Japan – low-cost equipment uses water to remove dioxins from incinerator exhaust

research team led by Tateo Usui, professor of chemical reaction engineering at Osaka University, announced on October 24, 2003, that it had developed simple dioxin-removal equipment in collaboration with Sumikin Kansai Industries Ltd.



Japan for Sustainability reports that the team has succeeded in removing dioxins, contained in exhaust fumes generated during waste incineration, by passing the fumes through water.



Dioxins can be decomposed at temperatures above 700 degrees Celsius. To reduce dioxin emissions from incinerators, some municipalities and others have adopted a method of incinerating waste at high temperatures and then filtering the exhaust after rapid cooling. This system is said to be too costly, however, to be adopted by all municipalities in Japan.



Hirotoshi Kawabata and other expert group members found that airborne carbon particles in exhaust gases were a major factor in the formation of dioxins, and came up with the idea of using water to remove the particles. They conducted experiments in which exhaust fumes were blown into water, and obtained good results of reducing the amount of dioxins in the fumes by more than 95 per cent. In addition, they have established a simple method to remove more than 95 per cent of dioxins in the water. They are conducting field trials of the system for practical use. The New Energy and Industrial Technology Development Organization (NEDO) and the Japan Science and Technology Agency (JST) also have invested in this project, with the aim of commercialization as soon as possible. The newly developed device is much simpler than conventional equipment. It is thus expected that dioxin removal equipment will become less expensive and more widely available than in the past