Restoring the Carbon Balance: Direct Air Capture and Recycling CO 2. ELLEN B STECHEL Arizona State University CO-DIRECTOR, ASU-LightWorks*

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1 Restoring the Carbon Balance: Direct Air Capture and Recycling CO 2 Date: Wednesday, 8 Feb 2017 Venue: SHATTUCK PLAZA HOTEL, Berkeley, CA ELLEN B STECHEL Arizona State University CO-DIRECTOR, ASU-LightWorks* *ASU campus wide initiative on light inspired research for energy and sustainability, impact and scale 1

2 Managing a waste product rather than a pollutant REDUCE, REUSE, RECYCLE, DISPOSE WHAT S LEFT AS LAST RESORT THINKING DIFFERENTLY ABOUT CO 2 CARBON NEUTRAL LIQUID HYDROCARBONS FROM RECYCLED CO 2 Energy Input (Reduction) REVERSING COMBUSTION ENDOTHERMIC ENERGY FROM SOLAR CARBON NEGATIVE STOCK MATERIALS GET CARBON INTO THE INFRASTRUCTURE CO 2 H 2 O Fuel O 2 CAPTURE & DISPOSE CO 2 PURE LIABILITY AND NO PRODUCT VALUE Energy Recovery (Oxidation) 2

3 CONCENTRATION OR CUMULATIVE EMISSIONS? Concentration 400 ppmv Total ~3100 Gt-CO 2 Preindustrial was ~2200 Gt-CO ppmv is ~3500 Gt-CO 2 We can mine the atmosphere for this resource Temperature change relative to ( C) Cumulative anthropogenic CO 2 emissions since 1870 (GtCO 2 ) 3

4 2040 ± 310 GtCO ± 35 GtCO 2 increase in atmospheric content SOURCES EXCEED SINKS Anthropogenic Fossil Burning + Land Use Vegetation and Land Accounts for ~76% of GHG Uptakes ~35% Uptakes ~25% 4

5 GLOBAL CARBON CREDIT CARD IS GOING INTO OVERDRAFT Atmospheric CO 2 : ~3000 Gt (billion metric tons) and >400 ppmv Proven fossil reserves: ~2800 Gt potential emissions Internationally accepted Paris goal: hold warming to < +2 C Can emit from fossil maybe Gt and roughly half stays Because CO 2 sources are exceeding CO 2 sinks, it is necessary to Restore the Carbon Balance by reducing sources and also adding sinks (natural and artificial) 5

6 ADDING ARROWS TO THE QUIVER What will it take to design for and build an economically viable carbon-based innovation ecosystem in ~25 Years? Decarbonization Energy Efficiency Renewables Adaptation Managing Impacts of Climate Change Capture, Reuse, and Recycle Transforming into Valuable Products Capture and Disposal Long-Term Sequestration Progress but Not Fast Enough Increasingly Necessary but expect suffering Synchronize Policy and Market Regimes Verified, Safe and Secure Waste Disposal Gt-CO 2 /yr or ~250 Mt-C/yr scale industry: steel, concrete, agriculture, coal, oil, and gas, and plastic is getting close 6

7 CARBON IS THE MOST VERSATILE OF ALL THE ELEMENTS Diamond Graphite Hexagonal Diamond Li-ion Batteries McLaren F1 Buckeyballs (C60, C540, C70) Amorphous Carbon Carbon Nanotube Carbon fiber reinforced polymer 52% plastics are used in an enormous and expanding range of products Essential for life, ensures a livable climate via the GH effect of CO 2, fossil fuels 7

8 MOST FUELS ARE ESSENTIALLY STORED SUNSHINE FOSSIL FUELS STORED BURIED SUNSHINE Gallon of gasoline ~100 tons* of prehistoric biomass, processed at low temperature for millions of years: ancient stored solar energy Bio-mimicry: need to accelerate the natural process and improve the efficiency with non-biological and industrial processes to make new energy carriers from modern sunlight: i.e., Solar fuels and materials. *JEFFREY S. DUKES, Climatic Change 61: 31 44, WE NEED A LOT OF ARROWS IN THE QUIVER. GARY DIRKS CURRENT SYSTEM HAS BUILT IN ENERGY STORAGE DESIGNED AROUND THAT FACT LIQUID HYDROCARBONS ARE ENERGY DENSE AND CONVENIENTLY STORED AND TRANSPORTED ECONOMICALLY EVEN OVER LONG DISTANCES THE QUESTION WE SHOULD BE ASKING IS WHAT WILL BE THE ENERGY CARRIERS OF THE FUTURE? (H 2, CO, CH 3 OH, NH 3, DME, CH 4 ) ELECTRICITY IS BEST USED AS IT IS PRODUCED PURE EXERGY (EXERGY IS THE AMOUNT OF WORK AN ENERGY SOURCE CAN THEORETICALLY GENERATE) BUT NOT EASILY STORED ESPECIALLY FOR SEASONAL SHIFTS 8

9 THE ADVANTAGE OF PRODUCING SYNGAS (CO & H 2 ) Can serve as a universal intermediate Make a lot of chemical based products Can unite fossil or biomass with direct solar technologies Bridge old energy to new energy Make more product for the same feedstock no process CO 2 o e.g. Solar reforming of CO 2 and natural gas (or biogas) or o Solar gasification of coal and/or biomass o Directly splitting water and CO 2, thermochemical, electrolysis, photo-electro-chemical, thermo-electro-chemical 9

10 MANY SOLAR FUELS PATHWAYS Solar to Electronic Solar Energy Solar to Heat H 2 O/CO 2 H 2 O/CO 2 H 2 O/CO 2 /NG/Coal/Biomass PEC PV CSP Electrolysis Thermolysis Thermochemical Reforming Pyrolysis Gasification Bio-chemical Photo-(Electro)-Chemical Dye-Sensitized Band Gap Excitation Artificial Photosynthesis Thermo-Chemical Electro-Chemical Catalytic Carbon Dioxide Intermediate Products H 2 /CO/CO 2 Fuel Synthesis Hydrogen Liquid Fuel, C x H y O z 10

11 CO H 2 O + sunlight SPLITTING BOTH CO 2 AND H 2 O Reverse Combustion 1.5 O 2 + CO (21.8 MJ) + 2 H 2 (40.8 MJ) Fuel (Syngas) Synthesis H 2 O + >CH 2 (1kg, 46.7 MJ) + heat (15.85 MJ) Final Liquid Fuel Product From the intermediates to final liquid fuel product nco + (2n+1)H 2 C n H 2n+2 + nh 2 O can capitalize on decades of syngas processing experience 11

12 AIR CAPTURE CLOSES THE CARBON CYCLE Mechanical Trees for Collecting CO 2 from the Environment Trees on steroids Air capture eliminates all exceptions No emission source need remain exempt Separates sources from sinks Democratizes carbon emissions Air capture can draw down CO 2 levels Can pay back carbon overdraft Requires vast CO 2 storage capacity 50 ppm remove 780 Gt CO 2 or ~20 Gt/yr for 40 yrs Air capture essential for sustainable liquid hydrocarbon fuels Synthetic fuel production from CO 2 and H 2 O Air capture with fossil liquid fuels Carbon use could be balanced by disposal Requires low-cost CO 2 storage 12

13 ASU* AIR CAPTURE TECHNOLOGY Passive filters of water sensitive sorbent materials are exposed to dry air, and washed clean with water amplifying CO 2 partial pressures hundredfold. *Klaus Lackner Passive air flows eliminate most air contacting costs Sidesteps limitations of conventional dilute gas separation Innovative sorbent is regenerated by moisture Anionic exchange resins affinity to CO 2 is controlled by moisture Substitute water for much more expensive energy Create clean simulated flue gas on demand anywhere Mass manufacture reduces costs Historically cost reductions of mass production have reduced costs (~$100/ton) close to material input costs (< $20/ton) 13

14 This can be essentially zero DAC HAS MANY ADVANTAGES COMPARED TO POINT SOURCE AND ONE BIG DISADVANTAGE Cleaner and Lower Temperature Integrate with heat available from the downstream processing This can be used downstream 10 Gt/yr minimum energy is 5 EJ/yr Less harsh conditions, longer cycle times, longer lifetime Compression minimized Fig 2.1 from the APS POPA Report Transport essentially eliminated Downstream processes can potentially use humidified CO 2 ; but must be clean of O 2 14

15 CLOSING THE CYCLE RESTORING THE CARBON BALANCE Direct air capture (DAC) Energy Input (Reduction) CO 2 H 2 O Fuel O 2 Recycling CO 2 to fuels Energy Recovery (Oxidation) Reversing combustion 15

16 Secure Energy Sustainable Fuels Thank you the audience for your attention and Wil Burns for the kind invitation Grateful acknowledgments to colleagues Klaus Lackner, James Miller, Bruce Rittmann, and Elisa Graffy, and many more 16