New York and Ghanaian Engineers Turn Sewage to Fuel




My story aired today on Deutsche Welle Radio.

Here’s the print version:



Environmental engineer Kartik Chandran is leading me through his Columbia University lab.

Facing a tub of murky water he explains, “So basically if you look at this reactor system you have sewage coming in, you have clean water going out and then you have the bacteria which are turned into energy as well.”

“Does it still smell?” I ask.

“You can take a peek,” he assures me, “it doesn’t smell at all.”

Chandran’s work in his New York City lab space may seem innocuous. But half way across the world he’s leading an upheaval. He wants to drastically change the way Sub-Saharan Africa looks at waste water.

“In a place like Ghana,” he says, “it’s a clean slate, where we can go in with a fresh model. Where the focus is not putting in a lot of energy and cost and then just treating waste water, but actually recovering something from it.”

In Ghana’s capitol of Accra, Chandran and his team are building the first facility that turns fecal sludge, the fecal matter and urine that human beings generate, into fuel. Specifically, biodiesel.

“Biodiesel is basically a mixture of the combination of methanol and fatty acids, fats,” Chandran explains. “[The fats] come out of the fecal matter. Fecal matter inherently contains some fatty acids. We also are going to put in a process to increase biologically the production of fatty acids from fecal matter, and then convert those also to biodiesel.”

Chandran’s goal is for the new facility to produce one cubic meter of biodiesel a day. That’s enough to fuel a truck about 10,000 miles.

Chandran and his team plan to break ground in Accra by the end of the summer. They will be the first to attempt to turn fecal sludge into biodiesel. The Bill and Melinda Gates Foundation has granted the project one point five million American Dollars in funding.

Ashley Murray is Chandran’s co-leader on the project in Accra. She’s also the founder of Waste Enterprisers. Waste Enterprisers aims to show how capitalizing on sewage can bring money to Ghana’s sanitation services.

Murray says some parts of Ghana do have modern sewage systems. But most human waste in Sub-Saharan Africa remains raw, in the form of fecal sludge.

“So [it’s] generated on site in either pit latrines or septic tanks,” Murray explains. “And then instead of being carried through a sewer system to go to a treatment plant, vacuum trucks go around and manually empty the septic tanks and then would bring them to a point of discharge.”

What’s that point of discharge usually look like?

“In Accra,” she says, “it looks like the ocean. [It’s a] massive public health and environmental hazard. It’s discharged directly onto the shore and then carried out by the waves. Definitely a detriment to the fishing industry, you certainly can’t develop any tourism along the coast, swimming in that water is a recipe for some pretty serous illness.When you get close to the site it’s just absolutely toxic. It’s like this acidic burning sensation in your nose when you get anywhere near it. Strong, just raw fresh human waste.”

Most sewage treatment plants in Ghana have failed from lack of stable funding. Murray hopes that turning fecal waste into a profitable fuel will keep the new facility solvent. Extra income will go back into other sanitation efforts.

“We will produce biodiesel and then sell that to the refinery,” Murray explains. “And then we anticipate being able to take a portion of our profits and reinvesting these back into the servicing of septic tanks and pit latrines. It’s kind of a win win, we’re cleaning up the environment, we’re getting the waste we need to produce our product, and we’re improving the accessibility of top notch sanitation services to the urban poor.”

Murray wants the facility to set a new precedent for thinking about human waste.

“We’re sort of abandoning this sort of idea of designing for disposal,” she adds, “and abandoning the idea that waste is just something you need to throw out and get as far from human populations as possible, to actually re-branding it as a resource and actually making a profit out of it, and that’s quite a revolution that we’re hoping to start.”

Back at Columbia University in New York, Chandran also sees the new facility as part of a greater ideal.

“As along as there are people on this planet,” he says, “we’ll generate ample amounts of sewage, something needs to be done. When you address sewage you address a lot of problems that face humanity today. Water quality, disease, recovery of resources, which we are doing now. So we are linking to the water cycle, to human health, the energy cycle. By looking at sewage we are addressing all of these.”

Chandran and Murray face a major roadblock to their goal of re-branding human waste. The ick factor. But Murray assures that waste-derived fuel products will undergo rigorous 3rd party testing for safety and quality.

-Deutsche Welle Radio, Audrey Quinn, New York.