Science, Technology and Inventions / By Julian Ryall
Ultimate Incinerator
H
ouseholds and companies across Japan produce millions of tons in waste material annually. Regulations on the disposal of trash have been tightened in recent years, largely out of concern for the amount of harmful by-products being released into our atmosphere — from PCBs and heavy metals, to carcinogenic dioxin. The nation’s waste landfills are unable to keep up with demand, and existing incinerators cannot completely screen out dangerous residues and gases before they are vented. A new incinerator designed by Dr. Hideo Katayama will solve all those problems by returning anything inside the burn chamber to its elemental components. “I don’t have the words to explain just how big a problem Japan is facing with trash,” says Katayama, 77. “One of the biggest problems is asbestos because there is no way to treat that material. My furnace is the only one that will be able to render such material safe for humans.” Asbestos has been a popular construction material since the late-19th century because it was relatively pliable, light and heat resistant. It was not until the 1930s that the potential dangers inherent in inhaling the tiny fibers were recognized, and it was much later before production was scaled down. “The fibers are like needles in a person’s lungs, but this machine’s
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melting process reduces them to tiny pebbles that are not harmful to people,” says Katayama, who was commissioned by then-Environment Minister Yuriko Koike in 2006 to write a report on asbestos, which has since been adopted as the government’s official position. Head of the ship-testing headquarters of the U.S. Navy at Yokosuka for 20 years from 1974, he has lectured at universities in the U.S. and Brazil, and holds a number of patents. He places high hopes on his Electric-Resistant Type Melting Furnace. “Other incinerators burn waste at a temperature of 800ºC, but that temperature will not dissipate dioxins,” he says. “My furnace burns at a minimum temperature of 1,500ºC and as high as 1,800ºC. But more important than the temperature is the fact that it burns at the same high heat throughout the chamber, meaning all the waste is treated equally.” Heated to that temperature, asbestos is reduced to tiny, harmless nuggets and a gas that is sucked out of the burning chamber and undergoes a filtration process. If contaminants (CO2 or dioxin) are still detected, the gas goes through another sprinkler and second filtration. This is repeated until acceptable levels are reached for the gas to be vented. The furnace is rectangular, instead of round in shape, enabling it to better maintain the balance between the high
Dr, Hideo Katayama: making asbestos harmless.
temperature and the electrical current by using electrodes that move horizontally within the chamber, instead of vertically. A pilot model built seven years ago was able to reduce one ton of household trash within a day; larger, commercial-use versions will be able to dispose of far larger amounts. It is not able elementally to reduce only high-level nuclear and radioactive waste. He estimates that $800,000 has been invested in the project, and a new demonstration furnace is scheduled for the year’s end to show potential customers its value. “We expect municipalities and large corporations to buy the system, and we have had lots of expressions of interest already, although they have so far been reluctant to build one because they are waiting for someone else to make one operational so they can actually see it in action,” he says. “That’s not really a surprise, I guess, because it is hard to believe what this incinerator actually does. As soon as one is operational, I think we will have trouble keeping up with demand.” Julian Ryall is The Daily Telegraph’s Tokyo correspondent.