Chemistry Reference
In-Depth Information
MANUFACTURE OF ALCOHOLS
Methyl alcohol:
heat
(1)
Wood
CH
3
OH
catalyst
heat, pressure
(2)
CH
3
OH
CO
+
2H
2
Ethyl alcohol:
yeast
(1)
Sugar
CH
3
C
H
2
OH
(2)
CH =CH
+
Sulfuric acid
CH
3
CH
2
OSO
2
OH
2
2
water
Sulfuric acid
CH
3
CH
2
+
OH
Higher alcohols:
CHO
catalyst
RCH=CH
2
+
CO +
H
2
RCHCH
3
+RCH
2
CH
2
CHO
heat, pressure
catalyst
hydrogen
CH
2
OH
+RCH
2
CH
2
CH
2
OH
RCHCH
3
The simple alcohols were originally prepared from natural products; e.g.,
the heating of wood in the absence of air (destructive distillation) produced
methyl alcohol, hence the name “wood alcohol.” It is now made from carbon
monoxide and hydrogen at high temperature and pressure over a catalyst.
Ethyl alcohol made by the fermentation of sugar in the presence of naturally
occurring yeast (making of wine) goes back to the beginning of man's history.
It is also made by the fermentation of grain or potatoes from which it gets
the name of “grain alcohol.” It is also made industrially by the reaction of
ethylene with water using sulfuric acid as a catalyst. Higher alcohols are
made by reacting olefins with carbon monoxide and hydrogen (a mixture
called synthesis gas) to produce a mixture of aldehydes, which are then
reacted with hydrogen gas over a catalyst to produce the corresponding
alcohols. The latter reaction is called
hydrogenation
.
