Front-end liquids handling typically represents one of the more energy intensive steps of natural gas processing operations. Stabilization towers, in particular, can be especially demanding in terms of energy consumption — making them an important area to evaluate when it comes to optimization and efficiency.
The size and design of a stabilization tower (or column) has a substantial impact on its ability to recover liquid hydrocarbons, remove corrosive components, and create transport-ready product. Optimal sizing of the cross-sectional area of the tower is essential to achieving efficient heat and mass transfer. It also directly affects how well vapor and liquid streams will mix and separate throughout the column.
Capacity of an individual tower will largely be determined by the composition of the stream and physical properties of the liquids in it. This is sometimes referred to as the system limit and is calculated using Stokes’ Law, which can be used to predict the velocity at which a liquid droplet (of specific size) will no longer travel downward through the vapor stream (source: NTNU). This provides a rough limit for sizing a tower with respect to its cross-sectional area.
In virtually every case, when determining the design specifications and size of a stabilization column, operators will be faced with a tradeoff between capacity and efficiency. Although it is not necessarily practical to minimize the size of a tower due to the possibility of having to modify or expand a facility in the event of a production increase, building in too much capacity can in many instances be disadvantageous.