No. 006
Classification of Technology:
Air Pollution Control
Type of Industry:
Chemical; Petrochemical
Subject:
Reduction of SOx and dust in Process Exhaust Gas
1. Purpose
To neutralize SOx and capture dust and steam vapor which are generated in the dissolving process of titanium ore with sulfuric acid by using large amount of alkaline solution and sea water.
2. Applied Technology and the Time
Technology was introduced from Germany in which jet condenser was eliminated and SOx / dust in wet gas were neutralized and captured by means of an alkali scrubber ( absorption tower ). Both neutralizing and capturing efficiency were subsequently improved by changing the flow of gas in the absorption column. ( No.2 scrubber in August, 1973 and No.3 - No.6 scrubbers June, 1975 )
3. Principle
SO3 + 2NaOH -> Na2SO4 + H2O
SO2 + 2NaOH -> Na2SO3 + H2O
Na2SO3 + 1/2 O2 -> Na2SO4
The amount of discharging steam, SOx and dust was reduced by guiding gas generated from the reaction tank through the mist catcher, cooler and alkali scrubber. In the scrubber, large amount of sea water are sprayed from the top of the column counter-currently to the gas, and NaOH solution is sprayed from nozzles located in several places at the middle of the column. Drain from the scrubber is discharged after pH adjustment and passing through a drain filter system. The general process flow is described on next page.
4. Effect and Achievement
 | Reaction tank outlet | Scrubber outlet |
| SOx ppm | 600 | 0.00 |
| Dust g/mN3 | 3 | 0.01 |
Gas Treating Capacity 15,000 m3 / 10 min.¥ unit
Implementing company:
Ishihara Sangyo Co., Ltd. Yokkaichi Factory
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