氢气安全TRA0104a_H2hazards.pptVIP

WELCOME TO Hydrogen Safety Training Package;HYDROGEN;Gas at atmospheric temperature and pressure Extremely flammable Colorless Odorless Tasteless H2 dissipates more rapidly than other gases;Lowest specific density (14-times lighter than air) Thermal conductivity is 7 times that of air Most non metallic and some metallic materials are permeable to H2 Non-toxic, simple asphyxiant Non-toxic for human beings Metallurgical: hydrogen embrittlement for steel Hydrogen attack at temperatures 250°C Boiling temperature : -253 °C /-423.0 °F/20°K at atmospheric pressure;Lightest of all Chemical Elements: Most abundant substance in the universe. Our sun is a nuclear reactor in which hydrogen continuously fuses into helium. Fusion process creates heat which warms our earth.;Liquid Hydrogen mass is only 70,8 g/l Hydrogen gas burns with a pale color flame, almost invisible Low temperature of liquid hydrogen can solidify any gas even nitrogen, but not helium;The amount of heat required to raise the temperature of hydrogen gas differs very little from that of nitrogen To heat by 1°C, 10 m3 of hydrogen at constant pressure requires 11,94 kJ Same temperature change for 10 m3 of nitrogen requires 12,08 kJ, but the weight is 14 times greater;By: Catalytic reforming of hydrocarbons (e.g. natural gas or naphta) Methanol reforming with steam Dissociation of ammonia (NH3) Electrolysis of water (H2O);Standard industrial grade 99.95% hydrogen 500 ppm N2 2 ppm O2  5 ppm H2O 3 ppm CH4  2 ppm CO + CO2 Cryogenic grade 99.99997% hydrogen for the electronics industry, obtained from liquid Hydrogen;Rocket Fuel (NASA, ARIANE) Chemical synthesis (ammonia, methanol) Oil refining Hydrogenation of organic oils for food use GTAW welding, plasma cutting, forming gas Reduction of oxygen (controlled atmosphere in metal working furnaces, electronics production, float glass) ;In the 60s and 70s, a number of cylinders and tubes failed in H2 service. They are now successfully