Air Pollution Control Technology in JAPAN
Desulfurization Equipment
Updated: November 1996
LILAC (SEMI-DRY) FLUE GAS DESULFURIZATION SYSTEM
1. Purpose
The LILAC FGD system has been developed to remove the sulfur oxide in the flue gas by spraying absorbent into the flue gas, reacting it to form calcium salts and removing with dust collector as dried materials. This system was developed jointly with Hokkaido Electric Power Co., Inc. and named as LILAC FGD System after the acronym of the absorbent-Lively Intensified Lime Ash Compound.
Process Flow
(1) LILAC Absorbent
(2) Compact Rotary Atomizer
(3) High Velocity Type Spray Dryer
Hokkaido Electric Power Company, Tomatoatsuma Power Station.
2. Performance
3. Features
(1) Desulfurization Efficiency: 70 - 90 %
(2) Construction Cost: 60 - 70 % of that of Wet Limestone Gypsum Process
(3) Operation Cost: Equivalent to that of Wet Limestone Gypsum Process
(4) Wastewater: None
(5) Byproduct: Dry Solid Powder suitable for land fill.
Other possibility of reuse is being developed.
The hot water curing of lime, flyash and gypsum mixture makes highly reactive absorbent due to the existence of amorphous calcium silicate in the absorbent.
In order to obtain higher desulfurization efficiency rotary atomizer is used.
Mitsubishi rotary atomizer uses high frequency induction motor which results approximately half in weight and 20% reduced power consumption.
The space velocity in the spray dryer is chosen around 2 to 3 m/s which is relatively higher than that of conventional spray dryers based on the results of Computational Fluid Dynamics (CFD) analysis. By employing this spray dryer space problems are overcome for retrofitting and FGD unit to an existing power generating plant.
Note (about symbols)