Carbon Composite Adsorbents for Post Combustion CO2 …...post-combustion CO 2 capture. •Site...

Carbon Composite Adsorbents for Post Combustion CO2 Capture

ENERGY FLAGSHIP

Presenter: Yonggang Jin Research Team: Shi Su, Yonggang Jin, Ramesh Thiruvenkatachari, Jun Bae, Xinxiang Yu

HiPerCap EU-Australia workshop, Melbourne, 25-27 March 2015

Lab Scale Study – Carbon Fibre Composites

Carbon Fibre (s) and Phenolic

resin binding material

Slurry or Paste

Vacuum Moulded to

honeycomb structure

Drying at 50-60ºC and

Curing at 130-150ºC

Carbonised with inert gas at

650-850ºC to pyrolize the resin

Activation at 650-950ºC to

achieve pore characteristics

Carbon Fibre (s) and Phenolic

resin binding material

Slurry or Paste

Vacuum Moulded to

honeycomb structure

Drying at 50-60ºC and

Curing at 130-150ºC

Carbonised with inert gas at

650-850ºC to pyrolize the resin

Activation at 650-950ºC to

achieve pore characteristics

Fabricated (HMCFC)

Length: 80mm, Dia: 30mm, Number of Channels: 17,

Microscopic morphology

Molding equipment

3 processing furnaces

Breakthrough Test Rig with Lab Scale Adsorption Chamber Adsorbent Characterisation

Adsorbent Testing Equipments

Fabrication and Testing of Lab Size Honeycomb Carbon Fibre Composite Monoliths

CSIRO carbon composite adsorbents for PCC 2 |

Solid Carbon Sorbent CO2 Capture Technology • Based on honeycomb carbon composite monoliths

Enable CO2 capture with low pressure drop

Potentially low energy consumption for adsorbent regeneration

• Lower heat capacity of solid adsorbents than liquid solvents

• Physisorption - lower heat of CO2 adsorption

• Utilisation of flue gas waste heat for CO2 desorption

Tolerant to moisture, SOx and NOx • Avoid flue gas pre-treatment prior to CO2 capture; this is important as

there are no FGD and SCR DeNOx facilities at coal fired power plants in Australia


Evolutionary Journey


Lab scale CO2 capture

(2006-2008)

Large scale CO2 capture with regeneration (2009-2011)

• Proof-of-Concept • Capture studies using

simulated flue gas

CO2 capture site trials

(2011-2014)

• CO2 capture combined with thermal and vacuum regeneration

• To evaluate CO2 capture and regeneration under real flue gas conditions

Lab scale studies Development of next generation carbon composite adsorbents (2010 – present)

Lab scale study New regeneration process with enhanced heat transfer (2011 – present)

NEXT

Large Scale Capture-Regeneration Studies

CF composites


Large size adsorbent (Ø 123 mm)

Lab size adsorbent (Ø 30mm)

Large scale CO2 capture-regeneration unit

• Two 2 meter long columns • Repetitive capture & regeneration capability • Thermal and vacuum swing regeneration

CO2 adsorption Isotherms at 25 oC

• 11.7 wt % at 760 mmHg • 3.5 wt % at 114 mmHg (15% CO2)

Large scale moulding unit for composite fabrication

R. Thiruvenkatachari, S. Su et al., International Journal of Greenhouse Gas Control, 2013, 13, 191-200.


Summary of Large Scale Study Results

Adsorption Breakthrough Profile Showing CO2 capture at Real Time

• CO2 capture carried out at ambient temperature and pressure • Simulated flue gas consisting of 13% CO2, 5.5% O2 and balance N2 • CO2 adsorption efficiency > 97% from adsorption breakthrough

0

5

10

15

20

25

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40

0

2

4

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8

10

12

14

16

00:00:00 00:14:24 00:28:48 00:43:12 00:57:36 01:12:00 01:26:24

Co

lum

n T

emp

era

ture

, C

an

d G

as

Flo

w R

ate

, S

LM

Ga

s C

on

c.,

%

Time, h:m:s

CO2 Conc O2 Conc

Gas Flow Rate Bottom Temp

Top Temp

R. Thiruvenkatachari et al., International Journal of Greenhouse Gas Control, 2013, 13, 191-200.


Thermal and Vacuum Regeneration Vacuum Regeneration

• Residual CO2 inside column after thermal regeneration

• Vacuum regeneration alone is ineffective • Heating is essential to desorb CO2 • Combined thermal and vacuum regeneration

with pure product purge is most effective • Very high purity of recovered CO2 • CO2 recovery > 95%

Individual Thermal Regeneration

0

10

20

30

40

50

0

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100

0:00:00 0:14:24 0:28:48 0:43:12 0:57:36 1:12:00 1:26:24

Des

orb

ed g

as v

ol,

L

Gas

co

nc,

%

Time, h:m:s

CO2

Gas Vol

Desorbed Gas Out

0

20

40

60

80

100

120

0

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0:00:00 0:04:49 0:09:39 0:14:28 0:19:18 0:24:07

Co

lum

n P

ress

ure

, K

pa

CO

2C

on

c, %

Time, hr:min:sec

CO2

Pressure

Vacuum Only

without Heating

Vacuum Stop

Start Heat

Combined Thermal and Vacuum Regeneration

0

20

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200

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Des

orb

ed g

as v

olu

me,

L

Des

orb

ed C

O2

con

c.,

%

Time, h:m:s

CO2 Conc

Gas Vol

Volume of CO2 by Thermal Regeneration

Volume of CO2 by Vacuum Regeneration

R. Thiruvenkatachari, S. Su et al., International Journal of Greenhouse Gas Control, 2013, 13, 191-200.


Site Trials of Prototype CO2 Capture Unit

• Objective – to evaluate the stability of honeycomb CF composite monolithic adsorbents

using the real flue gas at Vales Point Power Station – to test the effect of real flue gas characteristics on the operation and

performance of the CO2 capture unit

• Site installation, commissioning and testing

Opening of real flue gas to test

unit for first time at Vales Point

Power Station

Fully commissioned solid sorbent prototype

unit at Vales Point power Station Individual sensors to measure

SOx, NOx, CO and CO2 for

accurate measurement


Site trial testing involving two main scenarios

– CO2 capture performance with flue gas pre-treatment

– CO2 capture performance without flue gas pre-treatment

Process methodology adopted for site trials

Performance of carbon composite solid adsorbents evaluated:

– Stability of adsorbents to real flue gas evaluated from over 200 tests

– CO2 removal performance

– Solid sorbent performance to removal of other gases apart from CO2

Site Trials of Prototype CO2 Capture Unit (continued)

Flue gas IN

Caustic Scrubber System for Flue gas

Pre-treatment

Adsorption/ Gas capture

CO2 FlushingThermal & Vacuum Swing Regeneration

CO2 Recovered from Fluegas

Recovered CO2 for FlushingFlue gas without Pre-treatment


0

50

100

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200

250

300

350

0

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07:12 15:33 23:54 32:15 40:36 48:58

Gas

Co

nce

ntr

atio

n, p

pm

CO

2C

on

cen

trat

ion

, %

Time, m:s

CO2 SO2 (ppm)NO (ppm) NO2 (ppm)CO2 vol% SO2 ppmv

NO ppmv NO2 ppmv

Results of Site Trials

Adsorption & desorption: flue gas with pretreatment

pretreatment


0

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350

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00:00 03:57 07:53 11:50 15:47 19:44 23:40

Ga

s C

on

cetr

ati

on

, pp

m

CO

2C

on

cen

tra

tio

n, %

Time, m:s

CO2 vol% SO2 ppmvNO ppmv NO2 ppmv

SO2NO2NO

CO2

Results of Site Trials (continued)

Adsorption & desorption: flue gas without pretreatment


Results of Site Trials (continued)

Excellent stability to real flue gas over 200 site tests – CO2 adsorption efficiency consistently over 98% – CO2 desorption efficiency between 90-95%.

0

20

40

60

80

100

0102030405060708090

100

0 25 50 75 100 125 150 175 200

CO

2 D

eso

rpti

on

Eff

icie

ncy

, %

CO

2 A

dso

rpti

on

Eff

icie

ncy

, %

Run Number

Adsorption

Desorption

Adsorbent stability

Development of New-Generation Carbon Composite Adsorbents

Objective Enhance CO2 adsorption capacity (smaller footprint, lower capital and

operating costs)

Lower the cost of adsorbents using local biomass waste and brown coals

New-generation carbon composite adsorbents • Carbon nanotube (CNT) modified carbon composite monoliths

• Biomass derived carbon composites (HiPerCap WP2)


CNT Composites - Source of CNTs

• CPD &CCI are home made, Com the commercial product


CPD CCI Com

Preparation of CNT Composite Adsorbents


Prepared CNT composite monolith Schematic of composite preparation procedures

CF/CNT/Resin/MC/H2O

Mix Mould

Curing 150 oC 1hr

Carbonisation 650 oC 1hr (N2)

CO2 activation950 oC 15minCO2 adsorption

Characterisation

The current preparation method (physical activation with CO2) is simpler and more economic than chemical activation (e.g. with KOH) and functionalisation with basic groups

SEM Morphology

Morphology and macropore size distributions of CNT composites

16 | CSIRO carbon composite adsorbents for PCC

Morphology of activated phenolic resin

Y. Jin, S. Hawkins, C. Huynh, S. Su, Energy Environ. Sci., 2013, 6, 2591-2596.

0 100 200 300 400 500 600 700 8000.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

CO

2 a

dso

rbe

d (

mm

ol g

-1)

Pressure (mmHg)

CNT composite (Com-15)

CF composite

resin alone derived carbon

0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.00.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Po

re s

ize

dis

trib

utio

n (

cm

3 g

-1 n

m-1)

Pore size (nm)

CNT composite (CCI-15)

CF composite

resin alone derived carbon

Comparisons of CNT and CF composites


CNT composites exhibit much higher CO2 adsorption capacities • CO2 uptake: 15.9 wt% at 25

oC and 1 bar, and 5.2 wt% at 25 oC and 0.15 bar

• Up to 30% increase in CO2 adsorption capacity at 25 oC and 1 bar

• Over 45% increase in CO2 adsorption capacity at 25 oC and low CO2 pressures (0.15 bar)

CO2 uptake at 25 oC Narrow micropore size distributions


Adsorption Selectivity & Kinetics


0 100 200 300 400 500 600 700 8000

1

2

3

4

5

CO2-273K

CO2-298K

N2-273K

Am

ou

nt

ad

so

rbe

d (

mm

ol g

-1)

Absolute pressure (mmHg)

N2-298K

CO2 & N2 uptake adsorption Isotherms at 0 and 25 oC

Rates of CO2 adsorption at 25 oC

and 25 mmHg

• CO2/N2 selectivity: 32.6 at 273 K and 19.8 at 298 K • Fast adsorption kinetics observed in the CNT composites


0 50 100 150 200 250 3000

20

40

60

80

100

resin alone derived carbon (Res-60)

CNT composite (Com-15)

Ad

so

rptio

n c

om

ple

ted

(%

)Time (s)

Conclusions

• Porous carbon composite monoliths show great promise in post-combustion CO2 capture.

• Site trials demonstrate the excellent stability of the carbon composite adsorbent towards real flue gas.

• New-generation CNT carbon composite adsorbents exhibit significantly enhanced CO2 uptake particularly under low CO2 pressures, which is of more relevance for flue gas applications.


Acknowledgements

• Funding supports from:

Coal Innovation NSW for the site trials of prototype CO2 capture unit at the Vales Point power station

ANLEC R&D for the development of CF/CNT composites

CSIRO

• Site support from Delta Electricity


ENERGY FLAGSHIP

Thank you Dr Shi Su Senior Principal Research Scientist Team Leader Phone: 07 3327 4679 Email: [email protected] Web: www.csiro.au

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