Work Output of Multicomponent LNG Mixtures in Two-Phase Expanders

A two-phase expander recovers more work from a multicomponent LNG mixture than a single phase expander. The calculation of the recoverable work involves the complex thermodynamics of two-phase mixtures, and is best done utilizing property tables from the National Institute of Standards and Technology (NIST). The NIST tables are in turn based on equations developed by the European Gas Research Group (GERG-2008). Building on the work done by these distinguished groups, we are able to document the contributions to the enthalpy integral from the PV term versus the internal energy.