Ammonia present in coke oven gas is extracted by washing with___________________?
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Answer: B. Dilute ammoniacal liquor
Explanation
Dilute ammoniacal liquor selectively absorbs ammonia gas from crude coke oven gas mixtures via mass transfer. The aqueous solution acts as a scrubbing medium to capture volatile alkaline components efficiently. Using dilute ammoniacal liquor prevents the introduction of foreign chemical species into the recovery system. Coke oven gas is a byproduct of destructive distillation of coal containing various tarry and gaseous impurities. Ammonia recovery is economically important in steel mill byproduct plants for producing ammonium sulfate fertilizer. Scrubbing towers provide intimate countercurrent contact between the gas stream and the circulating liquid solvent.
Steel manufacturing facilities must clean coke oven gas thoroughly before using it as fuel in burners. Environmental regulations strictly limit gaseous ammonia emissions from industrial coking operations to prevent air pollution. Optimizing scrubbing temperatures ensures high absorption efficiency while minimizing unwanted tar condensation inside equipment. Caustic solutions are too expensive and aggressive for routine large scale industrial ammonia gas scrubbing. Dilute hydrochloric acid reacts to form solid ammonium chloride salts which can rapidly plug the scrubber. Ethanolamine is typically reserved for removing acidic carbon dioxide and hydrogen sulfide from hydrocarbon gases.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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