Prof. J. Carlos Abanades Spanish Research Council, CSIC-INCAR

abanades@incar.csic.es

Experiences from la Pereda pilot plant

1st Public SCARLET Workshop, Darmstadt University, 20th April 2016

Outline

Description of the 1.7 MWth pilot of la Pereda

Example of results and main trends

Potential improvements on postcombustion CaL

0.03 MWth pilot at INCAR-CSIC

Twin CFB reactor concept validation in

lab scale. Basic reactor and process modeling

From 2008 “La Pereda 1.7 MWth” pilot

From 2012

Reactions kinetics, deactivation studies, reactivation methods

Multicycle testing TG at CSIC

From 2000 Abanades and Alvarez, 2003.

Conversion limits in the reaction of CO2 with lime. Energy and Fuels, 17-

2, 308 -315

Rodriguez et al. 2010. Experimental investigation of a CFB reactor to capture CO2 with CaO. AIChe Journal, 57, pp. 1356 - 1366

Arias et al. 2013. Demonstration of steady state CO2 capture in a 1.7 MWth calcium looping pilot. Int. J. of Greenhouse Gas Control 18, 237–245

CSIC & the development of CaL technology

The 1.7 MWth CaL pilot at la Pereda

La Pereda Power plant: CFBC technology, 50 MWe La Pereda Power plant: CFBC technology, 50 MWe 2009-2012

2013-2015

2015-2017

LA PEREDA CO2 CAPTURE PILOT PLANT: DESCRIPTION

Calciner operating under air or oxy-combustion conditons

Double loop seal to control solid circulation between

reactors

Removable cooling bayonet tubes to change heat extraction in reactors

O2 and CO2 tanks and gas mixer, to change oxy-

combustion ratio

Calciner gas heater and indepent steam inyection

Continuous coal and limestone feeding system

Reactor Characteristics: •Height: 15 m •Made of refractory and Carbon Steel •High efficiency cyclones •Fully instrumentallized

Range of conditions during the CO2 capture test:

RESULTS

Carbonator temperature (ºC) 600-750 Carbonator superficial gas velocity (m/s) 2.0-6.0 Inlet CO2 volume fraction to the carbonator 0.12-0.14 Inlet SO2 concentration to the carbonator (mg/m3) 100-250 Inventory of solids in the carbonator (kg m-2) 100-1000 Maximum CO2 carrying capacity of the solids 0.10-0.50 Calciner temperature (ºC) 820-950 ºC Inlet O2 volume fraction to the calciner 0.21-0.35 Inlet CO2 volume fraction to the calciner 0-0.75 CO2 capture efficiency 0.4-0.95 SO2 capture efficiency 0.95-1.00

Operating conditions and results as expected in large scale systems

Outline

Description of the 1.7 MWth pilot of la Pereda

Example of results and observed trends

Potential improvements on postcombustion CaL

Publications of results from la Pereda pilot

• Demonstration of steady state CO2 capture in a 1.7 MWth calcium looping pilot; B Arias, ME Diego, JC Abanades, M Lorenzo, L Diaz, A. Sanchez, D Martínez, Int. Journal of Greenhouse Gas Control 18, 237-245, 2013.

• Emerging CO2 capture systems. J.C. Abanades, B. Arias, A. Lyngfelt, T. Mattisson, D.E. Wiley, H. Li, M.T. Ho, E. Mangano, S. Brandani; Int. Journal of Greenhouse Gas Control, 2015, vol 40, 126-166

• Experimental testing of a sorbent reactivation process in La Pereda 1.7 MWth calcium looping pilot plant ME Diego, B Arias, A Mendez, J.C. Abanades, M Lorenzo, L Diaz, A. Sanchez; Int. Journal of Greenhouse Gas Control, 2016, in press

• 2 book chapters • > 5 international conference proceedings

Results from the 1.7 MWth CaL pilot plant of la Pereda

B Arias, et al., Int. Journal of Greenhouse Gas Control 18, 237-245, 2013.

Example of steady state of CO2 capture

0

0.2

0.4

0.6

0.8

1

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

CO2 c

aptu

re e

ffici

ency

0

2

4

6

8

10

12

14

CO2 (

%vo

l)ECO2 eqECO2CO2 outCO2 in

- Inventory of solids in carbonator = 300-400 kg/m2 - Average carbonator temperature= 660 ºC - Xave = 0.3-0.1

>1500 h Operating in CO2 capture mode

Arias et al. 2013. Demonstration of steady state CO2 capture in a 1.7 MWth calcium looping pilot. Int. J. of Greenhouse Gas Control 18, 237–245

RESULTS

Typical example of steady state tests

CARBONATOR - Average carbonator temperature= 660 ºC - Inlet gas velocity= 3.5 m/s

OXYFIRED CALCINER - Average carbonator temperature= 915 ºC - Average gas velocity= 4.7 m/s

0.0

0.2

0.4

0.6

0.8

1.0

19:00 19:30 20:00 20:30 21:00 21:30 22:00 22:30 23:00

CO

2 cap

ture

eff

icie

ncy

0

2

4

6

8

10

12

14

Carb

onat

or C

O2

(%)

CO2 equilibriumCO2 experimentalCO2 inCO2 out

0

20

40

60

80

100

19:00 19:30 20:00 20:30 21:00 21:30 22:00 22:30 23:00

Calc

iner

CO

2 (%

)

0

10

20

30

40

50

60

Calc

iner

SO

2 (pp

m)

CO2 out

SO2 out

ECO2 ECO2

Effect of average sorbent activity on CO2 capture efficiency (Oxyfuel combustion-calcination mode)

Results from the 1.7 MWth CaL pilot plant of la Pereda

ucarb = 4.0-4.3 m/s Tcarb = 660-690ºC Xave = 0.21 Xave = 0.11

Closure of carbon mass balances CO2 mass balance in the system

CO2 reacting with CaO in the bed

CO2 removed from the gas phase

CaCO3 formed in the circulating stream of CaO = = CO2 produced by

calcination =

0

2

4

6

8

10

12

11:30 12:30 13:30 14:30 15:30 16:30

CO2 f

low

(km

ol/h

)

CO2 produced by calcination

CO2 captured in the carbonator

Basic reactor models: -Perfect mixing of solids -Plug flow of gas Reaction rate

CO2 mass balance closure

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6 7 8

CaCO3 formed in the circulation of solids (mol/m2s)

CO2 r

emov

ed fr

om th

e ga

s pha

se (m

ol/m

2 s)

CO2 reacting with CaO in the bed

CO2 removed from the gas phase

CaCO3 formed in the circulating stream of CaO = =

( )e2COavesXkdtdX

ν−ν=

aveaCO

CaOactive Xf

FN

2

=τ

Arias et al. 2013. IJGGC 18, 237–245

Modelling of a fluidized bed carbonator reactor to capture CO2 from a combustion flue gas M Alonso, N Rodríguez, G Grasa, JC Abanades Chemical Engineering Science 2009, 64 (5), 883-891

Experimental investigation of a circulating fluidized‐bed reactor to capture CO2 with CaO N Rodríguez, M Alonso, JC Abanades AIChE Journal 2011, 57 (5), 1356-1366

Experimental validation of the calcium looping CO2 capture process with two circulating fluidized bed carbonator reactors. A. Charitos, N Rodríguez, C Hawthorne, M Alonso, et al Ind. & Engng.Chem. Res. 2011 50 (16), 9685-9695

0.0

0.2

0.4

0.6

0.8

1.0

0.0 0.2 0.4 0.6 0.8 1.0τactive normalized

E CO

2 nor

mal

ized

Experimental

Calculated

CO2 mass balance closure

0

1

2

3

4

5

6

7

8

0 1 2 3 4 5 6 7 8

CaCO3 formed in the circulation of solids (mol/m2s)

CO2 r

emov

ed fr

om th

e ga

s pha

se (m

ol/m

2 s)

aveaCO

CaOactive Xf

FN

2

=τ

CO2 reacting with CaO in the bed

CO2 removed from the gas phase

CaCO3 formed in the circulating stream of CaO = =

Arias et al. 2013. Demonstration of steady state CO2 capture in a 1.7 MWth calcium looping pilot. Int. J. of Greenhouse Gas Control 18, 237–245

0.80

0.85

0.90

0.95

1.00

3:00 5:00 7:00 9:00 11:00 13:00 15:00

E SO

2

0

0.03

0.06

0.09

0.12

0.15

X CaS

O4

ESO2 carb

ESO2 calc

ExperimentalCalculated

RESULTS FROM THE 1.7 MWth CALCIUM LOOPING PILOT PLANT OF LA PEREDA

0,0

0,2

0,4

0,6

0,8

1,0

0,0 0,2 0,4 0,6 0,8 1,0

CO2 capture efficiency

SO2 c

aptu

re e

ffici

ency

SO2 mass balance in the system SO2 reacting with

CaO in the bed SO2 removed from

the gas phase CaSO4 formed in the

circulating stream of CaO = = CaSO4 in the purge of solids =

Accumulation of CaSO4 in the

inventory of solids

Investigation of SO2 capture in a circulating fluidized carbonator of a Ca Looping cycle B. Arias et al. Industrial & Engineering Chemistry Research, 2013, 52, 2700−2706

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0 5 10 15 20 25 30 35

N th

X ave

, XN, X

CaSO

4

XaveXN (Grasa et al 2006)XCaSO4 experimentalXCaSO4 calculatedCaO utilization

0

0.2

0.4

0.6

0.8

1

11:10 11:20 11:30 11:40 11:50 12:00

E CO

2

0

200

400

600

800

1000

1200

Inve

ntor

y of

solid

s (kg

/m2 )

ECO2 eq

ECO2

Carbonator inventory

Evolution of sorbent utilization with “lifetime” of particles in the system

dtXN

EFN

t

aveCa

tcarbCOth ∫= 0

)(2Number of times that the inventory of CaO is carbonated up to the maximum CO2 carrying capacity

RESULTS FROM THE 1.7 MWth CALCIUM LOOPING PILOT PLANT OF LA PEREDA

Outline

Why post-combustion CO2 capture by CaL ?

Fundamentals and current status of CaL

Potential improvements on postcombustion CaL . Improving sorbent activity . Reducing heat demand in the calciner . Other reactor designs and adaptation to other industries (cement)

Pilot experiments with recarbonation

http://recal-project.eu/

Carb

onat

or

Calc

iner

Loop seal-Recarbonator

‘Novel Calcium looping CO2 capture process incorporating sorbent reactivation by Re-carbonation’ EU RFCS project: 2012-2015

0.15

0.00

0.04

0.08

0.12

0.16

0.20

10:00 12:00 14:00 16:00 18:00 20:00

X

Time

Xr - Xsulf

Xave - Xsulf

Xave,R (exp.)

0.00

0.04

0.08

0.12

0.16

0.20

18:00 20:00 22:00 0:00 2:00 4:00 6:00 8:00

X

Time

Xr - Xsulf

Xave - Xsulf

Xave,R (exp.)0.08

The sorbent activity doubles due to recarbonation

Initial tests with recarbonation

Arias et al 2012. Energy & Env.Sci., 5, pp. 7353-7359 Grasa et al. 2014. I&EC Research 28, pp. 4033 - 4042 Diego et al. 2014. Energy Procedia 2015, GHGT12 Diego et al. 2016 I. Journal Greenhouse Gas Control, Volume 50, July 2016, Pages 14-22

CO2

<20% of heat demand in the calciner by increasing the oxygen

concentration up to 80%v

New process configuration with: -Less oxygen requirement (less OPEX) -Reduced size of calciner and ASU (less CAPEX)

CaO2 : Calcium looping CO2 capture technology with extreme oxy-coal combustion conditions in the calciner European Union RFCS project: 2014-2017 2015-2017

Calcination of CaCO3 with “superheated” CaO

Diego et al. Analysis of a double calcium loop process configuration for CO2 capture in cement plants Journal of Cleaner Production Volume 117, 20 March 2016, Pages 110–121

2002

Concluding remarks

Postcombustion Calcium Looping (CaL) has been succesfuly tested in several continuous large scale pilots for 1000s of hours.

Standard configurations of CaL, using highly mature process components, could be retrofitted to existing power plants, achieving capture efficiencies around 90%, energy penalties 6-8 net points and cost about 20-30% lower than oxyfired CFBCs.

There is scope for substantial reductions in penalty and costs: i.e. by reducing heat demand in the calciner through new reactor and process designs and by integration with other industries (i.e. cement ).

IF there was a market for CCS, Calcium looping technologies could be scaled up quickly by exploiting similarities with CFBCs

Secondary air

ROTARY KILN CLINKER COOLER

CLINKER GRINDING

PRE-HEATINGSTAGES

Limestone

CO2-lean flue gas

Coal

Pet cokePrimary air

CaO

Kiln flue gas

Concentrated CO2

ClayShale

Air

Excess air

Hot clinker

Cold clinker

Additives

Cement

CARB

ON

ATO

R

CALC

INER

ASU

CaCO3 CaO

Air O2

CaCO3

Other process variants: CaL for cement plants

2015-2018