South Korean scientists create waterless toilet system that can convert human waste into biofuels

Researchers at South Korea-based Ulsan National Institute of Science and Technology (UNIST) have created a waterless toilet system that can convert human waste into biofuels.

The system is part of a wider creative studio and research lab called the ‘Science Walden Pavillion’, which is now open to the public. It is nestled in the centre of the UNIST campus.

The Science Walden building, designed by Artist Seung-hyun Ko, co-founder of the Korean Nature Art Association (YATOO), consists of two floors with a total area of 122.25 square metres, featuring walls of translucent polycarbonate to allow visual connection between the inside and outside of the pavilion.

Jaeweon Cho, director of Science Walden Pavillion at the School of Urban and Environmental Engineering, UNIST, who is leading the project, said: "Science Walden Pavillion not only stands for a playground for both scientists and artist, but also the medium that connects arts and science."

He added: "The pavilion is a unique blending of creative studio and research lab, bringing arts and science together."

The major research facilities of this pavilion include "Waterless Energy-producing Toilet System" and "Microbial Energy Production System."

Not to be poo pooed

The waterless toilet system, located on the first floor of the pavilion, treats human excrement without using water. The system utilises a natural biological process to break down human waste into a dehydrated odourless compost-like material. Then, at the microbial energy production system, this compost-like material is converted into biodiesel or heat energy.

Once the grinding system inside the toilet converts faeces into a dry, odourless material, it will be transferred to a digestion tank, containing thousands of different microbes. The microbes inside the tank will, then, biodegrade the powdered human manure to generate carbon dioxide and methane. Using high pressure and membrane, carbon dioxide is extracted to culture green algae for biofuel while methane is stored for later use as a heating fuel.

The project aims to reduce urbanisation's negative footprint on ecosystems by safely converting human waste into viable renewable energy and possibly to a monetary values.

Cho said:  "Our ultimate goal is not only for the new toilet system to save water and operational costs for wastewater treatment plants, but for us to establish an ecosystem that supports technology innovation and drives economic diversification where human waste literally has a financial value."

To reduce the objection of using the facility, Cho and his project team added a unique artistic touch to this collaborative outdoor laboratory. In a statement, the UNIST state that it has designed a futuristic toilet with ground-breaking innovations in sanitation technology that is comfortable at the same time. A roof garden, which filters rainwater and provides insulation is another added value to this pavilion.

Digital currency

Separately, Cho has developed a smartphone application that can determine the monetary value of the treated human excrement. Using this application, people can soon trade their waste for a virtual or digital currency to use. At the pavilion, the team plans to expand into selling salads made with barley sprouts, which can be only purchased with such virtual currency.

"This is a very exciting project for us," said Cho. "We expect that this will become a pivotal stepping stone in the developing future of many countries facing dangerous sanitation issues and a lack of reliable, affordable energy."

If this experiment succeeds, the team plans to expand its use of the waterless toilet system and microbial energy production system in real life. This project has been carried out in collaboration with YATOO, Art Center Nabi, Paju Typography Institute (PaTI), and Hankuk Engineering Consultants (H.E.C.) in South Korea.