Improvements in the Manufacture of Soap and Glycerine.
Year: 1890

page_text: Date of Application, 27th Mar., 1890-Accepted, 24th May, 1890
VUM LEIE DIECIFICATION.
Improvements in the Manufacture of Soap and Glycerine.
I JAMES YATE JOHNSON of 47 Lincoln's Inn Fields in the County of Middlesex
Gentleman do hereby declare the nature of this Invention (which has been communi-
cated to me from abroad by Maurice Duclos of 9 rue D'Amboise Paris in the
Republic of France Soap Manufacturer) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
-statement:-
.
This Invention relates to an important improvement in the manufacture of soap
with a view more particularly to the production or recovery of glycerine.
Heretofore soap manufacturers have contented themselves with recovering a portion
of their glycerine by concentration of the lyes which after being used in the
manufacture of soap are charged with glycerine. The matter thus obtained contains
about 10 per cent. of fixed salts, it is consequently of very poor or moderate quality
and not to be compared with the glycerines of saponification produced in the
preparation of stearine.
The process according to this invention renders it possible with the materials
commonly produced in soap making, and without having recourse to tightly closed
vessels, to recover almost all the glycerine that has heretofore been wasted by the
soap makers and also to obtain this glycerine of the same qualities as the glycerine
produced in stearine works. The improved process, by thus utilising a material
heretofore regarded as a bye product of soap manufacture of no commercial value
and obtaining a useful product therefrom constitutes an important industrial result.
This process consists in causing the fatty matter to undergo a calcareous saponi-
fication in an open vessel but this method differs essentially from the primitive method
of saponification in open vessels as heretofore practised.
This primitive method required a minimum of from 14 to 15 per cent. of lime and
the glycerine remaining combined with the water of composition necessary for the
formation of lime soap was completely lost.
My foreign correspondent has discovered that an almost perfect saponification of
the fatty matter can be obtained by employing a quantity of lime of about 10 per
cent. or approximately the quantity chemically necessary for the formation of acid
soap of lime almost the whole of the glycerine thus set at liberty being recovered at
the same time if the operation be conducted as hereinafter described.
1. The milk of lime being prepared in the usual manner must be highly diluted
and contain at least 1000 kilos. of water to 100 kilos. of quick-lime. It is injected
into the boiler in small quantities upon the boiling oils maintained in ebullition by
violent injection of superheated steam.
The combination commences immediately and is completed at the end of about
6 hours boiling. The method may be modified by injecting finely divided boiling
oil into the body of the milk of lime.
2. The excess of glycerinous water or liquid is then drawn off from the bottom of
the boiler and contains about half of the total quantity of glycerine.
3. The soap of lime is afterwards washed several times for about four hours in
half its weight of water. During these operations which constitute a regular
boiling the calcareous saponification is completed at the same time that the last traces
of glycerine separate from the soap that is formed.
4. These liquors are added to those produced in the preceding operation and they
are concentrated to 28 Baumé in an evaporating apparatus worked by steam.
The soap of lime is afterwards attacked in the same boiler with sulphuric or
hydrochloric acid and the fatty acids collected in the known manner.

page_text: The entire operation can be performed in an ordinary soap boiler lined with lead
and provided at its lower part with an orifice for the discharge of the liquids.
The process hereinbefore described presents for soap manufactures advantages
have heretofore not been realized.
which
A. Almost the whole of the glycerine can be recovered in the condition of
glycerine of calcareous saponification without the employment of expensive apparatus
of small capacity and difficult to manipulate such as autoclaves or tightly closed
-vessels.
B. The fatty acids produced by this method, which dispenses with subjecting them
'to high temperatures, are of superior quality and enable a yield of soap to be
obtained equal to the amount of oil employed.
Having now particularly described and ascertained the nature of the said Inven-
tion and in what manner the same is to he performed, I declare that what I
claim is :-
1. The novel application in the manufacture of soap of the method of saponi-
fication enabling the glycerine to be obtained in a highly valuable form substantially
as herein before described.
2. The modifications in the ordinary processes herein described enabling the
quantity of alkali necessary for the commercial production of acid soap of lime to be
considerably reduced.
3. The complimentary application of washings and boilings enabling the calcareous
saponification to be completed and almost the whole of the glycerine to be recovered
substantially as hereinbefore described.
Dated this 97th day of March 1890
J. H. JOHNSON & Co.,
Agents.