Improvements in and connected with the Extraction of Sugar from Molasses by the use of Barium Compounds.
Year: 1897

page_text: Date of Application, 7th Aug., 1897-Accepted, 29th Jan 1898
COMPLETE SPECIFICATION.
Improvements in and connected with the Extraction of Sugar from
Molasses by the use of Barium Compounds.
I, LOTHAR STERNBERG, of No. 117, Wall Street, New York, in the 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:
Various barium compounds, as, for example, the so-called barium sulfid, have
heretofore been proposed and to some extent employed for. the extraction of sugar
from molasses. Such barium sulfid has been obtained from barium sulfate by
mixing the barium sulfate with powdered coal and reducing it in an ordinary
reverberating furnace. The calcined mass being then leached with water, gave
what is commonly spoken of as a solution of barium sulfid, but which is more
accurately designated as a solution of bariumhydroxisulfid, BaSHOH..
An impure solution of sugar, such as molasses, syrup or any juices containing
sacchariferous matter to which BaSHOH has been added, is preferably heated,
whereupon the sugar combines with one half of the barium contained in the
bariumhydroxisulfid and forms an insoluble barium saccharate, while the other
half of the barium combines with all the sulfur in solution in the form of barium-
hydrosulfid, according to the formula, to wit:
C₁₂H₂O+2 BASHOH=CHОBaO+BaS.H.+2H.O.
11
22 11
;
The insoluble barium saccharate having been separated by filter presses, or
otherwise, and washed and mixed with water, is then saturated with either car-
bonic acid or sulfurous acid and yields a precipitate consisting of any insoluble
barium carbonate or barium sulfite according to the acid employed together with
a pure solution of sugar which is separated from the precipitate and crystallized
in the usual manner.
In the prior step of the process, and for the purpose of insuring, so far as pos-
sible, the precipitation of all the sugar in the form of barium saccharate, there
is used an excess of, say, 5 to 10% of bariumhydroxisulfid, and this excess, to-
gether with bariumhydrosulfid and all the impurities originally present in the
sugar solution, remains in the residual solution or waste lye. Chemical reactions
which may posibly occur between these impurities and the barium compounds are
unimportant and need not be considered.
The object of the present invention is to deal with the above described waste
lye in such wise as to recover the barium and sulfur from it in forms adapting
them for profitable repeated use in extracting sugar from molasses, and the in-
vention consists in treating the waste lye with sulfurous acid which, by reaction
upon the bariumhydrosulfid and the bariumhydroxisulfid, gives barium sulfite
and sulfur according to the following formulas, to wit:

page_text: To insure the completeness of these reactions there must be present at least
the quantity of sulfurous acid required by the foregoing formulas, because other-
wise, besides, and instead of, five sulfur, hydrogen sulfid would be formed, as
shown by the following formulas, to wit:
my urogensumu uuu De forineu, as
shown by the following formulas, to wit:
:
(BaS,H₂+SO₂+ H₂O = BaSO₂+2H₂S
2
2
(BaSHOH+SO₁ = BaSO₂+ HS.
Of course the process may be so conducted that only the exactly required
quantity of sulfurous acid will come into contact with the waste lye by adding,
for instance, the waste-lye slowly and gradually to a solution of sulfurous acid,
stirring continuously, until the reaction of the solution has become just neutral,
but it is preferable to use an excess of sulfurous acid in order to insure the pre-
cipitation of all the sulfur.
When the precipitation has been completed, I add to the then acid mixture
sufficient barium carbonate (obtained by the saturation of barium saccharate with
carbonic acid) to bind the sulfurous acid, forming barium sulfite and disengaging
carbonic acid, which may or may not be again used to saturate other barium
saccharate.
The process may be so regulated that all the barium carbonate obtained from
the saccharate will be used in saturating the sulfurous acid in the waste lye, and
the lye will then contain, in the form of insoluble barium sulfite and sulfur, all
the barium and sulfur previously employed.
The barium sulfite and sulfur are separated from the waste lye by filter presses
and then dried and heated in a suitable furnace in the presence of air. The
barium sulfite is mostly transformed into barium sulfate which is again reduced to
"barium sulfid" for repeated use in precipitating sugar from molasses, while the
sulfur is burned to sulfurous acid preparatory to being again used to recover
barium and sulfur from the waste lye as described.
As the sulfur, obtained by the reaction of sulfurous acid upon a certain amount
of barium compounds from the waste lye is sufficient, when burned to sulfurous
acid, to precipitate the same quantity of barium compounds and to transform the
barium from the corresponding amount of barium saccharate into barium sulfite,
therefore theoretically no barium or sulfur ought to be introduced from outside
into the process, when once started, but practically, of course, there will always
be some loss of material, which has to be resupplied from an outside source.
The process may be practised in various forms of apparatus, a convenient form
being that shown in the accompanying drawings, which are as follows, viz:--
Figure 1 is a longitudinal vertical section showing a horizontal cylinder con-
taining a rotating stirrer and surmounted by a condensing tower.
Figure 2 is a transverse vertical section taken through the plane indicated by
the dotted line - on Figure 1.
The
The apparatus shown in the drawings consists of a horizontal cylinder A pro-
vided with a rotating stirrer, A. A pipe B, inserted into what for convenience
may be designated the rear end of the cylinder A, is intended for connection with
a source of supply of gaseous sulphurous acid obtained in the usual way.
front end of the cylinder A is provided near the top with a valved opening C,
through which, if required, water or liquid acid may be introduced into the cylinder,
and is provided near the bottom with the valves opening D through which,
if required, liquid may be removed from the cylinder. An opening E
.in the side of the cylinder near the front end serves as the normal
outlet through which. the liquid from the cylinder A flows continuously when the
apparatus is in operation. The position of the outlet E determines the height
of the liquid F in the cylinder A, the normal surface of such liquid being ap-
proximately indicated by the dotted line F¹.
A partition G extends downward from the top of the cylinder A to a line some-

page_text: what below the level of the outlet E and serves to prevent the escape through
the outlet, E, of the gaseous contents of the upper part of the cylinder.
Preparatory to starting into operation, the cylinder A is filled to the height
of the outlet E with a solution of sulfurous acid. The described waste lye is intro-
duced into the condensing tower H through the pipe I provided with the valve I',
and overflows from the upper chamber J of the condensing tower, through the
vertical pipe J into the next lower chamber K, and therefrom through the ver
tical pipe K into the next lower chamber L, thence through the vertical pipe L'
into the lowest chamber M, and therefrom through the pipe N to the lower part
of the rear end of the cylinder A.
The gaseous contents of the upper part of the cylinder A, consisting mainly of
oxygen and nitrogen from the air used to burn the sulfur, are drawn off by the
aid of a gas pump through the pipe 0, connected to the top of the condensing
tower. In this way they are caused to travel from the cylinder A through the
series of pipes 01, 0, 0³ and O', and under the lower edges of the concave shields
P, P2, P3 and P4, and thence through the upper strata of the bodies of lye con-
tained in the lower parts of the chambers M, L, K, J, the surfaces of these bodies
of lye being on a level with the tops of the pipes N, L', K' and J', and hence
somewhat above the lower edges of the said shields.
If the gases thus drawn off from the cylinder A should by careless manage-
ment or otherwise, contain any sulfurous acid or hydrogensulfid they will be ab-
sorbed by the waste lye in the chambers of the condensing tower.
It will be seen that by means of the valve I¹ the quantity of waste lye supplied
can be regulated, and that the quantity of gaseous sulfurous acid drawn into the
cylinder A through the pipe B, can be controlled by regulating the action of the
gas pump connected with the pipe O at the top of the condensing tower in such
wise that all the sulfur will be perfectly precipitated and that the overflow
through the outlet E from the cylinder A will always contain the desired quan-
tity of free acid. The overflow from the cylinder A is conducted to a suitable
tank where it is added to barium carbonate, as hereinbefore described.
chambers of the condensing tower are respectively provided with the valved
openings Q, R, S, T, through which, if required, the contents of the chambers
can be removed.
The
In order to accelerate the transformation of the barium-carbonate into barium-
sulfite it is advisable to heat the mass to boiling point. The sulfurous acid
which will be partly evaporated by the heat is conducted to an ordinary absorb-
ing tower in which it is again absorbed by coming into contact with barium-
carbonate, which mixed with water or saturated waste lye flows down the tower.
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. In the process of extracting sugar from molasses by the use of barium com-
pounds, the herein described treatment of the resulting waste lye with sulfurous
acid for transforming the barium and sulfur compounds present into insoluble
precipitates preparatory to their recovery, as set forth.
2. The process of extracting sugar from molasses which consists in the employ-
ment of barium compounds in the usual way, and in treating the resulting waste
lye with sulfurous acid, separating the resulting precipitates from the solution
by filter presses, and drying and calcining in the presence of air the solid residue
from the filter presses, and thereby transforming it into barium sulfate and
gaseous sulfurous acid adapted for repeated use, as set forth.
3. The process of extracting sugar from molasses which consists in the em-
ployment of barium compounds in the usual way, and in treating the resulting
waste lye with an excess of sulfurous acid, then saturating such excess with
barium carbonate, separating the resulting precipitates from the solution by
filter presses, and drying and calcining in the presence of air the solid residue

page_text: from the filter presses, and thereby transforming it into barium sulfate and
gaseous sulfurous acid adapted for repeated use, as set forth.
Dated this 7th day of August 1897.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.