Sour Water Stripping of Coal Gasification Waste Water

摘要

This vapor--liquid equilibrium model for carbon dioxide--ammonia--water--hydrogen sulfide--organics and all the ionic species was used for the preliminary design of the stripping column. A simple design procedure was selected and used to investigate the influence of various parameters on the process. These parameters include steam to sour water flow ratios, the number of theoretical plates, and various other parameters. There are two basic conclusions to the study. First, a significant fraction of the organics (in the range of 50%) will be removed in the steam. This organic loss in the steam severely limits the utility of the stripping column. There are two possible means of over-coming this difficulty; a distillation column could be installed instead of the stripping column or valuable compounds could be recovered from the steam. Only the latter alternative has any chance for economic viability. The second important conclusion is that in any process for the removal of ammonia and hydrogen sulfide, the sour water should first be passed through a flash drum to remove the majority of the carbon dioxide before entering the stripping column. The various unexpected problems encountered as the work developed are discussed in detail. (ERA citation 04:044215)