Hydrogen, at times shamefully neglected by the federal government, is blossoming into the new desired raw material.

Not only in view of the current shortage of natural gas, but the crisis has increasingly called attention to its importance.

Hydrogen should generate electricity, provide heat, move ships or trucks and make industry cleaner.

Provided it is “green”, i.e. generated with electricity from renewable sources.

However, it will not be possible to produce too much of it in this country because there is a lack of wind and solar energy systems.

When the old federal government presented its hydrogen strategy in 2020, it formulated the goal for the year 2030 of just installing generation plants of up to five gigawatts.

But on a small scale, niches are opening up, just another one in Münster.

As part of the Hytech research project, a two-stage test facility that produces hydrogen from the waste water of a brewery went into operation at the city's technical college.

Elmar Brügging from the Department of Energy, Buildings and Environment calls the process “dark fermentation”.

With this technique, the waste water is fermented in the absence of air and light, and is therefore dark.

This produces hydrogen and a mixture of organic acids, primarily acetic, lactic, butyric and propionic acid.

How high their concentration is depends on the starting material and how long it remains in the reactor.

The hydrogen can be used directly, the acids are further processed.

They serve as “food” for methanogenic bacteria.

This produces methane in a proportion of up to 75 percent, which can be fed into the natural gas grid.

The rest is carbon dioxide.

Brügging considers the fact that CO2 is produced in the process to be acceptable.

In the classic waste water treatment of the waste water, the carbon compounds would have to be broken down using a lot of energy, which might itself cause CO2 emissions.

And in the end, no molecules, no methane and no hydrogen, were obtained that could be used as energy carriers.

It would also be conceivable to use the carbon dioxide as a separate raw material, as it is required in many industrial chemical processes.

At the moment, however, it makes the most sense, according to Brügging,

"Effluents containing starch and sugar are particularly productive," says Brügging.

This includes everything that the food industry leaves behind.

The conversion into methane and hydrogen is doubly useful because it is precisely this type of waste water that can only be clarified with great effort.

"We hope that companies will integrate dark fermentation into their wastewater treatment in the future," says Juliana Rolf, who is a research assistant in charge of the reactor, which runs around the clock.

Because the usual wastewater treatment costs are eliminated and valuable materials are produced at the same time, the process could be financially worthwhile for the food industry.