National Technical University of Athens

School of Chemical Engineering

Laboratory of Thermodynamics & Transport Phenomena

UMR-PRU thermodynamic model:application to natural gas processing

CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam

V. Ko u l o c h e r i s , N . N o va k , A . P l a k i a , E . P e t r o p o u l o u , C h . B o u k o uva l a s , V. L o u l i , G . Pa p p a , E . Vo u t s a s

CAPE-OPEN

2019 Annual Meeting

Amsterdam

22-23 October

Introduction• UMR thermodynamic model• Motivation

Cape-Open property package

• UMR CAPE-OPEN application• UMR Property Package Setup

Simulation examples • Offshore natural gas processing• TEG dehydration• CPE in acid gas systems

Challenges• Speed• Robustness• New applications

Outline

CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam 2

UMR-PRU is an advanced cubic Equation of State (EoS)

• EoS-GE model, combining Peng-Robinson EoS with UNIFAC

• Thermodynamic properties of fluids (Density, Enthalpy, Heat Capacity, etc)

• Phase equilibria between fluids (Vapor-Liquid, Liquid-Liquid)

Predictive model applicable to the Oil & Gas Industry

• Phase envelope, flash calculations, liquid dropout, and thermodynamic

properties of natural gas and other petroleum fluids

• Mercury, water, acid gases, MEG, TEG, etc.

UMR-PRU thermodynamic model

CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam 3

Chemical thermodynamics for process optimization

✓ Expand research activity

✓ Attract interest from the industry

Motivation

CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam 4

Chemical Thermodynamics: Single and Multiphase Systems

Process Unit Design and Operation: Optimum Operating Conditions

Plant Design and Operation: Supply Chain Optimization

P (

bar

)

T (K)

Ongoing 10 year

collaboration with

Scale-up

UMR CapeOpen application

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Process Modelling

Component (PMC)

Process Modelling

Environment (PME) CAPE-OPEN

PMC : 1. UMR.dll : Fortran library for thermodynamic calculations2. Wrapper : C# library acting as a medium between UMR.dll and PME

UMR.dll Wrapper

UniSim

Aspen HYSYS

PRO/II

CAPE-OPEN

UMR Property Package Setup

CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam 6

UNISIM embedded flash : eThermo

Offshore NG processing

E. Voutsas, N. Novak, V. Vouli, G. Pappa, E. Petropoulou, Ch. Boukouvalas, E. Panteli, E. Skouras, Thermodynamic modelling of natural gas and gas condensate mixtures, in Natural Gas Processing from Midstream to Downstream. 2019.

7

88.6oC87 bar

108oC26 bar

2.1 bar

26oC86 bar

25oC25 bar

25oC7 bar

25oC1.6 bar

25oC84.5 bar

Export gas

Condensate

Well fluid

50oC210 bar

1st recompression scrubber

2nd recompression scrubber

1st stage separator

2nd stage separator

export gas recompression

2nd stage separator

3rd stage separator

1st stage recompression

2nd stage recompression

heater

Export gas cooler

cooler

cooler

cooler

3rd stage recompression

cooler

condensate cooler

scrubber

45oC69 bar

• Real, relatively simplified, topside process of a natural gas platform

• Gas condensate well stream for the production of rich gas and stabilized condensate

Feed fluid

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Feed fluid contains pseudocomponents!

TEG dehydration

Ind. Eng. Chem. Res. 2018, 57, 25, 8584-8604 9

t=27oCP=52 bar

t=75oCP=3.2 bar

tcond=100oCtreb=204.4oCP=1.3 bar

TEG dehydration by absorptionAim: 30 ppm dry gas water content

• UMR-PRU yields identical results in HYSYS and Unisim

• Comparison with HYSYS Glycol package (TST/NRTL)➢ Better prediction of thermodynamic properties with UMR-PRU implies more

accurate simulation results

Acid gas/alkanolamine/water mixtures

➢ Extended UMR-PRU (PR + extended UNIQUAC)

➢ Acid gases: CO2, H2S

➢ Amines: MEA, MDEA

✓ Phase equilibrium

✓ Chemical equilibrium

✓ Simultaneous chemical & phase equilibrium

✓ Chemical equilibrium solved in two sequential

flash drums

✓ Comparison of UMR-PRU with Acid-Gas model

➢ Better prediction of VLE with UMR-PRU

10CAPE-OPEN 2019 Annual Meeting, 22-23 October 2019, Amsterdam

Natural gas with H2S, CO2

Reactions with MEA or MDEA

Aqueous phase

Vapor phase

Challenges

• Speed✓The CAPE-OPEN simulation is tiresome compared to built-in

thermodynamic models

• Simulation robustness✓3 phase flash and phase stability may return artifacts

✓False labeling of phases as Liquid or Vapor

• New applications✓Trace components

✓4 phase flash

✓Hypothetical solids

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Thank you for your attention

Questions?

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