Evening star., 1916-05-07

/ Nitrogen is one of the things about
which the average man hears great
deal, but about which he obtains only
small measure of exact arkl specific
| information. Four -hfths of the fresh
air we breathe is nitrogen. 1t has been
estimated that upon every square yard
of the earth's surface there rests a
column of air containing 5.s tons of
pure nitrogen. Plants cannot exist
without nitrogen. During the discus
sion in the Senate of the extraction of
nitrogen from the air one senator
| asked whether animal health on this
globe might not be adversely affected
| il We were to take from the air hun
dreds of thousands of tons of its chief
constituent gas. Senators having an
understanding of the subject replied
that the uses of nitrogen in the form
of solid chemicals restored it in gas
form to the atmosphere. very much
after the nature OF evaporation of
water from the ocean makes the clouds
and the precipitation of moisture of the
clouds makes the ocean. There is no
magic in taking nitrogen out of the
atmosphere. 1t is no longer a mere
| la boratory experiment or process 1t
has beeen done for several years on
commercial scale in Norway and has
| been taken up in Germany, and Ger
many, with her Chilean supply of nj
| trates cut off, is making her enormous
amounts of military explosives with
the aid of nitric acid made with nitro
gen Withdrawn from the atmosphere.
The credit for discovery of the proc
ess is given in the books and by stu
dents of this subject to Birkeland and
Eyde, Norwegian chemists. That proc
ess called for immense electric power,
which could only be produced cheaply
enough by great water power. Two
other chemists, named Frank and Caro-.
found that when lime and coke were
fused in an electric furnace the re-
sultant calcium carbide would draw
nitrogen from the air and hold it. They
reduced this to powder and called IL
calcium cyanamide-a valuable fertiiiz-
er. Nitrogen is also obtained out OF the
atmosphere by freezing and liquefylng
the air.
Air is compressed and frozen solid
Then when the pressure is reduced the
air begins to thaw, the oxygen llquenes
at -253 degrees centigrade, while the
| nitrogen remains solid until the tenn
perature has risen to -211 degrees,
margin of AZ degrees. During this
thawing process the liquid oxygen can
be drawn off and leave nothing but
pure nitrogen. There are several proc
esses and many variations of processes
in the recovery of nitrogen from the
air The first American plant was set
up al Niagara Falls by c. S. Bradley
and r. Lovejoy. 1t was not a CONNER
cial success and it closed in 1904. But
the failure taught valuable lessons as
to how nitrogen could be extracted
from the air on a commercial basis at
a profit. The Southern Electro Chem
ical Company's factory at Great Falis,
S. c.. recently installed, is drawing nj
trogen from the air and turning out
about four tons day Of nitric acid at
its works.
Newspaper readers will remember
-I,t t1S <,S
the United States Army. in report
asked Congress to give him a special
appropriation to buy a reserve stock of
nitrates specially for the army. or else
for manufacturing nitrogen from the
air. In the Senate discussion of the
proposed nitrate plant the process of
taking nitrogen from the air was de-
and the greatest cold obtainable are
utilized in making cyanamide. By the
intense heat of the electric furnace
5000 degrees Fahrenheit-lime and
cium carbide. This is powdered and
placed in large drumlike ovens and
again brought by electricity to a white
heat. In the meantime wonderful ma
chimes are making liquid air by COM
pressing and cooling over and over
again clear. pure air, until at $50 de-
grees below zero. the air liquefles. Air
is four-ffths nitrogen and one-fifth
oxygen. When the liquid air Is warmed
little. only pure nitrogen gas is given
of. This Is pumped into m-shaped
ovens containing the white hot carbide,
by which 1t is absorbed and in which 1t
is permanently fxed. to be released
only when in the soil, and for the feed
ing of the plants. This product. when
cooled, ground and processed with spe-
cial machinery, is cyanamide."
So far as known the worlds greatest
nitrogen-producing plant is at odda,
Norway. A year and half ago it was
producing $4,000 tons of calcium ear
bide and $4,000 tons of calcium cyana-
mide per annum, in works run entirely
by water. 1t has been reported that the
capacity of the works has been en-
larged and that they are now produc-
Ing at the rate of 100000 tons of
cyanamide per year.