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Utilization of Gaseous Carbon Waste Streams
NAS, NAE, NAM Board on Chemical Sciences and TechnologyUtilization of Gaseous Carbon Waste Streams Webinar III
28 March 2018
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Baseline scenarios of CO2 emissions per year out to 2100. All 2° C scenarios require net negative CO2 emissions by ~ 2080.
ExxonMobil Outlook for Energy 2018: A view to 2040
Gig
aton
nes
emitt
ed C
O2/y
ear A more probable scenarios
cumulative emissions ~ 5000 GtCO2 by 2100
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IPCC Climate Change 2014 Synthesis Report
😢😢Likely scenarios have carbon emission
continuing well past 2100
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Crops capture 30 GtCO2 /year. Pasture: 48 GtCO2Total Global human emissions in 2015 =32 GtCO2
Source: The Methanol Economy, Alain Goeppert, Miklos Czaun, John-Paul Jones, Surya Prakash, George Olah Chem Soc Rev., DOI: 10.1039/c4cs00122b (2014)
• Reforestation
• Conversion of agricultural residues to chemicals, fuels and other useful products
• Capture and sequestration of excess CO2
• If we are to continue to use natural gas (CH4), we have to convert it to H2 and CO2 and sequester CO2.
Global greenhouse gas emissions by sector for 2005
Global CO2 emissions from cement production
Source: R.M. Andrew, Earth Syst. Sci. Data, 10, 195–217, 2018 https://doi.org/10.5194/essd-10-195-2018
CO2 cement emissions from
China 1980–2016
CO2 cement emissions from India, USA, Turkey,
Vietnam
Source: R.M. Andrew, Earth Syst. Sci. Data, 10, 195–217, 2018 https://doi.org/10.5194/essd-10-195-2018
SEAB Task Force Report on CO2 Utilization and Negative emissions Technologies
https://energy.gov/sites/prod/files/2016/12/f34/SEAB-CO2-TaskForce-FINAL-with%20transmittal%20ltr.pdf
The largest emitters of CO2 (in 2005)
1. Transportation fuels (15% of CO2 emissions)
2. Cement (5%)
3. Chemicals & plastics (4.1%)
4. Iron and steel (4%)
The utilization of captured carbon should focus on the major uses of carbon
“Sky” Scenario of how to transition to net zero emissions by 2070 and negative
carbon emissions by 2100
Source: https://www.shell.com/energy-and-innovation/the-energy-future/scenarios/shell-scenario-sky.html
Paris Agreement: Limit global average temperature to well below 2°C above pre-industrial levels; Pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels.
SHELL “Sky Scenario” to meet the Goals of the Paris Agreement (2018)
Source “Sky SHELL Scenarios Meeting the Goals of the Paris (2018)”
In Sky, passenger electric vehicles reach cost parity with combustion engine cars by 2025. By 2035, 100% of new car sales are electric in the
EU, US, and China, with other countries and regions close behind.
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100% renewable energy will require recycling combustion products
Electrochemical
Biochemical
Thermochemical
Photochemical
CO2
H2O
Liquid hydro-carbonH2, CO
H2 , O2
A challenge for the 21st Century
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How much does it cost to ship and store oil any where in the world?
2 ₵ /gallon of gasoline.
Oil tankers are transcontinental energy “transmission lines”
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Unsubsidized cost of tenewable energy costs (L.C.O.E.) at an increasing number of sites
around the world are < 3 ¢/kWh.
Costs at the best sites are expected to be~ 2 ¢/kWh by 2030
17Source: https://www.lazard.com/perspective/levelized-cost-of-energy-2017/
L.C.O.E of nuclear, coal, gas-combined cycle, utility scale solar and wind energy
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UK National Grid Electricity Costs
Onshore wind
Offshore wind
Natural gas
Wholesale price
2017 bid: £58 / MWh
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Clean electricity at 2 – 3 ¢/kWh opens up exciting opportunities
in electrochemistry
Large scale commercial electrochemical production of H2, O2 and CO may become a reality
Thermodynamics & Cost LimitsH20 = H2 + ½ O2 ; ΔG = 237.2 kJ/mol = 32.4 kWh/kg-
H2
$/kg-H2
Carbon-free Energy Cost ($/MWh)
Thermodynamic limit
• Artificial Alveolus for Efficient electrochemistry,• Artificial Alveolus for Highly Efficient Oxygen Reduction and Evolution
Jun Li … Steven Chu and Yi Cui (submitted)
Jun LiYi Cui
(HER) Reduction at cathode: 4 H+(aq) + 4e− → 2 H2(g)
(OER) Oxidation at anode: 2 H2O(l) → O2(g) + 4 H+(aq) + 4e−
2 H2O(l) → O2(g) + 2 H2(g)
Electrolysis of water
catalyst
hydrophobic polyethylene
- 1 atm
Hydrogen evolution reaction
The membrane (alveolus) structure shows 5x higher than the same catalyst using a solid electrode.
Comparison of catalyst performance on a alv-PE membrane with a flat membrane
Oxygen evolution reaction
Catalyst on metal electrode
alv-structure
Cathode: 4 H+(aq) + 4e− → 2 H2(g)
Anode: 2H2O(l) → O2(g) + 4 H+(aq) + 4e−
O2 H2
H2O in
O2
H2
O2
H2
10s of meter
s
Spacing~100 μm ?
A major cost barrier of electrochemical production is the physical size of the chemical plants. Separators keep OER and HER
electrodes from touching. The small gaps begin to approximate 3-D electrolysis
CO2 reduction
Equilibrium potential of -0.11 V (vs RHE) for CO2/CO• Lowest onset potentials of -0.27 V vs. RHE (160 mV overpotential for
CO2/CO). Peak FECO value of ~ 92% at -0.6 V vs. RHE
Conversion rate has to be increases by at least 10x and energy efficiency at higher current decreases due to resistive losses.
Ionic Liquid–Mediated Selective Conversion of CO2 to CO at Low Overpotentials, Richard Masel, et al. ,Science 334, 643 -644 (2011) DOI: 10.1126/science.1209786
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The Methanol EconomyAlain Goeppert, Miklos Czaun, John-Paul Jones, Surya Prakash, George Olah
Chem Soc Rev., DOI: 10.1039/c4cs00122b (2014)
H2 from electrolysis of water or the gasification of biomass plus CO2 to be used to produce methanol or DME.
• Brazilian sugarcane ethanol• Biomass Pyrolysis for Advanced
Biofuels• Cellulosic Biofuels• Synthetic Biology Production
from CO2• Lipid-Based Biodiesels
• Electro-fuels
• Biochar Carbon Sequestration
Is it possible to use engineered microbes to convert hydrogen and CO2 into ethanol, butanol of
other fuels?
If H2 is used as a feedstock, then low cost clean energy-based electrolysis avoids the “catch-radius” problems of cellulosic-based bio-fuels since clean
electricity can be easily transported over long distances
One potential new version of an electro-fuel
The utilization of captured carbon for cement materials is another application. The application of carbon-fiber based materials to date is
limited to high-strength/weight demands such as airplanes. The use of wood as a structural material is a form of CO2 capture and
sequestration.
“Processing bulk natural wood into a high-performance structural material”, Jianwei Song, et al. Nature 554, 254 (2018)
Processing bulk natural wood into a high-performance structural material, Jianwei Song, et al. Nature 554, 254 (2018)
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