Evening star., 1942-06-08
Second OF a SerieS.)
By THOMAS r. HENRY.

BY THOMAS r. HENRY.
The cheapest-probably by long
odds-source of butadiene, major
constituent of the buna types of
synthetic rubber, is crude petro-
leum.
When this petroleum comes from
the ground it Is mixture of sew
eral hundred different kinds of car
bon hydrogen molecules. These
start with methane. or marsh gas,
with one carbon and four hydrogen
atoms in its molecule When an
oxygen atom is added 1t becomes
methyl. or wood. alcohol. They
continue to the heavy asphalts
with several hundred carbon and
perhaps several thousand hydrogen
atoms in their gigantic molecules.
This crude oil must be split by
various distillation processes. The
fraction running from approximate
ly 5 to IS carbon atoms is taken
of and becomes gasoline. The frac-
ton from Is to about 100 carbon
atoms. which includes kerosene, is
taken of and becomes fuel oil.
Were Waste Products.
Below the gasoline fraction are
four gasses-methane, ethane, tryp-
tame and butane. In the past they
have been mostly waste products
which it was necessary to remove
before gasoline could be used as
motor fuel. They were burned
to keep the giant stills in opera
ton. Only a little of the highly
volatile butane. with four carbon
atoms. has been kept in winter gas
oline so that motors would start
easier.
They will not start so easy on
cold mornings this winter. by the
way. for the hitherto waste butane
has become one of the most val
liable substances on earth. To its
carbon atoms are linked 10 hydro
gen atoms.
First two of these hydrogens are
knocked of. usually by reactions
with the war gas. chlorine. This
forms another gas, butylene. with
eight hydrogen atoms. When two
of these are knocked of. in the right
way. the chemist gets the elusive
four carbon six hydrogen molecule
which Is butadiene
Difficult Chemical Process.
1t is an extraordinary complex and
difficult chemical process. Formerly
most of 1t had to be carried out in
a bath of ice water. Now, through
process developed by the Shell
Oil Co.. it can be done at tempera-
lures from $50 to 400 degrees Faren-
heit. thus vastly speeding and cheap
ening the process. Still, experts say
it is one of the most complicated
operations in industrial chemistry.
The cost still is not precisely de-
termined. 1t is estimated at from
10 to II cents a pound.
1t also may be possible to build ur
butadiene. The second simplest frac-
ton of crude petroleum is the gas
ethane 1t consists of two carbon
and six hydrogen atoms. Add an
OhHkCIl dllu IL UCIOlllCo NtliS
alcohol. If two ethane molecules
with all the hydrogen atoms knocked
from one of them can be combined
the result probably will be butadiene
This process still remains to be
worked out. Oil company chemists
are hard at work mastering the
details.
Promises Cheaper Butadiene.
Very recently still another process
has been worked out which promises
still cheaper butadiene. 1t forms
the basis of late accomplishments OF
Standard Oil Co. chemists, although
something of the sort has been pos
sible for several years. By means OF
it butadiene can be extracted dl-
rectly from crude petroleum by reg
ulating the conditions of the crack
ing process. 1t does not exist. per
Sc, in the oil which comes from the
ground but must be created In the
distillation itself.
With this process. 1t Is claimed
four things can be obtained at the
same time without further manipu-
Ia ation-butadiene, styrene. which is
the second essential ingredient of
synthetic rubber. 100-octane avia-
ton gasoline. and toluene. needed
in large quantities for war explo-
siveS.
BY any of these processes the oil
companies are prepared to make
butadiene in as great quantities as
are needed-when the plants are
ready. There are very great OBJ