Eco Waste system granted U.S. patentA double-burn incineration system, developed in Canada for medical, industrial and non-recyclable municipal waste, has been granted a U.S. patent, senior officers of Eco Waste Solutions, of Burlington, Ont announced this week.
The Eco Waste system features a double-burn process designed to reduce waste volumes by 90%, yield inert byproducts such as recyclable ash, emit a colourless, odourless exhaust, and produce thermal energy that can be converted to electricity or used to heat buildings. "Its emissions are odourless and clear, and rigorous, independent scientific testing has shown that their dioxin and furan concentrations are only one-tenth of allowable EPA limits-lower than any other," said Eco Waste president Frank Sherman. "We reduce a truckload of waste to a garbage can of inert ash-and that ash is used in the manufacture of concrete and asphalt," said executive vice-president Lucy Casacia, a metallurgist who, with Sherman, an engineer, developed the process. "Our U.S. patent means the economic benefits from our system will flow to our province and country," she added.
The basic system comes in two steel modules, one for each stage of the burn. Each module is about the size of a dumpster, making the system readily transportable for use on site. It is well suited to small municipal needs and is also effective for processing industrial and commercial waste. The system is capable of handling wastes such as scrap tires (which are gasified rather than converted to liquid), used motor oil, coolants, dye, paint sludge.
The configuration for medical waste includes a third module containing scrubbers to complete destruction of heavy metals and chlorinated gases typically found in medical waste streams. The system has also proved useful in isolated locations where on-site processing of waste is needed, such as CFS Alert, on the northern tip of Ellesmere Island in the high Arctic, and on an oil drilling platform in the Gulf of Mexico.
The first phase of the process is a slow, starved-air burn at about 1,000oF in the first module. This reduces the waste to ash and vapours over an eight to ten-hour period and is hot enough to destroy pathogens. The residue from this stage includes recyclable glass and metals. The second phase, a flash fire lasting two seconds at 1,850oF, obliterates the vapours and destroys the remaining toxins. The process is computer-controlled and can take a total of 12 hours, from loading through cleaning and preparation for the next load. The computer monitors and controls each burn, automatically keeping it consistent to correspond to the type of waste being processed and to ensure the most complete burn. Eco Waste says it is this computer monitoring and control feature that sets its system apart from other incineration technologies.
Eco Waste says capital costs for its system range from $250,000 to $4 million, depending on capacity. It is most cost-effective operating at a capacity of up to 50 tons per day, equivalent to about ten garbage truck loads of solids with up to 60% moisture content. Operating costs for processing medical waste are about 18 cents a pound, compared to the 30 to 40 cents charged by commercial waste haulers. The company currently has installations operating in several Ontario communities, as well as internationally in Hawaii, Alaska and England.
More information is available from Lucy Casacia at Eco Waste, 905/634-7022.