Process of Distilling Glycerine and similar Liquids, and of Treating the Residuum Obtained after Distilling Glycerine.
Year: 1893

page_text: Date of Application, 20th Dec., 1893
Complete Specification Left, 26th June, 1894-Accepted, 6th Oct., 1894
PROVISIONAL SPECIFICATION.
Process of Distilling Glycerine and similar Liquids, and of Treating
the Residuum Obtained after Distilling Glycerine.
I, JOSEPH VAN RUYMBEKE, a subject of the King of Belgium, but now
residing at No. 78 Wall Street, in the City of New York, County of New York
and State of New York, United States of America, Chemist, do hereby declare
the nature of this invention to he as follows:-
The material to be treated, which may be either partly refined glycerine or a
saturated solution of common salt in glycerine, is placed in a suitable still and is
heated constantly during the process of distillation. A steam coil within the still
is convenient for this heating. During the distillation a high vacuum (say twenty
eight inches or more) is maintained in the still, which is produced preferably by a
vacuum pump and free steam is injected into the liquid any where below its surface
and preferably at some distance above the bottom of the still. Before being
injected into the liquid the free steam is allowed to expand, and, to overcome the
loss of heat thus given up by this free steam in expanding, I reheat the said steam
before it enters the still, until, in its expanded form, it has regained its original
temperature or any temperature desired, it being understood that the temperature
should be always kept below the point at which tarry or other decomposition
products are formed. This injection of expanded steam of the proper temperature
and the continued heating of the material, causes the glycerine to be distilled off
very rapidly, and the product thus obtained is of great purity, being practically
free from decomposition products and therefore well adapted for the manufacture
of nitroglycerine.
By allowing the free steam to expand and by then reheating it before entering
the still, I am enabled to carry on my process with greater economy since a much
lower boiler pressure is necessary. As an illustration, I have found that the free
steam ordinarily expands in the still and is reduced in temperature about one
hundred degrees Fah., so that without reheating it, in order to get a temperature
of three hundred degrees Fah. at the still, it will be necessary to maintain the
steam at about four hundred degrees Fah. at the boiler. By first expanding the
steam and by then reheating it by the boiler steam, it is necessary to maintain
the steam at the boiler only slightly above the proper temperature of the steam
for distillation.
The means by which this free steam is reheated before entering the still are
subordinate to the spirit of the invention. Such reheating may be effected by
means of steam from the same boiler which supplies the free steam, in which case
it will be evident that the free steam, after expanding, will be reheated to a
temperature somewhat lower than the temperature of the boiler steam, i.e. only a
part of the heat lost in expansion is compensated for; but the free steam may also
be heated by steam froin a separate boiler, whereby the free steam can be heated
to any desired temperature. Other means for reheating the free steam are
apparent, such as by means of a bath of molten metal having a low melting point,
like lead, or by hot air, but in any case the means for reheating the free steam
should be such as will prevent material variations of its temperature, either to
reduce such temperature to so low a point as to be insufficient for distillation, or to
increase such temperature to so high a point as to decompose the material.
In distilling crude glycerine by means of free steam first expanded and then
reheated, the residue or "foots in the still will be practically free from
lecomposition products. These foots contain, in addition to the glycerine,

page_text: generally about five per cent. of salt, from twenty to thirty per cent. of acetate of
sodium, and from ten to fifteen per cent. of sodium salts of non-volatile organic
acids, together with some minor impurities. Ordinarily these organic salts of
sodium do not precipitate, and all the glycerine is not therefore distilled off from
the foots. By first converting such sodium compounds into salts of inorganic acids,
such as sulphuric or muriatic acid by addition of such acids or either of them to
the foots, a precipitate will be formed which can be readily separated by settling
or filtering. Such precipitate carries down with it most of the non-volatile acids
in the foots; and the acetic acid set free and remaining may be volatilized off and
collected in any suitable manner, or be passed over lime-stone to produce calcium
acetate. By thus treating the foots I obtain a practically clear liquor containing
a large percentage of glycerine and capable of being distilled as described in the
first part of this Specification, either separately or when mixed with crude
glycerine. Instead of adding the inorganic acid or acids directly to the foots it
is preferable to mix the proper quantity of such acid or acids with soap lye,
chemically purified and boiled down to salting point, and this acidulated lye is
then mixed with the foots, so that the resultant clear liquor will contain a larger
percentage of glycerine.
T 1000
JOSEPH VAN RUYMBEKE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Process of Distilling Glycerine and similar Liquids, and of Treating
the Residuum Obtained after Distilling Glycerine.
I, JOSEPH VAN RUYMBEKE, of No. 78 Wall Street, in the City of New
York, County of New York, and State of New York, United States of America,
Chemist, 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 :—
My said invention will be better understood by reference to the drawings, in
which :
Figure 1, is a diagrammatic view of a portion of a distilling plant, for the purpose
of illustrating said distillation process, and,
Figure 2, a side elevation of a convenient form of still and reheater in which the
novel steps of said process can be carried out.
In both of the above views corresponding parts are designated by the same letters
of reference.
Referring to Figure 1, A represents a still; a, is a heating coil in the still; b, is
an annular distributing pipe, perforated on its under side for injecting steam into
the still, such steam being prepared as I will presently point out; B, is a condenser;
C, is a receiving tank for the condensed distillate; D, is a vacuum pump; E, is a
heating cylinder preferably adjacent to the still c, is a steam coil within said heating
cylinder, which I will hereafter refer to as the expansion coil; d, is a pipe through
which steam is admitted to the expansion coil, and which should either be of smaller
diameter than the expansion coil, or else, should be provided with a valve so that
the inlet opening into the expansion coil may be made less than the outlet opening
of the said coil and may have any desired relation to the latter opening as to make
is a
it possible to obtain any desired expansion of the steam from the boiler; e,
pipe which connects the upper end of the expansion coil with the distributing pipe b;
f, is a pipe which connects the heating cylinder E, with any suitable surce of steam
supply, such as the steam boiler which supplies the injected steam; g, is a pipe
which connects said boiler or other source of steam supply with one end of the

page_text: coil a; h, is a pipe connected with the other end of the coil a, for carrying off
water of condensation from said coil, or, when there is no appreciable condensation,
for carrying off steam from said coil to any point desired; and, h¹, is a drip pipe
for the heating cylinder E.
In Figure 2, F, F, are heavy standards, four of which are used; G, G, are
heavy metal braces bolted to the upper ends of said standards, and H, H, are
cross braces, such braces being generally made of ordinary I-irons. The still A
is supported on said braces GH, by means of brackets i; and the heating
cylinder E, is also supported by means of similar brackets at the side of the still.
Both the still A, and heating cylinder E are made of boiler iron or steel of
sufficient thickness to withstand high pressures.
At the bottom of the still A, is a heavy metal door j, adapted to be bolted in
place and packed tightly to prevent leaking. The said door j, is provided with a
draw off pipe k, and a larger draw off pipe l, is generally provided at one side of
the said door. Both of said draw off pipes k, l, are provided with gate valves
therein, and by means of said pipes the residue in the still can be drawn off. The
door j, is used for the purpose of allowing the interior of the still to be reached
for the purpose of cleaning, &c. A pipe m, at the side of the still enables
the material which is to be distilled to be introduced therein, said pipe being
provided with gate valves which are to be closed when a sufficient quantity of
material has been introduced into the still. A water column n, at the side of the
still enables the amount of material therein to be readily determined. At the top
of the still extends the eduction pipe o, which leads to the condenser. p, is a pipe
which connects with a boiler or any other suitable source of steam supply, and,
is a four-way casting at the end of said pipe. Extending down from the casting,
midway between the still A, and the reheater E, is a steam piper, provided with
an enlarged condensation chamber s, at its lower end for receiving any water of
condensation which may accumulate in the steam pipes p or r.
The condensation
chamber is provided with a drip pipe, at its lower end, by means of which the
water of condensation may be removed therefrom. Extending out from the steam
piper, directly above the condensation chamber s, and entering the heating
cylinder E, is a steam pipe t, which connects with the lower end of the expansion
coil c, and which is of smaller diameter than the pipe of said expansion coil,
in order that steam in passing from said steam pipe t, into the expansion coil c,
will rapidly expand, its temperature being correspondingly diminished, as will be
understood. The object of allowing this steam to expand in this way will be
presently pointed out. The steam pipe t, is provided with a valve, therein, by
means of which the amount of steam passing through said pipe may be regulated.
It is obvious that the pipe t, may be of the same size as, or even larger than the steam
coil e, and that the valve ¹ may yet be so adjusted as to allow the steam to expand
in the steam coil as explained. The upper end of the expansion coil connects with
a pipe u, which passes out through the wall of the heating cylinder E, and enters
the still A, being connected at its lower end to the annular distributing pipe b,
preferably perforated on its under side as shown. In practice it is desirable that
the pipe, should be of the same or of a larger diameter than the expansion coil
so that the steam from the expansion coil may pass freely through the same. Pipe u,
is generally provided with a thermometer ³, between the still A, and the heating
cylinder E, where it may be readily inspected and by means of which the
temperature of the injected steam can be determined. Extending out from one of
the horizontal portions of the casting 9, is a pipe v, which leads into the top of the
heating cylinder E, and by means of which the said heating cylinder may be
supplied with steam from the boiler. The said pipe v, is provided with a valve o'
therein, by means of which the supply of steam to the heating cylinder can be
adjusted. A drip pipe h', at the lower end of the reheater is provided to draw off
any accumulated water of condensation. Extending out from the casting y is a
pipe, which passes into the still, and connects with the steam coil a, therein, such
pipe being provided with a valve ¹ therein, by means of which the supply of steam
9

page_text: to the coil a, can be readily regulated. Any water of condensation which may
accumulate in the coil a, may be removed therefrom, through the drip pipe /, at the
lower end thereof.
In carrying out said distillation process I proceed substantially as follows,
attention being particularly directed to Figure 1.
The material to be treated, which is either partly refined glycerin, or a saturated
solution of common salt in glycerin, is placed in the still A so as to fill the still to
about one-third of its capacity. Steam is now introduced through the pipe f, and
passes into and heats the heating cylinder E from which the water of condensation
is conducted away by means of the drip pipe . Steam from the boiler is also
passed through the pipe, and steam coil a, by means of which the material is
independently heated during the process of distillation. The steam from the
boiler has of course a temperature above that of the boiling point of the material
being distilled. To make distillation more rapid and to lower the temperature of
distillation a vacuum of about twenty-eight inches should be maintained in the
still by the vacuum pump D. Free steam preferably from the same boiler is
introduced through the pipe d, into the expansion coil c, and by reason of the large
size of the latter, this steam will rapidly expand and will consequently suffer a
diminution in temperature. Since however, the expansion coil c, is heated by free
steam in the cylinder E, the expanded steam in said coil will be reheated to about
the temperature of such free steam, or slightly below such temperature. It is
obvious that the free steam may be allowed to expand directly into the heating
cylinder E, and that it may be reheated by confined steam in a coil within said
cylinder. It is further evident that other means for reheating the steam after
expansion has taken place, may be used, such as by a steam jacket surrounding the
heating cylinder E, or by hot air, or by means of a bath of molten metal having
a low melting point like lead; but in any case it is desirable that the means of
reheating the free steam should be such as will prevent material variations in
temperature. From the expansion coil c, the steam which has been thus expanded
and then reheated passes through the pipe e, and is injected into the material
through the perforated distributing pipe b. This injection of expanded and
reheated steam will rapidly distil the material, and will carry the distillate over to
the condenser B, where it condenses and is caught by the receiving tank C, from
which it may be removed and concentrated.
The operation of the preferable form of still and reheater shown in Figure 2,
is substantially the same as that described, and will be readily understood. Steam
from the boiler and under boiler pressure is conveyed from the pipe p into the
pipes r, v and r. The steam from the pipe r, passes through the small steam pipe (,
and thence into the expansion coil c, where it rapidly expands as before explained
owing to the large size of the latter. The diminution in temperature of this
expanded steam is practically regained by heat absorbed from the free steam within
the heating cylinder E, conveyed thereto by the pipe . The amount of steam
supplied to the heating cylinder may be adjusted by the valve v', and should be
sufficient to reheat the proper amount of expanded steam up to the temperature
desired for distillation.
Steam from the pipe, enters the steam coil a, and beats the liquid in the still
during the distillation.
The particular advantage which properly expanded and reheated steam possesses
in distillation is, that the steam expands but slightly and cousequently causes
hut slight absorption of heat due to such expansion. When on the other hand,
ordinary free steam is used for distillation, it always expands very much in the
still, and absorbs heat from the contents of the still so that distillation is
retarded not only because of the diminution in temperature thus produced in the
material, but also because of the varying quantities of condensed steam retained
by the material.
With super-heated steam, that is to say, steam which has been heated to a
high temperature by fire heat or by other means, the same objections are found,

page_text: and although the diminution in temperature suffered by super-heated steam in
expanding in the still, whether a vacuum is used or not, may not be sufficient
to cause condensation, yet such steam is undesirable for the distillation of
glycerin or similar materials, since decomposition products will be inevitably
formed.
The glycerin prepared as above described may after concentration be again
distilled to eliminate the last traces of combined chlorine.
Although to obtain the best results the operation should be carried on in a
vacuum and with means of heating independent of the injected expanded and
reheated steam, yet to effect the distillation with the omission of either the vacuum
or the independent means of heating, or both, is also within the scope of this
invention, the essence of which consists in the injection into the glycerin of
expanded and reheated steam.
In the distillation of crude glycerin, the common salt and sulphate of soda,
with some other impurities are readily separated, but there are some organic
salts of sodium which do not precipitate, and which yield, after the distillation
of the glycerin, a residuum containing a large percentage of glycerin (thirty-
three per cent. and over) but which cannot be distilled off in the ordinary way.
I find that this residuum contains, in addition to the glycerin, generally about
five per cent. of salt, from twenty to thirty per cent. of acetate of sodium, and from
ten to fifteen per cent. of sodium salts of nou-volatile organic acids, together with
some minor impurities. By converting the sodium compounds in said residuum
into sults of inorganic acids, such as sulphuric or muriatic acids, the sodium
sulphate or chloride formed will readily precipitate, after which the acetic
acid set free may be volatilized off, whereby a practically clear liquor will be
obtained, containing a large percentage of glycerin, and capable of being easily
distilled.
Therefore, in treating the residuum of glycerin distillation for the purpose of
obtaining glycerin therefrom I proceed in detail as follows:
I first find the percentage of sodium carbonate which the residuum will yield by
combustion, which can be determined by incinerating a small portion of the
residuum, and having ascertained this I then calculate the amount of sulphuric
or muriatic acid which will be necessary to neutralize the sodium salt therein.
I then mix the proper amount of sulphuric or muriatic acid thus ascertained,
with soap lye, chemically purified and boiled down to salting point, the amount of
lye used being about equal to the residuum to be treated. This acidulated lye, is
then mixed with the residuum, and the sodium compounds therein are immediately
converted into sodium sulphate or chloride, and these salts are precipitated. In
practice I find that most of the non-volatile acids are also precipitated and carried
down with the sulphate or chloride.
The precipitated sodium sulphate or chloride and the non-volatile organic acids
may then be removed from the solution by settling or filtering. The insoluble
acids readily separate from the sulphate or chloride when the latter are re-dissolved
for the purpose of purifying. The solution being removed from the precipitate, is
now heated to drive off the water and the volatile acids therein, consisting almost
entirely of acetic acid, which latter generally corresponds to about two-thirds of
the sulphuric acid used. This acetic acid can be collected in any suitable way, or
may be passed over limestone to produce calcium acetate. After this evaporation
a clear liquid will be obtained, containing a large amount of glycerin, about
eighty per cent., which may be distilled off in any suitable way. I find in practice
that it is not convenient to continue the distillation of the glycerin beyond the
point where the residuum contains from fifty to sixty per cent. of glycerin, because
at this concentration it is sufficiently fluid to be readily removed from the still,
whereas if the concentration is carried further, the mass becomes too viscid, and if
the distillation be carried to the point where the residuum contains only
thirty per cent. of glycerin the mass becomes quite solid. Besides in this last
concentration, the glycerin distils off very slowly, causing loss of heat.

page_text: It is not necessary to distil the purified residuum separately, but the latter may
be added to the stock of crude glycerin concentrated to salting point, it being
practically identical in constitution with such crude glycerin.
It is to be understood that in place of using a single mineral acid as above
described, a sufficient quantity of a mixture of mineral acids may be used without
departing from the spirit of my invention.
It is not necessary to add the mineral acid or acids to the spent soap lye, and
then to add the acidified lye to the glycerin foots, yet such a mode of procedure is
convenient, as thereby a workable fluidity is imparted to the residuum, the lye added
being less viscid than the residuum treated.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In the art of distilling glycerin or similar liquids, the improvement which
consists in injecting expanded and reheated steam into the liquid maintained at
distilling temperature, as and for the purpose described.
2. In the art of distilling glycerin or similar liquids, the improvement which
consists in heating the liquid by independent means, and in injecting expanded
and reheated steam into the independently heated liquid maintained at distilling
temperature, as and for the purpose described.
3. In the art of distilling glycerin or similar liquids, the improvement which
consists in maintaining the liquid to be distilled, at a high vacuum, and in injecting
expanded and reheated steain into the liquid, maintained at distilling temperature,
as and for the purpose described.
4. In the art of distilling glycerin or similar liquids, the improvement which
consists in maintaining the liquid to be distilled at a high vacuum; in independently
heating the liquid; and, in injecting expanded and reheated steam into the
independently heated liquid maintained at distilling temperature, as and for the
purpose described.
5. In the art of distilling glycerin or similar liquids, the improvement which
consists in maintaining the liquid to be distilled at a high vacuum; heating the
liquid by means of confined steam; and, in injecting expanded and reheated steam
into the heated liquids, maintained at distilling temperature, as and for the purpose
described.
6. In the art of distilling glycerin or similar liquids, the improvement which
consists in maintaining the liquid to be distilled at a high vacuum; in heating
the liquid by means of confined steam; in expanding free steam before entering
the still in reheating such expanded steam by such confined steam so as to
compensate for reduction of temperature caused by the expansion; and in injecting
the expanded and reheated steam into the heated liquid maintained at distilling
temperature, as and for the purpose described.
7. A distilling apparatus, consisting of a still, an expansion coil, a heating
cylinder for the expansion coil, and a perforated delivery pipe in the still and
connected with the expansion coil, substantially as described.
8. A distilling apparatus, consisting of a still, a vacuum pump connected with
the still, an expansion coil, a heating cylinder for the expansion coil, and a
perforated delivery pipe in the still and connected with the expansion coil,
substantially as described.
9. A distilling apparatus, consisting of a still, a heating coil in the still, an
expansion coil; a heating cylinder for the expansion coil, and, a perforated
delivery pipe in the still and connected with the expansion coil, substantially as
described.
10. A distilling apparatus, consisting of a still; a vacuum pump connected
therewith; a heating coil for heating the contents of the still; an expansion coil
connected with the still and with a source of steam supply; and, a reheater for
reheating the expansion coil, substantially as described.

page_text: 11. A distilling apparatus consisting of a still; a vacuum pump connected
therewith; means for heating the contents of the still; an expansion coil connected
with the still and with the boiler, and, a reheater for heating the expansion coil,
substantially as described.
12. A distilling apparatus consisting of a still; a vacuum pump connected
therewith; a heating cylinder; an expansion coil in said heating cylinder and.
connected with the still; and, source of supply for steam in the said heating
cylinder and expansion coil, substantially as described.
13. A distilling apparatus consisting of a still; a vacuum pump connected
therewith; a heating cylinder adjacent to the still; and connected with a source
of steam supply; a heating coil within the still; and, an expansion coil in said
heating cylinder and connected with the still, substantially as described.
14. A distilling apparatus consisting of a still; a vacuum pump connected
therewith a heating cylinder adjacent to the still and connected with a source
of steam supply; a heating coil within the still, connected with the same source of
steam supply; a distributing pipe within the still; and, an expansion coil within
said heating cylinder and connected with said distributing pipe, substantially as
described.
15. A distilling apparatus, consisting of a still; a vacuum pump connected
therewith; a heating cylinder adjacent to the still, connected with a source of
steam supply; a heating coil within the still, connected with the same source of
steam supply, and, an expansion coil within said heating cylinder, connected with
the still and supplied with steam from the same source of steam supply,
substantially as described.
16. In a distilling apparatus, the combination of the standards F; the braces G
and H, bolted to the upper end of the same; the still A, and heating cylinder E,
supported by said braces; the steam coil a, within said still; and, the expansion
coil c within said heating cylinder, substantially as described.
17. In a distilling apparatus, the combination of the standards F, the braces G
and H, bolted to the upper end of the same; the still A and heating cylinder E,
supported by said braces; the steam coil a within said still the expansion coil c,
within said heating cylinder; and a common source of steam supply for said
steam coil, expansion coil and heating cylinder, substantially as described.
18. In the art of recovering glyceriu from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum a mineral acid in
sufficient quantity to liberate the organic acids and subsequently volatilizing the
volatile organic acid set free as and for the purpose described.
19. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum a mineral acid in
sufficient quantity to liberate the organic acids, separating the precipitate
formed, and then volatilizing the volatile organic acids as and for the purpose
described.
20. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum a mineral acid in
sufficient quantity to liberate the organic acids contained therein, said mineral acid
being dissolved in purified spent soap lye, separating the precipitate formed.
volatilizing the organic acids, and then distilling the purified residuum as and for
the purpose described.
21. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum sulphuric acid m
sufficient quantity to liberate the organic acids and subsequently volatilizing the
volatile organic acid set free, as and for the purpose described.
22. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum sulphuric acid, in
sufficient quantity to liberate the organic acids, separating the precipitate
formed and then volatilizing the volatile organic acids as and for the purpose
described.

page_text: 23. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the residuum sulphuric acid iu
sufficient quantity to liberate the organic acids contained therein, said sulphuric
acid being dissolved in purified spent soap lye, separating the precipitate formed,
volatilizing the organic acids and then distilling the purified residuum as and for
the
purpose described.
24. In the art of recovering glycerin from the residuum of glycerin distillation,
the improvement which consists in adding to the material treated a mineral acid
in sufficient quantity to set free the organic acids therein contained, separating
the precipitate formed, distilling off and collecting the volatile acids set free and
then distilling the purified residuum as and for the purpose described.
Dated this 20 day of oune 1
JOSEPH VAN RUYMBEKE.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.