WITH BIOMASS COMBUSTION IN THE CALCINER I. Martnez*, B. Arias, J.C. - - PowerPoint PPT Presentation

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WITH BIOMASS COMBUSTION IN THE CALCINER I. Martnez*, B. Arias, J.C. - - PowerPoint PPT Presentation

Oct 01, 2022 253 likes •474 views

9 th Trondheim Conference on CO 2 Capture, Transport and Storage, 12-14 June 2017 SECOND GENERATION CALCIUM LOOPING SYSTEM WITH BIOMASS COMBUSTION IN THE CALCINER I. Martnez*, B. Arias, J.C. Abanades Spanish Research Council (ICB and INCAR

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SLIDE 1

SECOND GENERATION CALCIUM LOOPING SYSTEM WITH BIOMASS COMBUSTION IN THE CALCINER

  • I. Martínez*, B. Arias, J.C. Abanades

Spanish Research Council (ICB and INCAR from CSIC) *imartinez@icb.csic.es

9th Trondheim Conference on CO2 Capture, Transport and Storage, 12-14 June 2017

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SLIDE 2

OUTLINE

Description of standard and 2nd generation CaL systems Process simulation assumptions Performance results and conclusions

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SLIDE 3

Flue gas

Air

Oxygen

Coal

ASU

Calciner >900ºC CO2 Flue gas with low CO2 content Carbonator 650ºC

CO2 for transport and storage

Limestone Purge

CPU

Coal Air

Power plant

CO2 recycle

Standard post-combustion CaL process

Energy

EXISTING POWER PLANT NEW OXY-FIRED CFB POWER PLANT

Energy

 Low energy penalty /low cost per ton CO2 captured  Low cost sorbent precursor  Purge of CaO: synergies with cement industry and others (i.e. desulfurization )  Pre-treatment of flue gas no needed (SO2 co-capture)  Benefits and limitations of large scale CFBCs (including oxy-CFB)

Benefits of Ca-looping

CaO CaCO3

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SLIDE 4

Flue gas Air Oxyg en C

  • al

AS U C alciner >900ºC C O2 Flue gas with low C O2content C arbonator 650ºC C O2for trans port and storag e L imes tone Purg e C PU C

  • al

Air Power plant C O2 recycle

Standard post-combustion CaL process

STANDARD Ca LOOPING CONFIGURATION: Oxy-fuel combustion in the calciner Natural limestone used a sorbent precursor Circulating fluidized bed combustors Disadvantages of oxy-fuel combustion in the calciner:

  • Energy penalty due to oxygen production (~200 kWhe/tO2)
  • Large investment cost
  • Low flexibility to load changes

Improvements of Ca-looping:

  • Advanced process configurations without oxy-combustion

(i.e. Indirect heat transfer through metallic walls/heat pipes, high temperature solid heat carriers …)

  • Second generation CaL processes (Reducing heat demand in the calciner)
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SLIDE 5

HEAT DEMAND IN THE CALCINER

  • Calcination of CaCO3
  • Sensible heat of recycled CO2
  • Sensible heat of circulating solids

20 40 60 80 100 120 25 30 35 45 55 65 75 85 100

%O2 in the comburent Heat demand in the calciner (%) Sensible heat with flue gas Sensible heat to solids Calcination heat

Minimize or reduce CO2-recycle:

  • 20% REDUCTION by increasing oxygen

contents up to 80%v.

  • Less oxygen needed (less OPEX)
  • Smaller ASU and calciner sizes (less CAPEX)

*Tcarb=650ºC, Tcalc=910ºC;Xave=0.15, Xcarb=0.11;Tcomburent : 300ºC

Effect of O2 in the comburent on calciner heat demand in a CaL standard scheme

Second generation post-combustion CaL process

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

Demonstration in a pilot (2-3 MWth) of ultra-rich O2 calcination technology

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SLIDE 6

Second generation post-combustion CaL process

HEAT DEMAND IN THE CALCINER

  • Calcination of CaCO3
  • Sensible heat of recycled CO2
  • Sensible heat of circulating solids
  • Increase the temperature of the solids

entering into the calciner

  • Improve the activity of the solid

Improve sorbent activity by means of recarbonation:

  • No energy penalty associated
  • No influence on sorbent mechanical properties
  • No need of additional reagents in the process
  • Less limestone consumption (less OPEX)

Loop seal-Recarbonator

Diego et al. 2016. Experimental testing of a sorbent reactivation in La Pereda 1.7 MWth calcium looping pilot plant Int. J. Greenhouse Gas Control, 50, 14-22

The sorbent activity increases up to 8-10 net points due to recarbonation

EU RFCS project: 2012-2015

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SLIDE 7

Second generation post-combustion CaL process

Flue gas

Air

Oxygen

Coal ASU Calciner >900ºC

CO2 Flue gas with low CO2 content

Carbonator 650ºC

CO2 for transport and storage

Limeston e Purge

CO2 recycle

2ND GENERATION Ca LOOPING CONFIGURATION: Pure oxygen used in the calciner Sorbent improvement by means of recarbonation

Coal Air

Power plant

Re-carbonator ≈ 800ºC

Biomass  Contribute to negative CO2 emission factors  Avoid typical operational problems (corrosion and deposition in heat exchange surfaces, reduction

  • f unburnt emissions, minor organic emissions ultimately captured in the CPU…)

Calciner < 900ºC

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SLIDE 8

OUTLINE

Description of standard and 2nd generation CaL systems Process simulation assumptions Performance results and conclusions

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SLIDE 9

Process modeling – General assumptions

Flue gas Air Oxygen Coal

ASU

CO2 Flue gas with low CO2 to stack

Carbonator

Limestone Purge CPU CO2 recycle

Condensate

Calciner Coal Air Power plant

CARBONATOR & CALCINER  Reactor models implemented  RPM kinetic model for the carbonation reaction  CO2 carrying capacity decay law ( Xave)  99 % SO2 capture efficiency CALCINER  95% calcination efficiency  3.5% O2 at outlet Existing CFB air-fired SC plant  hnet=43.3%  1000 MWth fuel input  FG with 14% CO2 AIR SEPARATION UNIT  95% O2 purity (Ar,N2)  Consumption: 200 kWh/tO2

STANDARD & 2nd GENERATION Ca LOOPING CONFIGURATIONS

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SLIDE 10

Flue gas Air Oxygen Coal

ASU

CO2 Flue gas with low CO2 to stack

Carbonator

Limestone Purge CO2 recycle

Condensate

Calciner Coal Air Power plant

CARBONATOR & CALCINER  Reactor models implemented  RPM kinetic model for the carbonation reaction  CO2 carrying capacity decay law ( Xave)  99 % SO2 capture efficiency CALCINER  95% calcination efficiency  3.5% O2 at outlet Existing CFB air-fired SC plant  hnet=43.3%  1000 MWth fuel input  FG with 14% CO2 AIR SEPARATION UNIT  95% O2 purity (Ar,N2)  Consumption: 200 kWh/tO2

Process modeling – General assumptions

CPU STANDARD & 2nd GENERATION Ca LOOPING CONFIGURATIONS

CO2 COMPRESSION AND PURIFICATION UNIT  Single flash auto-refrigerated process  Vent gas containing 3-4% inlet CO2  ≈ 115 kWh/tonCO2

Romano, M.C. Int. J. Greenhouse Gas Control, 2013, 18: 57-97

Rich CO2 20 bar 30ºC CO2 for transport Vent gas

Drier

  • 45ºC
  • 54ºC

23ºC

Multi- flow HX Knock-out drum IC compressor pump IC compressor

89 bar 150 bar

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SLIDE 11

Calciner Biomass

Process modeling – General assumptions

2ND GENERATION Ca LOOPING CONFIGURATION

Condensate

Flue gas

Air

Oxygen

ASU

CO2

Carbonator

Limestone Purge

CO2 recycle

Coal Air

Power plant

Re-carbonator

RE-CARBONATOR  CaCO3 content: Xcarb,R=0.02 + Xave,R  Excess CO2 [i.e. +50% over that needed for (Xcarb,R - Xave,R)]

Flue gas with low CO2 to stack CPU

Diego et al. 2014. I&EC Research 53, pp. 10059 - 10071

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SLIDE 12

Process modeling – General assumptions

HEAT RECOVERY IN THE Ca LOOPING SCHEMES Flue gas Air Oxygen Coal

ASU Calciner

CO2 Flue gas with low CO2 to stack

Carbonator

Limestone Purge

Coal Air Power plant

CO2 recycle

Energy

Air-fired SC plant 433 MW

Tcarb – 100ºC Tcarb Tcalc – 350ºC 350-60ºC Tcalc – 150ºC

Condensate

25-200ºC

CPU

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SLIDE 13

Process modeling – General assumptions

HEAT RECOVERY IN THE Ca LOOPING SCHEMES

USC STEAM CYCLE  Heat recovered in the EVA, ECO, SH, RH  Some of the HP & LP FWH replaced Romano, M.C. Int. J. Greenhouse Gas Control, 2013, 18: 57-97

ECO EVA SH RH

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SLIDE 14

Flue gas Air Oxyg en C

  • al

AS U C alciner >900ºC C O2 Flue gas with low C O2content C arbonator 650ºC C O2for trans port and storag e L imes tone Purg e C PU C

  • al

Air Power plant C O2 recycle

Process modeling – Operating conditions

STANDARD CaL SCHEME SECOND GENERATION CaL SCHEME  Carbonator CO2 capture efficiency: 90%  Carbonator temperature: 650ºC  Carbonator CO2 capture efficiency: 80%  Carbonator temperature: 690ºC  Calciner temperature: 910ºC  Fuel in the calciner: high-rank coal (0.7% S, 3% H2O and 6% ash; LHV=33 MJ/kg)  Calciner temperature: 890ºC  Fuel in the calciner: woody biomass (0.02% S, 15% H2O and 1% ash; LHV=16 MJ/kg)  Oxygen content in the oxidant: 40%v.  Oxygen content in the oxidant: 95%v.  Ratio F0/FCO2: 0.12 (0.6 kg /kg coal existing PP)  Ratio F0/FCO2: 0.05 (0.3 kg /kg coal existing PP)  CO2 carrying capacity decay law typical for limestone (Xr ≈ 7-8%)  Improved CO2 carrying capacity decay law due to recarbonation (Xr ≈ 16-17%)

Grasa et al. 2014. Energy & Fuels 28, pp. 4033 - 4042

Flue gas Air Oxyg en AS U

CO2

Flue gas with low C O2content Carbonator 650ºC C O2for trans port and storag e L imes tone Purg e C O2 recycle C

  • al

Air Power plant

Re-carbonator 750-800ºC

Biomass Calciner < 900ºC

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SLIDE 15

OUTLINE

Description of standard and 2nd generation CaL systems Process simulation assumptions Performance results and conclusions

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SLIDE 16

Specific CO2 emissions [kgCO2/MWhe] 66.5 134.0 CO2 emission factor [kgCO2/MWhe] 66.5

  • 219.4

Cost of Electricity (COE) [$/MWhe] 80.0 78.8 Avoided Cost (AC) [$/ton CO2 avoided] 34.8 23.1 Steam cycle net electric output [MWe] 434.0 280.1 Carbonator & calciner fans [MWe]

  • 19.0
  • 17.7

ASU [MWe]

  • 57.4
  • 39.0

CO2 compression and purification unit [MWe]

  • 71.0
  • 56.0

Net plant electric efficiency [%] 36.7 37.0

Simulation results

STANDARD CaL SECOND GENERATION CaL Maximum CO2 carrying capacity (Xave) [%] 12.5 19.9 Solid circulation at carbonator inlet [kg/m2·s] 6.4 3.4 CaSO4 / Ash content at carbonator inlet [%wt] 7.3 / 5.1 5.2 / 2.5 Kg limestone/kg total fuel to the plant [-] 0.35 0.14 Global CO2 capture ratio (inc. CPU) [%] 92.6 85.4 Heat demand in the calciner (LHV-based) [MW] 976.1 620.3 Fraction of energy to the calciner [%] 49.1 38.3

Methodology from Abanades et al. 2015. Emerging CO2 capture technologies, Int J Greenhouse Gas Control 40, 126-166

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SLIDE 17

Conclusions

  • An optimized Ca-Looping system (2nd generation) including sorbent reactivation by

recarbonation and a pure oxy-fuel combustion in the calciner has been simulated

  • Heat demand in the calciner can be significantly reduced in the 2nd generation Ca-

Looping system with respect to standard Ca-Looping configuration

  • Limestone consumption can be reduced by more than 50% compared to a

standard Ca-Looping system

  • The electric efficiency for the 2nd generation Ca-Looping system is slightly

improved compared to the standard Ca-Looping system

  • A negative CO2 emission factor results if biomass is used as fuel in the calciner,

which results in a great reduction of the CO2 avoided costs

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SLIDE 18

SECOND GENERATION CALCIUM LOOPING SYSTEM WITH BIOMASS COMBUSTION IN THE CALCINER

THANK YOU FOR YOUR ATTENTION

9th Trondheim Conference on CO2 Capture, Transport and Storage, 12-14 June 2017

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SLIDE 19

Detailed studies by CSIC

Effect of recarbonation on Xave – TG experiments

0.2 0.4 0.6 0.8 1 25 50 75 XN, XNR N

650 ºC Standard 700 ºC 800 ºC

Arias et al. 2012. Post-combustion calcium looping process with a highly stable sorbent activity by recarbonation. Energy & Env.Sci., 5, pp. 7353 – 7359.

The residual activity doubles

Grasa et al. 2014. Detemination of CaO carbonation kinetics under recarbonation conditions, 28, pp. 4033 – 4042.

700ºC Pure CO2 800ºC Pure CO2 650ºC 5%v CO2

“Recarbonation” during 5 min in pure CO2

Sorbent reactivation by recarbonation

𝑌𝑏𝑤𝑓 = 𝑠𝑂 ∙ 𝑌𝑂

𝑂=∞ 𝑂=1

= 𝐺

0 + 𝐺 𝐷𝑏𝑠0 𝑔 𝑑𝑏𝑚𝑑

𝑏1𝑔

1 2

𝐺

0 + 𝐺 𝐷𝑏𝑔 𝑑𝑏𝑠𝑐𝑔 𝑑𝑏𝑚𝑑 1 − 𝑔 1

+ 𝑏2𝑔

2 2

𝐺

0 + 𝐺 𝐷𝑏𝑔 𝑑𝑏𝑠𝑐𝑔 𝑑𝑏𝑚𝑑 1 − 𝑔 2

+ 𝑐 𝐺 − 𝐺

𝑇

𝐺

𝑌𝑂 = 𝑏1𝑔

1 𝑂+1 + 𝑏2𝑔 2 𝑂+1 + 𝑐

Maximum average CO2 carrying capacity

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SLIDE 20

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.)

Carbonator Calciner

Loop seal-Recarbonator The sorbent activity increases by 8-10 net points thanks to 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. International Journal of Greenhouse Gas Control, 50, 14-22.

Pilot experiments with recarbonation

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SLIDE 21

Economic parameters used:

Cost analysis

𝐷𝑃𝐹 = 𝑈𝐷𝑆 ∙ 𝐺𝐷𝐺 + 𝐺𝑃𝑁 𝐷𝐺 ∙ 8760 + 𝑊𝑃𝑁 + 𝐺𝐷 𝜃𝑄𝑚𝑏𝑜𝑢 𝐵𝐷 = 𝐷𝑃𝐹𝑑𝑏𝑞𝑢𝑣𝑠𝑓 − 𝐷𝑃𝐹𝑠𝑓𝑔𝑓𝑠𝑓𝑜𝑑𝑓 𝐷𝑃2 𝑙𝑋ℎ𝑓 𝑠𝑓𝑔𝑓𝑠𝑓𝑜𝑑𝑓 − 𝐷𝑃2 𝑙𝑋ℎ𝑓 𝑑𝑏𝑞𝑢𝑣𝑠𝑓

Economic assumptions TCR ref ($/kWe) 1900 TCR oxy ($/kWe) 2800 TCR CC ($/kWe) 280 TCR CPU ($/kWe) 180 TCR RECARB ($/kWe) 280 Fuel costs ($(GJ) 3 Limestone costs ($/t) 10 Capacity factor 0,85

Total capital requirements of whole CaL system TCRCaL=(TCRreference+TCRCPU)*(1-HCaL/Htotal)+(TCROxy-CFB+TCRRecarb+TCRCC)*HCaL/HTotal