Feature Article November 20, 2002
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Is Plasma Waste the way to the Future?In covering a North Frontenac council meeting a number of months ago, I penned an article noting that David James, a resident of Ardoch Road, had brought a new system for waste management to the attention of our municipal leaders. At that time, Mr. James had been brief in relaying information about the process, but he took things another step further by arranging for a formal presentation to Council at its meeting on November 12.
At that meeting, Pierre Carabin from PyroGenesis laid out for council the benefits of considering a Plasma Resource Recovery System, an 11-year-old technology process that converts waste into gas and a reusable slag. PyroGenesis, based out of Montreal, utilizes a plasma torch to burn shredded waste, turning the inorganics into a slag, and the organics into a gas that will run an engine.
As explained by Carabin, materials that go into our waste sites are organics (plastic, food, paper), inorganics (glass, metal), water, and toxics (heavy metals, volatile compositions). The usual treatment options are landfills, which can have leaching problems and are expensive to operate and close, or incineration, which can produce toxic ash and hazardous air emissions. One of the end products of the plasma system is a clean and combustible fuel that can be used in a high efficiency internal engine to produce electricity. Part of the exhaust heat from the engine dries and preheats more incoming waste. In the plasma recovery system, with firing temperatures in the thousands of degrees Celsius, no dioxins or furans are produced, and sulphurs as well as acids are scrubbed from the gas.
Carabin passed around some samples of the slag by-product, which resembled black, glassy rocks. Heavy metals and other hazardous inorganic materials are trapped within the slag, which is vitrified glass and soil, so there is no leaching. The slag is ten times harder than a brick, and can be used in a number of commercial applications, such as roadbeds, concrete, tiles and castings, or dumped in landfills. Even without a commercial use, the slag represents only 1% of the original wastes volume. Metals contained in the waste are tapped out separately and recycled.
Some of the other benefits expounded by Carabin were: compactness, with the plasma system being eight times smaller than a comparable capacity incinerator; and lower capital and operating costs. He also emphasized that there were no moving parts, the system was fully automated, and there were safety interlocks throughout.
One of the expected and obvious questions put to the presenter was the cost, and he replied that that would be dependent upon size, how much waste would need to be processed, and the types of materials in the waste. He did indicate that the system could handle multi-sites, with material being shredded before transport to the core location. The municipality could consider alternatives as to who might be responsible for each of the build, own, operate and transport aspects of such a process. Two important products of the plasma system are the resultant electricity and steam, which could be used locally, or sold. Any emissions from this type of treatment are well under current regulations, and Carabin noted that from shredder to gas, the entire process only takes a few seconds of time. There is no odour coming out, Carabin said, the only smell would be from the garbage going in. The PyroGenesis representative said his company could provide a level of expertise in working with the municipality to determine its needs, and Council was invited to tour PyroGenesis latest pilot plant in the upcoming new year.
But going back to the beginning of this article, Mr. James should be commended for the effort he has put forth in bringing this waste management option to our councils table.
