Combustion and beyond: Alternate reactive/energy systems Hai Wang University of Southern California 7ISFS, July 11-15, 2011

Energy Usage – current and future 2010 International Energy Outlook / US DOE 17 TW 24 TW

Growth in Demand Comes from China 2010 International Energy Outlook / US DOE

But the 2010 IEA projection was quite inaccurate

Current Projection Looks Rather Gloomy 2010 International Energy Outlook / US DOE

Energy Usage and Resources Current world energy usage rate is ~17 TW. 17 TW/6.7 billion people = 2.5 kW per person World energy demand is to increase by 40%, to 24 TW by Business-as-usual energy demand > 45 TW by the century end. 1 Fossil and fissile energy sources are finite 2 – Oil: 1354 billion barrels/31 billion barrels/yr = ~40 years – Natural Gas: 187 trillion m 3 /3 trillion m 3 /yr = ~60 years – Coal: 909 billion short ton/2.5 billion short ton/yr = ~380 years – Nuclear fission (~ 50 years) Uranium: ~11.5 million ton Thorium: ~34.5 million ton 2010 International Energy Outlook / US DOE 1.Intergovernmental Panel on Climate Change (IPCC), “Climate Change 2001: The Scientific Basis,” Cambridge University Press, Cambridge, UK (2001). 2.W.C. Sailor, “New Generation Nuclear Fission?” presented at the Aspen Global Change Institute meeting, Aspen, CO, July 2003.

Greatest Technological Achievements of the 20th Century 1.Electrification 2.Automobile 3.Airplane 4.Water Supply and Distribution 5.Electronics 6.Radio and Television 7.Agricultural Mechanization 8.Computers 9. Telephone 10.Air Conditioning and Refrigeration 11.Highways 12.Spacecraft 13.Internet 14.Imaging 15.Household Appliances 16.Health Technologies 17.Petroleum and Petrochemical Tech 18.Laser and Fiber Optics 19.Nuclear Technologies 20.High-Performance Materials U.S. NAE

Greatest Technological Achievements of the 20th Century 1.Electrification 2.Automobile 3.Airplane 4.Water Supply and Distribution 5.Electronics 6.Radio and Television 7.Agricultural Mechanization 8.Computers 9. Telephone 10.Air Conditioning and Refrigeration 11.Highways 12.Spacecraft 13.Internet 14.Imaging 15.Household Appliances 16.Health Technologies 17.Petroleum and Petrochemical Tech 18.Laser and Fiber Optics 19.Nuclear Technologies 20.High-Performance Materials U.S. NAE

Greatest Technological Achievements of the 20th Century 1.Electrification 2.Automobile 3.Airplane 4.Water Supply and Distribution 5.Electronics 6.Radio and Television 7.Agricultural Mechanization 8.Computers 9. Telephone 10.Air Conditioning and Refrigeration 11.Highways 12.Spacecraft 13.Internet 14.Imaging 15.Household Appliances 16.Health Technologies 17.Petroleum and Petrochemical Tech 18.Laser and Fiber Optics 19.Nuclear Technologies 20.High-Performance Materials U.S. NAE It’s all about combustion!

1.Make solar energy economical 2.Provide energy from fusio 3.Develop carbon sequestration methods 4.Manage the nitrogen cycle 5.Provide access to clean water 6.Restore and improve urban infrastructure 7.Advance health informatics 8.Engineer better medicines 9.Reverse-engineer the brain 10.Prevent nuclear terror 11.Secure cyberspace 12.Enhance virtual reality 13.Advance personalized learning 14.Engineer the tools of scientific discovery NAE Grand Challenges of the 21th Century

1.Make solar energy economical 2.Provide energy from fusion 3.Develop carbon sequestration methods 4.Manage the nitrogen cycle 5.Provide access to clean water 6.Restore and improve urban infrastructure 7.Advance health informatics 8.Engineer better medicines 9.Reverse-engineer the brain 10.Prevent nuclear terror 11.Secure cyberspace 12.Enhance virtual reality 13.Advance personalized learning 14.Engineer the tools of scientific discovery NAE Grand Challenges of the 21th Century The transition into a fossil-fuel depleted world presents great opportunities for combustion research. As a major driving force for 20th century achievement, combustion should continue to play a significant role in broader, renewable energy utilization.

Solar 1.2 x 10 5 TW on Earth’s surface 36,000 TW on land Biomass 5-7 TW gross (world) 0.29% efficiency for all cultivatable land not used for food Hydroelectric Geothermal Wind 2-4 TW extractable 4.6 TW gross (world) 1.6 TW technically feasible 0.6 TW installed capacity 9.7 TW gross Tide/Ocean Currents 2 TW gross Renewable Resources

Areas where Combustion Can Help Direct Biomass – Biofuel combustion Indirect Wind power – Carbon fibre Light weight, high strength, cost Solar – Photovoltaic thin films High efficiency & stability, cost Energy storage– Li ion batteries Fast charging, good discharging rate, cost

Solar 1.2 x 10 5 TW on Earth’s surface 36,000 TW on land Solar Resources 17 TW/36,000 TW on land (world)/15% efficiency = 0.3% land World land mass: 13,056 million hectares × 0.3% ~ 400,000 km 2 (the size of Iraq)

Challenge for Solar Energy – cost, cost, cost ! Coal Natural Gas Nuclear Wind Solar Geothermal Biomass Hydro Conventional Advanced with CCS Conventional combined cycle Advanced combined cycle Advanced combined cycle w CCS Conventional turbine Advanced turbine Onshore Offshore Photovoltaic Thermal

NREL Timeline of Solar Cell Efficiency

Dye-Sensitized Solar Cell (DSSC) Michael Gratzel (1991)

Dye-Sensitized Solar Cell (DSSC) S electrolyteTransparent conducting glass dyeTiO 2 S* hh ox (I 3 - )red (I - ) Redox mediator e-e- e-e- e-e E (V) maximum Voltage ~0.75 V Photoanode: Currently the most costly part in DSSCs

Photoanode and its Preparations Nanocrystalline TiO 2 thin films (~10  m thickness) Ideal particle size: nm Particles are single crystals Anatase performs better (versus rutile) Current technique for anode fabrication –Commercial TiO 2 powder (from combustion processes) –Making a paste/paint & screen printing –Sinter at 450 ◦ C (glass substrate only) –For DSSC applications: Staining with a dye

Tubular burner Shielding Ar C 2 H 4 /O 2 /Ar Synthesis Method – Premixed Stagnation Flame Flame Stabilizer TTIP Carrier gas Ar TTIP/Ar Electric mantle vOvO vOvO T max burner-stabilized flame Stagnation flame

Flame Structure (Ethylene-oxygen-argon,  = 0.4) Computations used the Sandia counterflow flame code and USC Mech II Mole Fraction O 2 C 2 H 4 H H 2 CO H 2 O 2 Distance from the Nozzle, x (cm)

Flame Stabilized on Rotating Surface (FSRS) Particle synthesis and film deposition in a single-step Drastically reduced cost for film preparation

TTIP Mesoporous film TiO 2 Vapor Nanoparticles Decomposition & oxidation Nucleation, coagulation Stagnation Flame Film Preparation Short growth time aided by thermophoresis = small size + narrow distributions

Typical Synthesis Flames Aerodynamically shaped nozzle (D = 1 cm) Nozzle-to-disc distance (L = 3.4 cm) Diameter of rotating disc 30.5 cm (0 to 600 RPM) 3.96%C 2 H %O 2 -Ar,  = 0.45, v 0 = 302 cm/s Adiabatic flame temperature = 2250 K Laminar flame speed (calc) = 96 cm/s Flame diameter = 3 cm Flame-to-disc distance = 0.29±0.03 cm Measured maximum temperature = 2124 K

Particle Properties – Effect of Disc Rotation Speed 10 nm  rad = 300 RPM 306 PPM TTIP1070 PPM TTIP

Particle Morphology & Film Properties 10 nm  rad = 300 RPM 306 PPM TTIP1070 PPM TTIP 5 minute 14  m Alumina 1070 ppm TTIP, 300 RPM Typically 5  m/min Net deposition rate = ~ 1  m/sec Film is highly porous but uniform

DSSC Performance 9% AM1.5

Combustion Issues Large area deposition: Scale up a pseudo one- dimensional premixed stagnation slot flame to several meters wide. The flame must be stable and never undergo extinction locally or globally. Heat release and management. Nanoparticle chemistry and transport in highly reacting flow. Flame aerosol kinetics and dynamics.