View
27
Download
0
Category
Preview:
Citation preview
Analysis of Fuel Cell Systems
Rangan BanerjeeEnergy Systems Engineering
IIT Bombay
Lecture in CEP Course on ‘Fuel Cell’ at IIT 14th November 2007
Overview of Talk
Energy Crisis – Motivation for fuel cells
Criteria
Listing of Pathways
Vehicles
Energy chain - Primary Energy Analysis
Cost Analysis
Renewable Hydrogen
Energy CrisisPresent energy systems – fossil fuel based (~80%)Finite fossil fuel reserves (Oil-Gas ~ 50 years, coal ~100 years)Adverse local, regional and global environmental impacts Global warming (Greenhouse gas problem)
Carbon Dioxide Concentrations
Carbon Dioxide Concentrations
Hydrogen EnergyCan hydrogen energy mitigate the energy problem?How does the hydrogen energy system compare with existing energy conversion routes?Is this a sustainable solution?A- Vehicle – 4 wheeler passenger car B-Distributed Power Generation
Hydrogen pathways
Photo chemical
Solar Energy Nuclear Energy Bio-Energy
Electricity
Wind
Thermal
ElectrolysisThermo chemical
Fossil-Fuel
Photo biological
Hydrogen
Gasification Fermentation
Cracking + Shift Reaction
Fuel Cell
ENERGY FLOW DIAGRAMPRIMARY ENERGY
ENERGY CONVERSION FACILITY
SECONDARY ENERGY
TRANSMISSION & DISTRN. SYSTEM
FINAL ENERGY
ENERGY UTILISATION EQUIPMENT & SYSTEMS
USEFUL ENERGY
END USE ACTIVITIES
(ENERGY SERVICES)
COAL, OIL, SOLAR, GASPOWER PLANT, REFINERIESREFINED OIL, ELECTRICITY
RAILWAYS, TRUCKS, PIPELINESWHAT CONSUMERS BUY DELIVERED ENERGYAUTOMOBILE, LAMP, MOTOR, STOVEMOTIVE POWER RADIANT ENERGYDISTANCE TRAVELLED, ILLUMINATION,COOKED FOOD etc..
Source : Energy After Rio: UNDP Publication.
CriteriaPrimary Energy Analysis – primary energy/
unit output (kJ/kWh , kJ/km )
Emissions - Local, Global
Cost - Initial Cost, Operating Cost,
Annualised Life Cycle Cost
Sustainability (Renewable?)
Primary Energy Analysis
Compare options based on primary energy input
MotivationFossil fuel scarcity, adverse environmental effects (local and global)Indian transport sector
22% of total commercial energy Share in total pollutant load; 70% in New Delhi, 52% in Bombay
Need for alternative transport fuels.Indian government’s emphasis on biodiesel, hydrogen ..
Fuel chains
Refinery
Vehicle (Utilization)
Filling stations (Petrol storage and delivery)
Crude oil production centre
Intercontinental crude oil transport
Petrol transport (via Rail/Truck)
Primary energy source
Vehicle (On-board storage and utilization)
Hydrogen production centre (Production and compression)
Filling stations (Hydrogen storage and delivery)
Pipeline transport
Hydrogen fuel chainFossil fuel chain
Base case Fossil fuel based fuel chainSmall-size passenger car (Maruti 800) manufactured by Maruti Udyog Limited
Petrol fuelled, 37 bhp (27 kW) IC engine
50% share in Indian passenger vehicle-market
560,000 units sold 2005-6
Vehicle ApplicationWeight (excl engine
+tank) 550 kgPassengers (max)
350 kgMarutiCR 0.01CD 0.42m2 front area100 km travel /day
Tank Engine
Petrol 40 kg 60 kg
CNG 140 kg 60 kg
FC 130 kg 15 M +15 FC kg
B1) PETROL ENGINE
SHAFT WORK
OIL MINING/REFINING
IC ENGINE
TRANSMISSION
TRANSPORT OF PETROL
η OM 95 %
η TP 97%
η PE 30 %
CRUDE OIL
η TRANS 70 %
B2) GAS ENGINE
SHAFT WORK
EXTRACTION
COMPRESSION
CNG ENGINE
NATURAL GAS TRANSPORT
η OM 95 %
η TD 97%
η C 90%
NATURAL GAS
η GE 40%
TRANSMISSION η TR70%
FUEL CELL (NG)η E 95 %
η GT 97 %
η FC 40 %
η REF 85 %
η PC 95 %SHAFT WORK
NATURAL GAS
EXTRACTION
NATURAL GAS TRANSPORT
HYDROGEN
STEAM REFORMING
ELECTRICITY
PEM FUEL CELL
POWER CONDITIONING
MOTOR
TRANSMISSION
ηm 90%
ηTR 91%
Vehicle Comparison
A1 Overall efficiency 19.4%3.31 kg of crude /100 km of travel
A2 Overall efficiency 23.2%3.0 kg of Natural gas/ 100 km of
travelFuel cell Overall efficiency 24.3%2.82 kg of Natural gas/ 100 km of travel
Vehicle Carbon Emissions
A1 – Crude oil (86% Carbon) 2.84 kg Carbon/100 km of travelA2- Natural gas (75% Carbon)2.25 kg Carbon/ 100 km of travel
Fuel cell ( 18 kg of Carbon / 1 GJ of Hydrogen energy – SMR)
FC 2.11 kg Carbon/100 km of travel
Hydrogen fuel chain – different routes
Hydrogen Production
Storage
Utilization
Steam methane reforming (SMR), Coal gasification, Water electrolysis, Renewable hydrogen (Photovoltaic-electrolysis, Wind power-electrolysis, Biomass gasification, Biological methods)
Compressed hydrogen storage, Metal hydrides, Liquid hydrogen storage, Complex chemical hydrides
Fuel cells (PEMFC), IC engine
Transmission Pipeline transport, transport via truck and rail
Comparison criteriaNon-renewable energy consumption per km travel (MJ/km)Greenhouse gas emissions per km travel (g CO2-eq/km)Cost per km travel (Rs./km)
Annualised life cycle costing (ALCC) methodExisting Indian prices.If technology is not available commercially in India, international prices are used
Resource constraints
Methodology
Life cycle assessment (LCA) All material and energy inputs to the process are identifiedTotal input energy required to extract, produce, and deliver a given energy output or end use
Energy use and corresponding emissions during fabrication of PV, electrolyzer, wind machine etc. are also taken into account.
Methodology contd..
Inventory (process energy and material) to produce one unit of output
Classification of total primary energy into non-renewable and renewable energy
Non-renewable energy useGHG emissions
Total primary energy required to produce required process energy and materials
Cost of different equipment and material required, discount rate, life of the equipment
Life cycle cost
Materials and other resources such as water, land etc required to produce 1 kg of hydrogen
Resource constraint
Amount of material and other resources required to meet the current demand
Process flow chartsSizing of different equipment required
Total GHG emissions in producing process energy and materials (using emission factors)
Resource constraint
Resource constraint
Material supply constraint
Area
Material constraint
Other constraint
Annual requirement/Reserve
Area required/Available land area
Annual requirement/Reserve
No constraint
Technical constraint, water for biomass based systems etc.
Source: Manish S, Indu R Pillai, and Rangan Banerjee, "Sustainability analysis of renewables for climate change mitigation," Energy for Sustainable Development, vol. 10, no. 4, pp. 25-36, 2006.
Energy analysisPower required at wheels
Transmission and IC engine efficiency
Fuel requirement from fuel tank
Input (Drive cycle,Vehicle weight,Front area, Air density, Cd, Cr)
IC engine vehicle
Power required at wheels
Transmission, Fuel cell and Electric motor efficiency
Fuel requirement from fuel tank
Input (Drive cycle,Vehicle weight,Front area, Air density, Cd, Cr)
Fuel cell vehicleSource: Manish S and Rangan Banerjee, "Techno-economic assessment of fuel cell vehicles for India," 16th World hydrogen energy conference, Lyon (France), 2006.
Indian urban drive cycle
Indian urban drive cycle :-
Low average speed (23.4 km/h) and rapid accelerations (1.73 to -2.1 m/s2)
European urban drive cycle :-
Average speed (62.4 km/h) and accelerations from 0.83 to -1.4 m/s2
0
2
4
6
8
10
12
14
16
18
20
0 500 1000 1500 2000 2500 3000
Time (s)
Spee
d (m
/s)
Avg. speed - EUDC
Avg. speed IUDC
Power required at wheelsThree forces acts on the vehicle (Assumption:-vehicle is running on a straight road with a zero gradient). These are
Aerodynamic drag {FDrag(t)} = 0.5ρAv(t)2Cd
Frictional resistance {FFriction(t)} = mgCr
Inertial force {FInertia(t)} = mf {f=dv(t)/dt}FTotal(t)=FDrag(t)+FFriction(t)+FInertia(t)PWheel(t)=FTotal(t)×v(t)
Data used for base case vehicleParameterParameter ValueValueAir density (kg/m3) 1.2
Coefficient of drag resistance 0.4
Coefficient of rolling resistance 0.01
Cargo weight (kg) 250
Frontal area (m2) 2
Transmission efficiency 0.7
Transmission weight (kg) 114
IC engine weight (kg) 90
Fuel tank weight (kg) 40
Fuel capacity (kg) 24
Vehicle body weight (kg) 406
Total weight (kg) 900
Result for base case vehicleParameterParameter ValueValueDriving range (km) 434
Cost (Rs/km) 2.8 (0.34)
Non-renewable energy use during operation (MJ/km) 2.6
GHG emissions (g/km) 180
Driving range of hydrogen vehicles should be at least half (~217 kms) for their public acceptance.
•Average daily travel Indian urban <100 kms.
•Vehicle to run for 2-3 days.
Hydrogen fuel chain – Options considered
Hydrogen fuel chain
Production
Steam methane reforming (SMR)
PV-electrolysis (PV)
Wind-electrolysis (WE)
Biomass gasification (BG)
Transmission
Pipeline transport
(PL)
Storage
Compressed hydrogen (C)
Liquid hydrogen (L)
Metal hydride (M)
Utilization
PEM fuel cell
(FC)
IC engine
(IC)
Hydrogen production – Steam Methane Reforming (SMR)
Feedstock - Natural Gas SMR: CH4 + 2H2O 4H2 + CO2
Life of plant 20 yearsExisting NG price Rs 8/Nm3, Price of Hydrogen Rs 48/ kg 4.3 Rs/Nm3 or 400 Rs/GJ
Variation of Hydrogen price with NG price
0
5
10
15
20
25
30
35
40
45
0 5 10 15 20
Natural Gas Price (Rs/Nm3)
Hyd
roge
n pr
ice
(Rs/
Nm
3)
PV-Electrolyzer System
• HYSOLAR (Saudi Arabia) 350 kW Alkaline electrolyser 65 m3/h peak (German-Saudi) ~5.8 kg/hr
PV arrayMPPT and DC-DC converter
Water
Oxygen
PEM Electrolyzer
Hydrogen
PV-Hydrogen
100 kg hydrogen/ dayElectrolyzer efficiency 70%Annual capacity factor 20%Module area 8800 m2
1300 kWp PV, 1200 kW electrolyzer
Wind-ElectrolyzerUtsira Plant
10 Nm3/h (~0.9kg/h)
48 kW electrolyzer
Two wind turbines 600 kW (peak) each
Source: Norsk Hydro
WECSAC-DC converter
Water
Oxygen
PEM Electrolyzer
Hydrogen
Wind-Electrolyzer
100 kg hydrogen/ dayElectrolyzer efficiency 70%Annual capacity factor 30%880 kW (peak), 784 kW electrolyzer
Biomass gasifier-reformer
Many configurations possible – atmospheric, pressurised, air blown, oxygen blown
No large scale systems
Hydrogen
SyngasBiomass
Air
Steam
Gasifier Gas cleaning
Methane steam reforming
Water gas shift reaction
Pressure swing adsorption
Comparison of hydrogen production methods
Indicator Unit SMR PV-electrolysis
WECS-electrol.
BiomassGasification
Non-renewable energy use
MJ/kg 182 67.5 12.4 67.7
GHG emission kg/kg 12.8 3.75 0.98 5.4
Life cycle cost* Rs/kg 48 1220 400 44.7
*At 10% discount rate Average load factors; PV-0.2, WECS-0.3, Biomass gasification-0.65
Hydrogen transmissionCan be transported as a compressed gas, a cryogenic liquid (and organic liquid) or as a solid metal hydride.Via pipeline, trucks, rail etc.Compressed hydrogen via pipeline
US, Canada and EuropeTypical operating pressures 1-2 MPaFlow rates 300-8900 kg/h
Hydrogen transmission-contd..
210 km long 0.25 m diameter pipeline in operation in Germany since 1939 carrying 8900 kg/h at 2 MPaThe longest pipeline (400 km, from Northern France to Belgium) owned by Air Liquide.In US, total 720 km pipeline along Gulf coast and Great lakes.
Results for transmission process
For 1 million kg/day, transmission distance 100 km, supply pressure 10 bar
Parameter Value Unit
Optimum pipe diameter 1 m
Transmission cost 6.93 (0.85UAH/kg) Rs/kg
GHG emissions 0.99 kg/kg
02468
101214161820
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
Pipe dia (m)
Tran
smis
sion
cos
t (R
s/kg
)
Transmission cost vs. pipe diameter
Hydrogen on-board storage and utilization
Demo hydrogen vehicles : Daimler-Benz, Honda, Toyota, Ford, BMW, General Motors, Daimler-Chrysler, MazdaOn-board storage: compressed gas, liquid hydrogen, metal hydride, organic liquidEnergy conversion device: internal combustion engine, fuel cell
Vehicles with compressed hydrogen storage
Name of thevehicle/Company
Energy conversiondevice
Net poweroutput
Storage system Range ofVehicle(km)
NEBUS (bus)(Daimler-Benz)
Fuel cells10 stacks of 25kW
190 kW 150 litre cylindersat 300 bar
250
Zebus (bus)(Ballard powersystems)
Fuel cells 205 kW Compressedhydrogen
360
FCX (Car)(Honda)
Fuel Cells 100 kW 171 litre at 350bar
570
FCHV-4 (car)(Toyota)
PEM fuel cell+ Battery
80 kW 350 bar 250
Model U(Ford motor co.)
Internal combustionEngine
113 kW@4500rpm
7 kg @690 bar ---
NECAR 2(Daimler Benz)
Fuel cell 50 kW Compressed gas ---
Vehicles with liquid hydrogen storage
Name of thevehicle/Company
Energyconversiondevice
Net poweroutput
Storagesystem
Range ofVehicle(km)
BMW 750-hl(BMW Corporation)
Hybrid, 12 cylindercombustion engine
--- 140 liters, cryostorage at -2530C
400
Hydrogen 3(General motors)
Fuel cell 60 kW 4.6 kg LiquidHydrogen at -253oC
400
Necar4(Daimler Chrysler)
Fuel cell 70 kW --- 450
Vehicles with organic liquid storage
Name of thevehicle/Company
Energyconversion device
Net poweroutput
Storage system
NECAR 5(Daimler Chrysler)
Fuel cell 75 kW Methanol(On board reformer)
FC5(Ford Motor company)
Fuel cell 65kW --do--
Mazda Premacy(Ford Motor company)
Fuel cell 65kW --do--
FCX-V2(Honda Motor company)
Fuel cell 60kW --do--
Vehicles with metal hydride storage system
Name of thevehicle/Company
Energyconversion device
Net poweroutput
Storagesystem
HRX2(Mazda MotorCorporation)
Wankel RotoryEngine
65kW TiFe
FCX-V1(Honda Motorcompany)
Fuel cell 60kW LaNi5
On-board storage + utilizationOption
On-board storage
Energy conversion device
Compressed H2
Fuel cell 21.03 17.8 0.24 0.83
Liquid H2 Fuel cell 21.06 17.8 0.24 0.80
Metal hydride Fuel cell 21.92 26.9 0.36 0.88
Compressed H2
IC engine 1.23 0* 0* 2.47
Liquid H2 IC engine 1.35 0* 0* 2.32
Metal hydride IC engine 4.17 32 0.42 2.74
Cost (Rs/km)
GHGg/km
Non-renewable energy use (MJ/km)
H2 use MJ/km
*Energy use and emissions in base case vehicle manufacturing neglected
Results for hydrogen storage (at filling stations)
Parameter Compressed hydrogen
Liquid hydrogen
Metal hydride
Unit
Delivery and storage cost
8.75 42.6 33.7 Rs/kg
GHG emissions 1.24 7.2 0.28 kg/kg
Non-renewable energy use
12.72 74 3.84 MJ/kg
PV-PL-C-FC
Cost break-up
1.2
19.95.8
2.6
0.0
0.1
8.6
VehicleFuel cellPhotovoltaicElectrolyzerTransmissionStorage
Specific fuel consumption- 6.9 g/kmCost- 29.6 Rs/km GHG emissions- 59.1 g/km BASE CASE
Rs 2.6/km
GHG 180g/km
PV-PL-C-IC
Cost break-up
1.217.3
7.9
0.1
0.2
25.5VehiclePhotovoltaicElectrolyzerTransmissionStorage
Specific fuel consumption-20.6 g/kmCost- 26.7 Rs/kmGHG emissions- 123.2 g/km
BASE CASE
Rs 2.6/km
GHG 180g/km
WE-PL-C-IC
Cost break-up
1.2
2.9
5.2
0.1
0.2
8.5VehicleWECSElectrolyzerTransmissionStorage
Specific fuel consumption- 20.6 g/kmCost- 9.7 Rs/kmGHG emissions- 66.1 g/km
BASE CASE
Rs 2.6/km
GHG 180g/km
SMR-PL-C-IC/SMR-PL-C-FCSMR-PL-C-IC
Specific fuel consumption- 20.6 g/kmCost- 2.5 Rs/kmGHG - 310 g/km
BASE CASE
Rs 2.6/km
GHG 180g/kmSMR-PL-C-FCSpecific fuel consumption- 6.9 g/km
Cost- 21.5 Rs/km
GHG - 122 g/km
BG-PL-C-IC Specific fuel consumption- 20.6 g/kmGHG emissions- 158 g/kmCost
CASE 1 Biomass freely available2.5 Rs/km
CASE 2 Biomass commercially grownDepends on land price4.7 Rs/km
BASE CASE
Rs 2.6/km
GHG 180g/km
Cost break-up
1.2
0.9
2.3
0.1
0.2
3.5 VehicleProductionLand costTransmissionStorage
Cost break-up
1.20.9
0.1
0.2
1.2
VehicleProductionTransmissionStorage
Case 1 Biomass freely available
Case 2 Biomass grown commercially
Hydrogen fuel chain BG-PL-C-IC
BiomassPipeline transport
Production and compression• Hydrogen 2 million kg per day• Area for biomass growth3800 km2 (380000 ha)• Power required 124 MW (for delivery at 10 bar)• Biomass gasifier rating 2000 MWe
H2-IC engine Vehicle
Compressed Hydrogenstorage and delivery
• Storage tank autonomyperiod half day• Storage capacity 1 million kg• Volume of storage 40 million liters @ 200 bar (40000 m3, sphere of 21.2 meter radius,)• Compressor power required143 MW (for hydrogencompression from 10 to 200 bar)
Filling stations
On-board compressedhydrogen storage with IC engine
• Hydrogen use: 2.47 MJ/km• 4.47 kg storage capacity for 217 km range• Storage tank
o Weight ~220 kgo Water capacity @ 200 bar 180 liters
• 2 million kg H2 per day for 1 million vehicles (100 km daily travel)
Biomass gasification
Conclusions (Vehicles)
Renewable hydrogen based fuel chains viable based on GHG emission and non-renewable energy use criteriaCost (Rs/km) higher (for photovoltaics, electrolyzer and fuel-cell based system) than existing petrol based fuel chain.IC engine vehicles lower cost but higher energy consumption than fuel cell vehicles.Hydrogen fuel chain based on SMR process (with compressed hydrogen storage and IC engine) is economically viable. However this fuel chain has higher GHG emissions.
ConclusionsRenewable hydrogen based fuel chains viable based on GHG emission and non-renewable energy use criteriaCost (Rs/km) higher (for photovoltaics, electrolyzer and fuel-cell based system) than the existing petrol based fuel chain.IC engine vehicles have lower cost but higher energy consumption than the fuel cell vehicles.Hydrogen fuel chain based on SMR process (with compressed hydrogen storage and IC engine) is economically viable. However this fuel chain has higher GHG emissions.
B1)DIESEL ENGINE
ELECTRICITY
OIL MINING/REFINING
DIESEL ENGINE
GENERATOR
TRANSPORT OF DIESEL
η OM 95 %
η TD 97%
η DE 40 %
CRUDE OIL
η GEN 95 %
B2) GAS ENGINE
ELECTRICITY
EXTRACTION
GAS ENGINE
GENERATOR
NATURAL GAS TRANSPORT
η OM 95 %
η TD 97%
η DE 42 %
NATURAL GAS
η GEN 95 %
FUEL CELL (NG)NATURAL GAS
EXTRACTION
NATURAL GAS TRANSPORT
HYDROGEN
STEAM REFORMING
ELECTRICITY
PEM FUEL CELL
η R 95 %
η GT 97 %
η FC 40 % (50%)
POWER CONDITIONING
η REF 85 %
η PC 95 %
Distributed Generation
B1 Overall efficiency 35%0.246 kg of crude /kWh of electricity
B2 Overall efficiency 37%0.25 kg of Natural gas/kWh of
electricityFuel cell Overall efficiency 30% 0.307 kg
of Natural gas/kWh of electricity (37% like A2 FC eff 50%)
Carbon Emissions
B1 – Crude oil (86% Carbon) 0.211 kg Carbon/kWhB2- Natural gas (75% Carbon)0.187 kg Carbon/kWh
Fuel cell ( 18 kg of Carbon / 1 GJ of Hydrogen energy – SMR)
FC eff 0.4 - 0.171 kg Carbon/kWh0.5- 0.136 kg Carbon/kWh
Discount RateCompare investment today with expected future benefitsDiscount rate represents how money today is worth more than in the futureNo theoretically correct valueLower bound – bank interest rate
Annualised Life Cycle CostAnnualised Life Cycle Costs (ALCC) -annual cost of owning and operating equipmentALCC = C0 CRF(d,n) + AC f + AC O&M CRF (d,n) =[ d(1+d)n]/[(1+d)n-1]discount rate d, Life n years, C0 Capital Cost,AC f , AC O&M , annual cost - fuel and O&M CRF – Capital recovery factor
ReferencesP. L. Spath, M. K. Mann, Life Cycle Assessment of Renewable Hydrogen Production via Wind/Electrolyses, NREL / MP-560-35404, February 2004, Colorado, USDOE.Pehnt M, "Life-cycle assessment of fuel cell stacks," International Journal of Hydrogen Energy, vol. 26, pp. 91-101, 2001.Newson E, Haueter TH, Hottinger P, Von Roth F, Scherer GWH, and SchucanTH,International Journal of Hydrogen Energy, vol. 23, no. 10, pp. 905-909, 1998.Sarkar A and Banerjee R, "Net energy analysis of hydrogen storage options," International Journal of Hydrogen Energy, vol. 30, pp. 867-877, 2005.Sandrock G, "A panoramic overview of hydrogen storage alloys from a gas reaction point of view," Journal of Alloys and Compounds, no. 293-295, pp. 877-888, 1999.Syed MT, Sherif SA, Veziroglu TN, and Sheffield JW, "An economic analysis of three hydrogen liquefaction systems," International Journal of Hydrogen Energy, vol. 23, no. 7, pp. 565-576, 1998.Manish S and Rangan Banerjee, "Techno-economic assessment of fuel cell vehicles for India," 16th World hydrogen energy conference, Lyon (France), 2006.Amos WA, "Costs of storing and transporting hydrogen," National Renewable Energy Laboratory,NREL/TP-570-25106, 1998.J. R. Bolton, Solar Photoproduction of Hydrogen, Solar Energy, Vol 57, Wol, pp 37-50, 1996.R. Hammersehlag, P. Mazza, Questioning Hydrogen, Energy Policy, 33 (2005), pp 2039-2043. Thank you
Recommended