Hydrogen
Overview
Hydrogen (H2), the lightest known element, is a flammable gas. Explosive mixtures can be formed when certain concentrations of hydrogen are mixed with oxygen, air, or other oxidizers. Hydrogen is not life sustaining. Small quantities are useful in gas blends for plasma cutting and some welding applications because of its high thermal conductivity and reactive nature. It is very useful when GMAW and GTAW – 300 series austenitic stainless steels.
TEchnical Information
Hydrogen Physical Properties
| Formula | H2 |
| Molecular Weight (lb/mol) | 2.02 |
| Critical Temp. (°F) | -400.0 |
| Critical Pressure (psia) | 187.50 |
| Boiling Point (°F) | -423.0 |
| Melting Point (°F) | -434.5 |
| Gas Density @ 70°F 1 atm (lb/ft3) | .0052 |
| Specific Volume @ 70°F 1 atm (ft3/lb) | 191.90 |
| Specific Gravity | .069 |
| Specific Heat @ 70°F (Btu/lbmol-°F) | 6.87 |
Hydrogen Uses and Applications
High-purity hydrogen finds widespread usage in the electronics industry as a reducing agent and as a carrier gas.
High-purity hydrogen is used as a carrier gas in gas chromatography.
Hydrogen finds some usage in the welding and cutting of metals.
Hydrogen:
- is used extensively in the metals industries because of its ability to reduce metal oxides and prevent oxidation of metals during heat treatment. It may be used either pure, as is often the case when heat treating stainless steel, or in a mixture with inert gases, argon or nitrogen. It is used in the production of carbon steels, special metals and semiconductors.is used for synthesis of ammonia.
- is used as a reagent to produce high-purity water.
- is used as fuel in fuel cell applications.
- is used in leak testing applications.
- is used in HF/DF chemical lasers.
- is used in large quantities, (bulk supply or on- site generation) for the hydrogenation of vegetable and animal oils to produce margarine and other fats, hydro- treatment of petroleum products, and hydrosulfuration of fuels in order to eliminate sulfur.
- is used as component in gas mixtures.
Hydrogen in large quantities is used in petrochemical processes that include hydrodealkylation, hydrodesulfurisation, hydrotreatment.
Hydrogen is used for combustion;
- in industry, it is used to supply oxygen-hydrogen torches for glass working (quartz, Pyrex®, etc.), in the fabrication of artificial precious stones (ruby, etc.), and for under water oxy-cutting
- in the laboratory, it is used in analyzer flames, reducing flame photometry detection instruments, flame ionization detection instruments, and fuel cells.
Extremely pure hydrogen is used in the chemical industry for fine reduction processes.
Liquefied hydrogen is used as a rocket fuel. In the laboratory liquid hydrogen is employed for solid physics research.
In the nuclear industry para-hydrogen is employed to fill bubble chambers.
In electrical power plants hydrogen is used as a coolant gas in turbo generators.
Hydrogen Purity Grades
| Product/Purity | Purity Percent | Part Number Prefix |
|---|---|---|
| Hydrogen: Research Grade | >99.9999% Oxygen < 0.1 ppm Water < 0.5 ppm Total Hydrocarbon (as CH4) < 0.5 ppm Nitrogen < 0.5 ppm Carbon Dioxide < 0.2 ppm | HYD6.0 |
| Hydrogen: Ultra High Purity Grade | >99.999% Oxygen < 2 ppm Water < 3 ppm Total Hydrocarbon (as CH4) < 0.5 ppm Nitrogen < 8 ppm | HYD5.0 |
| Hydrogen: Zero Grade | >99.99% Total Hydrocarbon (as CH4) < 0.5 ppm | HYD4.0Z |
| Hydrogen: High Purity Grade | 99.99% | HYD4.0 |
| Hydrogen: Industrial Grade | >99.95% Oxygen < 10 ppm Water < 34 ppm Total Hydrocarbon (as CH4) < 10 ppm | HYD |
Hydrogen Packaging Options
Hydrogen Transportation Information
| Proper Shipping Name | ID Number | Hazard Class or Division | Packing Group | Labeling Requirements | Passenger Aircraft or Railcar Quantity Limitations | Cargo Aircraft Only Quantity Limitations | Additional Shipping Description |
|---|---|---|---|---|---|---|---|
| Hydrogen, compressed | UN1049 | 2.1 | Not applicable | 2.1 | Forbidden | 150 kg | N/A |
Hydrogen Conversion Chart
| Weight | Gas | Liquid | ||||
|---|---|---|---|---|---|---|
| pounds (lb) | kilograms (kg) | cubic feet (scf) | cu meters (Nm3) | gallons (gal) | liters (l) |
|
| 1 pound | 1.0 | 0.4536 | 192.0 | 5.047 | 1.6928 | 6.408 |
| 1 kilogram | 2.205 | 1.0 | 423.3 | 11.126 | 3.377 | 14.128 |
| 1 scf gas | 0.19815 | 0.08988 | 1.0 | 0.02628 | 0.00882 | 0.03339 |
| 1 Nm3 gas | 0.19815 | 0.08988 | 38.04 | 1.0 | 0.3355 | 1.2699 |
| 1 gallon liquid | 0.5906 | 0.2679 | 113.4 | 2.981 | 1.0 | 3.785 |
| 1 liter liquid | 0.15604 | 0.07078 | 29.99 | 0.7881 | 0.2642 | 1.0 |