IMPROVEMENTS IN PURIFYING SACCHARINE SUB- STANCES
Year: 1879

page_text: LETTERS PATENT to Alexander Scott, junior, Joseph Duncan Scott, and Thomas
Robertson Ogilvie, all of Greenock, in the County of Renfrew, North Britain,
for the Invention of "IMPROVEMENTS IN PURIFYING SACCHARINE SUB-
STANCES."
Sealed the 28th October 1879, and dated the 10th May 1879.
PROVISIONAL SPECIFICATION left by the said Alexander Scott, Joseph
Duncan Scott, and Thomas Robertson Ogilvie at the Office of the Commis-
sioners of Patents on the 10th May 1879.
ALEXANDER SCOTT, junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock, in the County of Renfrew, North Britain. "IMPROVEMENTS
IN PURIFYING SACCHARINE SUBSTANCES."
This Invention comprises improved and economical modifications of processes to
be employed in purifying saccharine substances.
A first process is more especially applicable to saccharine substances containing
comparatively large quantities of potash, soda, and other bases, or their salts, and in this
process the saccharine substance is taken in the condition of a syrup, to which alcohol
and sulphuric acid are added in suitable proportion. Sulphates are formed with a
large proportion of the bases, and being insoluble in presence of the alcohol, become
precipitated and settle to the bottom of the vessel. The supernatant liquid is
decanted, and the precipitate is freed from adhering liquor by filtration and pressure
or other known means.
A second process is. applicable when the liquor resulting from the first process
contains organic impurities, which are precipitable by lime in presence of alcohol,
and consists in mixing with the liquor as much lime as will impart a slight alkaline
reaction. Organic lime salts and some sulphate of lime will be precipitated, and
after settling the supernatant liquor may be decanted, and liquor adhering to the
precipitate may be separated by filtration and pressure or other known means.
Before adding the lime it will sometimes be advantageous to add more alcohol, the
quantity thereof being dependent on the impurities present.
A third process is designed to separate from the sugar certain organic impurities
and coloring matters not precipitable by lime, and is applicable to liquor treated by

page_text: The
the first process only, or by both the first and the second processes.
The liquor is
diluted with water, and sufficient lime is added to form tribasic sucrate of lime with
the sugar present. If the liquor is diluted so as to make the alcohol of a strength
of 35 to 40 per centum before the addition of lime, the sucrate of limo will be
formed in a granular condition, and more of the organic impurities will be left in
the liquor than when sucrate of lime is precipitated in concentrated solution.
liquor may be diluted to a greater extent than that indicated, in which case it is
well agitated after adding the lime, and is then heated until the sucrate is precipi-
tated; and in this way a granular sucrate of good quality may be obtained from
very impure saccharine liquor. The sucrate of lime, after decantation of the super-
natant liquor, is washed with alcohol or water, or a mixture of both, and after
separation of the adhering alcohol by distillation or other known means, the sucrate
may be used for the defecation of saccharine juice or liquor, or it may be treated for
the separation of the sugar from the lime by means of carbonic acid or other known
process.
A fourth process is applicable partly instead of the first when the saccharine
substance to be treated is not considered to require treatment with sulphuric acid,
and it consists in adding to the saccharine substance in the condition of syrup twice
or thrice its volume of alcohol of a strength of 35 to 40 per centum, also as much
lime as will form tribasic sucrate with the sugar present. The mixture is well
agitated until the sucrate separates in a granular condition, and it is then allowed
to settle, and is subsequently treated like the sucrate obtained by the other processes
hereinbefore described.
The alcohol employed may be either ethyl alcohol or methyl alcohol, or a mixture
thereof, and baryta or strontia may be employed instead of lime.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Alexander Scott, Joseph Duncan Scott, and Thomas Robertson Ogilvie
in the Great Seal Patent Office on the 10th November 1879.
"E
ALEXANDER SCOTT, junior, JOSEPH DUNCAN SCOTT, and THOMAS ROBERTSON
OGILVIE, all of Greenock, in the County of Renfrew, North Britain. IMPROVEMENTS
IN PURIFYING SACCHARINE SUBSTANCES."
Our said Invention comprises improved and economical modifications or combi-
nations of processes to be employed in purifying saccharine substances.
In carrying out our Invention in the case of saccharine substances, containing
comparatively large quantities of potash, soda, and other bases, or their salts, we
take the saccharine substance in the condition of a syrup, and thereto add alcohol
and sulphuric acid in suitable proportion. For this purpose we prefer to employ a
closed cylindrical iron vessel fitted with stirring gear, and into this vessel, we first
run the alcohol and acid mixed together, and then add the syrup.
We find very
good results are obtained, when for every 1000 pounds of syrup at about 40 degrees
Beaumé, we use 100 gallons of alcohol, having a specific gravity of about 848, and
58 pounds of sulphuric acid if of the specific gravity of 1.84 for every 100 pounds
of salts contained in the syrup. The mixture is to be stirred for about an hour,
and as a result of the operation sulphates are formed with a large proportion of the
bases, and these sulphates being insoluble in presence of the alcohol become precipi-
tated and settle to the bottom of the vessel, when the mixture is left at rest for
about six hours. The supernatant liquid is afterwards decanted, and the precipitate
is freed from adhering liquor by filtration and pressure or other known means. The
separation of the liquor from the precipitated salts is conveniently effected in a
filter-press, between the plates of which pipes are arranged, in order that after the
salts are freed from liquor and washed they may be subjected to heat by means of
steam passed through the pipes, so as to drive off and thus save any adhering
alcohol.
A second process is applicable when the liquor resulting from the first process
contains organic impurities, which are precipitable by lime in presence of alcohol,
and it consists in running the decanted and filtered liquor into a closed cylindrical
iron vessel fitted with stirring gear, and therein mixing with it as much lime as will
impart a slight alkaline reaction. Organic lime salts and some sulphate of lime will
be precipitated, and after settling, the supernatant liquor may be decanted, and
liquor adhering to the precipitate may be separated by filtration and pressure or
other known means. Before adding the lime it will sometimes be advantageous to
add more alcohol, the quantity thereof being dependent on the impurities
present.
A third process is designed to separate from the saccharine substance certain
organic impurities and coloring matters not precipitable by lime, and it is applicable
to liquor treated by the first process only, or by both the first and the second
processes. In this third process the liquor, placed in a closed cylindrical iron veesel
fitted with stirring gear, is diluted with water, and sufficient lime (about four parts
by weight of newly slaked lime for every ten parts of the undiluted syrup) is added
to form tribasic sucrate of lime with the sugar present. If the liquor is diluted so-
as to make the alcohol of a strength of 35 to 40 per centum, before the addition of
lime, the sucrate of lime will be formed in a granular condition, and more of the
organic impurities will be left in the liquor than when sucrate of lime is precipitated
in a concentrated solution. The liquor may be diluted to a greater extent than
that indicated, in which case it is to be well agitated after adding the lime, and is
then to be heated until the sucrate is precipitated, and in this way a granular sucrate
of good quality may be obtained from very impure saccharine liquor. The sucrate
of lime, after decantation of the supernatant liquor, is washed with alcohol or water,
or a mixture of both, and after separation of the adhering alcohol by distillation or

page_text: other known means, the sucrate may be used for the defecation of saccharine juice
or liquor, or it may be treated for the separation of the sugar from the lime by.
means of carbonic acid or other known process.
A fourth process is applicable partly instead of the first when the saccharine
substance to be treated is not considered to require treatment with sulphuric acid,
and it consists in adding to the saccharine substance in the condition of syrup twice
or thrice its volume of alcohol of a strength of 35 to 40 per centum; also after the
alcohol has been well mixed with the syrup, as much lime as will form tribasic
sucrate with the sugar present. The mixture is to be well agitated until the sucrate
separates in a granular condition, and it is to be then allowed to settle, and is
subsequently to be treated like the sucrate obtained by the other processes herein-
before described. It is important for the syrup and alcohol to be mixed before the
lime is added, as when that is done the sucrate is precipitated in a convenient
granular condition, and is better adapted for subsequent treatment than when the
lime is added to the syrup before the alcohol.
The alcohol employed in carrying out our Invention may be either ethyl alcohol
or methyl alcohol, or a mixture thereof, and baryta or strontia may be employed
instead of lime.
Having thus particularly described our said Invention, and the manner of per-
forming the same, we have to state that we do not restrict ourselves to the precise
details herein described or referred to, and that we do not claim as a separate process
the precipitation of salts from saccharine substances by means of sulphuric acid and
alcohol, but that what we believe to be novel and original and claim as the
Invention secured to us by and in terms of the hereinbefore in part recited Letters
Patent is,-
1. The purifying of saccharine substances by means of the first process, combined
with or followed by the second or third process, or both second and third processes,
as hereinbefore described.
2. The purifying of saccharine substances by means of what is hereinbefore des-
cribed as the fourth process.
In witness whereof, I, the said Thomas Robertson Ogilvie, on behalf of the
said Alexander Scott, junior, Joseph Duncan Scott, and myself, have hereunto
set my hand and seal, this Seventh day of November, in the year of our
Lord One thousand eight hundred and seventy nine.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
THOMAS ROBERTSON OGILVIE. (L.S.)