Business Opportunities at the Forefront of Scientific Research 5 th - PowerPoint PPT Presentation

Business Opportunities at the Forefront of Scientific Research 5 th Annual Alumni Business Conference “Hot Topics in Business” March 26, 2010 Dr. Raymond L. Orbach Director, Energy Institute University of Texas at Austin orbach@energy.utexas.edu 1

Essential Role of Basic Science  Today’s energy technologies and infrastructure are rooted in 20th Century technologies and 19th Century discoveries — internal combustion engine, incandescent lighting.  Current fossil energy sources, current energy production methods, and current technologies cannot meet the energy challenges we now face.  Incremental changes in technology will not suffice. We need transformational discoveries and disruptive technologies.  21 st Century technologies will be rooted in the ability to direct and control matter down to the molecular, atomic, and quantum levels. Quantum Control of Electrons 4H + + 4e - 2H 2 O Mn O O Mn O Mn O O Mn Mn O Mn O O Mn Mn O O photosystem II Bio-inspired nanoscale assemblies – Separating electrons by their spin self-repairing and defect-tolerant for ―spintronics‖ and other Four-stroke Watt Steam materials and selective and specific applications of electron control. combustion engine, Engine, 1782 chemical reactivity. 1870s 2

Forefront of Scientific Research Three Opportunities That Matter: Sunlight to Fuels – production of H 2 without generation of CO 2 (Bard) Electrical Energy Storage at baseload levels (Goodenough) Offsetting the cost of CO 2 capture & pressurization by production of natural gas (Pope) 3

Sunlight to Fuels – Production of H 2 without generation of CO 2 Imagine: Direct conversion of sunlight to chemical fuels without use of plants or microbes: artificial photosynthesis  Sunlight provides by far the largest of all carbon-neutral energy sources – more energy from sunlight strikes the Earth in one hour (4.6 x 10 20 joules) than all the energy consumed on the planet in a year.  Despite the abundance, less than 0.1% of our primary energy derives from sunlight.  Sustainable energy will involve the conversion of solar energy economically and efficiently to chemical fuels and electricity. A multi-layered triple- junction solar cell designed to absorb  Identification of new materials that can efficiently absorb sunlight and then use that different solar photons. energy to catalyze a) splitting water into clean hydrogen fuel, and b) converting CO 2 to fuels.  Professors Allen J. Bard and Buddie Mullins are examining novel semiconducting metal oxides as promising photoelectrocatalysts.  Fabrication of columnar films at the nanoscale to generate a large contact surface area between the active electrode material and the electrolyte, and a short path for Photosystem II uses solar electrons to travel in order to minimize electron-hole recombination. energy to break two molecules of water into one oxygen molecule plus four hydrogen ions, meanwhile freeing electrons to drive other 4 reactions.

Sunlight Driven Hydrogen Formation Traditional photoelectrochemical water splitting is limited by  a cumbersome planar, two electrode configuration for light absorption and H 2 and O 2 generation. Current generation of ligh semiconductors used for absorbing visible solar spectrum t are intrinsically unstable. Precious metals (Pt, Pd) are needed for H 2 evolution. n-WO 3 One key constraint in photon absorbers for solar energy  conversion is that the samples need to be thick enough for sufficient absorption, yet pure enough for high minority carrier length and photocurrent collection. New nanorod configuration was recently developed to  orthogonalize the directions of light absorption and charge p-Si carrier collection, i.e. it separates longitudinal light absorption from transverse carrier diffusion to reactive surface.  The short diffusion paths to reaction broadens usable Solar powered water splitting scheme incorporating two materials to include earth abundant, resistive separate semiconductor rod-array photoelectrodes that semiconductors. Opposing nanorod configuration with sandwich an electronically and ionically conductive conductive ion membrane allows for compact device with membrane. inherent separation of O 2 and H 2 gas. High surface-to-volume ratio of nanostructure decreases  current density and permits use of broad range of new metals as sites for H 2 and O 2 evolution. 5 Spurgeon JM, Atwater HA, Lewis NS, Journal of Physical Chemistry C, 112, 6186-6193 (2008).

Baseload Electrical Energy Storage Imagine: Storing electrical energy generated by intermittent sources (wind, solar) at baseload magnitude, enabling usage when needed most and reducing the need for “peaking” generation  Many renewable energy sources such as wind and solar are intermittent — To make these energy sources truly effective and integrate them into the electrical grid, we need significant breakthroughs in electrical energy storage technologies.  Current lithium batteries use a liquid electrolyte and solid insertion-compound electrodes. They suffer from limitations in the amount of energy than can be stored in the battery per unit weight and volume, as well as high cost and safety concerns.  Professors Goodenough and Manthiram are exploring the use of a solid Li + -ion or Na + -ion electrolyte that separates a non-aqueous solution from an aqueous cathode.  Electrical energy can be converted into chemical energy in the cathode, that can then be pumped into tanks and stored until needed. The liquid can then be pumped back Energy and power densities of various into a fuel cell, converting chemical energy into electrical energy storage devices. Electrochemical capacitors bridge between batteries and energy, providing electricity when needed. conventional capacitors. 6

Nanomaterials are Key to Improved Battery and Capacitor Storage Current Battery Structure 3-D Nanoscale Electrochemical Battery Cell Structure + Positive Electrode Electrolyte/Separator ~ 10 nm Polymer Negative Electrode ( separator/ electrolyte ) Nanoparticle Oxide or ( electrode ) carbon — ( electrode )  Current battery consists of 2-dimensional structures of electrodes separated by electrolytes in a planar geometry. Nanostructured architectures for power storage (batteries, fuel cells, ultracapacitors, photovoltaics) provide many advantages over existing technologies to minimize power losses, improve charge/discharge rates and enhance energy densities.  Three-dimensional structures can further revolutionize the ability of these devices to accumulate, store and release charge at unprecedented levels. Electrodes in these architectures will consist of interconnected ~10nm domains and mesopores (10-50nm). Ultrathin, conformal and a pinhole-free separator/electrolyte are electrodeposited onto the electrode nanoarchitecture. Low melting point metals (mp<200°C) or colloids fill the remaining mesoporous volume. These designs have the potential for higher performance by separating the length scales for electronic and ionic transport, thereby accessing previously unachievable power and energy densities.  In addition, new nanoscale materials could be produced by self-assembly. Nature uses self-assembly to produce materials with specific functionality. These bio-inspired concepts have potential for the development of novel nanomaterials and architectures to enhance the development of chemical energy storage systems. The ability to apply these techniques to the fabrication of 7 battery electrodes could be revolutionary. Long et al., Chem. Rev 104, 4463 – 4492, 2004; Fischer et al., Nano Letters , 7, 281, 2007

Offsetting the cost of CO 2 capture & pressurization by production of natural gas • Pulverized coal fired power plants in the U.S. product ~ 2 Gt of CO 2 each year . In order to capture and pressurize CO 2 to a supercritical liquid, ~ 1/3 rd of the of the power plant’s energy is expended, making it uneconomical in today’s market. • Professor Gary Pope has suggested injecting the supercritical CO 2 into geopressured methane saturated aquifers, releasing natural gas that can be either sold or drive a combined cycle generator, offsetting the cost of CO 2 capture and pressurization. • When CO 2 is mixed with brine saturated with methane, the CO 2 will dissolve at its equilibrium solubility concentration, and the methane will come out of solution as methane gas. The methane gas will flow to the top of the aquifer and form a gas cap. About 1/3 rd of this gas can be produced from wells completed in the gas gap. • The total in-place volume of methane for Tertiary sandstones below 8,000 ft. in the Texas Gulf Coast is ~ 690 TCF, so ~ 230 TCF is recoverable, sequestering ~ 3,450 TCF of CO 2 (~ 170 Gt). • Compare with ~ 1,700 TCF of methane from all sources in U.S.

Summary: Opportunities that Matter Sunlight to Fuels – production of H 2 without generation of CO 2 (Bard): The oil industry uses large amounts of H 2 produced from CH 4 +2H 2 O=4H 2 +CO 2 . Hence, sunlight- to-fuels would displace a major source of CO 2 . Electrical Energy Storage at baseload levels (Goodenough): The reserve margin of ~20% can be reduced for wind and solar energy, thereby increasing penetration into the grid of renewable energy. Offsetting the cost of CO 2 capture & pressurization by production of natural gas (Pope): Reducing the cost of CO 2 capture and pressurization, and storage in saline aquifers, can make sequestration economically possible. 9