If G denotes insoluble gas in the gas stream and L represents non-volatile solvent in the liquid stream, how is the absorber's operating line slope expressed___________________?
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Answer: A. L/G
Explanation
Overall material balances around an absorption column yield an operating line equation with slope L over G. Insoluble gas flow rate G remains constant throughout the height of the absorption tower. Non-volatile solvent flow rate L also remains constant, establishing a stable operating line slope. Absorption columns transfer soluble gas from a carrier gas stream into a liquid solvent. Operating lines graphically represent material balances between gas and liquid bulk phases. Graphical construction methods like McCabe Thiele use operating line slopes to determine stage requirements.
Gas sweetening plants absorb hydrogen sulfide from natural gas using liquid amine solutions. Chemical manufacturers scrub toxic chlorine emissions from exhaust streams using caustic liquid solutions. Design engineers adjust liquid and gas flow rates to optimize operating line slopes for economy. Inverting the ratio to G over L reverses the proper material balance coordinate geometry. Stating that the slope is always less than one ignores operational designs where liquid rates exceed gas. None of these fails to recognize that the standard mass balance directly produces the L over G ratio.
- Subject
- Engineering
- Category
- Chemical Engineering
- Topic
- —
- Difficulty
- medium
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