IMPROVEMENTS IN TREATING VEGETABLE SUBSTANCES IN ORDER TO OBTAIN PULP FOR MAKING PAPER AND FOR OTHER USEFUL APPLICATIONS
Year: 1884

page_text: TRUVIDIONA
We, THOMAS GRAHAM YOUNG, of Durris, in the County of Kincardine, North
Britain, Gentleman, and JoHN PETTIGREW, Junior, of Dinside, of the same County,
Chemist, do hereby declare the nature of our said invention for "IMPROVEMENTS
IN TREATING VEGETABLE SUBSTANCES IN ORDER TO OBTAIN PULP FOR MAKING
PAPER AND FOR OTHER USEFUL APPLICATIONS," to be as follows, that is to say :—
The said Invention has for its objects the treatment in an improved manner of
any vegetable substance capable of yielding pulp for making paper, and for other
useful applications and it is advantageously applicable to wood and other vegetable
substances which are not easily reduced to pulp by ordinary processes.
Invention is applicable to vegetable substances in a raw or more or less manu-
factured condition.
The
The Invention consists in boiling or digesting the vegetable substance in a
solution of or containing nitric acid or a mixture of nitric acid and nitrous acid and
in subsequently treating the substance with a solution of an alkali, of an alkaline
earth, or of an alkaline salt. In carrying out the Invention the vegetable substanco.
and the solution of nitric acid or a mixture of nitric acid and nitrous acid aro
placed in a suitable boiler and heat is applied by preference so as to make the
solution boil; and provision is by preference made for condensing and returning to
the boiler the portion of the solution which evaporates. The boiling is continued
until the vegetable substance is found to be disintegrated the solution of nitric acid
or mixture of nitric acid and nitrous acid is then drained off and a solution of an
alkali or of an alkaline earth, or of an alkaline salt is added and the vegetable
substance is digested therein by preference with the aid of heat.
It is an advantage of the process that it bleaches the cellulose to a certain
extent or facilitates the subsequent bleaching operations.
Dated this twelfth day of November 1884.
EDMUND HUNT,
Applicants' Agent.

page_text: !
We, THOMAS GRAHAM YOUNG, of Durris, in the County of Kincardine, North
Britain, Gentleman, and JOHN PETTIGREW, Junior, of Dinside, in the same County,
Chemist, do hereby declare the nature of our said invention for IMPROVEMENTS
IN TREATING VEGETABLE SUBSTANCES IN ORDER TO OBTAIN PULP FOR MAKING
PAPER AND FOR OTHER USEFUL APPLICATIONS" and in what manner the saine is
to be performed, to be particularly described and ascertained in and by the
following statement, that is to say :-
Our said Invention has for its object the treatment in an improved manner of
any vegetable substance capable of yielding pulp for making paper and for other
useful applications and it is advantageously applicable to wood and other vegetable
substances which are not easily reduced to pulp by ordinary processes. Our
Invention is applicable to the vegetable substances in a raw, or more or less
manufactured condition.
Our Invention consists in boiling the vegetable substance in a solution of or
containing nitric acid; and in subsequently treating the substance with a solution
of an alkali, or of an alkaline earth, or of an alkaline salt.
In carrying out our Invention the wood or other vegetable substance is placed in
a suitable vessel or boiler and a solution of the acid is added to it in quantity
sufficient to cover the substance. The strength of the solution will require to bo
varied in different cases, but in treating ordinary pine wood the solution may
contain about 20 per centum of acid. The action of the acid is aided by heat
which may be applied so as to raise the temperature within the vessel or boiler to
about the boiling point of the solution.
The vessel or boiler is connected by a pipe or pipes to a condenser in such a way
that liquefiable vapors arising from the solution may be condensed and returned to
the vessel or boiler. The time during which the boiling should continue will vary
with the various vegetable substances treated, about 40 minutes being a suitable
time for ordinary pine wood, whilst a shorter time is sufficient for esparto grass.
When the boiling operation is completed the solution is run off, and adhering
acid can be removed by washing or otherwise.
The partly treated fibrous materials are next placed in a suitable vessel or boiler
to be treated with an alkali or alkaline earth or alkaline salt. As an example it
may be stated that for treating wood a suitable solution contains about 5 per
centum by weight of caustic soda for the original weight of the wood. In this
alkaline solution the fibrous materials are kept at a boiling temperature or nearly 3
so for about 30 minutes, under atmospheric pressure; or a higher pressure may be
used, in which case less time will be required.
The first part of the hereinbefore described process acts on the resinous or other
matters associated with the fibres; and the second part of the process removes
these matters in such a way that the fibres are reduced to a pulp which may be 4
washed and bleached and afterwards dealt with like ordinary pulp. The spent
soda solution may be treated in the ordinary way for recovering the soda.

page_text: The acid used in the first part of the process may be obtained in the vessel or
boiler by acting on a nitrate with an acid or acid salt; and the presence of small
quantities of other acids or of other impurities will not prevent the desired action
from taking place.
The gaseous oxides of nitrogen resulting from the oxidising action on the matters
associated with the vegetable fibres may be recovered by leading them from the
condensers to a tower in which they are acted on by air and steam.
The acid solution may be used for acting on two or more successive charges of
vegetable materials; and when exhausted or much contaminated with foreign
matters it may be subjected to distillation whereby a large portion of the acid may
be recovered so as to be usable over again. The residue in the still will contain
some oxalic acid and some nitric acid, both of which may be recovered.
Having now particularly described and ascertained the nature of our said
Invention and in what manner the same is to be performed we declare that what
we claim is
1. The treatment of vegetable substances capable of yielding fibres suitable for
paper making and other purposes with a solution of nitric acid substantially as and
for the purposes herein before described.
2. The combination of the process forming the subject matter of the preceding
claim with the subsequent treatment of the product thereby obtained with a
solution of an alkali or alkaline earth or alkaline salt, substantially as hereinbefore
described.