Thermodynamic Data to Support High-Temperature Syngas Quench Design: Vapor-Liquid Equilibrium Calculations

Published

January 1, 2008

Author(s)

Allan H. Harvey

Abstract

procedure has been developed, based on a dilute-solution model of the liquid phase and the rigorous virial expansion for the vapor phase, for modeling the vapor-liquid equilibrium between water and a synthesis gas consisting primarily of H2, CO, and CO2. Calculations of the vapor-liquid equilibrium have been performed at temperatures and pressures typical for a quench step in an IGCC power plant. The uncertainty in the calculated vapor-phase mole fraction of water is less than 0.01, and is primarily due to the omission of higher-order terms in the virial expansion. Other thermodynamic calculation methods were examined and compared to the more rigorous calculations. The ideal-gas assumption for the vapor phase seriously underestimates (by about 0.09 mole fraction at typical conditions) the water content of the equilibrium vapor. The Peng-Robinson equation performs much better, producing vapor-phase mole fractions of water that differ from the more rigorous results by amounts similar to the uncertainty in the virial approach.

Citation

EPRI Report

Pub Type

Journals

Keywords

synthesis gas, virial equation, aqueous systems, Henry's law, IGCC, vapor-liquid equilibria

Citation

Harvey, A. (2008), Thermodynamic Data to Support High-Temperature Syngas Quench Design: Vapor-Liquid Equilibrium Calculations, EPRI Report (Accessed April 19, 2024)