Multicomponent Vapor–Liquid Equilibrium Measurement and Modeling of Ethylene Glycol, Water, and Natural Gas Mixtures at 6 and 12.5 MPa

Francois J. Kruger, Georgios M. Kontogeorgis, Even Solbraa, Nicolas von Solms*

*Corresponding author for this work

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Abstract

High pressure subsea natural gas dehydration (NGD) units using ethylene glycol (MEG) absorption have been proposed. To expand the experimental database and assist design qualification, new vapor–liquid equilibrium (VLE) experimental data have been measured for a 20-component glycol–water–natural gas mixture at T = (288–323) K, p = (6.0, 12.5) MPa, and wMEG,feed = (90, >99.8) %. MEG, H2O, CO2, N2, and alkane (methane to n- and i-pentane) phase distributions have been quantified. Experimental uncertainty ranges from ±2–42%, with the greatest uncertainty for the quantification of trace components. Experimental results are modeled using the Cubic-Plus-Association (CPA) equation of state. Overpredictions (∼9%) are observed for the water content of the vapor phase. CO2 is shown to have a large effect on yMEG, leading to modeling deviations in the order of 65%. A relatively accurate prediction of the natural gas partition coefficients was observed for major components C1–C3 and CO2, with modeling errors ranging from 5% for methane to 10% for CO2. More significant deviations were observed for trace components, with the largest deviation of 73% N2. The CPA model provides both satisfactory and conservative results suitable for use in NGD process designs. On the basis of this work, operation at subsea conditions would significantly improve dehydration capability.
Original languageEnglish
JournalJournal of Chemical and Engineering Data
Volume63
Issue number9
Pages (from-to)3628-3639
ISSN0021-9568
DOIs
Publication statusPublished - 2018

Bibliographical note

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acs.jced.8b00495.

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