Updated: July 2002

1. Outline

The Mitsui Dry Type Dioxin Removing Unit utilizes the activated coke (AC) that it developed and removes dioxins, volatile organic substances, cyanides, and heavy metals such as mercury from the exhaust gas of the incineration facility.
It is ensured in the demonstration and verification test conducted by Japan Environmental Sanitation Center that this unit has performance that can fully accommodate the regulations.

2. Process Description

2-1. Features and Performance of the Processing System
Depending on needs, the processing system is selected.
1) AC on moving bed system (circulating type)
Contact processing with exhaust gas is performed while activated coke in the adsorber is being circulated.
Feature and performance:

(1) This system is suitable to the incineration facility that mainly has a large gas volume and requires high dioxin removal performance (at least 99%).
(2) Not only dioxins in the exhaust gas but also dust can be removed at the same time.
(3) Denitrification is allowed by blowing ammonia before introduction of the exhaust gas.
(4) Processing at the exhaust gas temperature of 150 to 200ºC is suitable, so the exhaust gas can be processed without heating after heat collection.

2) AC on moving floor system (circulation type) + Regenerator attached
Activated coke and dust that adsorbed dioxins on the moving floor are heated in an ambience without oxygen.
Features and performance:

(1) Dioxins adsorbed are almost completely (at least 99.9%) decomposed and made harmless.
(2) This system is economical because activated coke can be recycled.

3) AC on fixed bed system
Exhaust gas passes through the fixed AC layer and is processed.
Features and performance:

(1) Since the exhaust gas process is performed by combining several modularized adsorption tower units, this system is effective for a small-scale incineration facility which has a smaller processed gas volume.
(2) Since the circulation equipment is not required, the unit is compact.
(3) Consumption of activated coke is little and long-time operation can be performed without refill.
(4) Since dust deposited in the activated coke layer is periodically removed by the reverse washing air and shaker, pressure loss in the system is stabilized even though operation is continued for many hours.

2-2. Features and Performance of Activated Coke
Each system uses activated coke. Activated coke of Mitsui Mining is a carbon absorbent with a porous inner structure manufactured through its developed technology.
Features and Performance:

(1) A small-hole structure suitable for dioxin adsorption is provided.
(2) Activated coke has a sufficient strength and a lower degree of wear.
(3) Activated coke has high performance of desulfurization and denitrification and is effective for dust removal.
(4) Activated coke can be supplied in a stable manner.
(5) Activate coke has an economical price.

3. Performance

Dioxines adsorbed are almost completely (at least 99.9%) decomposed and made harmless.

4. Application

Refuse incineration facility
Other various incineration facilities

5. Others