Israeli trash treatment plant makes clean energy

TEL AVIV, Israel -- ArrowBio Waste Management Technologies didn't start out as an alternative energy company, and technically still isn't one.

But the company's site at a waste treatment facility just outside Tel Aviv has a 1 megawatt production capacity, and sites in planning stages around the world will add between 7.5 megawatts and 9 megawatts to its capability.


ArrowBio's on-site generator is powered by biogas, the rich methane gas mixture released when organic trash decomposes. About 25 percent of this energy goes to power the machinery at the site. The other 75 percent of the non-polluting power goes back onto the national grid, and the Israel Electric Corp. credits the company for it.

"We can invest a lot less energy and get a lot of gas, relative to the investment," ArrowBio's co-Chief Executive Officer, Yair Zadik, told United Press International.

A megawatt of alternative energy doesn't make much of a difference in Israel, where the peak energy demand is expected to reach 9,700 megawatts this summer, according to the Israel Electric Corp.

But with rising oil prices and a growing concern for the environment, Israel, like other countries all over the world, is making a push to rely on more sources of alternative energy. During his induction ceremony at the beginning of May, Israeli Minister of National Infrastructures Benjamin Ben-Eliezer said the issue was at the top of his list of priorities.

One of Arrow's driving principles is to "close the loop," Zadik said; that is, to reuse as much of the garbage as possible. As much as 75 percent of the 100 metric tons that comes through the facility each day is reused as biogas through traditional recycling and as agricultural fertilizer.

The company started in 1975 as Arrow Ecology Ltd., a waste treatment firm specializing in contaminated liquids such as those from oil refineries. In 1996, Arrow developed the patented process it now uses to sort and treat trash by adding water, Zadik said.

"We came to the conclusion that our knowledge of liquids would give us better results with solids," he said.

The idea was in direct contrast to other waste treatment processes, which operate on the assumption that first the water must be removed from the trash before it can be treated or burned.

"Water is not the enemy," Zadik said. In fact, "water is the best ally" for waste treatment.

The company uses water in two ways. First, water is used to separate different kinds of trash. When submerged, plastics will float on the surface, biodegradable material will absorb some water and hang suspended in the middle, and metal, stones and glass will sink to the bottom of the container.

Additionally, the water helps the biodegradable material break down. Arrow uses a "'hydrocrusher,' high-shearing streams of water," to do this, Zadik said.

"The use of water allows for high degradability," he said.

"Nature relies on water for its most important processes," Zadik continued. "When (scientists) want to determine if there's life on another planet, what do they look for? Water."

"The main idea was, if we succeed in taking organic, biodegradable material and bring it to liquid or semi-liquid form, then we know how to treat it," he said.

Not only that, but Zadik said the company has found that converting the trash to biogas from its liquid form is more energy efficient than dealing with the garbage in its solid state.

He added that the process doesn't require adding much water, since between 30 percent and 35 percent of trash is liquid. The anaerobic process by which the organic waste decomposes to produce biogas also creates water as a byproduct, which the company can reuse, Zadik added.

In 1998, the part of Arrow dealing with solid trash treatment, ArrowBio, separated from Arrow Ecology Ltd. ArrowBio signed contracts for two treatment plants in Australia and Pachuca, Mexico, and the deals are now in planning stages.

Both new plants will have larger capacities than the one outside Tel Aviv. The Sydney, Australia, plant will process between 270 metric tons and 280 metric tons of trash per day, while the Mexican facility will see 500 metric tons daily.

As such, the Sydney site will have an energy capacity of between 2.5 megawatts and 3 megawatts, and the Mexican plant will produce between 5 megawatts and 6 megawatts of power, Zadik said.

Another facility planned for Western Australia will process 90,000 metric tons of garbage a year and create enough electricity to power 2,500 homes, ArrowBio's Web site said. The facility will also produce 10,000 metric tons of fertilizer, 19,000 metric tons of recyclables, and 11,700 kiloliters of treated water for irrigation, the company said.

ArrowBio already has several sites for new plants in mind, including California and Spain, Zadik said. The company is also one of the finalists in competition for a waste treatment contract in New York, he said.

The company might also decide to produce extra energy from the plastic trash in the future.

"Right now, it's more cost effective to use plastic for recycling," Zadik said, citing the high demand in China and India for plastics.

"At another point in time, it might be more cost effective to use it for energy," he said.