Research on CO2Condensation Technology

Prof. Zhongyang Luo

State Key Laboratory of Clean Energy UtilizationZhejiang University

Global CO2 Emission

8512

334

825

1109

1800

2010

6522

316

654

832

1559

200119971990

61755836World297274Japan

6461034Former USSR

822620China14801345USA

CO2 Emission

(Mtc)

Country

Source: Energy Information Administration/International Energy Outlook 2001

CO2 Emission in China

1.8615.518.215180.36688322001

65

12

11

8

Mtc

4.461927776.51,1151,1092010

1.461814880.46618221997

1.3717.213881.46258011996

1.2915.89882.95146201990

%%Mtc%MtcMtcNatural GasPetroleumCoalTotal

CO2 Condensation

CO2 Separation from Flue GasO2/CO2 CombustionIGCCPGCC

Part 1 Part 1 Research on COResearch on CO22

SeparationSeparation

CO2 CaptureAdsorption of the gas by use of molecular sieves Physical absorptionChemical absorptionlow temperature (cryogenic) processes Membranes

PF+FGD

Adsorption

Typical layout of a carbon dioxide (adsorption) capture plant

Membranes

Principles of gas separation and gas absorption utilizing membranes

Physical absorption

Physical absorption using Selexol is the most appropriate technique to remove CO2 –CO2 Wheel

Chemical absorption

Removal CO2 by NH3 Scrubbing for Urea Production

US DOE– Win-WIN Scheme for CO2 Sequestration via Aqua Ammonia Scrubbing—28% Amonia capture 97% CO2SETRC of China and Tsinghua University make experimental research.

Removal CO2 by NH3 Scrubbing for Urea Production

Integration of CO2 sequestration through NH4HCO3 Production

Cryogenic Processes--Frosting

Cryogenic methods for CO2 capture options –Ecole de Mine de Paris, France

Scheme of CO2 Sequestration by Membrane Contactor

Pumps

FGD Membrane Contactor

Heater

Flue Gas

StorageTank

Regenerator

CO2

AbsorptionLiquid

Cooler

Heater

Supplement liquid

10NM3/H Test Facility

Shape and Structure of the Polypropylene Hollow Fiber Membrane

Characteristics of MembraneAverage diameter of micropores: 0.02 ×0.2µmPorosity: 35-50%Longitudinal tensile strength: > 120MPaRapture strength: > 1.0MPaGas permeation rate:

2.0 × 10-2cm3(STP)/cm2⋅ s⋅ cmHg

CO2 Sequestration Process

Gas AbsorptionLiquid

Hollow Fiber Membrane Contactor

Flue Gas

Absorption

Liquid

Effect of Absorption Liquid Temp. on CO2 Sequestration Eff.

0

10

20

30

40

50

60

70

80

90

100

25 30 35 40 45 50 55

Absorption Liquid Temp.（℃）

Rem

oval

Eff

.（%）

MEA

MDEA

氨基酸盐

Effect of Absorption Liquid Concentration on CO2 Sequestration Eff.

0

10

20

30

40

50

60

70

80

90

100

0 0.5 1 1.5 2 2.5 3 3.5

Absorption Liquid Concentration（mol/L）

Rem

oval

Eff

.（%）

MEA

MDEA

氨基酸盐

Effect of Flue Gas Velocity on CO2 Sequestration Eff.

0

10

20

30

40

50

60

70

80

90

0.2 0.3 0.4 0.5 0.6

Flue Gas Velocity（m/s）

Rem

oval

Eff

.（%）

1mol/L的MEA

2mol/L的MEA

Pressure Drop

0

100

200

300

400

500

600

0.1 0.3 0.5 0.7

Flue Gas Velocity（m/s）

Pres

sure

Dro

p（

Pa）

BoilerAshRemoval

FGD

Coal

Air

COMembraneScrubbing

2 CORecovery

2

CO Removal From Conventional PCF Power Plant2

Part 2 Part 2 O2/CO2 combustion system

Advantages of Oxygen Rich Combustion

Using O2/CO2 mixture in combustion system, raising CO2 content to 95%Not necessary to separate CO2 from flue gasImprovement in boiler efficiencyReduction SOx, NOx emission Simplification of flue gas treatment

CORecovery

2

Pulverized Coal

Air

O

Flue Gas Recycling

O /CO Combustion Process2 2

AshRemoval

Boiler

AirSeparation

O /CO2 2

2

O2/CO2 CombustionCombustion

Test Facility 流化床

Combustion Efficiency

95.0

95.2

95.4

95.6

95.8

96.0

20 25 30 35

O2 (%)

η (%)

O2/N2O2/CO2

SO2 Emission

0

20

40

60

80

0 1 2 3 4 5 6 7 8u (m/s)

SO2 R

emov

al E

ff. (

%)

Air-FB

O2/CO2-FB

Air-CFB

流化床

0

20

40

60

80

100

0 1 2 3 4 5

Ca/S molar rate

SO2 R

emov

al E

ff. (

%)

Air-FB

O2/CO2-FB

Air-CFB

Nox Emission

200

250

300

350

400

1050 1100 1150 1200 1250

Bed Temperature (K)

NOx (ppm)

Air-FB

O2/CO2-FB

Air-CFB

100

150

200

250

300

350

0.7 0.8 0.9 1 1.1Primary/Total Flow Rate

NOx (ppm)

Air-FB

O2/CO2-FB

Air-CFB

流化床

75t/H Oxygen Enriched Combustion CFB Boiler

分离器

EHE

给料

炉膛

返料器

气化炉

Part 3 Part 3 IGCC

IGCC1

WasteWaterTreatment

GasCleanupGasifier

Expander

AirSeparationUnit

CombustionChamber

HeatRecoverySteamGeneration

SteamTurbine

GasTurbineCompressor

G

G

GMoisturewater

Air

Nitrogen

Oxygen

Slag

RawFuelGas Clean Fuel Gas

To SulphurRecovery

WaterCoal

Waste WaterStack Gas

IGCC2

WasteWaterTreatment

GasCleanupGasifier

Expander

AirSeparationUnit

CombustionChamber

HeatRecoverySteamGeneration

SteamTurbine

GasTurbineCompressor

G

G

GMoisturewater

Air

Nitrogen

Oxygen

Slag

RawFuelGas Clean Fuel Gas

To SulphurRecovery

WaterCoal

Waste WaterStack Gas

Oxygen

CO2

IGCC3

WasteWaterTreatment

Shift/CleanupGasifier

AirSeparationUnit

CombustionChamber

HeatRecoverySteamGeneration

SteamTurbine

GasTurbineCompressor

GGMoisture

waterAir

NitrogenOxygen

Slag

RawFuelGas

To SulphurRecovery

WaterCoal

Waste WaterStack Gas

Separator

CO2

H2

Part 4 Part 4 PGCC

Gasifior

Heat Exchanger,

Clean SystemGas Turbine

Boiler

Combustor

Steam Turbine

Generator

Generator

Coal

Semicoke

Hot Gas Clear Gas

Flue Gas

Steam

Oxygen

PGCC

Clear System

Part 5 Part 5 Near–zero Emission or Chemical

Looping Gasification

Near zero emissions coal utilization technology with combined gasification and

combustion

Chemical Looping Gasification (CLG)

Near zero emissions coal utilization technology with combined gasification and combustion

CoalBiomass

Steam

Char¡¢ash¡¢ CaCO

CaO¡¢ash

Limestone

CO

Pressure or atmosphereCFBcombustor

PressureCFBGasifier

User

SOFCpower

Dust removal

Steam turbine

HRSG CondensationCO disposal

Ash drain

Water

Gas turbine

DustRemovalH2

2

3

H2

H2

2

H2

H2OO2

Air

Gas turbine

AirAirHeater

Exit

AirAir separation

CFB Gasifier：CO2 acceptor gasification process (~25bar)

Main reactions in gasifier：C+H2O=CO+H2-131.6kJ/mol

CH4+H2O=CO+3H2-206.3kJ/mol

CO+H2O=CO2+H2+41.5kJ/mol

CaO+CO2=CaCO3+178.1kJ/molH2S+CaO=CaS+H2O Coal

Biomass

Steam

Char¡¢ash¡¢ CaCO

CaO¡¢ash

Limestone

CO

Pressure or atmosphereCFBcombustor

PressureCFBGasifier

Ash drain

H2

2

3

O2

CFB CombustorChar combustion CaCO3 calcinationHydrogen combustion

Main reactions in CFB combustor：

CaCO3=CaO+CO2-178.1kJ/mol

C+O2=CO2+393.791kJ/mol

H2+1/2O2=H2O+286kj/mol

CoalBiomass

Steam

Char¡¢ash¡¢ CaCO

CaO¡¢ash

Limestone

CO

Pressure or atmosphereCFBcombustor

PressureCFBGasifier

Ash drain

H2

2

3

O2

H2 from SOFC

Advances:

Reduce the requirements on gasification. Only part of coal with high activity is gasified and the char with lower activity is burned in CFB combustor.

Realize Anaerobic Hydrogen Production with CO2 acceptor gasification and high concentration CO2for disposal in combustor

Realize near zero emission: few NH3 generating during gasification may be removed easily, H2S is captured by CaO in gasifier and transformed into CaSO4 in the combustor. Other pollution gas may be disposal together with CO2 gas stream.

Advances：

System is simplified by applying two circulating fluidized bed reactors.

Lower operation pressure (20~30bar) reduce the difficulties and cost.

High efficiency with applying SOFC

Efficiency calculation for a samplePower generation:400MWCoal gasification ratio: 0.7Operation Pressure: 25bar

Proximate analysis/w%, ar

Ultimate analysis/w%, ar Heat value/MJ/kg,

arM V A C H O N S Qdw

2.7 25.17

21.62 63.39

3.88 6.51 0.78

1.13

23.143

66.52System efficiency（％）

413538.88Net Power generation（kW）

99821.12Power consumption of the air compressor, kw

25955Power consumption of the air separation（kW）

3956.7Power generation from the steam turbine cycle,kw28Efficiency of steam turbine cycle （％）

152115.31Power generation from the gas turbine（KW）

59Efficiency of gas turbine cycle（％）

269208.48Power generation from the SOFC（kW）

51Oxygen utilization ratio in the SOFC（％）

85Fuel utilization ratio in the SOFC（％）

4.25Limestone supplement（kg/s）

1.1Excess oxygen ratio

1482.44Heat loss of the combustor（kJ/s）

1135Temperature in the combustor（K）

25Pressure in combustor（bar）1.42Hydrogen production rate（kmol/s）

0.7Coal gasification ratio3120.93Heat loss of the gasifier （kJ/s）

1205Temperature in the gasifier（K）

25Operation Pressure（bar）18.35Coal feed rate（kg/s）

CalculationItem

Effect of gasification ratio and operation pressure

0.55 0.6 0.65 0.7 0.75 0.8Gasification ratio

64

65

66

67

68

69

70

Syst

em e

ffici

ency

(£¥)

10 15 20 25 30Operation pressure£¨bar£©

60

61

62

63

64

65

66

67

68

69

70

Effic

ienc

y£¨£

¥£©

0.60.70.8

Experiments on char combustion in an atmosphere Fluidized bed combustor

出口气体

气体采样分析

压强机

N2O2CO2

气体混合器

流量计

反应器

气体预热器

Char combustion in different reaction atmosphere

0 50 100 150 200 250 300time (s)

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8ca

rbon

con

vers

ion

rate

O2/CO2=61/39%O2/CO2=45/55O2/CO2=31/69AirO2/CO2=11/89

GE Current Options

3.944.22￠/kWHrCOE(1st Year)

Low sulfur (compliance) coals favored

All Coals plus liq. &solid opportunity fuels

FeedstocksFuel Flexibility40%40%%HHVEfficiency0.010.005lb/MMBtu- PM0.040.01lb/MMBtu- SO20.020.02lb/MMBtu-NO

Emissions$1,225$1,450$/KWCapitalSCPCIGCC

1. Pure Oxigen Combustion

2. O2 /CO2 Combustion---- Combustor need to be change

3. Shift Syngas to H2+CO2, Then Separate CO2 with MEA or Frosting

4. Separation of Flue Gas

5. Similar with Version 21

IGCC -- CO2 Condensation

1. Retrofit of IGCC

2. O2 /CO2 Combustion

3. Separation of Flue Gas

Compare of IGCC, SCPC +Seperation and O2 /CO2 Combustion

1. Capacity： 2×1000 MW2. Capital： 8388.05Million RMB3. Capital per KW：508 $/KW4. Coal：Shenfu Dongshen Coal5. Boiler：520 Million/Unit6. Efficiency: 45.16 %7. Coal Consumption：272 g/kW·h8. Ratio of Electricity used by Plant：6.5%9. COE：0.392RMB/kW·h

Compare of IGCC, SCPC +Separation and O2 /CO2 Combustion

With Membrane for CO2 Separation1 Velocity in the Membrane 0.2m/s,2. Size of Absorber 90M*90m*90m3. Price of Membrane: 20yuan/m2,4. Total area of Membrane:: 0.58 Million m2

5. Cost of 2 Seperator: 240 Million RMB6. Cost of the Total System: 600 Millions7. Separation Efficiency: 90%8. Capital per KW： 72.7 $/KW9. COE: increased 0.165 RMB/Kwh10. Total COE: increased 0.172RMB/Kwh

Compare of IGCC, SCPC +Seperation and O2 /CO2 Combustion

With CO2/O2 Combustion for CO2 Condensation

1 System for Oxygen 1760 Million RMB2. Total Cost of Retrofit: 2000 Millions RMB3. Cost per ton CO2 RMB/ton CO24.. Capital per KW： 242 $/KW5. COE: increased 0.108 RMB/Kwh6. Total COE: increased 0.131 RMB/Kwh

Compare of IGCC, SCPC +Seperation and O2 /CO2 Combustion

• Condensation technology for the CO2need to be evaluated,

• Utilization of CO2 is a best way for CO2control, need to be form the cycle–- Cycle Economy

Conclusion

Thank You Very Much !