Primary coolers capture roughly _______________ percent of the total tar present in raw coke oven gas?
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Answer: B. 25
Explanation
Primary coolers reduce the temperature of hot raw coke oven gas coming from the ovens. Cooling causes heavy hydrocarbon vapors to condense, capturing roughly twenty-five percent of total tar. This initial cooling protects downstream equipment from heavy fouling and tar accumulation. Raw coke oven gas leaves ovens at very high temperatures carrying suspended tar and moisture. Direct or indirect water-cooled heat exchangers lower the gas temperature in stages. The condensed tar drains into collection sumps for processing in the by-plant recovery section.
By-product recovery plants rely on primary coolers to condition gas for subsequent chemical scrubbing. Efficient tar removal prevents blockages in ammonia scrubbers and booster compressor systems. Thermal energy removed in these coolers can sometimes be reclaimed for facility heating purposes. Option A suggests five percent, which significantly underestimates primary cooling tar condensation efficiency. Option C proposes fifty-five percent, which is higher than typical primary stage recovery yields. Option D suggests seventy-five percent, typical of total tar removed across multiple downstream stages.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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