Desorption method of activated carbon adsorbed dioxin in exhaust gas treatment system of waste incinerator

摘要

PROBLEM TO BE SOLVED: To make active carbon recyclable by a method wherein the active carbon on which SO₂, etc., contg. excessively NH₃ is guided into a desorption tower whose top and bottom are made to be air lock devices and it is heated at a specified temp. to make undecomposed NH₃ exist and dioxin is decomposed from a time when desorption of SO₂ is finished. ;SOLUTION: In an exhaust gas treating apparatus of a refuse incinerator, SO₂, etc., contg. excessively NH₃ are adsorbed on active carbon being an adsorbent in an adsorbing tower. In order to circulate this active carbon, the active carbon is introduced into a desorption tower in which air lock devices which passes the active carbon but does not pass air are provided at the top and the bottom parts. In this instance, NH₃ being much more excessive than ordinary case is fed in the flue of the adsorbing tower to increase undecomposed ammonia in the desorption tower. In addition, the active carbon in heated at 350°C or higher for one hour or longer in the desorption tower to make undecomposed NH₃ exist in the active carbon. Thereafter, at a time when desorption of SO₂ approaches finishing, dioxin is decomposed with a large amt. of H₂ generated by decomposition of NH₃.;COPYRIGHT: (C)1999,JPO