Chemical reaction and effective interfacial areas in gas absorption

Abstract

Experiments have been carried out in a packed column to test the hypothesis that the interfacial area effective for gas absorption with chemical reaction depends on γ, where γ = factor by which reaction increases capacity of absorbent factor by which reaction increases rate of absorption . For physical absorption, γ = 1. For absorption into certain buffer solutions, γ ⪢ 1, and effective interfacial area is much larger than for physical absorption. For absorption with “instantaneous reaction”, γ ∼ 1 and the effective interfacial area is equal to that for physical absorption. Provided γ exceeds a certain value, the effective interfacial area does not depend on γ, so that values of the effective interfacial area determined by reactions with a sufficiently high γ have a general significance. The experiments show that it is not simply the occurrence of a chemical reaction but the value of γ to which it leads which determines the effective interfacial area. Values of the interfacial area determined with high γ should not be used for the design of physical absorbers.