Israel turns sludge to energy

Israeli startup transforms sewage sludge into fuel
By David Brinn December 07, 2006

Sewage sludge is the last place where you'd expect to find something valuable. But the brains behind Israeli startup BioPetrol say it is exactly the place where it is possible to find gasoline and natural gas. The company has developed a method of extracting oil out of sewage sludge, and converting it into various petroleum products.

"Sludge is a huge environmental problem all over the world and we have a good actual solution for it," says Hillel Lerman, BioPetrol's business development director.

The US produces 5.3 million metric tons of sewage sludge each year (dry weight, not including the water that carries it). According to the GreenLeft website, about 16% of sewage sludge is incinerated, and the ashes are buried in landfills; 38% of sludge is landfilled directly; 36% is spread onto farmland or forest land or otherwise mixed into soils; and 10% is handled in other ways (piled on the land and abandoned, for example).

BioPetrol's technology provides a solution for recycling sewage sludge via a thermo-chemical process called pyrolisis. This recovers the hydrocarbons in the sludge, producing oil, gas and char products. In addition the process also extracts valuable chemicals that can be used as chemical feedstock.

According to Amit Mor, an energy consultant with EcoEnergy who is providing guidance to Biopetrol, a ton of high-quality sludge can produce about 30 kilograms, or 66 pounds, of oil. In addition the process can also convert pulp, agricultural waste, plastics and tires into oil. "Sludge is both a major problem and major opportunity", he told CNET.com, a technology website. "On the one hand it's a major pollutant, and cities pay $50 a ton or more to get rid of it. On the other hand, it contains significant amounts of good-quality light oil."

BioPetrol, which was founded four years ago as part of the Mofet B'Yehuda technological incubator in Kiryat Arba, is poised to turn the problem into opportunity. According to Lerman, the spark behind the company originated with Ari Sofer, a sewage sludge disposal specialist with 20 years experience working with wastewater treatment plants both in the United States and Israel.

"Ari brought the idea of transforming sewage sludge into liquid fuel to the incubator program in Israel," he told ISRAEL21c. "But while he had the idea, not being a scientist he didn't know how to go about implementing it and looked for someone who had experience in the scientific applications that he was talking about."

Sofer found that person in Dr. Yafim Plopski, a scientist from the former Soviet Union who emigrated to Israel 15 years ago with a PhD in chemical and technology of fuels.

"He had worked there in the process of extraction of fuel from organic material, and the worked for 10 years in Israel as chief scientist with a company called Pama which spent many years to produce oil from shale," explained Lerman. "They built a huge power plant in the Negev and actually developed a good process. But at the time, the price of oil didn't justify enough interest in that kind of development, and the company eventually closed."

That was good news for Sofer and BioPetrol however, as Plopski joined the company in the capacity of chief scientist, a position he's held since the company was launched. With seed money provided for two years by the Israeli government's Office of the Chief Scientist, the BioPetrol team began working on a process to convert sludge into liquid, synthetic oil.

According to Herman, conventional methods of sewage sludge disposal - land filling, ocean dumping, compost and incineration, are causing irrevocable environmental damage. This is seen in the contamination of underground water reservoirs and fertile land, the pollution of oceans and the emission of hazardous gases into the air. Sludge fertilizer is already banned in some European countries.

The BioPetrol process is aimed recycling sewage sludge which contain a high degree of organic matter through a thermo chemical pyrolysis process in order to recover hydrocarbons that make up the structure of sewage sludge. Pyrolysis of sewage sludge produces oil, gas and char products. Their technology is capable of processing carbon wastes, other than sewage sludge, including agri-wastes, bagasse, pulp and paper residues, tannery sludge and other end-of-life products such as plastics, tires and the organics in municipal solid waste.

"We finally arrived at a process that converts sludge to liquid, synthetic oil through pirolysis, using high temperatures and high pressure. But our innovation was implementing process with lower temperature and pressure - more moderate conditions, thus safer," said Herman.

Having graduated from the incubator program and now standing on their own, BioPetrol is ready spread its wings. They're about to move from Kiryat Arba to new facilities in Ramat Hovav, and more importantly, they have plans to build a pilot plant within a sewage treatment plant, most likely in the Jerusalem area, according to Lerman.

"We're about to sign an agreement with an Israeli chemical company which will finance the plant. That will be our first major outside investment since we left the incubator program," he said, adding that the cost of plant would be approximately $1 million.

"The sooner we have the plant set up and prove it can work on a big scope, the sky's the limit. Each and every small town and big city with a sewage treatment plant will be potential customers."

According to Herman, BioPetrol's solution is a win-win one for all concerned.

"Sludge is the one of the biggest environmental problems throughout the world. Incineration is the only option now, and it costs a lot of money and emits harmful gasses from the plant. Our solution poses no environmental problems at all. After the transformation of the oil, all that's left is 5% of ashes which can be buried and forgotten," he said.

And in a neat case of an environmental circle, BioPetrol's ultimate goal is use the oil produced to power the operation of the sewage treatment plant - and their sludge treatment plant.

"The process will finance itself."