Project ForgeMass Transfer
Mass Transfer Operations
GATE 2014
Hard
Assuming the mass transfer coefficients in the gas and the liquid phases are comparable, the absorption of CO2 from reformer gas (CO2+H2) into an aqueous solution of diethanolamine is controlled by
- gas phase resistance
- Bliquid phase resistance
- Cboth gas and liquid phase resistances
- Dcomposition of the reformer gas
Explanation
Diethanolamine reacts very rapidly with CO2, which effectively drives the liquid-phase CO2 concentration at the interface toward zero and removes the liquid-side resistance to mass transfer (the fast reaction 'consumes' the resistance). With comparable film coefficients but a negligible liquid-side resistance due to the fast reaction, the overall resistance is controlled by the gas phase.
Source: GATE CH 2014 (2014)
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