How does Oya work?



Human waste is emptied into the pre-treatment tank. A hot water boiler is used to raise the temperature of the waste to 70 degrees Celsius to kill pathogens in the waste. A solar panel is used to offset the use of fossil fuels.

The human waste is recirculated through a pipe connected to an ultrasound unit. The ultrasound unit breaks apart cells in the faecal matter and releases water from them to make the dewatering step easier.


The pre-treated waste is emptied into large electrokinetic bags.

The electrokinetic bags have a metal lining which acts as an electrode. A current is passed through the bags which forces the water out.

Water treatment

The water removed from the electrokinetic bags is filtered through a membrane or biological water treatment unit.

The filtered water can be used in industry or agriculture. The remainder can be concentrated into a nitrate and phosphate rich product, potentially suitable for use as a soil improver.


The dewatered human waste is combined with other high calorific value waste streams (such as household or industrial waste) and passed into the pyrolyser.

Waste enters the pyrolysis chamber where it is heated to about 800 degrees Celsius and thermally decomposes to create a carbon char and syngas.

Char passes into the gasifier chamber where steam and air are injected to further react and reduce the char volume.

Syngas enters the combustion chamber where it is combusted with a controlled amount of air to produce heat. The heat is passed over the pyrolysis chamber to maintain the temperature. Excess heat is recovered and converted to electricity.

Did you know?

Every day 2 million tons of human waste are disposed of in water courses

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