From dump to the pump

Jeffery never liked the sound of fuel being pumped into his minibus taxi. It was always an expensive experience.

That's now history. Jeffery fills up with methane gas at one of Johannesburg's most unusual filling stations, located high on top of the East Rand waste landfill.

He's participating in the joint German-South African EnerKey energy research project, which produces biomethane from landfill gases.

"Waste-to-fuel" is the name of the technology that allows the 29-year-old taxi driver to fill his minibus taxi with biomethane.

The fuel is produced in several steps from gas that is captured from deteriorating waste products. Although he had to covert his vehicle to be able to burn gas, he says the investment has paid off.

"Most of the time I spend about 2,000 rand (180 euros, $235) for petrol for the whole week," he says. "But with the gas, it's less. It's close to 1,600 so I can save about 700 to 800 a week."

Making up for shortcomings

Jeffery has Eddie Cooke to thank for his fuel savings of over 20 percent. Cooke is technical director at Novo Energy in Johannesburg. The company is testing the pilot project in collaboration with the University of Johannesburg and the Federation of German Research Institutes.

"The burning of methane as a fuel produces a lot fewer emissions," Cooke says. "And it will also be a lot cheaper fuel."

The technology taps into a South African shortcoming - the lack of large-scale waste separation. The country's waste-disposal sites are full of organic, bio-degradable waste, which is broken down by bacteria and produces various gases.

In addition to methane, the gases include carbon dioxide and nitrogen as well as smelly hydrogen sulphide. Combined, they create a dirty and strongly vaporous gas cocktail that, thanks to the new technology, can now be converted into biomethane.

"From the extraction from the landfill through wells inserted into the landfill, the gas goes through a cleaning process, which starts with a hydrosulphide removal," says Cooke. "We have achieved up to 95 percent methane purity in our gas."

The methane content must be 87 percent for biomethane to be usable as a fuel for natural gas-powered vehicles. That's a level that Eddie Cooke's pilot facility already exceeds.

Environmental considerations

Edison Muzenda, a professor for chemical engineering at the University of Johannesburg and one of the research project's partners, sees a future for biomethane fuel in the city's transportation concept.

"The cost of public transport in South Africa is very high," he says. "We are confident that we can reduce transport costs maybe by 30 percent. That would be a very good contribution, if we can cut down on costs for the poor population."

In the coming years, Cooke hopes to see up to 5 percent of all vehicles in South Africa powered by biomethane produced from waste. Although methane is considered a climate-altering greenhouse gas, he doesn't view it as a serious threat to the environment.

"If methane is released without actually combusting it, it has a negative effect on the ozone, but we actually use the energy value of the methane, combusted in a controlled environment inside a vehicle's engine," he says. "The methane is then changed over to CO2 and water, which are the combustible products of the methane and not as harmful as the methane itself."

Jeffery, the taxi driver, has no intention of returning to gasoline. "After five years, 80 percent of the people will see how the gas works and how they can save," he says.

And he aims to show how.