IMPROVEMENTS IN THE MANUFACTURE OF CHLOROFORM AND ACETIC ACID OR PURIFIED ACETATES
Year: 1885

page_text: I HENRY EDWARD NEWTON of the Office for Patents, 6 Breams Buildings
Chancery Lane in the County of Middlesex Civil Engineer do hereby declare
the nature of the invention for " IMPROVEMENTS IN THE MANUFACTURE OF
CHLOROFORM AND ACETIC ACID OR PURIFIED ACETATES" and in what manner the
same is to be performed, to be particularly described and ascertained in and by
the following statement:-
The object of this invention is the treatment of residual crude acetates, arising
from the proper chemical treatment of the products which are received from the
decomposition of wood at high temperatures to obtain products from which
chloroform can be produced, and a residual matter from which latter acetic acid or
purified acetates may be obtained.
.
This invention is based upon the discovery that when a crude acetate, as of lime,
is subjected to dry distillation, only very small quantities of acetone (CH.. CO. CH.)
boiling at 56° C. are formed, while very considerable quantities of Dimethylacetal
CH. (O CH)2, boiling between 60° and 65° C., Ethylmethylacetal C₂H. (О C, H.)
OCH, boiling at about 85° C. Methyldimethylketone (CH. CO. CH. CH,.).
boiling between 75° and 77° C.. Methylethylketone (CH.. ČO. C, H.) boiling.
between 75° and 80 C. Diethylketone (C, H.. C O. C. H) boiling between 75°
and 85° C. Metacetone C, H₁, O boiling between 82° and 86° C., and other still.
higher boiling ketones, as dumasin and other liquids, together with a large quantity.
of an apparently oily substance, which also holds some of the before stated,
ketones &c in solution, are the result of the process.
This invention is based upon the further discovery that while pure acetone,
yields when distilled with a hypochlorite only 33 % of chloroform, the above,
enumerated ketones and other liquids all of which possess higher boiling points
than does acetone, will yield, when freed from water and treated with a hypochlorite,
chloroform in the large and unprecedented quantity of measure for measure.

page_text: This yield is due to the fact that while a purified acetate, say of lime, yields large
quantities of acetone and only (comparatively speaking) small quantities of foreign
bodies, the crude article say of lime, which contains also formiate of lime, proponiate
of lime, butyrate of lime and very often salts of a still higher composition, together
with other foreign bodies, tarry substances &c which are the result of the dry
distillation of wood gives when subjected to the process of dry distillation, as borne
out by actual experiment, just the opposite result, viz; small quantities of acetone
and large quantities of foreign bodies varying in boiling point between 60° and
180° C respectively.
One branch of the invention consists in the production of chloroform by first
obtaining the liquids (rich in chloroform yielding agents) that result from the
decomposition of a crude acetate at high temperatures mixing said liquids with a
hypochlorite, and then distilling the same.
In separating these liquids from the crude acetates by distillation at high
temperatures in a suitable vessel I also obtain a residue consisting of carbonate of
lime acetate of lime, carbon and slight tarry impurities, in a most favorable condition
for conversion into acetic acid or purified acetates.
Another branch of the invention, therefore consists in the process of treating
crude acetates for the production of chloroform by distilling the same at a high
temperature whereby are obtained not only the rich chloroform producing agents
but also a residue in suitable condition for conversion into acetic acid or purified
acetates.
In practically carrying the invention into effect I place a quantity, about
100 pounds, say of crude acetate of lime, in a suitable vessel and subject the same
to dry distillation at a high temperature, maintained at about 300° to 500° Celsius,
until volatile products are no longer condensed. The result of this is about
32 pounds of a liquid consisting of a stratum of an aqueous liquid, upon which
floats a stratum of an oily liquid the proportion being about as 4 of the former is
to 1 of the latter. The aqueous liquid which is rich in chloroform yielding agents
before referred to is then removed as ready for use. The oily liquid, which also
contains large quantities of the before referred to chloroform yielding agents is then
subjected for their recovery either to fractional distillation, or it may be by washing
with tepid water, and the resulting aqueous liquid is added to that previously
removed. The combined aqueous liquids will possess a specific gravity of 0.965,
to 0.975.
In thus distilling the crude acetate the greater part of the chloroform producing
agents contained in the crude acetate are obtained, and in addition thereto a residue
is left in a favorable condition for ready conversion into acetic acid or purified
acetates. In this distilling operation, care should be taken not to carry the
temperature so high as to destroy the chloroform-yielding agents.
Now in order to obtain crude chloroform from the above mentioned aqueous
liquid I proceed to bring it into reaction in the following manner, viz; I take of
the above described aqueous liquid, rich in chloroform producing agents a quantity,
say 9 pounds, and mix it with about 40 pounds of chloride of lime or any other
suitable hypochlorite and about 15 gallons of water, and subject the whole to
distillation in the usual manner for the production of crude chloroform
crude chloroform so produced will be found to possess a specific gravity varying
from 1.465 to 1.485 and may be rectified in the usual manner.
The
From 32 pounds of liquid made by this process from 100 pounds of crude acetate,
and which contains some acetone I obtain, of chloroform a yield of about measure
for measure, when we consider said liquid, deprived of its water as a basis of
comparison. I have also demonstrated that by separating from said liquid the
small portion of acetone it contains, I still obtain from such liquid the large yield
of about measure for measure, and hence this may be done without departing from
the essence of this invention.
In this improved process it will be observed that the distillation of the acetate
is carried on at a temperature at least as high as that at which the before-mentioned

page_text: liquids are formed and that they are recovered in an aqueous liquid and in an
oily liquid, and that as each of these liquids is rich in said chloroform producing
agents and it is due to the utilization of said agents that the proportionate large
yield of chloroform is produced, it is to be understood that this process includes
the production of chloroform from either the oily liquid or the aqueous liquid, or
both, which result from the distillation of the crude acetate at the high degree
stated or such temperature as will recover these agents.
From this process also results the partial purification of the crude acetate by the
elimination therefrom of the rich chloroform-producing agents; and the residue
left in the vessel, which consists of carbonate of lime, undecomposed acetate of
lime, carbon, and slight tarry impurities, is treated for the recovery of acetic acid,
or purified acetates, by "leaching" with water. The aqueous solution thus
obtained is composed of water, acetate of lime, and slight impurities, and will be
treated by the ordinary known process for obtaining these products, namely; either
acetic acid or purified acetates.
By preference I use the article of commerce known as crude brown acetate of
lime, but any other crude acetate may be used with like beneficial results.
The yield of crude .chloroform from the above described quantity of liquid,
namely; nine pounds, ranges between 4 and 5 pounds. The yield of acetic acid
or purified acetates will vary according to the degree of temperature used in the
distilling operation, and according to the quality of the crude acetate employed,
and its yield will range from between 20 to 25 per cent of the original quantity of
acetic acid contained in the crude acetate employed.
Thus are produced from a cheap base valuable and comparatively large quantities
of both chloroform and acetic acid or purified acetates, at a very low cost.,
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed as communicated to
me by my Foreign Correspondents I declare that what I claim is
1. The process of producing chloroform and valuable residual products consisting
in subjecting crude acetates to dry distillation at high temperatures to remove the
fluid products therefrom then subjecting such fluid products to the action of a
hypochlorite, condensing the chloroform obtained therefrom, and purifying the
residual products of the dry distillation substantially as described.
2. The production of chloroform from the liquid products resulting from the
decomposition of crude acetates at high temperatures by subjecting said liquid
products to the action of a hypochlorite and removing the chloroform by distillation,
substantially as described.
3. The process of treating crude acetates, said process consisting in separating
out the chloroform yielding agents by distilling the crude acetate at a high
temperature and leaving a residue suitable for conversion into acetic acid or
purified acetates, substantially as described.