Unilever are creating Oya, a community scale sanitation treatment system to serve over 2,500 people.
Oya will take in human waste alongside other wastes that cause harm to the community, such as clinical, household and industrial wastes. These waste materials will be converted to useful products such as water, energy, ash and soil improver.
Oya will modify a commercially available pyrolysis unit to treat human waste streams. Pyrolysis is the decomposition of material using heat in the absence of oxygen. This creates an inert ash and a syngas, which is combusted to produce heat.
Human waste normally contains too much water to be pyrolysed, and so two solutions will be explored to unlock the use of this technology:
- Use of supplementary waste streams
Human waste can be mixed with other harmful waste streams, such as clinical, industrial and household wastes. These waste materials will provide extra energy to run the system. To find out more about the different wastes that will be tested on Oya, please click here.
The pyrolysis unit can process waste with up to 35% water and still produce enough heat in this process to maintain the high temperatures of the machine. The dewatering processes will be designed and a water treatment unit will be created to clean the black water that is extracted. To Find out more about the dewatering process, please click here.
Oya will be built and tested in 2014 on a sewage treatment works in the United Kingdom.