Improvements in the Manufacture of Acetic Acid, Soluble Acetates, and Calcium Sulphite.
Year: 1889

page_text: Date of Application, 1st Nov., 1889-Accepted, 14th Dec., 1839
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Acetic Acid, Soluble Acetates,
and Calcium Sulphite.
JAMES EDWARD JOHNSON JOHNSON F.I.C. F.C.S. of Crown Chemical Works
Marsh Gate Lane Stratford in the County of Essex Manufacturing Chemist do.
hereby declare the nature of this invention and in what manner the same is to he
performed, to be particularly described and ascertained in and by the following
statement
My Invention relates to the production of Acetic Acid and Soluble Salts of Acetic
Acid and Calcium Sulphite from Calcium Acetate.
In the preparation of Acetic Acid from Calcinam Acetate of Commerce the usual
initial process is to employ Sulphuric Acid or Hydrochloric Acid or Sulphate of Soda
to effect decomposition of the Calcium Acetate resulting in valueless bye products-
that is to say bye products which would require too costly manipulation to render
them of adequate marketable value.
According to this my invention there are no bye products.
My process is as follows:-
1. Equal weights of Calcium Acetate and water are mixed in suitable vessels of
about five hundred gallons (500) capacity adapted to withstand fire or provided with
a steam jacket and fitted with ordinary stirring apparatus inside to keep the thick
liquid in motion; the semi liquid mass is heated to about one hundred degrees (100°)
Fahrenheit either by fire or steam heat. Sulphur dioxide gas is then passed through
or into the semi liquid mass (which is maintained in motion all the time by the
stirrer). Decomposition takes place, Sulphite of Calcium & Acetic Acid being
formed in accordance with the equation
So soon as the mass is thoroughly saturated with the gas-one hundred parts (100)
of Calcium Acetate of eighty per cent. (80%) require about one hundred &
foriy (140) volumes of Sulphur dioxide-the stream or flow of the latter is stopped-
the Sulphite of Calcium is separated by decantation & filtration from the Acetic Acid
and the Acetic Acid may be purified (should the quality of the Acetate operated upon
or other causes necessitate rectification) by the process-preferably-described in iny
Patent No. 13,336, 1887, "Johnson Johnsons Improvements in the manufacture of
Acetic Acid & apparatus therefor," or other suitable & well known means.
2. The treatment of the semi liquid & heated Calcium Acetate with a soluble
Sulphite Salt (such as the Sulphite of Soda or Potash &c.) in the same description of
apparatus as previously stated, the stirrer keeping the solution in motion till mutual
decomposition takes place. In this case Calcium Sulphite & Acetate of Soda (or
Potash &c.) result.
About sixty parts (60) dry Sulphite of Soda are sufficient 'to decompose one
hundred (100) parts Calcium Acetate of eighty per cent. (80%).
"
The Acetate of Soda (or Potash &c.) may be purified, if necessary, by the usual
well known methods. This second part of my process may be more conveniently &
economically carried out in two other
a
ways " & "" as follows:-"a." By
mixing with the Calcium Acetate liquor, cither Carbonate or Hydrate of Soda or of
Potash &c. and then saturate this mixture with the Sulphur dioxide gas.
"." Sulphur
dioxide gas is passed through or into the Calcium Acetate liquor until the latter is
decomposed, and then Carbonate or Hydrate of Soda or of Potash &c. is added in
suitable proportion.
The result is similar by either method & these operations are conducted at about

page_text: one hundred degrees (100°) Fahrenheit whilst the material is kept in motion, as
previously described. Calcium Sulphite & Acetate of Soda or of Potash &c. are
produced & the soluble Acetate may be decanted & filtered from the Calcium
Sulphite.
The following equations will serve to indicate (as an example) the reactions which
take place in the treatment of the Calcium Acetate with a soluble Sulphite Salt
etcetera viz. :-
(resulting in the same compounds as in the previous case with one molecule of water)
Calcium Acetate, Sodium Carbonate & Sulphur dioxide:-
Ca (C, H, O₂) + Na, CO3 + SO,
=
2 Na C, H, O₂+ Ca SO₁ + CO₂
(producing Acetic of Soda & Sulphite of Calcium & Carbon dioxide going off as gas).
As Carbonic Acid tends to facilitate the reaction I prefer to use those salts
containing Carbonates of the alkalies etcetera, in this part of my process.
The Calcium Sulphite produced by my method, when Calcium Acetate of
eighty per cent. (80%) is operated upon, would contain about thirty per cent.
(30%) of Sulphurous Acid & amongst the many uses to which it may be put is
that of a disinfectant or it may be decomposed and the Sulphurous Acid resulting
therefrom used for operating on fresh quantities of Calcium Acetate or for the
production of Sulphite Salts.
I can also treat the weak & impure Acetic Acid (Pyroligneous Acid) resulting
from the destructive distillation of Wood &c. by my process, by neutrallizing such
Acid with Calcium in the ordinary way and then treat the Calcium Acetate liquor so
formed as set forth above.
Having now particularly described & ascertained the nature of my said Inven-
tion & in what manner the same is to be performed, I declare that what I
claim is :-
1st. In the manufacture of Acetic Acid the use of Sulphur dioxide (SO₂) & soluble
Sulphite Salts as abovo specified.
2nd. The Improved method of producing Acetic Acid by passing Sulphur dioxide
through or into Calcium Acetate in a semi liquid condition, substantially as set
forth.
3rd. The Improved method of producing Acetate of Soda, Potash &c. by either
adding a soluble Sulphite Salt to the solution of Calcium Acetate, or by decomposing
the Calcium Acetate in solution-before or after mixing Carbonate or Hydrate of
Soda or of Potash &c. with the same-by passing through or into the material
Sulphur dioxide substantially as set forth.
4th. The production of Sulphite of Calcium as above specified.
5th. The treatment of weak & Impure Acetic Acid (Pyroligneous Acid) &
proceeding substantially as set forth.
Dated this First day of November 1889.