Scientist builds device that turns urine into biogas

A Mexican scientist has come up with a novel way to generate clean energy using human urine. He has now patented a device, dubbed the Urine Fuel Cell, to produce biogas which can help create electricity or be used as a replacement for natural gas; and is often cited as a clean and carbon-neutral alternative to fossil fuels.

Dr. Gabriel Luna-Sandoval, from the University of Sonora near the US border, said he came up with the idea by chance. He observed that some of the components of urine—such as hydrogen and oxygen—could be utilised to generate energy. He tested the hypothesis using electrodes to send electricity into the urine to separate oxygen and hydrogen, with the latter becoming a biogas that can be stored.

"I put copper electrodes - they were really just cables - inside and there was a current. I saw that it started to froth up and make bubbles, but urine has a problem in that it goes down. But with investigations, which didn't affect the cell of urine, I saw there was this problem that there was a lot of froth by putting a lighter in it and saw that it lit up. I saw that there is hydrogen here with this electrolysis," he told Reuters.

Luna-Sandoval has been working on pee-powered energy for about a decade. In 2006 he developed a device to harness the energy of urine and in 2011 started processing a patent for his device.

The researcher has been reported as saying that a liter of biogas can be produced from five litres of urine. With the average human producing over a litre of urine a day, Luna-Sandoval believes families can cook dinner and heat water using the power of pee.

"About 15 millilitres of urine is enough and considering that we produce 1.4 litres of urine then if you're a family then if you have 1.4 times two, three or four, depending on the family, then we have more than enough urine for the family to bathe themselves and to cook," he added.

The sky's the limit for this Mexican scientist, or rather the solar system. With mankind's ambition to ultimately build settlements on another planet, Luna-Sandoval believes urine could be used to support life on other worlds.

"In fact, it would be viable to have cells for combustible urine to inhabit Mars because you can start producing oxygen and hydrogen because it will be in an artificial environment in capsules so you will be able to use fire, the oxygen, the hydrogen that is produced in the cell. What can you do with this urine? I imagine with the projects coming you can filter it so as to drink the water once it is filters. Those are some of the possibilities it has," he said.

The product is still in its initial phase but Luna-Sandoval already has big plans for his device, including building a larger model that can help power homes.

Researchers from other institutions also believe urine could be a potent energy source. In 2013, scientists at the University of the West of England in Bristol, England demonstrated how urine could partially charge a mobile phone using microbial fuel cells (MFC) that use organic matter to generate electricity. The fuel cell uses live bacteria grown on carbon fibre anodes that feed on the urine, breaking it down and generating electricity which is stored in a capacitor.

Speaking to Reuters in 2013, lead researcher Dr. Ioannis Ieropoulos said urine has real energy potential: "It's an abandoned source and it's a waste product that is now being considered as a resource which is something that is quite amazing." — Reuters