hybrid pdms testing and techno-economic model

the ENERGY lab

Nicholas Siefert

Hybrid PDMS Testing and Techno-economic Model

Task Technical Coordinator Pre-combustion Solvents NETL CO2 Capture Conference

8/1/2014

Team Members: Sweta Agarwal, Hunaid Nulwala, Elliot Roth, Fan Shi, Wei Shi, David Miller, Dave Hopkinson, Bob Enick, John Kitchin, and Dave Luebke

• Overall goal of project • Experimental Data on Pre-combustion Solvents • Discussion of Process Flow Diagram • Capital & Operating Cost Breakdown of Equipment • Economic Model / Levelized Cost Estimate • Future work

Outline

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• Objective: Lower the cost of capturing CO2 from syngas • Approach: Develop hydrophobic solvents for separation of

CO2 from warm syngas

High Molecular Weight PDMS - Background

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• Higher CO2 and H2S selectivity against H2 at lower temperature

• Constraint: Selexol will absorb any remaining water in syngas

Background: Why Selexol must operate < 40oC

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0%10%20%30%40%50%60%70%80%90%

100%

40 90 140 190Syngas Temperature [°C]

Water Remaining in Syngas vs. Temperature

Experimental Results

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Selexol vs. Hybrid @25oC

• Hydrophilic • Viscosity = 5.8 cP • MW = 280 • Specific heat = 2.06 kJ/kg∙K • Density = 1030 kg/m3

• Thermal cond = 0.19 W/m∙K • Surface tension ~ 32 mN/m • Vapor Pressure = 0.0007

mmHg • CO2/H2 selectivity ~ 80

• Hydrophobic • Viscosity = 4.8 cP • MW = 438 • Specific heat = 1.77 kJ/kg∙K • Density ~ 936 kg/m3

• Thermal cond = TBD* • Surface tension = 22.1 mN/m • Vapor Pressure << 0.0007


Selexol *AspenPlus estimates that the thermal conductivity is 0.10 W/m∙K

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0 5 10 15 20 25 30 35 40

CO2 S

olub

ility

(w

t% in

clud

ing

CO2)

CO2 Partial Pressure (bar-a)

CO2 Solubility in Hybrid-PDMS 25°C

Experimental NETL

Experimental U. Pitt

Experimental NCCC

ComputationalSimulation NETL

0

50

100

150

200

250

300

0 5 10 15 20 25 30 35

H2 S

olub

ility

(pp

m w

t)

H2 Partial Pressure (bar-a)

H2 Solubility in Hybrid-PDMS 25°C and 40°C

Experimental NETL 25CExperimental NETL 40CExperimental U. Pitt 25CExperimental U. Pitt 40CComputational NETL 25CComputational NETL 40C

• 8 L of Hybrid PDMS-PEGDME were synthesized at NETL and shipped to NCCC

• Hybrid solvent was tested for CO2 solubility at 20oC and 40oC

• Solvent had tendency to foam and create fine aerosols at higher temperatures – Due to low surface tension,

low viscosity, and low density – Increases absorber diameter,

but can decrease height

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PDMS Scale up & NCCC Testing

Selexol vs. Ionic Liquid @25oC

• Hydrophilic • Viscosity = 5.8 cP • MW = 280 • Specific heat = 2.06 kJ/kg∙K • Density = 1030 kg/m3

• Thermal cond = 0.19 W/m∙K • Surface tension ~ 32 mN/m • Vapor Pressure = 0.0007


• Hydrophobic (0.23 wt% H2O) • Viscosity = 28 cP (wet) • MW = 399 • Specific heat = 1.11 kJ/kg∙K • Density ~ 1515 kg/m3

• Thermal cond = TBD* • Surface tension = TBD* • Vapor Pressure <<< 0.0007


Selexol

Ionic Liquid Selexol

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 2 4 6 8 10 12 14 16Conc

entr

atio

n (m

ol C

O2

/ L

Nea

t Sol

vent

)

Partial Pressure (bar)

Ionic Liquid

H-PDMS

Selexol

CO2 Solubility at 25oC in different Solvents

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0.01

0.02

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0 5 10 15 20 25 30

Conc

entr

atio

n (m

ol H

2/L

Solv

ent)

Partial Pressure (bar)

Ionic Liquid

H-PDMS

Selexol

H2 Solubility at 25oC

System Modeling

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System Modeling: Data Regression in Aspen Plus

• Data Regression to estimate the required pure and binary parameters

• Regression requires input of both thermodynamic & kinetic variable

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• PC-SAFT method used for H-PDMS and Selexol

• ENRTL-RK method used for Ionic Liquid

System Modeling: Aspen Plus Modeling

• Model for Physical Solvent based CO2 capture using flash regeneration adapted from MIT IGCC-Selexol capture Aspen Model

15 Field and Brasington, “Baseline Flowsheet Model for IGCC with Carbon Capture,” Ind. Eng. Chem. Res., 2011, 50 (19), p 11306.

Rate-based Absorber

HP Flash-Recycle

Pressure Swing Regeneration

Solvent Chiller

System Modeling: Aspen Plus Modeling

• Base Model for CO2 capture using flash regeneration adapted from MIT IGCC-Selexol capture Aspen Model

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Field and Brasington, “Baseline Flowsheet Model for IGCC with Carbon Capture,” Ind. Eng. Chem. Res., 2011, 50 (19), p 11306.

Our Economic Model

• Economic Model Assumptions: – There is an existing IGCC Power Plant with H2S Removal – 1 Years for Construction (for CO2 Capture Equipment) – 30 Years of Operations with O&M = 4% of Capital per year – 80% Capacity Factor – 5% Inflation-Adjusted Interest Rate – Plant Cost Ratio = 5 = Total Capital Cost / Bare Equipment Costs – Bare Capital Cost estimates calculated from equations taken

from various sources (Sieder Textbook, AspenPlus, IECM) • Used to calculate the levelized cost of capturing CO2

– Levelized cost = Operating costs plus capital costs levelized per ton of CO2 captured

– Values are normalized compared with Selexol

Operating Cost Incurred due to lower power

genreation 34.7%

Operating Cost Incurred due to lost H2

1.3% CO2 Compression

Operating Cost 19.5%

Solvent Based CO2 Capture

Operating Cost 10%

Fixed O&M 13.8%

CO2 Compression Capital Cost

9.7%

Solvent based CO2 Capture Capital Cost

10%

WGS Capital Cost 1.8%

Operating & Levelized Capital Cost Distribution Chart: Selexol Normalized

Value = 1.00 For Levelized Cost per CO2 Captured

Note: Levelized Cost at 10°C was less than 40°C

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1.0

H-PDMS (10°C) Selexol (10°C) NETL Ionic Liquid(40°C)

Nor

mal

ized

Leve

lized

Cos

t of C

aptu

ring

CO2

Comparison of Levelized Cost of Capture

Fixed O&M Cost

Levelized WGS, Captureand Compression CapitalCost

Capture Operating Cost

Compression OperatingCost

Gas not going to BraytonCycle Penalty Cost

Future Work

• Test Ionic Liquid Solvent at NCCC, and continue testing at NETL

• H2S testing for both H-PDMS and Ionic Liquid

• Model both H-PDMS and Ionic Liquid in a full IGCC-CCS system model with two-stage H2S/CO2 removal

• Include H2 & H2O separating membrane upstream of two-stage H2S/CO2 removal in order to potentially lower the levelized cost even further

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• Thanks to: NETL SCC, Sweta Agarwal, Hunaid Nulwala, Elliot Roth, Fan Shi, Wei Shi, Regina Woloshun, David Miller, Dave Hopkinson, Bob Enick, John Kitchin, and Dave Luebke

Thank You

Back-up Slides

Glossary

PC-SAFT : Perturbed Chain statistical associating fluid theory NRTL: Non-random two-liquid ENRTL-RK: Electrolyte NRTL with Redlich Kwong vapor phase properties

System Modeling: Preliminary Results of Net Power Consumed

Enick et al., “Hydrophobic polymeric solvents for the selective absorption of CO2 from Warm Gas Stream that also contain H2 and H2O,” CCUS Conference, Pittsburgh, PA, May 15 2013

PDMS Solubility using Raman: Dr. Kitchin CMU

CO2

H2 • CO2 and H2 Raman

spectroscopy can be used to determine solubility

CO2 and H2 Raman spectroscopy can be used to determine selectivity

Absorber: $11M

Flash Units & Separator: $1.5M

Bare Equipment Costs: H-PDMS

Recycle Compressor and Cooler : $2M

Solvent Pump: $0.5M

Solvent Chiller: $4M

Bare Equipment Costs: CO2 Compression Cycle

150 atm liquid CO2 21 atm 80 atm

11 atm

Cost of LP Compressor and Intercooler: $4.5M

Cost of MP, HP Compressors, Intercoolers and Liquid CO2 Pump: $12.7M


genreation 35.4%


1.4%

CO2 Compression Operating Cost

18.8%


Operating Cost 10%

Fixed O&M 13.6%


9.0%


10%


Levelized Cost Distribution Chart: H-PDMS


genreation 35.4%


1.4%


18.8%


Operating Cost 10%

Fixed O&M 13.6%


9.0%


10%


Levelized Cost Distribution Chart: H-PDMS Normalized to

Selexol, Levelized Cost per CO2 Captured = 0.98 +/-0.07 Uncertainty reflects uncertainty in CO2&H2 Solubility as measured by different researchers



genreation 43.1%


0.2%


22.5%


Operating Cost 10%

Fixed O&M 11.3%


10.9%


10%


Levelized Cost Distribution Chart: NETL Ionic Liquid Normalized to

Selexol, Levelized Cost per CO2 Captured = 0.79 +/-0.04 Uncertainty reflects uncertainty in H2 Solubility


hybrid pdms testing and techno-economic model

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