Tetra Tech, Inc. · NASDAQ:TTEK
Tetra Tech — Technical Presentation (December 2009)
30 slides from Tetra Tech's technical presentation, Dec 10, 2009
Slide 1: Potential Environmental Impacts of Hydrogen-Based Transportation & Power Systems
POTENTIAL ENVIRONMENTAL IMPACTS OF HYDROGEN-BASED TRANSPORTATION & POWER SYSTEMS Tetra Tech, Inc. Stanford University Potomac Hudson Engineering, Inc. Tom Grieb Tetra Tech, Inc. Research & Development Group [email protected] 10 December 2009
Slide 2: Project Objectives
Project Objectives • Compare emissions of hydrogen, the six criteria pollutants (CO, SOx, NO2, PM, ozone, and lead) and GHGs from near and long-term methods of generating hydrogen for vehicles and stationary power systems • Evaluate effects of emissions on climate, human health, ecosystem and struct
Slide 3: Presentation Overview
Presentation Overview • Modeling Scenarios and Sensitivity Analyses • Hydrogen Soil Sink and Deposition Velocity Modeling Approach • GATOR-GCMOM Simulations • Simplified Global Hydrogen Model • Findings and Summary 3
Slide 4: Modeling Scenarios and Sensitivity Analyses
Modeling Scenarios and Sensitivity Analyses • IPCC Scenario 2050 A1B used as 2050 Base Case • 2050 A1B with 90% HFCV penetration in developed countries and 45% HFCV penetration in other countries and where the H2 is produced by steam-reforming of natural gas at centralized facilities. • Emission fac
Slide 5: Fossil-fuel Emissions (Tg/yr) Used in GATOR-GCMOM
Fossil-fuel Emissions* (Tg/yr) Used in GATOR-GCMOM 1995+WHFCV 2000 2050 A1B 2050 A1B+SHFCV H2 8.2 8.4 14.6 17.2 NO 37 48.2 153 149 NO2 6.35 8.21 26.1 25.4 N2O 11.02 11.1 9.7 9.6 CO 119.1 294 514 484 CO2 21,010 25,560 95,900 93,200 Methane 275.9 284 357 356 Methanol 2.65 4.52 13.0 13.8 Ethene 2.54 4.
Slide 6: Hydrogen Production Sensitivity Analyses
Hydrogen Production Sensitivity Analyses • Used GREET model to estimate emission factors for other H2 production methods • Dispersed natural gas steam reforming • Coal with and without sequestration • Renewables, e.g. solar electrolysis • Biomass • Also compared emissions for alternative scenarios f
Slide 7: H2FC Vehicle Emission Rates from GREET - 2050 g/mile
H2FC Vehicle Emission Rates from GREET - 2050 g/mile Pollutant NG-Dispersed NG - Central Solar Coal w/o seques Coal with seques Biomass PM10 0.086 0.097 0.072 0.569 0.587 0.083 PM 2.5 0.042 0.045 0.021 0.144 0.149 0.026 NO x 0.132 0.151 0.046 0.057 0.075 0.106 VOC 0.022 0.022 0.004 0.030 0.031 0.010
Slide 8: GATOR-GCMOM Deposition Velocity Approach
GATOR-GCMOM Deposition Velocity Approach Vdeposition depends on: • Aerodynamics resistance (Ra) • Laminar sublayer resistance (Rb) • Land use resistance classes (Rs,l) fl Vd = ∑ Ra + Rb + Rs,l The soil sink is the largest term in the global atmospheric H2 budget and has a wide range of uncertainty 8
Slide 9: Changes in GATOR-GCMOM Focused on Soil Deposition
Changes in GATOR-GCMOM Focused on Soil Deposition • Temperature (Smith-Downey et al., 2006) • Soil Moisture Dependency (numerous researchers) 9
Slide 10: Field Studies of Hydrogen Deposition Velocity
Field Studies of Hydrogen Deposition Velocity Sources: Novelli (1999);Gerst and Quay (2001); Yonemura et al (2000); Rahn et al (2002); Conrad and Seiler (1985); Liebl and Seiler (1976); Lallo et al (2008); Jacobson (2009) 10
Slide 11: Annually-averaged dry deposition velocity (cm/s) of H2
Annually-averaged dry deposition velocity (cm/s) of H2 Model verification: Annually- Annually-averaged dry depositional velocity on land (0.041 cm/s) calculated by the model are consistent with the global average measured in field studies 11
Slide 12: Modeled H2 Surface Mixing Ratio
Modeled H2 Surface Mixing Ratio Predicted atmospheric hydrogen using new hydrogen uptake module 12
Slide 13: GATOR-GCMOM Model
GATOR-GCMOM Model • Model is a global-through-urban Gas, Aerosol, Transport, Radiation, General Circulation, Mesoscale, and Ocean Model. • Model uses 4°S-N x 5°W-E global domain and 42 layers up to 55 km; 25 layers in troposphere (5 in bottom 1km) and 16 in stratosphere. • Model solves atmospheric g
Slide 14: GATOR-GCMOM Processes
GATOR-GCMOM Processes • Gas processes • Cloud processes • Emission • Subgrid clouds, size-resolved physics • Photochemistry • Liquid/ice growth on aerosol particles • Gas-to-particle conversion • Liquid drop freezing/breakup • Cloud removal • Hydrometeor-hydrometeor coagulation • Hydrometeor-aerosol
Slide 15: GATOR-GCMOM Modeling Scenarios
GATOR-GCMOM Modeling Scenarios • IPCC Scenario 2050 A1B • 2050 A1B with 90% HFCV penetration in developed countries and 45% HFCV penetration in other countries and where the H2 is produced by steam-reforming of natural gas. • Contemporary global emissions conversion case where all worldwide on-road
Slide 16: Summary: Wind-generated HFCV Case
Summary: Wind-generated HFCV Case • Converting the world’s fossil-fuel on-road vehicles (FFOV) to hydrogen fuel cell vehicles (HFCV), where the H2 is produced by wind-powered electrolysis, is estimated to reduce current global emissions by: • CO2 by ~13.4%, • NOx ~23.0% • nonmethane organic gases ~1
Slide 17: Effects of wind-HFCV on Global Climate and the Ozone Layer
Effects of wind-HFCV on Global Climate and the Ozone Layer Net surface cooling, stratospheric warming Increase stability of UTLS reducing transport of water vapor Surface ozone decreased by about 1 ppbv globally and up to 5 ppbv regionally Increase in UTLS ozone 17
Slide 18: Summary: 2050 A1B Case with HFCV
Summary: 2050 A1B Case with HFCV 10-years Simulation • Conversion will cool global surface temperatures, on average. • Conversion will also reduce emissions: · CO2 · CO · NOx · aldehydes · and black carbon. • Conversion will slightly increase H2 and SO2 locally due to leakage and power plant emissio
Slide 19: 2050 H2 Minus 2050 Base After 10 yr
2050 H2 Minus 2050 Base After 10 yr Natural gas- gas-HFCV decrease surface ozone, increased upper- upper- tropospheric/lower stratospheric ozone, No net stratospheric ozone loss due to H2 19
Slide 20: 2050 H2 Minus 2050 Base After 10 yr
2050 H2 Minus 2050 Base After 10 yr Natural gas- gas-HFCV decreased surface temperatures on average 20
Slide 21: 2050 H2 Minus 2050 Base After 10 yr
2050 H2 Minus 2050 Base After 10 yr Natural gas- gas-HFCV decrease surface ozone and ozone deaths 21
Slide 22: Simplified Global Hydrogen Model
Simplified Global Hydrogen Model • Focuses on hydrogen only • Uses a simplified approach to allow longer periods of simulation • Can quickly examine different hydrogen emission scenarios and perform sensitivity analysis 22
Slide 23: Simplified Global Hydrogen Cycle
SIMPLIFIED GLOBAL HYDROGEN GYGELE TROPOSPHERE H, PRODUCTION { Tdeavone peste agen HCHO+ hy > xHo+ yCO+=* Hp RELEASES H, sink! Hy+OH+ H,O ++ 23
Slide 24: Sources and Sinks for Global Hydrogen Budget
Sources and Sinks for Global Hydrogen Budget 24
Slide 25: Comparison of Predicted Hydrogen Results vs. Values Calculated by Other Researchers
Comparison of Predicted Hydrogen Results vs. Values Calculated by Other Researchers Category Previous Researchers Predicted Here Hydrogen burden in 136-155 154 troposphere, Tg Hydrogen burden in 42-43 45 stratosphere, Tg Global hydrogen burden, Tg 188 199 Present day hydrogen mixing ratio in troposp
Slide 26: Examples of Response of Hydrogen to Leakage
Examples of Response of Hydrogen to Leakage (differentials shown) 26
Slide 27: 21st Century Predictions of Troposphere Hydrogen Concentration
21st Century Predictions of Troposphere Hydrogen Concentration 27
Slide 28: Approach to Environmental Effects
Approach to Environmental Effects • Human Health: Compared predicted concentrations for six criteria pollutants and lead to national ambient air quality standards; evaluated areas in US with concentration differences to see if potential for changes in local exceedances; compared changes in criteria
Slide 29: Summary and Conclusions
Summary and Conclusions • Converting the world’s fossil-fuel vehicles (FFOV) to hydrogen fuel cell vehicles (HFCV), where the H2 is produced by wind- powered electrolysis, is estimated to reduce current global emissions of CO2 by 13.4%, NOx ~ 23.0%, nonmethane organic gases ~18.9%, black carbon ~8%,
Slide 30: Summary and Conclusions
Summary and Conclusions • SHFCVs expected to increase upper tropospheric/lower stratospheric ozone. • Greater reductions in CO2 over a longer simulation period expected to result in greater tropospheric cooling and stratospheric warming, causing greater reductions in surface ozone and greater net in