Gas processing is comprised of several different processes that work to achieve the specifications required for pipeline-qualified gas. A typical gas processing schematic begins with condensate removal and stabilization, which is then followed by acid gas treating. Acid gas treating works to remove corrosive components like H2S and CO2 in order to meet pipeline specifications. The resulting acid gas is then sent to sulfur removal units, as well as tail gas cleanup units, to be further recovered or incinerated. At this stage, the gas stream is sent to a dehydration unit which removes the water in order to prevent freezing and the formation of hydrates. A common gas pipeline specification for outlet gas water content is 7 lb/MMSCF. Once these processes have been completed, typically the gas is then considered pipeline-qualified gas. Before the gas is considered pipeline gas, sometimes a nitrogen rejection unit will be utilized to remove remaining nitrogen. The natural gas would typically be processed in a cryogenic gas plant, with the main column being the demethanizer, to separate out the heavier hydrocarbons, such as ethane, propane, butane, etc., which are then sent to a fractionation unit, because they are valued higher as individual components than as natural gas.
For Demethanizers/Deethanizers, Koch-Glitsch typically recommends INTALOX® ULTRA random packing, which achieves a relatively low pressure drop and can add additional capacity.
For Glycol Contactors, Koch-Glitsch typically recommends FLEXIPAC® HC® structured packing, which is well suited for the low liquid rates and high vapor rates.
For Amine Contactors/Regenerators, Koch-Glitsch provides both trayed and packed bed solutions. Commonly used products include FLEXITRAY® valve trays and INTALOX® ULTRA random packing.
DEMISTER® mist eliminators are often utilized to prevent Amine or Glycol losses, which could otherwise be carried out the top of the tower by the vapor.