260418 CY Danva DinForsyning 1055

Study proposes to use waste water for Power-to-X

A sustainable production is essential to us at HØST PtX Esbjerg. Currently we are exploring the possibility of using waste water as our primary water resource. The magazine “Waste water” covered the topic in their October ’22 issue.

Substantial amounts of water are required for the electrolysis process at HØST PtX Esbjerg, and with the current outlook, there is great potential for turning this into a societal win-win situation. Together with local utility company DIN Forsyning, we are investigating whether it is possible to use municipal waste water. The Danish Society for Waste Water (Spildevandsteknisk Forening) took a peak into our activities in their latest issue of the Waste water magazine (Spildevand).

Ultra-clean water for electrolysis

- The water which will be used for the production has to be extremely clean, and we have decided not to use drinking water as this is a limited resource which we must uphold for drinking water purposes. We have considered if seawater could be an option, but the desalination of seawater is a very energy-consuming and expensive process. This leaves us with the option of selecting either technical water, - i.e. - ground water unfit for drinking - or waste water, states Marco Haubjerg, Engineer in the HØST PtX project.

Regardless of the kind of water selected, it must be cleansed to a level even cleaner than demineralised water. Ultra-clean water cannot contain any traces of minerals or salts. Initially, the most obvious solution was that DIN Forsyning would supply technical water, but according to Marco Haubjerg, the most attractive solution from an environmental perspective, is demineralized waste water.

An important contribution

- If we manage to use demineralised waste water, then this will be a significant contribution to a sustainable Power-to-X (PtX) production in the future. And there is lots of waste water. We are working on developing the best possible water-cleansing technology to obtain the ultra-clean water quality. It is crucial to demonstrate the feasibility of this approach before launching it large-scale, says Marco Haubjerg.
A solution which can be exported

If we succeed with a technological solution, it will resonate positively far beyond Danish borders, claims David Dupont-Mouritzen, Project Director at HØST PtX Esbjerg. - In addition to contributing to global CO2-reductions in hard-to-abate sectors, we strive to contribute with local job creation and local CO2 reductions. Thereby, we hope to strengthen Denmark’s possibility to become the frontrunner of a new, green industry. This is a new way of using process technologies, and we also provide unique knowledge to related areas – such as the use of waste water. Knowledge and experience, which can not only be used locally, but possibly also improve sustainability woldwide.

Read the entire article in the magazine Spildevand (in Danish) here.

Photo: DIN Forsyning.