IMPROVEMENTS IN AND APPARATUS FOR THE SEPARATION OF ACETIC ACID FROM CRUDE PYROLIGNEOUS ACID AND SPIRIT
Year: 1880

page_text: LETTERS PATENT to Benjamin Biggs, of No. 3, Laurence Pountney Hill, in
the City of London, Merchant, for an Invention of "IMPROVEMENTS IN
AND APPARATUS FOR THE SEPARATION OF ACETIC ACID FROM CRUDE
PYROLIGNEOUS ACID AND SPIRIT,"
PROVISIONAL SPECIFICATION left by the said Benjamin Biggs at the Office
of the Commissioners of Patents on the 13th September 1880.
BENJAMIN BIGGS, of No. 3, Laurence Pountney Hill, in the City of London,
Merchant. "IMPROVEMENTS IN AND APPARATUS FOR THE SEPARATION OF ACETIC
ACID FROM CRUDE PYROLIGNEOUS ACID AND SPIRIT."
In distilling wood to produce acetic acid and wood naptha, the wood is put
into iron retorts and the liquor which distils over contains tar, acid, and wood
naptha. The greater part of the tar is allowed to settle, and the supernatant
liquor, which consists chiefly of acetic acid and wood naptha, is in some cases
treated with sufficient lime to neutralize the acid, and is then put into a still
and the wood naptha is distilled off, and the residue is boiled down and dried
and gives the ordinary brown acetate of lime. In this case vessels of iron can
be used, as the acid is rendered neutral by the addition of the lime.
When distilled acetate of lime (sometimes called grey or white acetate of lime)
is to be produced, the greater part of the tar is separated from the liquor, as
herein before described, which is then put into a copper still and distilled. The
naptha first comes over and is received by itself, and the acid is then distilled
from the remaining tar which is left in the still. This distilled acid saturated
with lime makes the distilled or white or grey acetate of lime of commerce, and
treated with litharge makes brown sugar of lend.
According to my Invention I use an earthenware still or a still formed of slabs
of stone or other similar material, which still 1 heat by means of a coil of metal
pipe (preferably copper pipe tinned on the outside), and I connect the said still
with an air pump, and distil over the wood naptha and acetic acid in vacuo.
By my Invention the production of the acid is cheapened, and owing to the low
temperature at which it is possible to work in vacuo, a purer acid is produced than
that produced by the ordinary process.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Benjamin Biggs in the Great Seal Patent Office on the 12th March 1881.
BENJAMIN BIGGS, of No. 3, Laurence Pountney Hill, in the City of London,
Merchant. "IMPROVEMENTS IN AND APPARATUS FOR THE SEPARATION OF ACETIC
ACID FROM CRUDE PYROLIONEOUS ACID AND SPIRIT."
In distilling wood to produce acetic acid and wood naptha, the wood is put into
iron retorts and the liquor which distils over contains tar, acid, and wood naptha.
The greater part of the tar is allowed to settle, and the supernatant liquor, which
consists chiefly of acetic acid and wood naptha, is in some cases treated with
sufficient line to neutralize the acid, and is then put into a still and the wood
naptha is distilled off, and the residue is boiled down and dried and gives the
ordinary brown acetate of lime. In this case vessels of iron can be used as the acid
is rendered neutral by the addition of the lime.
When distilled acetate of lime (sometimes called grey or white acetate of lime) is
to be produced, the greater part of the tar is separated-from-the- liquor,--as
herein before described, which is then put into a copper still and distilled. The
naptha-first-comes-over-and-is-passed-into-one receiver, and the acid is then
_.distilled_from_the_remaining tar and passed into another receiver, the tar being left
in the still. This distilled acid saturated with lime makes the distilled-or-white-or-
grey acetate of lime of commerce, and treated with litharge makes brown sugar of
lead.
In separating the naptha and acid according to my Invention, I use a still
formed by preference of earthenware or slabs of stone or other suitable material,
which is not affected by acetic acid, and provided with the necessary arrangements
for introducing the liquor to be distilled and removing the tar, and I heat the
contents of the still by means of steam or hot water passed through a coil of metal
pipe placed therein, the said pipe being preferably tinned on the outside, and
I connect the still with an air pump, or I connect the condenser with which the
still is connected with an air pump or other suitable apparatus for exhausting air,
by means of which pump or apparatus I create a vacuum or partial vacuum in the
still, and I distil over the wood naptha and acetic acid in vacuo.
By my Invention, owing to the low temperature at which it is possible to work
in vacuo, a purer acid is produced than that produced by the ordinary process.
Having thus described my Invention, I wish it to be understood that I do not
limit myself to the use of the apparatus herein before described, but I claim,-
Distilling naptha and acetic acid from the distillate of wood in vacuo.
In witness whereof, I, the said Benjamin Biggs, have hereunto set my hand
and seal, this Eleventh day of March, in the year of our Lord One thousand
eight hundred and eighty one.