Improvements in the Treatment and Utilization of Esparto-liquor and other similar Waste Liquors and By-products.
Year: 1891

page_text: Date of Application, 8th Aug., 1891
Complete Specification Left, 6th May, 1892--Accepted, 18th June, 1892
PROVISIONAL SPECIFICATION.
Improvements in the Treatment and Utilization of Esparto-liquor
and other similar Waste Liquors and By-products.
I WILLIAM HENRY HIGGIN of Lever Grange, Great Lever, Bolton, in the
County of Lancaster, Bachelor of Science in the University of London and
Chemical Manufacturer do hereby declare the nature of this invention to be as
follows:-
My said invention relates to improvements in the method of treating esparto-
liquor and other similar waste liquors and by-products such for example as the
caustic soda lye which has been used to boil esparto-grass, straw, wood, or other
fibrous materials used in paper making or the resultant wash liquors from such
materials, as is well understood. The object of my invention is to obtain acetate of
sodium from such waste liquors and by-products and to recover the alkali used in
their preparation. When carrying my invention into effect I evaporate the liquor
and subject the residual mass to carefully regulated heat in such a manner that it
is maintained at a temperature slightly below that at which acetate of sodium
decomposes under these conditions and which in the case of the residue from esparto
liquor for example would be about 400° centigrade, the mass being subjected to this
heat until it ceases to give off the strongly smelling gases evolved under this treat-
ment. As a result I have found that some of the organic matter is not destroyed
but remains combined with the soda in the form of acetate of sodium. The product
of my improved treatment is a dry friable mass containing frequently 15 per cent. of
its own weight of anhydrous acctate of sodium. Upon treatment with water in a
suitable manner it yields a solution containing the greater part of the acetate of
sodium along with some carbonate of sodium and a proportion of organic matter.
There is also a quantity of black residue which upon being burned leaves in the
form of a white ash the greater portion of the alkali originally used as carbonate of
soda. In practice it will probably be found that different liquors and by-products
require slight variations in the temperatures at which my process will be best
carried out, but in any case the temperature should always be as nearly below the
point at which the acetate decomposes as is safe, regard being had to the danger of
local or accidental overheating. Too low a temperature is to be avoided because
the resultant mass is more soluble in water and the acetate cannot therefore be so
readily separated.
Dated this 7th day of August 1891
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in the Treatment and Utilization of Esparto-liquor
and other similar Waste Liquors and By-products.
1, WILLIAM HENRY HIGGIN of Lever Grange, Great Lever, Bolton, in the
County of Lancaster, Bachelor of Science in the University of London and
Chemical Manufacturer, 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, that is to say :-
My said invention relates generally to an improved method of treating the
alkaline liquors which have been used to boil raw fibrous materials for use in paper
making and other manufactures, such for example as the caustic soda lye which has

page_text: been used to boil esparto-grass, straw, wood or other fibrous materials for the
purpose of obtaining the raw fibres in a condition suitable for paper making as is
well understood.
The object of my invention is to obtain acetate of sodium from such liquors and
by-products and to recover the alkali used in their preparation.
The improved process is carried into effect by evaporating the water contained in
the solution and then subjecting the residual mass obtained thereby in any suitable
apparatus to carefully regulated heat in such a manner that it is maintained at a
temperature slightly below that at which acetate of sodium begins to decompose
and which in the case of residue from esparto-liquor for example, would be about
400 degrees centigrade.
The mass is subjected to this heat until it ceases to give off the strongly smelling
gases evolved under this treatment. The subjection of the residual mass to this
carefully regulated temperature is the chief point in my improved process, because
if the indicated temperature should be unduly exceeded the acetate of sodium
present in the mass would be decomposed and lost while if too low a temperature
were employed the acetate of sodium would be obtained in considerably less quantity.
When properly conducted at or about the temperature 1 have indicated, the
result of the process is that some of the organic matter is not destroyed but remains
combined with a proportion of soda in the commercially valuable form of acetate of
sodium. The mass is maintained at the requisite temperature until the strongly
smelling gases are no longer given off whereupon it may be withdrawn. I have
mentioned 400 degrees centigrade as a suitable temperature to use because the
production of the acetate is practically complete at that temperature which is
nevertheless still about 50 degrees below the point at which decomposition of the
acetate under these circumstances would take place.
Another advantage of the high temperature is that the resulting mass or "char"
produced at that heat is of the most favourable nature for the extraction of the
acetate and its subsequent refining. I wish however to state expressly that the
application of any temperature below the decomposing point of acetate and above
200 degrees centigrade will result in the production of acetate in large quantity in
the mass although as I have already stated the results will not be so good as where
a temperature of about 400 degrees centigrade is used as directed. The resulting
mass or "char" produced at the lower temperatures is also less amenable
to treatment for the recovery of the acetate than is the mass
"char"
or
obtained by the higher temperature. The said resulting "char" or mass,
as obtained preferably from the higher temperature under the most improved
method of carrying my invention into effect, consists of a dry easily pulverised coke-
like mass which contains frequently about 15 per cent. of its own weight of anhydrous
acetate of sodium. When treated with water in a suitable manner it yields the
most of the contained acctate of sodium along with some carbonate of sodium and
organic matter as a solution. There is also a quantity of black insoluble residue
which after drying may be burned, when it leaves as a white ash a large proportion
of the alkali originally used in the preparation of the liquor as carbonate of soda.
In practice it will be found that different liquors or by-products require slight
variations in the temperatures at which my improved process can be best carried
out but in any case the temperature should always be as nearly below the point at
which the acetate decomposes as is safe, regard being had to the danger of local or
accidental overheating.
Too low a temperature is to be avoided because as I have explained not only is
the acetate obtained less in quantity, but also the mass is more soluble in water and
the acetate cannot therefore be so effectually separated.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is:
The improved method of treating esparto-liquor and other similar liquors,

page_text: solutions and by-products so as to obtain acetate of sodium therefrom, the said
method being carried into effect by wholly or partly evaporating the water from
such liquors or solutions, and treating the residue by carefully regulated heat so
that the temperature of the residue shall exceed 200 degrees centigrade but shall
never reach the heat at which sodium acetate is decomposed thereby producing
a mass or "char" which upon treatment with water yields a solution of acetate
of sodium along with other matters substantially as described and shown.
Dated this 4th day of May 1892
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.