Download Document

Carbon-Negative Energy Systems
Daniel L. Sanchez
Postdoctoral Research Scientist
Carnegie Institution for Science
Department of Global Ecology
Stanford, CA
FCEA/CSTMS/ASU Carbon Dioxide Removal Workshop
February 8, 2017
BECCS provides important flexibility for stringent
climate change mitigation, even with limited
biomass resources
Increased research, development, and
demonstration of BECCS is necessary
CCS improves outcomes for bioenergy in lifecycle
assessment
2
We can leverage near-term opportunities for BECCS
to reach commercial deployment
Bioenergy with Carbon Capture and Sequestration
(BECCS)
Biomass
(fixes CO2
from
atmosphere)
Energy
conversion
process with
carbon
capture
CO2 for
compression
and
sequestration
3
Carbon-negative
energy products
1) Biomass harvesting
4
2) Biomass capture & conversion
3) Energy products
Canadell and Schulze (2014)
Value of deployment: Western North America
• Use high-resolution
power sector planning
model
– SWITCH
– High temporal and spatial
detail
• Constrain to sustainable
biomass supply
• Understand co-evolution
of BECCS with other lowcarbon supply options
5
Representation of limited biomass availability
6
Sanchez et al., Nature Climate Change (2015)
7
Sanchez et al. (2015)
8
Sanchez et al. (2015)
RD&D needs
R&D
• Large-scale biomass logistics
• Gasification (high-temperature, oxygen- or
steam-blown, pressurized, entrained flow
gasification)
• Systems integration
• Gas cleaning
Deployment
• Delivery of identified, accessible, and permitted
large-scale CO2 storage
• Particular challenge in regions without a
developed hydrocarbon exploration and
production industry
9
Fragmentation, funding, R&D policy
Fossil Energy
• CCS
demonstration
• CO2 utilization
• Clean coal
Not
• Standalone
biomass
gasification
BECCS
BETO
• Feedstock
logistics
• Conversion
processes
• Biorefinery
demonstration
Not
• Fossil coconversion
• CCS
DOE deployment programs should take the form of a crosscutting initiative
10
11
Sanchez et al. (Under Review)
Lifecycle assessment: benefits of biomass
integration
12
Sanchez and Kammen, Nature Energy (2016)
The “best” use of land for climate mitigation
Capturing CO2 from bioenergy processes enhances CO2 mitigation potential
13
Evans et al. (2015)
Near-term deployment of ethanol+CCS
Capture costs: ~$20/tCO2 from fermentation
First markets: CA’s Low Carbon Fuel Standard ~$75/ton abated
Carbon Capture Utilization and Storage Act $50/ton stored
14
World’s first BECCS facility - Decatur, IL
15
Options to decrease carbon intensity of products
1 - Increase ratio of biomass / coal inputs
(a)
Sulfur
Coal
Air
O2
CO2
Recycle
2
Steam
Air
Separation
Unit
2 - Increase shift of syngas in WGS reactor
3
Water-Gas
Shift
(WGS)
Gasification
3 - Recycle CO 2 from sulfur removal to AGR
Sulfur
Removal
R
Electricity
Integrated
Gasification
Combined
Cycle
(IGCC)
Acid Gas
Removal
(AGR)
H2 O
CO + H 2 O -> CO 2 + H 2
N2
Biomass
1
(b)
2
Coal
Gasfication
Sulfur
Fuels
(Gasoline,
asoline, Diesel)
Dies
2
2
Acid Gas
Removal
(AGR)
Tropsch
Synthesis
Tropsch
Refining
Combined
Cycle
Power
Island
Flexibility to balance product cost and carbon reduction goals
Recycle
Steam
team
Biomass
Gasification
G
Tar Cracking
and Filtering
1
16
Options to decrease carbon intensity of products
1 - Increase ratio of biomass / coal inputs
2 - Recycle CO 2 from sulfur removal to AGR
3 - Autothermal reforming + shift prior to
electricity production
S
Sulfur
Thermochemical conversion
enables products with wide range
Removal
+ H O -> CO intensities,
+H
ofCOcarbon
process efficiencies
and
process scales
FischerFischerBypass
O2
CO2
Recycle
Water-Gas
Shift
(WGS)
2
Air
Separation
Unit
CO2 (for compression and
sequestration)
Bypass
CO2 (for
for c
compression
omp res
and
sequestration)
sequestratio
Electricity
Elect
3
Autothermal
Reformer
Water-Gas
Shift
CO
O2
Removal
Sanchez and Kammen, Nature Energy (2016)
BECCS provides important flexibility for stringent
climate change mitigation, even with limited
biomass resources
Increased research, development, and
demonstration of BECCS is necessary
CCS improves outcomes for bioenergy in lifecycle
assessment
17
We can leverage near-term opportunities for BECCS
to reach commercial deployment
Appendix
18
“Negative-emission technologies are not an insurance policy, but
rather an unjust and high-stakes gamble.”
-Anderson and Peters (2016)
The necessity of negative emissions to meet
emissions reductions goals provide strong
motivation for increased research, development,
and demonstration of these technologies.
19
~3 PgC/yr [GtC/yr]=
30% of current (2014) global emissions
Three “stabilization wedges”
Cumulative capital investment through 2050: over $1.9 trillion
Deployment: 24 GW/yr of BECCS by 2040
20
21
Anderson and Peters, Science (2016)
D.L. Sanchez, D.S. Callaway. “Optimal Scale of
Bioenergy with Carbon Capture and Storage (BECCS)
Facilities” Applied Energy, 170, 437-444 (2016)
D.L. Sanchez, et al. “Biomass
enables the transition to a carbonnegative power system across
western North America.” Nature
Climate Change, 5, 230–234
(2015)
22
D.L. Sanchez, D.M.
Kammen. “A
commercialization strategy
for carbon-negative energy”
Nature Energy, 1, 1-4
(2016)
Why study deployment?
• Existing analyses have relatively
simple representation of the
energy economy
• Goals:
– Inform near-term efforts to
build facilities
– Integrate into existing energy
systems
– Respect regional considerations
– Complement existing energy
and climate policy
23
Scenario analysis
• Technology availability and environmental policy (carbon cap)
86%
 BECCS
 No biomass
 No biomass, no
CCS
105%
120%
145%
24
Sanchez et al. (2015)
Unit Commitment
/ Dispatch
Time Frame
• Short-term (sub hourly to
one year)
• Long-term (year to decades)
Free
Variables
Operational
Constraints
Typical
output
•
•
•
•
•
• How much generation and
transmission to install
• Planning regulations
• Environmental policy
• Annual generation, generation
and transmission capacity
builds/retirements, emissions,
electricity prices,
credit/allowance prices
• (Mixed integer) linear program
Which units to use
How much to produce
Plant ramping / operation
Power flow
Sub-hourly unit level
generation, powerflow,
locational marginal prices,
emissions, ancillary service
prices, curtailments
Typical
• Mixed integer non-linear
Formulation
program
25
Capacity
Expansion
SWITCH model
• SWITCH- a loose acronym for Solar, Wind, Hydro, and Conventional
generation and Transmission Investment
• Dispatch solved simultaneously with investment decisions (generation and
transmission)
• Objective: minimize net present cost of meeting demand in all simulated
hours in all investment periods
• Subject to: carbon and renewable policy constraints, linearized operational
constraints, simplified transmission constraints
• Typically run from present-day through 2050
26
Role of flexibility in power systems dispatch
27
27
Sanchez et al. (2015)
Technology roadmaps
• Climate change mitigation requires gigawatt-scale carbon dioxide removal
technologies, yet few examples exist beyond niche markets
• Goal: Propose commercialization strategy for carbon-negative energy
• Framing: Thermochemical conversion of hydrocarbons to electricity and/or
fuels
• Catalog needs and interventions to support emerging near-zero emissions
technologies
– research & development, demonstration, finance, policy, and social engagement
28
Sanchez and Kammen, Nature Energy (2016)
Conclusions about deployment
• BECCS, combined with aggressive renewable deployment and fossil-fuel
emission reductions, can enable a carbon-negative power system in
western North America by 2050 with up to 145% emissions reduction from
1990 levels
• In most scenarios, the offsets produced by BECCS are found to be more
valuable to the power system than the electricity it provides
• This suggests a different climate change mitigation pathway than others
have proposed
29
30
Courtesy of Scott McDonald, ADM
31
Courtesy of Scott McDonald, ADM
BECCS deployment can be cost-effective
Process simulation
Techno-economic analysis +
scaling
Pipeline routing and
optimization
Estimate of abatement cost
and potential
Lifecycle analysis of corn
ethanol + CCS
Comparison to existing and
potential subsidies
Compare to:
• CA’s Low Carbon Fuel Standard [Executive Order S-1-07]
~$75/ton
• Carbon Capture Utilization and Storage Act [S.3179]
~$50/ton
32
Works cited
D.L. Sanchez, D.M. Kammen. “A commercialization strategy for carbon-negative energy”
Nature Energy, 1, 1-4 (2016).
D.L. Sanchez, J.H. Nelson, J. Johnston, A. Mileva, D. Kammen. “Biomass enables the transition
to a carbon-negative power system across western North America.” Nature Climate Change, 5,
230–234 (2015).
D.L. Sanchez, D.S. Callaway. “Optimal scale of carbon-negative energy facilities.” Applied Energy,
170, 437–444 (2016).
D.L. Sanchez, D.M. Kammen. “Removing harmful greenhouse gases from the air using energy
from plants.” Frontiers for Young Minds, 3:14, doi: 10.3389/frym.2015.00014.
D.L. Sanchez, J.H. Nelson, J. Johnston, A. Mileva, D. Kammen. “Emissions accounting for
bioenergy with CCS.” Nature Climate Change, 5, 495–496 (2015).
33
Flexibility and scale
• Thermochemical conversion 
products with wide range of
carbon intensities, process
efficiencies and process scales
• Flexibility to balance product cost
and carbon reduction goals
• Co-utilization  increase
efficiency, decrease unit costs,
lessen feedstock variability, extend
impact of scarce biomass
• Smaller systems  smaller
minimum capital expenditures,
greater experimentation
34
Fossil
Fuels
Biomass
Low-carbon
& carbonnegative
products
An agenda for transition
• Cumulative capital investment through 2050 >$1.9 trillion (2015$, 4% real)
• Deployment of up to 24 GW/yr of BECCS by 2040
• To achieve this within 15-20 years, governments and firms must commit to
RD&D on an unprecedented scale
• Likely to work best in developed economies
“This strategy holds advantage for existing industries, supply
chains, and workforces. Here, firms can embrace a gradual
transition pathway to deep decarbonization, limiting economic
dislocation and increasing transfer of knowledge between the
fossil and renewable sectors.”
35
Sanchez and Kammen (2016)