(113d) Reaction-Enhanced Acid Gas Transport in Membranes and Absorbers

Authors: 
Meldon, J. H. - Presenter, Tufts University


There is long-standing industrial and academic interest in the transport of acid gases - i.e., carbon dioxide, hydrogen sulfide and sulfur dioxide (the emphasis here will be on the first two) - in liquid (particularly aqueous) media containing solutes with which they react reverisbly. The chemical reactions tend to enhance rates of gas transport and, when the reactions are reversible, to do so under steady-state operating conditions.

This paper begins with a brief overview of relefvant research within the contexts of industrial-scale gas separations (i.e., absorber/stripper systems) as well as membrane-based systems, the latter of which have at times been used to model transport in blood and other physiological media.

It then examines the fundamental physico-chemical phenomena and parameters - e.g., relative time scales of diffusion and reaction, ionic diffusion potential effects, reaction-based coupling of the transport of two acid gases -as well as the effects of weak acid buffers, amines, amino acids and proteins, upon transport rates and selectivity.

It concludes with a discussion of promising areas for future research.