SIMULTANEOUS ABSORPTION OF AN ACID GAS (H2S) AND A BASIC GAS (NH3) IN A SCRUBBING DEVICE

H 2 S and NH 3 are major contaminants in many synfuel process gas streams. The H 2 S is frequently removed by dissociation and reaction in scrubbers using alkaline scrubbing liquids. Some of the NH 3 is removed by simple dissolution in the same unit; the remaining NH 3 can be removed in a second scrubber using a mildly acidic liquid. The first scrubbing stage in such a system is novel in that an acidic gas (H 2 S) and a basic gas (NH 3 ) are absorbed simultaneously. In this paper, the interesting behavior of this simultaneous acid gas-basic gas scrubbing process is described and discussed. The percentage H 2 S and NH 3 , absorption as a function of the injected liquid pH, the liquid-to-gas ratio, and the NH 3 content of the gas stream have been determined.