Transcript Document 7138599

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Effective Utilization of
By-product Oxygen of
Electrolysis Hydrogen Production
International Energy Workshop 2003
23 – 25 June. 2003 at IIASA
T. Kato, M. Kubota, N. Kobayashi, Y. Suzuoki
Nagoya University,
Furo-cho Chikusa-ku Nagoya, 464-8603, Japan
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Hydrogen
Energy Carrier in Future Energy System
Electricity
Fossil Fuel
Heat
Biomass, MSW
Hydrogen
Transportation
Fuel
Wind, Solar
Nuclear
Storage
Industrial
Material
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Hydrogen Supply
Near Term
Long Term
SOLAR or WIND ELECTROLYTIC HYDROGEN
source: Joan M. Ogden, “Developing an infrastructure for hydrogen vehicles: a Southern
California case Study, Int. J. of Hydrogen Energy, Vol.24 (1999) pp.709-730
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Energy System with Hydrogen
City Area
Hydro power
Nuclear power
electricity
electricity
electricity
Wind power
FCV
water
electrolysis
household
hydrogen
storage
Chemical
Industry
Photovoltaic power
Micro gas
turbine
PEFC
mCGS
City Center
DHC
electricity
Gas engine
CGS
nuclear
oil
PEFC
CGS
hospital etc.
other power plant
PEFC
mCGS
natural gas
city gas
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Hydrogen Production Technologies
40
Hydrogen Production Cost
[2000US$/GJ]
Electrolysis (PEM)
30
Biomass gasification
(BCL)
Steam methane reforming
(SMR)
20
10
0
0.001
0.01
0.1
1
10
100
Hydrogen Production Rate (10 6Nm3/day)


Investment cost and O&M cost ＝＞from original literatures
Feedstock cost
Natural gas：0.3 $/GJ, Biomass：0.39 $/GJ, Electricity： 0.053 $/kWh
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Creating New Function of Water Electrolysis
• Cost Reduction in Water Electrolysis
• Enhancement of Renewables (Wind, PV)
Anode :
2 H2O ---> O2 + 4 H+ + 4 eCathode :
4 H+ + 4 e- ---> 2H2
Global reaction : 2 H2O ---> 2 H2 + O2
4eCathode
2H2
Anode
4 H+
O2
2H2O
electrolyzer
Effective Utilization of By-product Oxygen
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Effective Utilization of By-product Oxygen
City Area
Hydro power
Nuclear power
electricity
electricity
electricity
Wind power
FCV
water
electrolysis
oxygen
storage
Fossil Fuel
CO2 capture
O2
pure oxygen
blown boiler
Chemical
Industry
household
hydrogen
storage
Micro gas
turbine
oxygen blown
power plant
PEFC
mCGS
City Center
DHC
steam turbine
electricity
nuclear
oil
H2
Photovoltaic power
Electric
Furnace
Glass
Melting
other power plant
Gas engine
CGS
PEFC
CGS
hospital etc.
PEFC
mCGS
natural gas
city gas
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This Presentation



Oxygen production technologies
Oxygen demand and energy saving
potential by oxygen utilization
Balance between oxygen demand and byproduct oxygen supply of water
electrolysis hydrogen production
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Oxygen Production Technologies
Energy
Oxygen
Purity
Consumption
(kWh/Nm3-O2) (Vol. %)
Cryogenic
Air Separation
Pressure Swing
Adsorption (PSA)
Applicable
Capacity
(Nm3/n)
0.5 – 0.6
99 +
8,000 +
0.5
93 - 95
8,000 -
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Equivalent Efficiency Improvement
by Utilization of By-product Oxygen
Water Electrolysis (efficiency = 71 %)
Input : electricity 5,000 kWh
Output : hydrogen 1,000 Nm3, oxygen 500 Nm3
Full utilization of by-product oxygen
=> Reduction of 250 kWh on Cryogenic Air Separation
(0.5 kWh/Nm3-O2)
=> Apparent performance of water electrolysis
Input
: electricity 4,750 kWh
Efficiency :
76 %
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Oxygen Demand in Japan
oxygen demand (106 Nm3)
12000
pulp bleaching
glass melting
stainless steel
non-ferrous metals
medical care
shipbuilding
electric furnace
blast furnace
10000
8000
6000
4000
2000
0
1996 1997 1998 1999 2000 2001
year
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Potential of Additional Oxygen Demand



Electric Furnace
Glass Melting
Gasification


Electric Power Generation


Biomass, MSW, Coal, etc.
Oxygen-blown Combustion
Others
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Electric Arc Furnace
Scrap
Electric Arc
Oxygen + Fuel
(temperature rise)
Oxygen (Deoxidation)
Steel
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Electric Furnace: ECOARC (NKK, Japan)
ECOARC (NKK, Japan)
Conv. ECOARC
Electricity
(kWh/t-billet)
380
150
Oxygen
(Nm3/t)
33
45
source: http://www.jfe-holdings.co.jp/archives/nkk_360/No.45/45n1.html (in Japanese)
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Electric Arc Furnace in Japan


Annual Production: 29 x 106 ton/yr in 2002
When all existing electric arc furnaces are
replaced with newly developed technology,


primary energy reduction : 62,849 TJ/yr
additional oxygen demand : 346 x 106 Nm3/yr
(total oxygen demand : 1,300 x 106 Nm3/yr)
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Glass Melting
Conventional Air-blown
Glass Melting Furnace
Oxygen-blown
Glass Melting Furnace
Burner
Port
Flame
Melting glass
Flame
Doghouse
Regenerator
Oxy-fuel burner
Blower
Melting glass


Chimney
Damper


smaller size
higher efficiency
lower emissions
larger investment cost
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Comparison between Air-blown Combustion
and Oxygen-blown Combustion
in Glass Melting Process
8
6
4
2
NOx
Emission
0.005
0.30
CO2 (Nm3/kg-glass)
10
0.006
NOx (Nm3/kg-glass)
energy (MJ/kg-glass)
12
Energy
Consumption
0.004
0.003
0.002
0.001
air
oxygen
0.25
0.20
0.15
0.10
0.05
0.00
0.000
0
CO2
Emission
air
oxygen
Oxygen requirement = 0.3 Nm3/kg-glass
Energy reduction = 16 MJ/Nm3-O2
air
oxygen
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Glass Melting in Japan



Oxygen-blown furnace is not introduced except
electric glass production because of higher
investment cost.
Annual production of sheet glass, glass fiber
wool products, glass fiber textiles, glass
foundations and glass containers was totally
4.4 x 106 t/yr in the last 3 years.
When oxygen-blown furnace is introduced

primary energy reduction : 20,951 TJ/yr

additional oxygen demand : 1,313 x 106 Nm3/yr
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Cumulative Capacity of Commercial
Gasification Projects in the World
syngas capacity (106 Nm3/day)
250
200
150
100
50
0
1940 1950 1960 1970 1980 1990 2000 2010
year
Coal
Petroleum
Gas
Biomass/MSW
Petcoke
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Example of Oxygen Requirement
in Gasification Process
Api Energia IGCC (Italy)
Plant size:
• 59 t/h of feed
• 130 t/h of syngas
• 127 t/h of Nitrogen
• 62 t/h of Oxygen
• GT: 190 MW
• ST: 100 MW
• HRSG: 280 t/h
• Aux Boiler: 140 t/h
• Export steam to
refinery: 65 t/h
John L. Spence, “api ENERGIA IGCC Plant Status”, 2000 Gasification Technologies Conference (2000)
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Oxygen Combustion
Natural Gas Combined Cycle Power Plant
CH4 : 902 MW
(16.4 kg/s)
1320oC
1.6MPa
O2
72.1kg/s
191 MW
GT
Efficiency : 44 % (HHV)
Input : CH4 902 MW
Output: Electricity 400 MW
GT 191 MW
ST 213 MW
Aux - 4 MW
806oC
0.1MPa
593oC
15MPa
recycled
exhaust
(85%)
STH
120oC
exhaust component
CO2 = 31.2 %
H2O = 62.3 %
O2 = 6.4 %
STL
213 MW
wasted
exhaust
(15%)
h=75%
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Future Hydrogen Demand for Vehicles

Japan (governmental target value(1))
FCVs
(vehicles)
Hydrogen
(106
Nm3)
50,000
160
2020 5,000,000
4,250
2010

Hydrogen of 4,250 106 Nm3/yr
is supplied by water electrolysis
By-product oxygen
2,125 106 Nm3/yr
California (estimated value(2))
630 x 106 Nm3/yr in 2020 for
350,000 passengers cars, 150,000 light trucks and 330 buses
source: (1) WE-NE Phase II task I, “Investigation and Study for System Evaluation”, annual report on FY2002 (2003)
(2) Joan M. Ogden, “Developing an infrastructure for hydrogen vehicles: a Southern California case Study, Int. J.
of Hydrogen Energy, Vol.24 (1999) pp.709-730
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reduction of energy consumption
per unit oxygen use (MJ/Nm3)
Potential of
By-product Oxygen Consumption
potential supply of by-product oxygen
of electrolysis hydrogen productoin
(FCV: 5,000,000 in 2020)
200
180
160
electric arc
furnace
140
120
100
80
60
glass melting
40
20
oxygen-blown
NGCC (400MW)
0
0
500
1000
1500
2000
oxygen demand (106 Nm3/yr)
2500
3000
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Oxygen Price for Medical Use
1US$=121.529yen
oxygen price (US$/Nm 3)
1000
gas oxygen with cylinder (1,500L, 500L)
gas oxygen with cylinder (7,000L, 6,000L)
liquid oxygen with removable tank
liquid oxygen with stationary tank
100
10
1
0.1
1
10
100
1000
10000
3
annual oxygen demand (Nm )
100000
1000000
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Conclusions



In industrial processes and power plants, potential
demand of oxygen is large enough to consume byproduct oxygen of water electrolysis hydrogen production.
When by-product oxygen is fully utilized in industrial
processes, process energy efficiency would be improved
remarkably.
Oxygen-blown power plant would be economical option
for capturing CO2 emission relative to conventional NGCC
with CO2 capture process.
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Future Works


Taking into account limitations in the real world

Available renewable energy for water electrolysis

Storage and transportation of oxygen and hydrogen
Economic assessment

Oxygen-blown power plant with CO2 capture