Hydrolysis of Carbonyl Sulfide: A Potential Source of Downstream Sour Gas
Thomas J. Bruno, W C. Andersen, K I. Henning
rbonyl sulfide (COS), which occurs as an impurity in commercial sources fo propane can hydrolyze in the presence of water to form hydrogen sulfide (H2S) and carbon dioxide (COS) is not itself corrosive, the hydrolysis product H2S is corrosive, especially in the presence of water. In this paper, we summarize the results from studies that address the issue of COS hydrolysis in propane, thought to be a major problem in the LPG industry. First, a series of kinetics measurements were performed on the hydrolysis reaction in propane. In these measurements, mixtures of COS in propane were prepared and placed in a reaction vessel, and then a controlled quantity of water was added. The decrease in COS and the appearance of H2S, as monitored chromatographically, provided access to the reaction rate and ultimate equilibrium compositions. In addition to the rate measurements, we have tested prepared mixtures of COS in propane using a variant of the ASTM copper strip corrosion test. Although the copper strip corrosion test is a very crude, qualitative indicator, a correlation between our kinetics measurements with the rate measurements has been noted.