Chemistry Reference
In-Depth Information
HYDROGEN (H
2
)
Properties
Hydrogen is the lightest and most abundant element.
It is a colorless, odorless gas that can be liquefied
under pressure. It is highly explosive when mixed
with air and burns to produce only water.
Commercial grades
Supplied as liquid in steel cylinders and as a gas under
pressure in pipelines.
Uses
Production of ammonia and methanol, refining of
metals from oxide ores, petroleum refining,
hydrogenation of fats and oils, preparation of higher
alcohols, and other chemicals. Most of the hydrogen
produced is used captively (i.e., by its producer).
H
2
O
CH
4
+
H
2
O
CO
+
H
2
CO
2
+
H
2
Manufacture
natural
gas
water
synthesis
gas
carbon
dioxide
hydrogen
The hydrogen is separated from the carbon dioxide by
contacting the mixture with a liquid chemical
(monoethanolamine), which absorbs the carbon
dioxide. The latter can be recovered in high purity
from the monoethanolamine.
Suppliers
Air Products and Chemicals, Air Liquide America,
BOC Gases, Praxair.
The original source of hydrogen for chemical purposes is the splitting of
water into its components (oxygen and hydrogen) with electricity (electrol-
ysis); however, using hydrocarbons from natural gas or petroleum is less
costly. Because hydrogen is so abundant, there is considerable speculation
and research underway on ways to use it as an energy source, for example,
in fuel cells to provide electricity for homes, buses, trucks, and automobiles.
A
fuel cell
produces electricity when the hydrogen fuel combines with
oxygen from the air. The exhaust is only water so fuel cells are
non-polluting
.
In some applications, metal cylinders or tanks will be required to store the
hydrogen under pressure.
