Hydrocarbon Dew Point Control (Mechanical Refrigeration) Units

Hydrocarbon dew point is the temperature at which the hydrocarbon components of a natural gas begin to condense out of the gaseous phase into a liquid phase. Hydrocarbon Dew Point Control Units are designed to treat natural gas to meet pipeline gas specification or any specific requirement for downstream utilization of the gas. HCDP is a function of the gas composition as well as the pressure. It is used in the natural gas industry as a quality parameter. It will be specified in the contract from producers through processing, transmission and distribution companies to the end users. HCDP process utilizes mechanical refrigeration (propane refrigeration) to chill and partially condense raw natural gas to separate out the heavier hydrocarbon components. The condensed hydrocarbon liquids are then distilled in a stabilizer distillation column to produce a pentane plus (C5+) natural gasoline condensate. To avoid hydrate formation, glycol is injected, this accomplishes dew point control of both water and hydrocarbon in a single unit. 

Mechanical Refrigeration Units have several advantages, such as that outlet pressure is equal to inlet pressure, lessening the pressure drop through the plant, and reducing the need for residue gas compression.