Evaluation of Carbon Dioxide Capture From Existing … Library/Events/2014/2014...Evaluation of Carbon Dioxide Capture From Existing Coal Fired Plants by Hybrid Sorption Using Solid

Evaluation of Carbon Dioxide Capture From Existing Coal Fired Plants by Hybrid Sorption Using Solid Sorbents (CACHYSTM)

NETL CO2 Capture Technology Meeting

Pittsburgh, Pennsylvania July 29-Aug 1, 2014

Steve Benson, Dan Laudal, Harry Feilen, Kirtipal Barse, Scott Johnson

University of North Dakota – Institute for Energy Studies

Srivats Srinivasachar Envergex LLC

Presentation Overview

2

Project Overview

Technology Fundamentals

Progress and Current Status

Future Plans

Funding

3

Initial Funding – STTR project – Envergex and UND

Project Funding U.S. Department of Energy Carbon Dioxide Capture RD&D program

Bench-scale testing

October 2011 to September 2014 (No-cost extension through Dec. 2014)

Total Project Funding: $3,690,000 DOE Share: $2,952,000

Cost Share: $738,000

• US Department of Energy - NETL

• UND Institute for Energy Studies

• Envergex LLC

• Lignite Energy Council/NDIC

• ALLETE Group

• Minnesota Power

• BNI Coal

• SaskPower

• Barr Engineering

• Solex Thermal Science

4

Project Participants

Project Objectives

Overall Project Objectives Improve current state-of-the-art (amine scrubbing) by developing a novel

sorbent-based, post-combustion CO2 capture technology Achieve at least 90% CO2 removal from coal combustion flue gas Demonstrate progress toward DOE target of less that 35% increase in

levelized cost of electricity (LCOE) for plant with CO2 capture Demonstrate at bench-scale level a sorbent-based technology for capture

of CO2 by hybrid sorption (CACHYS™) from coal combustion flue gas Develop key information on sorbent and technology effectiveness

5

Technology Background and Fundamentals

CACHYS™ Hybrid Sorption Process

7

• Key component – metal carbonate salt

• Reacts with CO2 to form adduct. Reversible with heat addition

• Additive/process conditions - enhance adsorption kinetics + reduce adsorption/regeneration energy

Coal-fired PlantSorbent

Treatment

CO2

Adso

rber

Rege

nera

tor

Filter Flue Gas: Low CO2

Flue Gas: High CO2

Compressed CO2

Cond

ense

r

Extraction Steam (~150oC)

HX -Heat

Regenerated Sorbent

CO2-loaded Sorbent

E-CACHYS™

Fresh Sorbent

CACHYSTM Process Advantages

Advantages Low reaction heat ~ 40-80 kJ/mol

CO2 (novel chemistry and process conditions)

High sorbent capacity (> 7 g CO2/100 gm sorbent)

Increased sorption kinetics (smaller–sized equipment)

Use of low cost, abundantly available materials for sorbent

Use of commercially-demonstrated equipment design/configuration

Reduced capital and operating costs

8

020406080

100120140160180200

Heat

of r

eact

ion

(kJ/

mol

CO

2)

CACHYSTM Process Testing Objectives

9

• Confirmation of energetics

• Confirmation of sorbent capacity

• Confirmation of reaction kinetics

• Sorbent integrity

• Sorbent handling

Progress and Current Status

Technical Approach and Project Scope

Scope of work includes eight main tasks Task 1: Project Management and Planning

Task 2: Initial Technology and Economic Feasibility Study

Task 3: Determination of Hybrid Sorbent Performance Metrics

Task 4: Bench-Scale Process Design

Task 5: Bench-Scale Process Procurement and Construction

Task 6: Initial Operation of the Bench-Scale Unit

Task 7: Bench-Scale Process Testing

Task 8: Final Process Assessment

11

Significant Accomplishments

TGA/DSC Desorption Energy Data

0

20

40

60

80

100

120

140

A B C D

Des

orpt

ion

Ener

gy

(kJ/

mol

CO

2)

Hybrid Standard

13

• Desorption energy ~ 30-80 kJ/mol CO2 • Below target of 80kJ/mol CO2 and significantly lower

than standard carbonate process (130 kJ/mol CO2)

Fixed/Bubbling Bed Reactor: Multi-cycle Sorbent Testing

14

HCK-4 HCK-7

• Both sorbents exceeded goal of 7.0 g CO2/100g of sorbent and maintained capacity over the 100 cycle tests

Technical and Economic Feasibility Study

• Initial Technical and Economic Feasibility (550MWe) – Total O&M $28,290,000 – Capital Charge $102,504,000 – Total Cost $130,794,000 – CO2 Captured 3,614,000 Tons – Cost of CO2 Capture $36.19/ton – Cost of Electricity Increase 40%

15

16

Bench-Scale Facility

Sorbent manufacturing Sorbent drying system – rotary tube dryer

SEM Image – CO2 Loaded

17

SEM Image – Regenerated

18

19

Bench-Scale System Design – Block Flow Diagram

Separator 1(Fabric Filter 1)

Separator 2(SO2 Scrubber)

Reactor 1 (Circulating

Fluidized Bed)

Separator 3(Cyclone)

Separator 4(Fabric Filter 2)

Heat Exchanger 1(Solex Heater)

Reactor 2(Solex

Regenerator)

Heat Exchanger 2(Solex Cooler)

Separator 5(Particulate

Filter)

Separator 6 (Condenser)

30 acfm Flue Gas

<0.001 lb/hr Ash

Ash-FreeFlue Gas

5.2 lb/hr Fresh NaOH Solution

4.9 lb/hr Recirculated

Scrubbing Solution

Moist,Ash-and-SO2-Free

Flue Gas

RecirculatedSorbent

Sorbent Fines

CO2 Lean Flue Gas

0.2 lb/hr Purge Solution

220 lb/hrUtilized Sorbent

220 lb/hrRegenerated Sorbent

Sorbent Fines

Steam and CO2

Steam and CO2

13 lb/hr CO2

Steam and CO2

Condensate

Gas Conditioning

Adsorber

Regenerator

Regenerator Off-gas System

20

Bench-Scale Facility

Integration of bench-scale facility at UND’s steam plant

Control Room

Process Tower

Storage

Two 20 ft. shipping containers 30 ft. tall process tower fabricated by UND Flue gas sampled from either of two coal-fired boilers

21

Summary of Bench-scale Results to Date

• Parametric Testing: Short duration tests aimed at optimizing specific parameters

Tests to date have focused on operation of individual process components

Longer term, integrated tests are currently underway

• Adsorber: Demonstration of hybrid sorption benefits – large increases in capture and kinetics

Capture as high as 85% has been achieved to date

Working capacity of > 6 wt% (75% utilization after adsorption, 20% after regeneration)

Identified optimal process conditions and design basis

• Regenerator: Demonstration of hybrid sorption benefits – reduction of the regeneration energy

CO2 purity ~99%

Demonstrated positive impact of direct steam on desorption rate and energetics

Adsorber Testing – Data Summary

22

0

20

40

60

80

100

A B C D E F G H I

CO2 C

aptu

re %

Hybrid Sorption

Standard Sorption

A Zero Additive F Increased Fresh Feed B Sorbent Recirculation G Increased Gas Res. Time C Sorbent with Additive H Decreased Flue Gas CO2 D Sorbent Recirculation I Increased Gas Res. Time E Increased Additive Loading

23

Regenerator Testing

10

20

30

40

0

1

2

3

4

5

6

8:30 9:30 10:30 11:30 12:30 13:30

Sorbent Utilization, %

CO

2 Flo

w, l

b/hr

CO2 flow rateDesorbed CO2, lb/hrSorbent Utilization

Direct Steam On

Direct Steam Off

• Use of direct steam facilitates CO2 desorption

24

0

3

6

9

12

15

18

60

80

100

120

140

160

180

09:30 10:30 11:30 12:30 13:30 14:30

Regenerator Pressure (psig) Te

mpe

ratu

re (°

C)

Regenerator Indirect Steam Temp Regenerator - Sorbent Exit TempDirect Steam Temp Regenerator Pressure

Increasing Steam Flow

Steam Flow Stopped

• Use of direct steam increases sorbent temperature via exothermic reaction that reduces regeneration energy – confirms observations during lab-scale work

Regenerator Testing

25

Integrated Testing

• Achieved reasonable CO2 mass closures over an extended period

0

10

20

30

40

50

60

70

80

90

100

110

120

130

140

0

2

4

6

8

10

12

14

12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00

Closure, wt%

CO2 c

aptu

re/d

esor

ptio

n (lb

/hr)

CO2 Captured, lb/hrCO2 Desorbed, lb/hrCO2 Mass Closure, %

60

62

64

66

68

70

72

74

76

78

80

12:30 13:00 13:30 14:00 14:30 15:00 15:30 16:00 16:30 17:00Te

mpe

ratu

re (°

C)

FB1 1/4FB1 2/4FB1 3/4FB1 4/4

• Very good control of the exothermic heat of reaction in the adsorber

26

Operational Challenges/Mitigation Strategies

Challenges:

• Adsorber Capture efficiency

Reliable sorbent circulation

• Regenerator Condensation and flowability

Desorption rate

Mitigation Strategies: • Adsorber

Longer residence time/sorbent recirculation

Ensure sufficiently large surge volumes

• Regenerator Identification of stagnant zones Ensure heating of all contact surfaces Use of “soot blowers” and vibration Online cleaning Higher temperature operation

Scale up to larger diameter beds will alleviate many of the challenges experienced during bench scale operation

27

Remaining Work

• Complete Bench-scale Testing: Sorbent and process performance

Identify attrition rates and performance with SO2-containing flue gas

Adsorber and regenerator multi-cycle evaluation

Obtain data for scale-up and process economics

Determine environmental, health and safety (EH&S) concerns

• Final Process Assessment: EH&S

Final Technical and Economic Feasibility Study

28

Future Plans

• E-CACHYSTM

Developed as part of a DOE SBIR/STTR Phase I grant

Goal to increase sorbent capacity by 2x CACHYSTM sorbents

Capacity targets were achieved while maintaining other benefits of hybrid sorption

Phase II application was submitted to DOE - received notice of intent to award

• Phase II STTR Develop improved sorbent manufacturing methodologies

Modification of the existing bench-scale facility to accommodate improved sorbent

Demonstrate a new process configuration that greatly reduces the impact of sorbent attrition

Develop an improved hybrid sorption technology that will further reduce the cost of CO2 capture

Acknowledgements

Project Funding and Cost Share • U.S. Department of Energy (DOE-NETL) • Lignite Energy Council/NDIC • ALLETE (Minnesota Power and BNI Coal) • SaskPower • Solex Thermal • UND

DOE-NETL Project Manager – Andrew Jones

29

Contact Information Steven A. Benson

Institute for Energy Studies, University of North Dakota (701) 777-5177; Mobile: (701) 213-7070

[email protected]

Srivats Srinivasachar Envergex LLC

(508) 347-2933; Mobile: (508) 479-3784 [email protected]

Dan Laudal Institute for Energy Studies, University of North Dakota

(701) 777-3456; Mobile: (701) 330-3241 [email protected]

Harry Feilen Institute for Energy Studies, University of North Dakota

(701) 777-2730; Mobile: (701) 739-1199 [email protected]