1 The Potential of Hydrogen in a Climate-Constrained Future Tom
Kreutz Princeton Environmental Institute Princeton University
Presented at the 2005 AAAS Annual Meeting, Symposium:
Sustainability - Energy for a Future without Carbon Emissions 19
February 2005, Washington, DC Slide 2 2 CMI Project Areas: - Carbon
capture (Kreutz, Larson, Socolow, Williams) - Carbon storage
(Celia, Scherer) - Carbon science (Pacala, Sarmiento, GFDL) -
Carbon policy (Bradford, Oppenheimer) -Integration (Socolow,
Pacala) Funding: 15.1$ from BP, 5 M$ from Ford The Carbon
Mitigation Initiative (CMI) at Princeton University, 2001-2010
Slide 3 3 Brief sketch of the hydrogen landscape Overview of our
work on production of low- carbon H 2 and electricity from fossil
fuels (primarily coal) A potential role for centralized H 2
production in an emerging H 2 economy Outline of Talk Slide 4 4
Drivers for the H 2 Economy H 2 is abundant and can be utilized
relatively and cleanly (via combustion, electrochemistry) Energy
security Air pollution Climate change Common clean chemical energy
carrier from: - renewables, - fossil fuels, - nuclear power, -
fusion, etc. Slide 5 5 Difficulties with the H 2 Economy Efficiency
losses during production Safety Cost: - distribution - storage (at
both large and small scales) - utilization - safety Storage Slide 6
6 H 2 Issues Zealotry Safety Straw men Poorly designed systems Pie
in the sky Different goals, time scales Response to climate change
Oil prices, politics of nuclear power Other ways to solve the
problems H 2 is a package deal Slide 7 7 The Case for Hydrogen -
Climate Change 1.Most of the century's fossil fuel carbon must be
captured. 2.About half of fossil carbon, today, is distributed to
small users buildings, vehicles, small factories. 3.The costs of
retrieval, once dispersed, will be prohibitive. 4.An all-electric
economy is unlikely. 5.An electricity-plus-hydrogen economy is
perhaps a more likely alternative. 6.Hydrogen from fossil fuels is
likely to be cheaper than hydrogen from renewable or nuclear energy
for a long time. Slide 8 8 Brief sketch of the hydrogen landscape
Overview of our work on production of carbon-free H 2 and
electricity from fossil fuels (primarily coal) A potential role for
centralized H 2 production in an emerging H 2 economy Outline of
Talk Slide 9 9 Motivation for Studying Coal (vs. Gas) Plentiful.
Resource ~ 500 years (vs. gas/oil: ~100 years). Inexpensive (low
volatility). 1-1.5 $/GJ HHV (vs. gas at 2.5+ $/GJ). Ubiquitous.
Wide geographic distribution (vs. middle east). Carbon intensive.
Potentially clean. Gasification, esp. with CCS, produces few
gaseous emissions and a chemically stable, vitreous ash. Ripe for
innovation. Globally significant. For example: China: extensive
coal resources; little oil and gas. Potential for huge emissions of
both criteria pollutants and greenhouse gases. Slide 10 10 Annual
U.S. Carbon Emissions (2002) Lets focus for a moment on the power
market... Slide 11 11 Process Modeling Heat and mass balances
(around each system component) calculated using: Aspen Plus
(commercial software), and GS (Gas-Steam, Politecnico di Milano)
Membrane reactor performance calculated via custom Fortran and
Matlab codes Component capital cost estimates taken from the
literature, esp. EPRI reports on IGCC Benchmarking/calibration:
Economics of IGCC with carbon capture studied by numerous groups
Used as a point of reference for performance and economics of our
system Many capital-intensive components are common between IGCC
electricity and H 2 production systems (both conventional and
membrane-based) Slide 12 12 Commercially Ready Coal IGCC with CO 2
Capture CO 2 venting: 390 MW e @ 1200 $/kW e, LHV = 43.0%, 4.6 /kWh
CCS: 362 MW e @ 1500 $/kW e, LHV = 34.9%, 6.2 /kWh Slide 13 13 An
example of such a plant... Slide 14 14 Our Reality... Slide 15 15
Economics of Coal IGCC with CO 2 Capture and Storage (CCS) Coal
IGCC+CCS becomes competitive with new coal plants at ~100 $/tC
Slide 16 16 Coal IGCC+CCS Coal IGCC + CCS is a hydrogen plant!
Slide 17 17 H 2 Production: Add H 2 Purification/Separation Replace
syngas expander with PSA and purge gas compressor. Reduce the size
of the gas turbine. Slide 18 18 H 2 Production from Coal with CCS
1070 MW th H 2 LHV (771 tonne/day) + 39 MW e electricity,
efficiency LHV =60.9%, H 2 cost=1.04 $/kg Slide 19 19 Disaggregated
Cost of H 2 from Coal with CCS Typical cost is ~1 $/kg (note: 1 kg
H 2 ~ 1 gallon gasoline) Slide 20 20 The carbon tax needed to
induce CCS in H 2 production from coal is significantly lower than
that for electric power Economics of H 2 from Coal with Carbon
Storage Slide 21 21 H 2 Production from Coal with CCS Incremental
cost for CO 2 capture is less for hydrogen than electricity because
much of the equipment is already needed for a H 2 plant. Slide 22
22 Where Might that H 2 be Used? Displacing traditional H 2 from NG
(1% of global primary energy). At 200 $/tonne C, H 2 for industrial
boilers, furnaces, and kilns becomes competitive with gas at 4
$/GJ. Slide 23 23 System Parameter Variations System Performance:
-gasifier/system pressure -syngas cooling via quench vs. syngas
coolers - hydrogen recovery factor (HRF) -hydrogen purity -sulfur
capture vs. sulfur + CO 2 co-sequestration - membrane reactor
configuration - membrane reactor operating temperature - hydrogen
backpressure - raffinate turbine technology (blade cooling vs.
uncooled) System Economics (Sensitivity Analysis): -membrane
reactor cost (and type) -co-product electricity value, capacity
factor, capital charge rate, fuel cost, CO 2 storage cost, etc.
Slide 24 24 Membrane System Results Summary No matter how hard we
work, the cost of coal-based H 2 with CCS is ~1 $/kg! Slide 25 25
Hydrogen in the Transportation Sector Slide 26 26 Production Cost
of H 2 (Scale=1 GW th HHV) Slide 27 27 Add CO 2 Transport and
Geologic Storage... Slide 28 28 Add H 2 Storage and Distribution
Pipelines... Slide 29 29 Add H 2 Refueling Stations... Slide 30 30
Add the Incremental Vehicle Cost... Switching to H 2 as a
transportation fuel is expensive! The cost of H 2 production is
only a small piece of the whole. Slide 31 31 Brief sketch of the
hydrogen landscape Overview of our work on production of low-
carbon H 2 and electricity from fossil fuels Is there a role for
centralized H 2 production in an emerging H 2 economy? Outline of
Talk Slide 32 32 Slide 33 33 H 2 DEMAND DENSITY (kg/d/km 2 ): YEAR
1: 25% OF NEW Light Duty Vehicles = H 2 FCVs Blue shows good
locations for refueling station Slide 34 34 H 2 DEMAND DENSITY
(kg/d/km 2 ): YEAR 5: 25% OF NEW LDVs = H 2 fueled Slide 35 35 H 2
DEMAND DENSITY (kg/d/km 2 ): YEAR 10: 25% OF NEW LDVs = H 2 fueled
Slide 36 36 H 2 DEMAND DENSITY (kg/d/km 2 ): YEAR 15: 25% OF NEW
LDVs = H 2 fueled Slide 37 37 What is this Curve? Time Consumption
Slide 38 38 The Elephant-in-the-Snake Problem Le Petit Prince,
Antoine de Saint Exupry or How does Ohio swallow a 1 GW th H 2
plant? Slide 39 39 2004 NRC Report: The Hydrogen Economy:
Opportunities, Costs, Barriers, and R&D Needs Among the major
messages of the report: -The (50 year) transition to a hydrogen
fuel system will be best accomplished through distributed
production of hydrogen, because distributed generation avoids many
of the substantial infrastructure barriers faced by centralized
generation. (pp. 117) -It seems likely that, in the next 10 to 30
years, hydrogen produced in a distributed rather than centralized
facilities will dominate. (pp. 120) Slide 40 40 2004 NRC Report:
Consensus Slides Distributed production of hydrogen by SMR is
likely transition strategy Potential role for natural gas
conversion to supply hydrogen both in transition (small,
distributed) and long term (large, centralized generators) Focus
DOE program on development of mass-produced hydrogen appliances for
fueling stations (SMR and POX/ATR) Downsize effort on centralized
generation Slide 41 41 Likelihood of a H 2 Economy Primary drivers
for a U.S. H 2 economy: 1) secure energy supply, 2) improved air
quality, 3) reduced greenhouse gas emissions. H 2 via distributed
SMR provides only one of these (#2). Will a H 2 economy emerge in
this scenario? H 2 from coal IGCC+CCS satisfies all three drivers.
Yes, large scale, dedicated H 2 plants from coal with CCS are
economically problematic in the transition. However, slipstream H 2
from coal IGCC+CCS is not. Slide 42 42 Coal IGCC+CCS Coal IGCC +
CCS is a hydrogen plant! Slide 43 43 Slipstream Hydrogen System
Design H 2 production piggybacks off of coal IGCC+CCS: - H 2 is
economical (marginal production cost ~0.8 $/kg) and has a stable
price relative to natural gas-based H 2. -H 2 flow rate is flexible
(only PSA, compression and storage change to match increasing
demand). Assume medium-sized refueling stations (1 tonne/day H 2 )
for commercial/government fleet vehicles -Begin with a handful of
plants, and increase to many over time. Slide 44 44 An Alternative
Scenario The U.S. gets serious about climate change in the next
quarter century (before fusion, large-scale renewables). The cost
of CO 2 emissions becomes high enough to force significant
reductions in the power sector (~100 $/tC). CCS is shown to be a
safe and economical strategy. All new coal power plants are
IGCC+CCS, built near demand centers (cities). Arbitrary quantities
of low-carbon H 2 is available to those demand centers for industry
and transportation. The H 2 economy builds from this base. Slide 45
45 Scenarios Investigated Temporal: early fleet phase through
commuter phase Geographic: two limiting cases (Ohio case study): -
city gate plant Cincinnati, 24 driving miles -distant plant
Columbus, 106 driving miles (91 rural) Slide 46 46 -Slipstream H 2
from coal IGCC+CCS is competitive with distributed SMR. Preliminary
Results Slide 47 47 Preliminary Results - At low demand (< 20-50
tonne/day), trucked H 2 from CGCC+CCS is lowest cost option;
pipelines thereafter. Slide 48 48 NRC Report Results Our work
agrees with theirs. Slide 49 49 Preliminary Results Dont upsize the
gasification train! Displace or replace power instead. Slide 50 50
Year 2000-2003 data:CincinnatiColumbusOhio Population (million
people)2.01.611.4 Light Duty Vehicles (million)1.61.38.9 LDV
gasoline (10^6 gal/day, at 20.1 mpg)2.52.014 LDV H 2 use
(tonne/day, at 60 mpge)8286644675 LDV H 2 requirement (MW th HHV H
2 )135810907673 HPQ plants needed for all H 2 116 Electric capacity
(GW e )6.65.332.3 EPQ / (total electric demand)6%7%1% EPQ plants
needed for all power181589 (Coal for H 2 ) / (coal for
electricity)10% 11% H 2 from EPQ+X% (tonne/day H 2 )48 55 Fraction
of total H 2 from "extra" coal (i.e. HHV = 33.9% 37.7%) 48%
Electricity and H 2 Plants with CCSEPQHPQ Coal input (MW th,
HHV)10361962 Power output (MW e )36239 H 2 output (tonne/day)-771
Efficiency (%, HHV)34.9%68.4% Product cost (/kWh, $/kg H 2 )6.21.0
How does this play out in Ohio? Slide 51 51 Slipstream H 2 Upshot
Slipstream H 2 with compressed H 2 truck delivery is an economical
(~2 $/kg, delivered), flexible source of low- carbon H 2 from
indigenous coal. This H 2 can be used by fleets of (and commuters
with) H 2 ICVs (and later, FCEVs). It requires nearby IGCC+CCS, and
associated high carbon prices. Since the former is an oft-cited
outcome of a serious climate management regime, a H 2 economy for
transportation seems to me much more likely than before because it
aggressively addresses climate change.
