Biogas from human waste

Environmental engineer Eckhard Kraft and his team at the University of Weimar are designing portable lavatories which harvest methane and make it available for energy. Kraft believes these units may eventually act as a source of fuel for refugee camps around the world, while also helping solve sanitation problems.

"I'm thinking of using this biogas for cooking purposes,” Kraft said in an interview with broadcaster Westdeutscher Rundfunk. The energy could also be used for other purposes, he added. "Lighting is also a huge problem in refugee camps. Providing light at night would improve safety."

It isn't always easy to get people to understand how important hygiene issues are in refugee camps, Kraft said. "It sounds a bit crazy, because first you've got to feed the people, and make sure they get drinking water. But the sanitary problem is often neglected," he said.

The UN Refugee Agency (UNHCR) says that some 2.4 million people around the world are currently living in about 300 refugee camps. UNHCR estimates that one third of the refugee camps have inadequate waste disposal and latrine facilities.

Proper disposal of human waste is crucial for preventing the spread of disease. Meanwhile, energy shortages mean that cooking rice or other foodstuffs distributed in camps becomes difficult.

It was discussing issues like these with refugee camp volunteers that first prompted Kraft to think about energy harvesting. "They said that within three or four days, people had used up all the firewood within reach. So they needed fuel.”

Biofuel production onsite could help reduce costs, as less fuel and firewood would need to be transported into the camps.

According to the UNHCR, an average size refugee camp holds about 20,000 people. Kraft says a camp like this needs about 10 of his methane extracting units.

The waste produced by a camp's inhabitants would not provide enough methane to meet all their energy needs, but it would make a significant contribution.

Germany currently provides the UNHCR with mobile water treatment plants for emergency use in camps around the world. Following the earthquake in Haiti at the beginning of this year, one of these mobile units provided water to some 75,000 people.

Kraft would like to see his energy harvesting lavatories included in the package of emergency treatment units which Germany offers.

But so far, it has been difficult to raise the necessary funds to continue research and begin producing the units. Most manufacturers say they need an order of about thousand before it makes sense to start production.

Innovative biogas projects are being tested around the world, but they tend to be static units which are not designed to be moved. In Kenya, engineers have started testing units at health clinics. The Biosan project is headed by Sibilike Makhanu, a professor at Masinde Muliro University of Science and Technology in Kakamega.

"Large areas of Kenya have no running water or experience severe shortages. This includes refugee camps, schools, hospitals, slum areas in many urban centres and prisons. Schools still use pit latrines and the land has practically been exhausted," Makhanu explained in an interview with Deutsche Welle.

Aside from addressing the shortage of facilities, he explained that recycling this energy "contributes to decreasing global warming from burning methane instead of releasing it into the atmosphere".

Safety Concerns

While working on the Biosan project, Makhanu encountered a number of problems. Standing tanks of human waste are potential breeding grounds for maggots and flies. There are also serious safety and environmental concerns. The methane gas produced by human waste is both an explosive and an asphyxiation hazard.

"Methane gas is odourless and so one would not know that it is leaking," Makhanu explained. "In large waste treatment plants, a lot of methane gas is released and can even cause air accidents.”

Eckhard Kraft believes it is possible to make his methane extraction units safe. He explains that the gas can be transported away from the site once it has been harvested and stored in a safe facility.

But it has been difficult to get people to accept the idea of using gas taken from latrines. Kraft expects the idea to be accepted more readily in Asia, where most people have been cooking with gas before entering the camps. He said more education will be needed in camps in Africa, where cooking over a fire is more common.

Meanwhile, the idea of converting excrement gathered at refugee camps into biogas, water and fertilizer is gaining attention. At a refugee camp in earthquake ravaged Haiti, energy harvesting toilets used by a family of five were reported to produce an hour of biogas, enough to cook a meal.

Report by: Saroja Coelho

Edited by: Anke Rasper