Chapter 10 - Natural gas liquids recovery

Abstract

This chapter discusses the natural gas liquids recovery. Most natural gas is processed to remove the heavier hydrocarbon liquids from the natural gas stream. These heavier hydrocarbon liquids commonly referred to as natural gas liquids (NGLs) include ethane, propane, butanes, and natural gasoline (condensate). Recovery of NGL components in gas not only may be required for hydrocarbon dew point control in a natural gas stream, but also yields a source of revenue, as NGLs normally have significantly greater value as separate marketable products than as part of the natural gas stream. Lighter NGL fractions, such as ethane, propane, and butanes, can be sold as fuel or feedstock to refineries and petrochemical plants, while the heavier portion can be used as gasoline-blending stock. The price difference between selling NGL as a liquid and as fuel, commonly referred to as the “shrinkage value,” often dictates the recovery level desired by the gas processors. This chapter presents the basic processes used to separate natural gas liquids from the gas, fractionating them into their various components, and describes different methods for the natural gasoline and liquefied petroleum gas (LPG) treatment.