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Sustainable Fossil Fuels?

Sustainable Fossil Fuels?. Klaus S. Lackner Columbia University April 2004. World Needs Low Cost Energy. Fossil Energy contributes 80 to 90% of the total World Energy. Cannot eliminate the biggest resource from the world market.

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Sustainable Fossil Fuels?

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  1. Sustainable Fossil Fuels? Klaus S. Lackner Columbia University April 2004

  2. World Needs Low Cost Energy Fossil Energy contributes 80 to 90% of the total World Energy Cannot eliminate the biggest resource from the world market 10 billion people trying to consume energy as US citizens do today would raise world energy demand 10 fold

  3. Fossil Fuels VitalFor World Economy … but this does not make them sustainable

  4. 350 300 250 200 150 -400000 -300000 -200000 -100000 0 Fossil Carbon Accumulates in the Air CO2 increase in the atmosphere accounts for 58% of all fossil CO2 emissions Changes in the industrial age are large on a geological scale +4 Industrial age CO2 increase +2 0 Temperature Changes (ºC) -2 CO2 (ppmV) -4 -6 -8 Anthropogenic increase of carbon dioxide is well documented for 20th century. -10 Age (years) Petit et al., Nature 399 Vostok, AntarcticaIce Core data

  5. 8,000 Gt 7,000 Gt 6,000 Gt 5,000 Gt 4,000 Gt 3,000 Gt 4 2,000 Gt 3 2 1,000 Gt 0 Gt 20th Century 20th Century 50,000 Gt ??? Oil, Gas, Tars & Shales Carbon Sources and Sinks       Coal Methane Hydrates 21st Century’s Emissions ??? Scales of Potential Carbon Sinks Soil & Detritus Ocean Atmo-sphere Plants pH < 0.3 2000 1800 constant 39,000 Gt Carbon Resources

  6. Methane Hydrates 10,000 - 100,000 GtC World Fossil Resource Estimate 8000 GtC 5 1, 2, 3, 4 or 5 times current rate of emission???? 21st century emissions 4 3 2 1 The Mismatch in Carbon Sources and Sinks 1800 - 2000 Fossil Carbon Consumption to date 50% increase in biomass 180ppm increase in the air 30% of the Ocean acidified 30% increase in Soil Carbon

  7. Hydrogen economy cannot run on electricity There are no hydrogen wells Tar, coal, shale and biomass could support a hydrogen economy. Wind, photovoltaics and nuclear energy cannot.

  8. Net Zero Carbon Economy CO2 extraction from air CO2 from concentrated sources electricity or hydrogen Permanent & safe disposal Mineral carbonate disposal Capture of distributed emissions

  9. Sustainability A technology or process is sustainable at a specific scale and for a specific time, if no intended or unintended consequences will force a premature abandonment

  10. Private Sector Carbon Extraction Farming, Manufacturing, Service, etc. Carbon Sequestration Public Institutions and Government guidance Carbon Board certification Permits & Credits Certified Carbon Accounting certificates

  11. Net Zero Carbon Economy CO2 extraction from air CO2 from concentrated sources Permanent & safe disposal

  12. Lake Michigan 21st century carbon dioxide emissions could exceed the mass of water in Lake Michigan

  13. Short Term Answers • Enhanced Oil Recovery • Coal Bed Methane Extraction • Injection into abandoned wells • Injection into deep saline reservoirs Ultimately carbonic acid must be neutralized

  14. Slow Leak (0.1%/yr) 5 Gt/yr for 1000 years Storage 5000 Gt of C 200 years at 4 times current rates of emission Current Emissions: 6Gt/year Constraints on Disposal Methods • Safe Disposal • Minimum Environmental Impact • No Legacy for Future Generations • Permanent and Complete Solution • Economic Viability Economically tolerable: 1 cent/kWh $20/t of CO2 Nuclear Energy Limit: $60/t of CO2 $10/ton of CO2:  8.5¢/gallon Fast leaks are catastrophic (Lake Nyos) Slow leaks cause greenhouse emissions Dilution causes irrevocable change

  15. Energy States of Carbon The ground state of carbon is a mineral carbonate Carbon 400 kJ/mole Carbon Dioxide 60...180 kJ/mole Carbonate

  16. Net Carbonation Reaction for Serpentine Mg3Si2O5(OH)4 + 3CO2(g)  3MgCO3 + 2SiO2 +2H2O(l) heat/mol CO2 = -63.6 kJ Accelerated from 100,000 years to 30 minutes

  17. Magnesium resources that far exceed world fossil fuel supplies

  18. Rockville Quarry

  19. ZECA Process 1 GW Electricity Coal Strip Mine Zero Emission Coal Power Plant 70% Efficiency Coal CO2 4.3 kt/day Mineral Carbonation Plant Earth Moving ~40 kt/day 28 kt/day 36% MgO 11 ktons/day Heat Open Pit Serpentine Mine Sand & Magnesite ~1.4 kt/day Fe ~0.2 kt/day Ni, Cr, Mn ~35 kt/day Mining, crushing & grinding: $7/t CO2 — Processing: $10/t CO2 — No credit for byproducts

  20. Serpentine and Olivineare decomposed by acids • Carbonic Acid - Requires Pretreatment • Chromic Acid • Sulfuric Acid, Bisulfates • Oxalic Acid • Citric Acid • …

  21. ALBANY’S SUCCESS W.K. O’Conner, D.C. Dahlin, D. N. Nilsen, R. P. Walters & P.C. Turner Albany Research Center, Albany OR Mg3Si2O5(OH)4+3CO2(g)  3MgCO3+2SiO2+2H2O(l) 200,000 years reduced to 30 minutes Suggests simple cost-effective implementation

  22. Acid Recovery: Solvay Process • Neutralize with ammonia • Recover through heating

  23. Net Zero Carbon Economy CO2 from concentrated sources CO2 extraction from air Permanent & safe disposal

  24. CO2 N2 H2O SOx, NOx and other Pollutants  Zero Emission Principle Air Need better sources of oxygen Power Plant Carbon Solid Waste

  25. Compare to C + O2 CO2 + 393.5 kJ CaO as an enthalpy carrier CaO + C + 2H2O  2H2 + CaCO3 + 0.6 kJ O2 + 2H2 2H2O + 571.7 kJ 178.8 kJ CaCO3 + heat CaO + CO2 392.9 kJ Output

  26. CaO + C + 2H2O  CaCO3 + 2H2 De-carbonizer Gasifier Calciner Heat Lime/Limestone Cycle Closed Cycle for Gas Zero Emission Coal CO2 H2O Air H2O H2O H2O Cleanup H2O Gas Cleanup CH4, H2O CaCO3 CO2 Fuel Cell Coal Slurry CO2 H2 CaO Polishing Step Ash N2 H2 H2

  27. Net Zero Carbon Economy CO2 extraction from air CO2 from concentrated sources Permanent & safe disposal

  28. Air Flow CO2 diffusion Ca(OH)2 as an absorbent Ca(OH)2 solution CaCO3 precipitate CO2 mass transfer is limited by diffusion in air boundary layer

  29. 1 m3of Air 40 moles of gas, 1.16 kg wind speed 6 m/s 0.015 moles of CO2 produced by 10,000 J of gasoline Air CO2 Volumes are drawn to scale

  30. How much wind?(6m/sec) Wind area that carries 10 kW 0.2 m 2 for CO2 80 m 2 for Wind Energy Wind area that carries 22 tons of CO2 per year

  31. Wind Energy v = 6m/s 130 W/m2 Sunshine 200 W/m2 Biomass 3 W/m2 Extraction from Air Power Equivalent from gasoline v = 6 m/s 60,000 W/m2 Areas are drawn to scale

  32. 60m by 50m 3kg of CO2 per second 90,000 tons per year 4,000 people or 15,000 cars Would feed EOR for 800 barrels a day. 250,000 units for worldwide CO2 emissions

  33. Boundary Layer

  34. Wind Energy - CO2Collection • Wind Energy • Convection tower, Wind Mill etc. • Extract kinetic energy • Wind Turbines • 30% extraction efficiency • Throughput • 130W/m2 @ 6m/s wind • Cost • $0.05/kWh • CO2 Collection • Convection tower, absorbing “leaves”, etc. • Extract CO2 • Sorbent Filters • 30% extraction efficiency • Throughput • 0.64g/(s·m2) @ 6m/s wind • Cost by analogy • $0.50/ton of CO2 Additional Cost in Sorbent Recovery

  35. Ion exchanger: Na2CO3 + Ca(OH)2 2Na(OH) + CaCO3 A First Attempt Calciner: CaCO3CaO+CO2 Air contactor: 2Na(OH) + CO2 Na2 CO3

  36. Objections • CO2 in air is too dilute • Cross section of structure is affordable • Binding energy of sorbent scales logarithmically • G = RT log P/P0 • Liquid absorbers will saturate • Energy consumption diverges • Cost of sorbent recovery • CaCO3+ 180 kJ CaO + CO2 • CaO + H2O  Ca(OH)2 + 65 kJ

  37. 115m 15 km3/day of air 15 km3/day of air Cross section 10,000 m2 air fall velocity ~15m/s Water sprayed into the air at the top of the tower cools the air and generates a downdraft. 300m As electricity producer the tower generates 3-4MWe 9,500t of CO2 pass through the tower daily. Half of it could be collected

  38. Cooling Tower Design Diameter ratio of smoke stack to capture tower is 3001/2 =17 Any design that moves air can be used for CO2capture

  39. Exotic Designs

  40. Process Schematic Hydroxylation Reactor Ca(OH)2 CaO (4) CO2 H2O NaOH Fluidized Bed (1) H2O (2) CaCO3 (3) Na2CO3 CaCO3 (6) CH4 Solid Oxide Membrane Limestone Precipitate Dryer O2 Trona Process Capture Device (5) Air (O2, N2) Oxygen Depleted Air Combined Combustion- Separation Source: Frank Zeman

  41. Net Zero Carbon Economy CO2 extraction from air CO2 from concentrated sources electricity or hydrogen Permanent & safe disposal Mineral carbonate disposal Capture of distributed emissions

  42. CO2 CO2 H2 H2 CH2 Materially Closed Energy Cycles O2 O2 Energy Source Energy Consumer H2O H2O

  43. Sustainable on indefinite time scales

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