Sour gas sweetening may also be carried out continuously in the flowline by continuous injection of H2S scavengers, such as amine-aldehyde condensates. Contact time between the scavenger and the sour gas is the most critical factor in the design of the scavenger treatment process. Contact times shorter than 30 sec can be accommodated with faster reacting and higher volatility formulations. The arnine-aldehyde condensates process is best suited for wet gas streams of 0.5-15 MMscfd containing less than 100 ppm H2S.
The advantages of amine-aldehyde condensates are water (or oil) soluble reaction products, lower operating temperatures, low corrosiveness to steel, and no reactivity with hydrocarbons.