GPSA Section 16 · Ortloff GSP Process · Cryogenic NGL Recovery
Understand GSP process design, split-vapor reflux, turboexpander operation, and cryogenic NGL recovery optimization
The GSP is a cryogenic NGL recovery process where the feed is split into two streams: the main stream (60-75%) is expanded through a turboexpander for power recovery and cooling, while the subcooler stream (25-40%) is cooled by demethanizer overhead to provide cold reflux to the column top.
Standard GSP achieves 85-96% ethane recovery and 98-99.5% propane recovery. The process operates with cryogenic demethanizer temperatures of -120°F to -150°F and typical specific power consumption of 20-35 HP/MMSCFD.
The GSP process requires dehydrated feed gas at typical inlet pressures of 600-1200 psia. Feed must be dried to prevent ice and hydrate formation in the cryogenic sections of the plant.
Turboexpander isentropic efficiency is typically 82-88% in GSP plants. The expander recovers power from the gas expansion while providing the cooling needed for NGL condensation and recovery.
It is used to design cryogenic NGL recovery plants, calculating turboexpander power, demethanizer reflux, and ethane/propane recovery per GPSA Section 16.
It calculates turboexpander power requirements, demethanizer reflux ratios, and ethane and propane recovery percentages.
The calculator follows GPSA Section 16 methods for cryogenic NGL recovery plant design.