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Hydrogen Basics . Hydrogen First Discovered 1766 - Henry Cavendish Named for being a “water former” 1 Proton, 1 Electron H2 - Diatomic Molecule, 2 Protons, 2 Electrons Colorless, Odorless, and has no Taste. Hydrogen Basics. Burns with a pale Blue Flame Lightest Element in the Universe
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Hydrogen Basics • Hydrogen First Discovered 1766 - Henry Cavendish • Named for being a “water former” • 1 Proton, 1 Electron • H2 - Diatomic Molecule, 2 Protons, 2 Electrons • Colorless, Odorless, and has no Taste
Hydrogen Basics • Burns with a pale Blue Flame • Lightest Element in the Universe • H2 = 1Mol = 1.0016 Grams • Disperses Rapidly - 1/16 the Density of Air • Flammable from 4% to 75% Concentration (40,000 to 750,000ppm) • Non-Toxic • Environmentally Benign
Hydrogen Safety • Applicable Codes & Standards • NFPA 50A - Standard for Gaseous Hydrogen Systems at Consumer Sites. • Covers the Storage of Hydrogen • ASME/ANSI B31.3 - Process Piping • Covers the Marking of Hydrogen • CGA G-5 - Hydrogen • Covers the Basics of Hydrogen • CGA G-5.4 - Standard for Hydrogen Piping Systems at Consumer Locations. • Covers the Design of Hydrogen Piping Systems • CGA G-5.5 - Hydrogen Vent Systems • Covers the Venting of Hydrogen
6” x 24” 33 cu-ft 29 lbs 1.0 kWh 6” x 37” 80 cu-ft 65 lbs 2.5 kWh 9” x 56” 197 cu-ft 125 lbs 6.1 kWh 9” x 60” 261 cu-ft 140 lbs 8.0 kWh Hydrogen Storage Hydrogen is sold in high pressure steel or aluminum bottles which come in many different sizes. The actual storage capacity is dependent on bottle volume and fill pressure. Each kilowatt hour produced, requires 32 cubic feet of hydrogen Example Bottles Sizes:
HEAT HYDROGEN FUEL CELL ELECTRICITY OXYGEN
FOSSIL FUELS ANODE ELECTROLYTE CATHODE HEAT HYDROGEN FUEL CELL ELECTRICITY OXYGEN
ALKALINE PHOSPHORIC-ACID SOLID OXIDE MOLTEN CARBONATE DIRECT METHANOL PROTON EXCHANGE MEMBRANE
ALKALINE • One of the oldest designs • 70% efficient • Catalyst is a non-precious metal • Operates at 75-150°F
PHOSPHORIC-ACID • The most developed • 40% efficient • Platinum catalyst • Operates at 400°F • Unsuitable for cars
SOLID OXIDE • The most developed • 40% efficient • Platinum catalyst • Operates at 400°F • Unsuitable for cars
MOLTEN CARBONATE • Best suited to power towns • 50-60% efficient • Catalyst is a non-precious metal • Operates at 1830°F • Produces steam
DIRECT METHANOL • CH3OH and steam supplied • No need for a reformer • Methanol is a liquid • Operates at 180°F • 3-4 years behind the others
PROTON EXCHANGE MEMBRANE • Operate at low temperatures • Have a platinum catalyst • Can handle changing power demands • Good candidate for automobiles • Starts quickly
PEM DIFFUSION LAYER CATALYST POLYMER ELECTROLYTE CATALYST DIFFUSION LAYER
ElectronsfromHydrogen Electrical Load e- e- O2 H2 H+ e- Oxygen Molecules e- O2 H2 H+ e- H+ e- H+ O Water molecules forming Hydrogen Molecules + H - H+ e- H H O H+ - H + H+ H+ H Proton exchangemembrane electrolyte Catalyst/Electrode Catalyst/Electrode How a PEM Fuel Cell Works