Improvements in the Production or Extraction of Glycerine from Waste Products.
Year: 1898

page_text: Date of Application, 26th Apr., 1898-Accepted, 23rd Dec., 1898
COMPLETE SPECIFICATION.
Improvements in the Production or Extraction of Glycerine from
Waste Products.
I, COUNTESS ROMAIN DE DIESBACHI (née Jeanne de Beaurepaire Souvagny), of
the Chateau de Remaugies par Montdidier, Department of the Somme, in the
Republic of France, do hereby declare the nature of this invention and in what
manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The wash relating to the distillation of wine, grain, molasses, beet roots, and
speaking generally, from any alcoholic fermentation, contains glycerine, which
is formed during the alcoholic fermentation, at the expense of the sugar; this
glycerine, partly drawn over by the ebullition, is retained by the distilling-column
or by the analysing-apparatus, it can therefore be recovered from these residues,
in which it is lost under ordinary circumstances.
The object of this invention is to extract the glycerine from this wash or
residues.
The process consists essentially in first evaporating the wash to a suitable
degree, in a closed receptacle, so as to enable the salts to deposit; in subse-
quently neutralizing this evaporated wash or residue by means of a suitable
chemical agent; and in finally causing superheated steam to pass into this
concentrated wash, at an appropriate temperature, so as to disaggregate the mass
and to carry off the glycerine which is condensed in a suitable apparatus, pro-
vided for this purpose.
It has, already been attempted, to extract glycerine from distillers' wash by
combining the glycerine with fatty acids, so as to form glycerides, insoluble in
water, which are separated by washing, and to treat the said glycerides by way
of saponification with the view of obtaining the free glycerine. This attempt
has not, however, yielded any practical result.
Again the lyes from soap-works have been treated with lime with a view to
neutralizing them, and superheated steam is employed for the purpose of carry-
ing off the glycerine from the residues of soap and stearine works.
In order to carry the process into practice, the distillers' wash to be treated
is so evaporated as to reduce the same to a suitable degree of concentration.
This concentration is preferably effected in a closed vessel, in order to enable the
salts to deposit. This deposition of the salts is advantageous, because by ridding
the wash thereof, the chances of injurious combinations, occurring in the
subsequent treatment, are far less, and the quantity of glycerine, obtained, is
greater.
In practice evaporation is produced by putting the wash into a tank closed,
but for a pipe leading below the level of water in an open vessel so that the
water vapours are condensed. The tank it will be seen is thus closed to the
outside air so that no chemical or mechanical action of that air on the contents
can take place. The wash is submitted to a gentle heat of not more than 70° C..
in order to evaporate the water contained in it and so obtain a more dense and

page_text: compact product. This concentration should not, however, be carried farther
than what is required to evaporate about 10ths of the water, so as to prevent
the formation of acroleine by the dehydration of the glycerine.
The kind of salts deposited vary according to the nature of the residue or
wash. Generally they are chlorides, tartrates, sulphates, or phosphates of
potassium, calcium, or aluminium.
The second operation consists in treating this concentrated wash, after it has
been partly freed from its salts, by an appropriate chemical agent, so as to
neutralize the free acids thereof, in order that these acids may not be enabled to
act on the glycerine by way of fixing or decomposing the same under the influ-
ence of the high temperature. As a neutralizing agent I preferably employ
lime, but it may be soda.
66
Washes of molasses, beet root etc., contain strong sulphuric or hydrochloric
acids, because these have been purposely added to the products submitted to
distillation, in order to "saccharify" the grain or intervert" (invert) the sugar
of the molasses or beet root. In grape or wine wash, tartaric acid is also found.
These free acids would decompose the glycerine at the 'distilling temperature.
It is therefore important to neutralize them.
The neutralizing agent when lime may be either in powder or as milk of lime.
The quantity of lime is based upon that required to fix the free acids and varies
naturally with the quantity thereof.
The lime salts formed (sulphates, tartrates, etc.) are precipitated and are
collected with the excess of lime, if any, at the bottom of the tanks. The
liquid, extracted from the salts and lime, is added to the mass to be subsequently
distilled or treated by superheated steam, and the lime and salts form bye
products.
The third operation consists in treating the concentrated wash, after it has
been freed from the greater part of its salts and after its neutralization, with
superheated steam, which must be of a suitable temperature, in order that the
glycerine may be vaporized without being, however, decomposed.
The distillation should take place at a low pressure; the required temperature
(about 190° C.) should be reached gradually with a pressure not exceeding one
atmosphere. As soon as 30° C. are reached a 50 centimetre vacuum is made in
the apparatus, which is maintained till the end of the distillation.
For this latter operation a separating apparatus may be used of the kind, for
example, which are at the present time employed in stearine or soap works for
the distillation of the raw glycerine. A suitable apparatus for the purpose is
illustrated in the accompanying drawing such apparatus being composed of a
furnace a, a retort b, two coils c and d, surrounded by a tank e, and two closed
receiving vessels f and g. The hot gases of combustion, leave the hearth a',
and, following the direction of the arrows, around the baffle plates a², enter the
flue a³, running spirally round the retort b and escape by the chimney opening at.
When the temperature in the retort is sufficiently high, which can be seen by
the thermometer h, dipping into it, the damper as is closed and a opened, so
that the hot gases escape by the opening a.
Tubes &, containing steam to be superheated, are placed in the furnace in such
a way as to give the greatest possible heating surface. These tubes are all
united, and the end one passes into the retort where, after forming a coil, it
finishes in a rose ¹ placed at the bottom of the retort. This rose has only holes
at the sides, which allow the superheated steam to penetrate the mass contained
in the retort, carrying with it the ammonia and glycerine. The ammonia, being
much more volatile than the glycerine, is first driven off and passes by the upper
tube c, the tap d¹ being closed. This tube e descends to the tank e which is
filled with cold water, and, passing through it in a coil, conducts the ammonia
into the closed vessel g.
When all the ammonia is extracted, the glycerine begins to be carried along
by the superheated steam. The tap is then closed and d¹ opened. The

page_text: glycerine descends by the pipe & which passes in a coil through the tank filled
with cold water and conducts it to the closed vessel f.
The retort is put into communication with an ejector. by means of a tube
provided with a vacuum gauge ¹. The residues or washes are contained in a
vessel X and are introduced into the retort by the funnel y closed by a valve y¹.
The retort has also a blow off cock 7. The superheated steam supply pipe has
a pressure gauge and tap.
Finally the condensed glycerine, is purified by any suitable means, according
to the impurities contained therein, which are dependent upon the varying
nature of the waslí treated and upon the degree of purity desired to be obtained.
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 process of extracting the glycerine, contained in distillers' wash from
wine, grain, molasses, beet-roots and the like and in general from residues of
any alcoholic fermentation; which consists in causing superheated steam to pass
into the wash, previously prepared for this purpose, which steam carries the
glycerine with it, and subsequently condensing and purifying the glycerine
substantially as described.
2. The process of extracting the glycerine, contained in distillers' wash
resulting from wine, grain, molasses, beet-roots and the like and in general from
residues of any alcoholic fermentation consisting in concentrating the wash to a
suitable degree by evaporation, then treating it with a chemical neutralizing
agent, then subjecting the same to the action of superheated steam at a suitable
temperature, and finally condensing and purifying the glycerine substantially as
described.
3. The process of extracting the glycerine contained in distillers' wash resulting
from wine, grain, molasses, beet-roots and the like and in general from residues of
any alcoholic fermentation, consisting in concentrating the wash to a suitable degree
by evaporation in a closed receptacle, to rid the same from the salts by deposition,
then treating the same with lime, in order to neutralize its free acids, then sub-
jecting it to the action of superheated steam at a suitable temperature, and finally
condensing and purifying the glycerine, carried off by the superheated steam,
substantially as described.
020
1000
PHILIP M. JUSTICE,
55 and 56, Chancery Lane, London, Chartered Patent Agent,
For the Applicant.