AN IMPROVED METHOD OF OBTAINING GLYCERINE FROM THE SPENT LYE PRODUCED IN THE MANUFACTURE OF SOAP
Year: 1883

page_text: LETTERS PATENT to George Payne, of the Calder Soap Works, Wakefield
in the County of York for an Invention of "AN IMPROVED METHOD OF
OBTAINING GLYCERINE FROM THE SPENT LYE PRODUCED IN THE MANUFACTURE
OF SOAP,"
PROVISIONAL SPECIFICATION left by the said George Payne at the Office
of the Commissioners of Patents on the 6th November 1883.
GEORGE PAYNE, of the Calder Soap Works, Wakefield, in the County of York
"AN IMPROVED METHOD OF OBTAINING GLYCERINE FROM THE SPENT LYE PRODUCED
IN THE MANUFACTURE OF SOAP
77
My invention relates to the treatment of the spent lye resulting from the
manufacture of soap, for the purpose of obtaining glycerine therefrom, and is
carried into practice in the following manner.
I take a convenient quantity of the said lye as it comes from the soap-works
and add thereto some caustic lime, say about three parts by weight of the lime to
four parts of the lyo, and I boil them together for a few minutes. The result is
that nearly the whole of the fatty and resinous matters contained in the lye are
precipitated. I then add to the liquid a mineral acid, preferably hydro-chloric,
the acid being slightly in excess, and I boil this mixture. Then I neutralizo the
excess of acid by lime. In some cases it may be found necessary to repeat the
above described process to bring the product into the desired condition.
After these operations have been satisfactorily accomplished I evaporate the
product and distil the glycerine in any well known manner.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said George Payne in the Patent Office on the 6th May 1884.
GEORGE PAYNE, of the Calder Soap Works, Wakefield, in the County of York,
"AN IMPROVED METHOD OF OBTAINING GLYCERINE FROM THE SPENT LYE PRODUCED
IN THE MANUFACTURE OF SOAP
"
'
My invention relates to the treatment of the spent lye resulting from the
manufacture of soap, for the purpose of obtaining glycerine therefrom.
The essential feature of my said invention is the addition of caustic lime to the
lye and the boiling of the solution thus obtained, (previously to its treatment with
acid) to partially free it from the fatty or resinous soap which it contains, and
which is subsequently wholly eliminated by treatment with acid and, if necessary,
by a repetition of the process.
My invention may be conveniently and advantageously carried into practice as
follows, that is to say ;-
I take a suitable quantity of the said lye, either in the weak state in which it
comes from the soap-works or after concentration, and add thereto a small quantity
of caustic lime, say about three parts by weight of the lime to four hundred parts
by weight of the lye, and I boil them together for about one or two hours. The
result is that nearly the whole of the fatty or resinous matters contained in the lye
are precipitated. I then remove the precipitate and add to the liquid a mineral
acid, preferably hydrochloric, the acid being slightly in excess, and I boil this
mixture until the decomposition appears to be completed. I then remove the fatty
or resinous matters floating on the surface and neutralize any excess of acid by
lime or other alkali or alkaline earth. In some cases it may be found necessary to
repeat the above described process to bring the product into the desired condition,
that is to say, to entirely eliminate the fatty or resinous matters.
After this result has been satisfactorily accomplished, I evaporate the product
and distil the glycerine in any well known manner.
Having thus fully described my said invention and the manner of performing
the same I wish it understood that I claim;-
The above described method or process of obtaining glycerine from the spent lyo
produced in the manufacture of soap.
In witness whereof I the said George Payne have hereunto set my hand and
seal this Fifth day of May in the year of Our Lord One thousand eight hundred
and eighty four.
DAVATE