2017 NETL CO2 Capture Technology Project Review Meeting

August 24, 2017

Brice Freeman, Jay Kniep, Richard Baker, Tim Merkel, Pingjiao Hao

Gary Rochelle, Eric Chen, Yue Zhang, Junyuan Ding, Brent Sherman

Bench Scale Development of a Hybrid

Membrane-Absorption CO2 Capture Process

DE-FE0013118

1

• Award name: Bench-Scale Development of a Hybrid Membrane-Absorption CO2 Capture Process (DE-

FE0013118)

• Project period: 10/1/13 to 5/31/18

• Funding: $3.2 million DOE + $0.75 million cost share

• DOE-NETL Project Manager: Andy Aurelio

• Participants: MTR, University of Texas at Austin

• Overall goal: Evaluate a hybrid post-combustion CO2 capture process for coal-fired power plants that

combines membrane and amine absorption/stripping technology.

• Project plan: The key project work organized by budget period is as follows:

– BP1: Develop process simulations and initial cost assessments for the hybrid process, determine

preferred hybrid configuration. Fabricate membrane modules.

– BP2: Prepare the SRP pilot plant for hybrid testing. Test each capture system separately under hybrid

conditions.

– BP3: Conduct a parametric tests on the integrated hybrid capture system at UT-Austin’s SPR Pilot

Plant. Use test data to refine simulations and conduct TEA.

Project Overview

2

CO2 depleted

flue gas

U.S. Patents 7,964,020 and 8,025,715

30

40

50

60

70

0 20 40 60 80 100

CO2 capture rate (%)

Cost of

CO2 captured

($/tonne)

Single-step process, no recycle

Two-step process with CO2 recycle

DOE target

Motivation for the Hybrid Process

Two-step process with CO2 recycle

Hybrid Parallel Configuration

4

Benefits:

• Increases the concentration (driving force) of CO2 in flue gas.

• Reduce the volume of gas sent to the capture unit.

• Air sweep is a very efficient use of membranes.

• MTR’s membrane contactor is modular and compact.

• Hybrid concept can be used with different capture technologies.

Challenges:

• The sweep stream impacts boiler performance; ~0.75%

efficiency derating.

• Hybrid partner must be able to capitalize on higher CO2

concentrations.

• Overall, hybrid systems increase operational complexity.

Pilot plant

testing at UT

Austin

Integrated

Boiler Testing

at B&W(FE-0026414)

Hybrid Parallel Configuration

5

Benefits:

• Increases the concentration (driving force) of CO2 in flue gas.

• Reduce the volume of gas sent to the capture unit.

• Air sweep is a very efficient use of membranes.

• MTR’s membrane contactor is modular and compact.

• Hybrid concept can be used with different capture technologies.

Challenges:

• The sweep stream impacts boiler performance; ~0.75%

efficiency derating.

• Hybrid partner must be able to capitalize on higher CO2

concentrations.

• Overall, hybrid systems increase operational complexity.

Pilot plant

testing at UT

Austin

Integrated

Boiler Testing

at B&W(FE-0026414)

Hybrid Parallel Configuration

6

Benefits:

• Increases the concentration (driving force) of CO2 in flue gas.

• Reduce the volume of gas sent to the capture unit.

• Air sweep is a very efficient use of membranes.

• MTR’s membrane contactor is modular and compact.

• Hybrid concept can be used with different capture technologies.

Challenges:

• The sweep stream impacts boiler performance; ~0.75%

efficiency derating.

• Hybrid partner must be able to capitalize on higher CO2

concentrations.

• Overall, hybrid systems increase operational complexity.

Pilot plant

testing at UT

Austin

Integrated

Boiler Testing

at B&W(FE-0026414)

Sample Results from B&W Integrated Tests

(FE-0026414)

7

Membrane-Boiler Test Results

• 5 weeks of testing on natural gas, Powder River Basin (PRB), and Eastern Bituminous coal

• 90% capture and a variety of partial capture conditions were achieved

• Boiler flame was stable allowing a full battery of stream conditions and boiler

efficiency measurements to be conducted

Main skidSweep module

Boiler Impacts from B&W Tests(FE-0026414)

• Furnace heat absorption is lower (FEGT)

• Convection pass heat absorption is higher due

to improved heat transfer coefficients.

• Convection pass outlet heat flux is higher

• Air heater heat absorption is higher

• Air heater flue gas outlet heat flux is higher

• Total heat absorption is slightly reduced

• Validated earlier derating assumption; 0.75% at

18% O2 in inlet secondary air.

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Coal 30P M1 & M2 Coal 27P M2 Only Bit 32P 07 Bit 30P 06

20-Oct-16 18-Oct-16 3-Nov-16 2-Nov-16

Test Duration (h:mm) 7:00 7:15 6:00 3:04

PRB PRB Bit. Bit.

Load (MW) 1.5 1.4 1.6 1.5

FEGT (°C) 1,179 1,259 1,175 1,254

Convection Pass Exit Temperature (°C) 397 380 408 388

Air Heater Exit Temperature (Flue Gas) (°C) 217 210 222 212

53% 0% 75% 0%

Furnace Absorption (MW) 0.52 0.66 0.40 0.77

Convection Pass Absorption (MW) 0.96 0.91 1.11 0.90

Convection Pass Outlet Heat Flux (MW) 0.50 0.43 0.54 0.44

Total Heat Absorption (MW) 1.62 1.68 1.65 1.77

Air Heater Absorption (MW) 0.19 0.16 0.18 0.14

Air Heater Outlet Heat Flux (Flue Gas) (MW) 0.31 0.27 0.36 0.30

Date

Fuel

Membrane Secondary Air Ratio

Test Name

w/

recycle

w/out

recycle

University of Texas at Austin: SRP Pilot Plant

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Pilot Plant Modifications

10

MTR Skid (BP3)10-in AFS

Cold High

Pressure

Cross

Exchanger

HP Blower

(BP3)

Absorber

Column Ext &

Intercooling

skids

Structure

modification

11

Absorber

V-104

T-420

Tank

P-104-DI P-520

P-430

P-420

H-430

H-420

Knock-Out

Filter

H-112-DI

Gas Chiller

V-105-DI

Absorber

Feedtank

P-106-DI

H-113 H-520

H-525H-535

V-540AFS

P-550

H-545

Skid

Condenser

H-515

V-550

CO2/

Condensate

P-560

Air

H-107

V-103

CO2-Accum.

C-104-DI

HP Blower

CO2 Recycle

CO2 Make-upMTR Membrane

Skid

Vent to ATM

BP3

SRP Pilot Plant Hybrid Flowsheet

Simulated Hybrid Test Conditions

• 29 conditions with 5 m (30 wt%) piperazine (PZ)

• Inlet CO2: 12 & 20% (DOE/MTR), 4% (CCP4)

• Solvent rate: 3 – 24 gpm with 350 or 600 cfm air

• Lean loading: 0.18 – 0.27 mol CO2/equivalent PZ

• Rich loading: 0.30 – 0.38

• 84 to 99% CO2 removal

• Two absorber configurations

– 3 x 10-ft solvent

– 2 x 10-ft solvent, 1 x 10-ft water wash

• Stripper Temp: 135oC, 150oC12

Absorber Performance

1.25%

2.50%

5.00%

10.00%

20.00%

0.29 0.31 0.33 0.35 0.37 0.39

CO2

penetration (%)

Rich loading (mol CO2/equiv PZ)

350 cfm w 30 ft packing

600 cfm w 30 ft or 350 cfm w 20 ft

600 cfm with 20 ft

13

0.6

0.8

1.0

1.2

1.4

1.6

1.8

2.0

1 2 3 4 5 6 7 8

Predicted NTU/

Measured NTU

L/G (lb/lb)

Failure at high L/G probably due to liquid distribution

20%

12%

3.5%

Gas inlet CO2

Aspen Plus® Model Predictions of CO2 Removal by

Independence

14

2

3

4

5

6

0.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29

Heat Duty (GJ/MT CO2)

Lean Loading (mol CO2/mol alk)

3.4 - 4.3% CO2

12 - 20% CO2

Q = Qsensible + Qlatent + Qcondenser

Heat Duty is Independent of CO2 Concentration

Minimum heat duty at 0.22-0.26 lean loading still includes some heat loss.

2

4

8

0.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29

Heat Duty (GJ/MT CO2)

Lean Loading (mol CO2/mol alk)

Test Plan Predictions

Pilot Plant Results

Q = Qsensible + Qlatent + Qcondenser

[includes some heat loss]

Initial Modeling Under Predicts Measured Heat Duty

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3-12% CO2

Total Equivalent Work

(including some heat loss)

200

250

300

350

0.15 0.17 0.19 0.21 0.23 0.25 0.27

WEQ

(kWh/MT CO2)

Lean Loading (mol CO2/mol alk)

Compression to 150 bar

WEQ = WSteam + WCompressor + WPump

20% CO2

17

30

32

34

36

38

40

0.28 0.30 0.32 0.34 0.36 0.38 0.40 0.42

Weq(kJ/mol CO2)

Rich Loading (mol CO2/mol alk)

90±3% Removal

98-99% Removal

"Other" Removal

Lean Loading = 0.24±0.02 mol CO2/mol alk

Weq Near Optimum Depends on Rich Loading

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Initial Model Under Predicts Equivalent Work

200

400

0.15 0.17 0.19 0.21 0.23 0.25 0.27 0.29

WEQ

(kWh/MT CO2)

Lean Loading (mol CO2/mol alk)

WEQ = WSteam + WCompressor + WPump

Test Plan Predictions

SRP Results

19

Performance of Cold Cross Exchanger

U = 1455L1.11

100

200

400

800

1600

3200

0.1 0.2 0.4 0.8 1.6

U (W/m2-oF)

Average solvent rate, L (kg/s)

2017

2015

20

Pressure Drop Enhances Exchanger Performance

50

100

200

400

800

1 2 4 8 16

Heat transfer coefficient (W/K.m2)

Average pressure drop (psi)

Cold Exchanger

y = 181x0.69

Hot Flashing Exchanger

Hot Flashing P&F

Exchanger Performs Well

21

Cold Bypass Reduces Loss of Sensible Heat

22

0

2

4

6

8

10

12

14

16

0.00 0.05 0.10 0.15 0.20 0.25

Middle approach T

(oF)

Cold bypass ratio

Piperazine Management Results and Observations

• Precipitation minimized by 5 m PZ (only one incident)

– Instrument air loss + chilled water to IC = precipitation

– Melted at 80oC with heat gun

• Foaming Unexpected

– Moderate unexpected absorber pressure drop at high gas flow rate

– Reduced with the addition of antifoam

• Oxidation is acceptable

– NH3 emissions of 3 to 10 ppm, could still be reduced

• Aerosol requires high SO3

– PZ emissions doubled with 10 -100 ppm SO3

• Corrosion of CS could be acceptable for stripper shell

– 175 (SS), 325 (CS) mm/yr in hot lean PZ23

Conclusions from Simulated Hybrid Test Campaign

• Absorber & stripper performed well with 20% CO2

• Absorber performance predicted acceptably by “Independence”

– Absorber model is most accurate for 4% and 12% CO2

– Liquid distribution is poor at high L/G

• Energy requirement independent of inlet CO2

– Heat loss needs more analysis

– Nominal smallest Weq = 215 kWh/t at 0.23 lean loading

• Exchangers provide 4-8 oF pinch with 5 to 10% cold bypass

• Hot flashing P&F exchanger provides reliable heat transfer

24

Next Steps

Budget Period 3

• Integrate MTR’s plate-and-frame skid with UT Austin’s SRP Pilot Plant

• Perform integrated testing campaign under hybrid-parallel conditions

• Develop TEA based on test results, final project report

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Hybrid Project Team

• DOE-NETL:

– Andy Aurelio (Federal Project Manager)

• MTR:

– Brice Freeman (PI)

– Richard Baker (Technical Advisor)

– Pingjiao “Annie” Hao (Sr. Research Scientist)

– Jay Kniep (Research Manager)

– Tim Merkel (Dir. R&D)

• U. Texas - Austin:

– Gary Rochelle (co-PI)

– Eric Chen (Research Associate)

– Frank Seibert (Sr. Research Engineer)

– Darshan Sachde (Graduate Student)

– Brent Sherman (Graduate Student)

– Yue Zhang (Graduate Student)

– Junyuan Ding (Graduate Student)26