PROCESS AND APPARATUS FOR PURIFICATION OF ALCOHOL
Year: 1884

page_text: I, CHARLES DENTON ABEL of N° 28 Southampton Buildings, Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent do hereby
declare the nature of the said invention for "PROCESS AND APPARATUS FOR
PURIFICATION OF ALCOHOL" to be as follows:-
The alcohol obtained by fermentation of saccharine matters is mixed with water,
generally about 50 per cent, and contains a number of secondary products usually
known as essential oils, along with a proportion of aldehyde. The object of this
invention is to remove these impurities so as to produce an alcohol almost pure and
of good flavour. The process for this purpose is founded on the principle that these
essential. oils and aldehyde are soluble in hydrocarbons which are themselves
scarcely soluble in alcohol at 50°. Thus if crude alcohol diluted to this extent is
agitated with a pure hydrocarbon such as essence of petroleum, the essential oils
and aldehyde are taken up by the hydrocarbon, which can be decanted and
purified for future use by frequent washings with sulphuric acid at about 66° and
finally with anhydrous or fuming acid. A convenient form of apparatus is of the
following description. A deep vessel containing the dilute alcohol has the hydro-
carbon pumped into it through a perforated pipe near its bottom. The hydrocarbon
rising in subdivided condition through the liquid clears it of the impurities, and its
arrival at the top may be seen in a glass globe at the top of the vessel, or in a
receptacle provided with sight glasses. From this globe or receptacle the mixture
of hydrocarbon and the impurities descends by a pipe to the bottom of a second
vessel charged with water and provided with a number of horizontal baffle plates.
The hydrocarbon mixture rises in a zig zag course through the water, and from the
top of the water vessel it descends to the bottom of a similar vessel charged with
chloride of calcium or a solution thereof. After rising through this, the hydro-
carbon descends to the bottom of a deep lead-lined vessel charged with sulphuric
acid at 66°, and finally it is made to rise through a vessel containing fragments of
marble. After several hours of repose the hydro carbon is ready for subsequent use.
The process is facilitated by dissolving in the dilute alcohol a little common salt or
other neutral salt readily soluble in the liquid.
,
-
T
1
C
1004
ABEL & IMRAY,
Agents for the Applicant,
28, Southampton Buildings,"
London, W.C.

page_text: I, CHARLES DENTON ABEL, of No 28 Southampton Buildings, Chancery Lane
in the County of Middlesex, Consulting Engineer and Patent Agent, do hereby
declare the nature of my invention for "PROCESS AND APPARATUS FOR PURIFICATION
OF ALCOHOL" and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
This invention relates to an improved process and apparatus for purifying
crude alcohol in order to obtain, by one single process of distillation, the total
amount of ethylic alcohol contained therein with practically perfect elimination
of the secondary products contained therein, usually known as essential oils, and
aldehyde.
In fermenting saccharine matters, there is obtained a mixture of alcohol, of organic
matters, and of water, which is distilled in order to obtain an alcoholic solution
of increased strength which generally contains about 50 per cent of water. By
the said fermentation there is generally produced, in addition to the ethylic
alcohol, numerous secondary products, the nature of which varies according to the
fermentable matter employed, and according to the mode of conducting the
operation. Among these products there are invariably homologue alcohols of
the series CN H2 +20, as also their ethers, and in particular butylic and amylic
alcohols. There is also present acetylic aldehyde resulting from the partial
oxidation of the alcohol during the fermentation.
In order to obtain from the crude materials a pure alcohol of good flavour, it was
heretofore necessary to employ distilling apparatus of a very complicated nature
and operating with fractional distillation. The absolute separation of the essential
oils and aldehyde was only effected by very careful and expensive processes, and
notwithstanding all the precautions taken, the alcohol of commerce, generally, still
contains a percentage of the foreign matters which are of a more or less deleterious
nature. The present invention has for its object to obtain the whole of the ethylic
alcohol in a perfectly pure condition by previously separating the essential oils and
aldehyde, so that it is only necessary afterwards to separate the water by afsingle
process of distillation, in order to obtain pure alcohol. The improved process is
based on the solubility of the essential oils and aldehyde contained in alcohol at 50°
Beaume in certain solvents. Thus in agitating crude alcohol at 50° with a hydro-
carbon, for example, the hydrocarbon not being soluble in alcohol at 50° Beaume,
exercises a dissolving action upon the essential oils; these products being relatively
but little soluble in weak alcohol but soluble in any proportion with hydrocarbon
The aldehyde, although soluble in any proportion in aqueous alcohol, is also
dissolved; but only by means of repeated, contact. After having agitated the
mixture and then left it to subside, the hydrocarbon will be found 'swimming on
the surface of the weak alcohol and containing almost the whole amount of the
essential oils and a part of the aldehyde previously contained in the alcohol.
If, instead of operating upón crude alcohol, it is simply desired to purify alcohols
already rectified but containing still impurities, it would be necessary to reduce
these alcohols in strength in order to prevent the solution of the hydrocarbon in

page_text: the alcohol. As solvents are employed liquid hydrocarbons which are by preference
taken from the volatile products of petroleum such as are generally known as
essence of petroleum. These essences are purified and rendered inodorous by the
known method of repeated washing by means of sulphuric acid at 66° Beaume and
finally with sulphuric anhydride.
Mode of operation. As already stated, the process may be carried out by
repeated washings followed by decantations. For this purpose, the crude alcohòls
being introduced into a hermetically closed vessel of large dimensions, there is
introduced into the vessel a certain quantity of hydrocarbon; and by any suitable
mechanical contrivance a violent agitation is produced, after which, the mixture is
allowed to rest, in order, afterwards, to decant the hydrocarbon saturated with oils,
after which, the process is repeated until the bydrocarbon, gives off no more odour
in evaporating. For renovating the hydrocarbon it is washed with sulphuric acid.
This method of operating being, however, not very practical for working on a large
scale, it is preferred to carry out the process by means of apparatus which I will
now describe.
The construction of the apparatus employed is shown in elevation and partly in
section on the accompanying drawing. A is a cylindrical reservoir of sheet metal
containing the crude alcohol; on the upper part is fixed a glass globe a or, in place
hereof, may be employed a small metal chamber with glass sight-holes. At its
lower part, the reservoir A has a cock b which is connected externally, by a pipe,
with a pump p and internally with a finely perforated pipe t. B is a cylindrical
vessel, having internal baffle plates c, which is filled with pure water and is
connected by a pipe d and a cock e with the upper part of A. C is a vessel similar
to the preceding one, a communication being established between its lower part and
the top of the preceding one. It is filled with a saturated solution of chloride of
calcium. D is a lead cylinder also containing baffle plates of lead f and filled with
sulphuric acid at 66° Beaume. Lastly, E is a vessel charged either with pieces of
marble or of any other carbonate such as carbonate of lime.
The vessel A is filled with the crude alcohol to be treated, the globe a being
left empty. The four other vessels are filled with the several liquids above
mentioned. The pump p is now made to force hydrocarbon into the vessel A,
the hydrocarbon in passing rapidly in a finely divided state through the crude
alcohol takes up the impurities therefrom into the glass globe. The hydro-
carbon being continually introduced, it flows from the globe through the pipe d
into the bottom of the vessel B and passing up through the water contained
therein the traces of alcohol carried with it are taken up by the water. From the
top of the vessel B, the hydrocarbon passes to the bottom of the vessel C and
in passing up through the chloride of calcium contained therein, the watery
constituents are separated from the hydrocarbon. It then passes into the bottom
of the vessel D and in rising through the sulphuric acid contained therein, the
essential oils and aldehyde are separated from the hydrocarbon, forming sulpho-
conjugated acids.
The hydrocarbon is thus entirely regenerated and in passing through the vessel E,
charged with pieces of marble or other suitable substance, any traces of sulphuric
acid contained in the hydrocarbon become neutralised, so that on issuing from the
vessel E the bydrocarbon is perfectly pure and is again forced by the pump p into the
vessel A. The above described circulation of the hydrocarbon being continued until
it is found that the crude alcohol is sufficiently purified, it is then only necessary
to allow the liquid to remain quiescent for several hours, in order to obtain the
complete separation of the hydrocarbon, after which, the alcohol is withdrawn for
the purpose of rectification. In order to increase the insolubility of the essential
oils and their ethers in the crude alcohol, and also to obtain a more rapid separation
by means of the hydrocarbon, a cheap salt, readily soluble in crude alcohol, may
be advantageously mixed therewith, such as, for instance, chloride of sodium.
Although the above improved process has been described as applied to crude

page_text: alcohols at 50° Beaume, it will be readily understood that it is applicable to all
Crude alcohols whether above or below 50° Beaume from whatever source they may
be produced.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1, The method substantially as herein described, of separating from crude
alcohol, impurities such as essential oils and aldehyde by repeated washing with
a solvent.
2, The use for the purification of alcohol by the method referred to in the
preceding claim, of pure hydrocarbons extracted from petroleum, or other liquid
that will not dissolve in crude or dilute alcohol but is capable of mixing in any
proportion with essential oils and aldehyde.
3, The admixture with the alcohol to be treated according to the method referred
to in the preceding claims, of salts soluble in the said alcohol, such as chloride of
sodium, in order to increase its density and to diminish the solubility of the
essential oils therein.
4, The use of apparatus constructed and operating substantially as herein
described with reference to the accompanying drawing, for effecting the separation
of impurities from alcohol by means of hydrocarbons and for regenerating the
latter.