Innovations in Technology for Detoxifying Medical Waste - Pyrolysis Equipment in Hatoyama Town, Saitama Prefecture (June 1998)

Innovations in Technology for Detoxifying Medical Waste - Pyrolysis Equipment in Hatoyama Town, Saitama Prefecture (June 1998)

In the late 1990s, in the shadow of the stagnation that followed the collapse of Japan's bubble economy, pollution problems and environmental regulations were being further strengthened. Particular attention was paid to the disposal of medical waste. In addition to the fear of AIDS and hepatitis infections, the problem of dioxin emissions from incineration had become a serious social issue, and small incinerators set up at individual medical facilities were being closed throughout the country. Amid the urgent need for a new method of waste disposal, a pyrolysis device developed by a manufacturer in the town of Hatoyama, Saitama Prefecture, met the needs of the times.

The device performs a two-step process of steaming waste in an oxygen-free state and then heating it to a high temperature of 800°C. Because it shuts out oxygen, it is less hazardous than combustion. Because it shuts off oxygen, it produces fewer toxic gases than combustion, and the heating process is characterized by its ability to thoroughly sterilize infectious pathogens. It is superior to conventional incinerators in that it can control dioxin and sulfur oxide (SOx) emissions, and it can handle both infectious waste and special industrial waste containing chemicals.

A related technology that became popular around the same time was the autoclave sterilization method. This method uses high-temperature, high-pressure steam to sterilize waste and make it safe without incineration, and was expanded as a treatment device in hospitals. Gasification and melting furnace technology has also advanced, and municipalities have introduced systems that gasify waste at high temperatures while melting residues and reusing them as slag. Furthermore, ultra-high temperature decomposition technology using plasma arc furnaces was also studied, and the trend toward more complete detoxification was spreading.

In parallel with the development of these technologies, the "Dioxin Control Law" of 1997 and the "Law Concerning Special Measures against Dioxin" of 2000 were enacted, and emission standards for treatment facilities were tightened. Hatoyama's pyrolysis equipment was symbolic of the shift in waste treatment from incineration to detoxification, in response to these stricter laws and regulations.

This case anticipated the philosophy of "minimizing environmental impact by rendering waste harmless through a controlled process," rather than simply disposing of it, and was an important step forward in laying the foundation for today's waste management and recycling-oriented society.