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

H2S and NH3 are major contaminants in many synfuel process gas streams. The H2S is frequently removed by dissociation and reaction in scrubbers using alkaline scrubbing liquids. Some of the NH3 is removed by simple dissolution in the same unit; the remaining NH3 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 (H2S) and a basic gas (NH3) are absorbed simultaneously. In this paper, the interesting behavior of this simultaneous acid gas-basic gas scrubbing process is described and discussed. The percentage H2S and NH3, absorption as a function of the injected liquid pH, the liquid-to-gas ratio, and the NH3 content of the gas stream have been determined.