Polygeneration and CO2 Capture - Stanford UniversityProf. Li Zheng, Tsinghua CEC Polygeneration and...

Prof. Li Zheng, Tsinghua CEC

Polygeneration and CO2 Capture

Li Zheng, Ni Weidou

Tsinghua BP Clean Energy Research & Education Center

August 23rd, Beijing


Outline

Energy challenges China is facing: strongly related with coal

Polygeneration could be a comprehensive way to solve China’s energy problem

Polygeneration and CO2 capture

Conclusions


Statistics of China Energy

Primary energy in China

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

1988 1990 1992 1994 1996 1998 2000 2002 2004

Year

bil. tce

Coal fraction in total energy mix

50

60

70

80

90

100

1985 1990 1995 2000 2005

Year

coal fraction / %

-

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

1965 1970 1975 1980 1985 1990 1995 2000

Year

million toe

oil NG hydel nuclear

1.5

1


Current and future energy mix of China


0

12

3

4

56

7

8

2000 2010 2020 2030 2040 2050

year

100Mt

demand China prodn.

Increasing Dependence on Oil Import


Energy intensities (GDP @ market exchange rates)

2.408

0.861

0.6410.491

0.4090.293 0.287 0.234 0.221 0.202 0.183 0.12 0.104

0

0.5

1

1.5

2

2.5

FSU

Chi

na

Indi

a

Non

-OEC

D

Sout

h K

orea

Bra

zil

Wor

ld

Mex

ico

USA

OEC

D

EU-1

5

Hon

g K

ong

Japa

n

toe per $1000 GDP (2000$ mkt fx)

8.3 times of Japan

4.3 times of OECD

3.9 times of USA

1.3 times of India


China’s CO2 emission: 2nd place and increase fast

0

2000

4000

6000

8000

10000

1980 1990 2000 2010 2020 2030

年份

CO2 / Mt

US/美国 China/中国 Russia/俄罗斯 Japan/日本

Source: IEO2004, EIA/DOE


CO2 emission from power and transportation @2001

total CO2 emission: 3050 Mtcoal: 2340 Mt, 76.8%

oil: 640 Mt tons, 21.1%

coal power: 50.9% of total coal consumption, CO2=1190 Mt

transportation: total=148 Mtgasoline: 14.2Mt, CO2=52 Mt

diesel: 26.7Mt, CO2=97Mt

CO2 emission: Power : transportation=8:1

Sources: IEO2004, EIA/DOE，中国能源统计年鉴2004


Coal vs Energy challenges China is facing

Energy securityespecially import oil dependency

Energy efficiency improvement

Environment pollutionSOx，NOx，dust

mercury, inspirable particulates

GHG emission

coal dominant

coal expected to help


Polygeneration: a promising comprehensive solution

Coal

Direct

burning

Acid rain, particulate, CO2

Element S

Gasification island

Clean syngas

Liquid fuel synthesis

Hydrogen

Hydrogen

production

CO2

CO2 sequestration

Future hydrogen economy

Other chemical products

Alternative vehicle fuels

Alternative LPG

Used in urban

Town gas

Clean and

high-efficiency

power generation

Fuel cell car

Coal

Direct

burning


Element S

Gasification island

Clean syngas


Hydrogen

Hydrogen

production

CO2

CO2 sequestration




Alternative LPG

Used in urban

Town gas

Clean and

high-efficiency

power generation

Fuel cell car

Coal

Direct

burning


Element S

Gasification island

Clean syngas


Hydrogen

Hydrogen

production

CO2

CO2 sequestration




Alternative LPG

Used in urban

Town gas

Clean and

high-efficiency

power generation

Fuel cell car


Polygeneration: a comprehensive solution

Ease the pressure for energy resource: due to higher efficiency to co-produce multi-products; use high sulfur coalEase and buffer shortage of liquid fuel: large scale production of alternative fuels as methanol, DME, F-T liquid and hydrogenSuperior environmental behavior: eliminating conventional pollutants completely, less incremental cost for heavy metals and inspirable dustUltimate clean energy solution for small town and rural area:

To provide clean town gas for urban areas with no NG supplyTo provide DME as an alternative to and using the infrastructureof LPG for distributed small towns and rural areas

Meet future CO2 reduction requirement:the coal gasification based systems can be easily shifted to CO2capture with less incremental costIt is also easier and cheaper to change into H2 production


Polygeneration and CO2 reduction

Polygeneration by its nature can make the CO2capture easy

Different polygeneration configurations could meet time progressive CO2 reduction needs

Polygeneration can reduce CO2 with less efficiency penalty and less incremental capital cost


WTT CO2 emission of different coal-derived fuels

0.0E+00

8.0E-02

1.6E-01

2.4E-01

3.2E-01

11-G

PME

OH

+Tan

12-L

PME

OH

+Tan

13-H

2+G

as

14-H

2+Pi

pe

15-H

2+LH

2

16-H

2+H

ybri

de

17-L

PDM

E18

-300

kt/y

MeO

H

19-1

20kt

/y M

eOH

20-4

0kt/y

MeO

H

CO2 emission kg/MJ

Transportation subsystem Refueling subsystem Production subsystem

0%

10%

20%

30%

40%

50%

60%

70%

1-GPM

EOH+IGCC+T

ank

2-Po

lyGPM

EOH+T

ank

3-LP

MEOH+T

ank

4-PL

PMEOH+T

ank

5-SL

PMEO

H+T

ank

6-Po

lyH2+

Gas7-

PolyH

2+Pi

pe8-

PolyH

2+LH

29-

PolyH

2+Hyb

ride

10-P

olyLP

DME

Efficiency %

CO2 emission of oil (~10-13g/MJ)

1-GPMeOH+IGCC2-Parallel polygeneration, recycle 3-LPMeOH+IGCC4-Parallel polygeneration, once-through5-Series polygeneration, once-through

How can coal based system be competitive with

oil in CO2?


Polygeneration by its nature can make the CO2 capture easy

Coal

SyngasGenerator

Combined/HybridCycle

O2

Ash/PM MercuryPure Sulfur

Dilute CO2

Slag

Concentrated CO2

Chemical Process

MeOH DME F-T Liquid

Heavy Oil

Petro Coke

Ethanol

Gas Adjustment

Cleaning

Bypass

Recycle (Optional)

+

Hydrogen

Biomass

Wastes

Natural Gas

ASUAir N2

Gas Production and Preparation Section

Fuels or Chemicals Production Section

Power Generation Section

PolygerationCarbon CMeOH

CO2 concentrated

CO2 in flue gas


Power-MeOH Polygenerationwith CO-rich gas and in once-through mode (no shift)

Conc. CO2 out: 14.7%

dilu. CO2 out: 74%

Assume MeOH_CO2=10g/MJ Elec_CO2=221.7 g /MJ

Pure elec_CO2=222-250g/MJ

CO2_reduction=11%

η=46.8%


Power-MeOH Polygenerationwith H2-rich gas and in once-through mode (w. shift)

SHIFT

Conc. CO2 out:58.9%

dilu. CO2 out: 31.5%

Assume MeOH_CO2=10g/MJ

Elec_CO2= 114 g/MJ

Pure elec_CO2=222-250g/MJCO2_reduction=48.7-54.4%

η=39.73%


Coal to MeOH with shift and recycle

108 g CO2/MJ Concentrated CO2 out 102 g/MJ

Diluted CO2 out 6 g/MJ


Four steps for polygeneration development--meeting time progressive CO2 reduction needs by different

configurations

1. By increasing IGCC efficiency

2. Co-production of power and high value added chemicals or fuels

e.g. Power + Methanol

3. CO2 recovery from power and/or hydrogen productionCO2 capture in H2 production from coal gasification

CO2 capture from IGCC plant

CO2 capture from IGCC+H2 production

4. Hybrid cycle with SOFC to increase efficiency further


To Increase IGCC efficiency

coal IGCC without CO2 capture

Diluted CO2180~190 gCO2/MJ

Electricity

η=52.49%

by using

•9H gas turbine

•dry powder coal gasification

•high temperature dry cleaningCO2 reduced by 15-25% than supercritical PC plant


Co-production of power and methanol

coal Power+MeOHw/o shift

Diluted CO2, 74%221.7 gCO2/MJ

MEOH

Electricity

Concentrated CO2, 14.7%

coal Power+MeOHw. shift

Diluted CO2, 31.5%114.0 gCO2/MJ

MEOH

Electricity

Concentrated CO2, 58.9%

η=46.8% (LHV) CO2 reduced by 11% than supercritical PC plant

η=39.7% (LHV) CO2 reduced by 49-54% than supercritical PC plant


CO2 recovery from power and/or hydrogen production

coal Power+H2Power ratio 0%

Diluted CO2, 10~18%8.4~28.6 gCO2/MJ

H2

Concentrated CO2, 82~90%

coal Power+H2Power ratio 50%


H2

Electricity

Concentrated CO2, 91%

CO2 reduced by 92.5~93.3%


coal IGCC with CO2 capture

Diluted CO230.8 gCO2/MJ

E



Hybrid cycle with SOFC to increase efficiency further

coal SOFC CO2capture w/o shift


Electricity

Concentrated CO2, 80%reduced by 84.4-86.1%

coal SOFC CO2capture w. shift


Electricity

Concentrated CO2, 94.3%reduced by 95.5-96%

coal SOFC CO2 capture w. 50% power


H2

Electricity

Concentrated CO2, 96.1%reduced by 97.1-97.5%

coal SOFC hybridw/o CO2 capture

flue gas CO2155-160 gCO2/MJ

Electricity

CO2 reduced by 28-38%


CO2 reduction by increasing energy efficiency of power generation

� � � � � � IGCC SOFC�� 0

10

20

30

40

50

60

70

��

��

(LH

V�

%)

39� 4551� 52.5

60� 65

� � � � � � IGCC SOFC�� 0

50

100

150

200

250

300

��

��

��

(gC

O2/M

J) 222� 250

180� 190� � � 15%� 25% 155� 160

� � � 28%� 38%

PC plant IGCC SOFC Hybrid PC plant IGCC SOFC Hybrid


Efficiency penalty and incremental capital cost for CO2reduction

SCP IGCC SOFC77 SOFC930

10

20

30

40

50

60

Gen

erat

ing

effic

ienc

y (L

HV

,%) Before reducing

After reducing

41.6

28.3

52.5

42.6

64.5 64.556.957.2

SCP IGCC SOFC77 SOFC930

100

200

300

400

500

128.66

52.96

209.32

526.53

Cap

ital c

ost (

RM

B/to

nne

CO

2)

Capacity factor 85%

7.67.39.913.3∆η

SOFC93SOFC77IGCCSCP


Conclusions

Polygeneration is a promising comprehensive solution for energy challenges China is facing

CO2 emission from coal power is 8 times higer than that of transportation and has characters of large scale and central emission. Therefore, CO2 reduction from coal power should be the major start point.

Polygeneration by its nature can make the CO2 capture easy

Different polygeneration configurations could meet time progressive CO2 reduction needs

Polygeneration can reduce CO2 with less efficiency penalty and less incremental capital cost


backup slides


Example 2: 600 MW IGCC plant with HT dry cleaning, w/o CO2 capture

Diluted CO2 180~190 gCO2/MJ

Efficiency 52.5% (LHV)

CO2 emission less than supercritical plant 15~25%


600 MW IGCC plant with HT dry cleaning, w. CO2 capture

Diluted CO2 ：180~190 gCO2/MJ

Efficiency：52.5% (LHV)

CO2 emission less than supercritical plant 15~25%


600 MW IGCC plant with ambient temp. cleaning, w/o CO2 capture

HP BFW

A

COS

MDEA CLAUS/SCOT

Shell

HP

HPA

IP

IP

HP BFW

LP

LPLP


Power+MeOH production witn CO-rich syngas once through

Selexol

CO2

BFW

TC

L P HPIP

B

B

BFW

C

C

110

LP

IP HP

COS

Diluted CO2：74%，221.7 gCO2/MJ


CO2 emission less than supercritical plant 11%


Power+MeOH production with shift reactor

Selexol

CO2

BFW

WGS

TC

L P HPIP

B

B

BFW

C1

C

110

LP

IP HP

C2

C1 C2

Diluted CO2：31.5%，114 gCO2/MJ


CO2 emission less than supercritical plant 11%


IGCC+H2 production with different power fraction


减排CO2的煤气化SOFC混合循环


减排CO2的煤气化SOFC混合循环（带水煤气变换）

Shell

/

EXP

SOFC阳极阴极

B

A

HP

IP

IPLP LP

BC

A

HP

HTS

LTS

C

K.O.CO2

CO2

G

1

23

45

6


能量效率和二氧化碳排放对比总结

� � � � � � IGCC SOFC�� 0

10

20

30

40

50

60

70

��

��

(LH

V�

%)

39� 4551� 52.5

60� 65

� � � � � � IGCC SOFC�� 0

50

100

150

200

250

300

��

��

��

(gC

O2/M

J) 222� 250

180� 190� � � 15%� 25% 155� 160

� � � 28%� 38%

PC plant IGCC SOFC Hybrid PC plant IGCC SOFC Hybrid


采用常温净化系统的煤气化SOFC混合循环电厂（无补燃，单压SOFC结构）

HP BFW

A

COS

MDEA CLAUS/SCOT

Shell

A

HP

HP

IP

IP

HP BFW

LP LP

EXP

阳极

阴极

燃烧

室

回热器

SOFC



CO2 reduction rates of different configurations

Diluted CO2 87%201 gCO2/MJ(MeOH+Power)

Electricity from 40% coal power plant 235 gCO2/MJCO2 reduction for electricity about 15%

CoalElectricity

MeOH

Concentrated CO2 13%


Analysis of power plants with CO2 mitigation (contd.)

CO2 mitigation cost ($/ton C)

96.5

208.8209.5

310.5

0

50

100

150

200

250

300

350

NGCC Coal-SCS Coal-USC IGCC



Efficiency (% HHV)

43.142.740.5

53.6

373128.9

43.3

0102030405060


CO2 VentedCO2 Captured



CO2 mitigation cost ($/ton C)

96.5

208.8209.5

310.5

0

50

100

150

200

250

300

350



Coal Gasification System Ready for Large-Scale H2 production and Utilization


Coal Gasification is the Core of Future New Thermal Cycles

When coupled with High Temperature Solid Oxide Fuel Cell (SOFC), the efficiency of IGCC-SOFC could be up to 60%~65%.SOFC has the similar function like Water Gas Shift for increasing CO2 concentration in syngas


General Conclusions

According to the projection of energy demand and supply, coal will still play the dominant role (50%~60% in 2050)

Coal utilization will contribute about 70%~75% of CO2 in China (at present 76.8%)

Coal mainly will be used for power generation in future (up to 80%, at present about 45~50%)

It means coal fired power plants will contribute 60% or more CO2 of total


Genetic characteristics of polygeneration system

Heritage of all environmental virtues of IGCCSOx, NOx, dust, Mercury

Simplicity and higher efficiencyonce through→reduce the size and energy consumption of recycling

CO-rich gas synthesis →saving shift reactor

more flexibility for balancing energy recovery and simplicity of the system

Nature of easy CO2 captureconcentrated CO2+diluted CO2

meets time progressive CO2 reduction requirements by different configuration (e.g. w. or w/o shift reactor)


Conclusions

Polygeneration has the nature of easy CO2 captureDifferent configurations could meet time-progressive CO2 reduction demand and can evolve up to near zero CO2 system.When coupled with CO2 sequestration, coal derived synthetic fuels has the prospect to be competitive with other fuels.Polygeneration is the sustainable, technically consistent, technologically realistic, economically beneficial, and ecologically friendly way for CO2 mitigation, capture, and further sequestration. It is really the most important strategy in China.


END

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Polygeneration and CO2 Capture - Stanford UniversityProf. Li Zheng, Tsinghua CEC Polygeneration and...

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