of fossil fuels. The direct uptake of the entire steam production combined with the focus on raw material recovery makes this installation an example for Europe.

In a follow-up phase, Aquafin is planning to start up full-scale phosphorus recovery, representing some 2,000 tonnes of pure phosporus a year. By opting for mono-processing, phosphorus can be recovered more efficiently from biomass. Phosphorus is an essential building block for life, being among other things an important component of our DNA, our cell walls and our bones. We ingest it via our food, and it is also a basic component in mineral fertilisers for agriculture and horticulture. Phosphate ores are, however, a finite resource, and with only limited supplies naturally present in Europe. Via our food, phosphorus finds its way into domestic waste water, from where Aquafin will recover it with this new sludge processor.

The sludge mono-processor will carry out the end treatment of two-thirds of all Flemish sludge from domestic waste water. Aquafin is leading this extensive DBFMO project with tight reins to ensure that the far-reaching ecological objectives can be achieved.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.