AN IMPROVED MODE OR PROCESS FOR OBTAINING GLYCERINE FROM SOAP-MAKERS' SPENT LYES
Year: 1870

page_text: LETTERS PATENT to William Edward Newton, of the Office for
Patents, 66, Chancery Lane, in the County of Middlesex, Civil
Engineer, for the Invention of "AN IMPROVED MODE OR PROCESS FOR
OBTAINING GLYCERINE FROM SOAP-MAKERS' SPENT LYES."-A communi-
cation from abroad by Benjamin Talbot Babbitt, of the City and
State of New York. United States of America.
PROVISIONAL SPECIFICATION left by the said William Edward
Newton at the Office of the Commissioners of Patents, with his
Petition, on the 22nd June 1870.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Civil Engineer, do hereby declare
the nature of the said Invention for "AN IMPROVED MODE OR PROCESS FOR
OBTAINING GLYCERINE FROM SOAP-MAKERS' SPENT LYES," to be as follows:-
In the present Invention instead of using common salt to effect the
separation of the soap from the spent lye caustic alkali is employed, by

page_text: which the glycerine is taken up. The resulting liquor is then boiled
with fresh tallow or fat, by which the alkali is absorbed, leaving a liquor
. consisting of glycerine and water, and from which is obtained the
glycerine by evaporating the water.
SPECIFICATION in pursuance of the conditions of the Letters Patent
filed by the said William Edward Newton in the Great Seal Patent
Office on the 22nd December 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-second day of June, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Edward Newton, Her special licence;
that I, the said William Edward Newton, my executors, administrators,
and assigns, or such others as I, the said William Edward Newton, my
executors, administrators, and assigns, should at any time agree with,
and no others, from time to time and at all times thereafter during the
term therein expressed, should and lawfully might make, use, exercise,
and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "AN IMPROVED
MODE OR PROCESS FOR OBTAINING GLYCERINE FROM SOAP-MAKERS' SPENT LYES,"
being a communication to me from abroad by Benjamin Talbot Babbitt,
of the City and State of New York, United States of America, upon the
condition (amongst others) that I, the said William Edward Newton, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the
Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the same

page_text: is to be performed, to be particularly described and ascertained in and
by the following statement, reference being had to the Drawing hereunto
annexed, and to the letters and figures marked thereon (that is to say):—
In the manufacture of soap it has heretofore been customary after the
boiling of the tallow or fat with the alkaline solution to effect the
separation from the soap of the spent lyc containing the glycerinc
(which has been extracted from the tallow or fat) by means of a
solution of common salt. Some attempts have been made to extract the
glycerine from this solution, but no method (that has heretofore been
tried) has been made commercially profitable, and the solution has been
commonly thrown away and wasted.
.
In the present Invention instead of using common salt to effect the
separation of the soap from the spent lye caustic alkali is employed, by
which the glycerine is taken up. The resulting liquor is then boiled.
with fresh tallow or fat, by which the alkali is absorbed, leaving a liquor
consisting of glycerine and water, and from which is obtained the
glycerine by evaporating the water.
The process is conducted in the following manner :-After the soap
has been formed in the usual way by boiling the tallow or fat with an
alkaline solution I pump into or otherwise introduce among it in the
boiler (which may be an ordinary kettle) a sufficient quantity of a
solution of caustic soda, of a density of about thirty-five degrees of
Beaumé's hydrometer, for the purpose of taking up all the water and
glycerine; on the contents of the boiler being allowed to cool the liquor
composed of water, caustic soda, and glycerine falls to the bottom,
leaving the soap floating upon its surface. The quantity of the caustic
soda solution introduced to the soap is immaterial provided it be
sufficient, as an excessive quantity can do no injury. Instead of the
caustic alkali being introduced in solution it may be introduced in
powder with the same effect. The liquor may be used over and over
again several times (in the same manner as the caustic alkaline solution
is used) for separating the water and glycerine from other charges of
soap in the same or other boilers. For this purpose the liquor may be
pumped directly from the boiler in which it has been used into another
boiler, or it may be drawn off into a suitable receptacle and pumped
therefrom back into the same boiler after a new batch of soap has been
produced therein; but previous to every repetition of its use it should be
bleached by throwing into it a quantity of lime reduced by water to a

page_text: pasty state, and afterwards decanting the liquor from the lime. The
use of this liquor in this way may be repeated until (by testing a small
quantity by boiling with a suitable quantity of fresh tallow to absorb all
of its alkali) the resulting solution of glycerine and water is found to
have a specific gravity of about thirty degrees of Beaumé's hydrometer,
when the liquor may be reduced with water to a suitable alkaline
strength to enable its alkali to be readily absorbed by tallow or fat, and
be then boiled with tallow or fat till what is left of it shows no alkali
by test, and therefore contains nothing but glycerine and water. On
evaporating the water from this liquor by heat the glycerine remains.
In the last-mentioned operation of boiling with tallow or fat a sufficient
quantity of the tallow or fat must be used, and additions may be made
until there is sufficient to absorb all the alkali, and it is obvious that any
excess of tallow or fat will do no injury. The tallow or fat may be
afterwards converted into soap in the usual way.
Having now described the Invention which has been communicated
to me by my foreign correspondent, and having explained the manner
of carrying the same into effect, I claim, as the Invention secured to me
by Letters Patent as aforesaid, the extraction of glycerine from soap-
makers' spent lye by treatment with caustic alkali and subsequent
boiling with tallow or fat, as herein set forth.
In witness whereof, I, the said William Edward Newton, have here-
unto set my hand and seal, the Twenty-second day of December,
Tow One thousand night hundred and covent