IMPROVEMENTS IN THE NITRIFI- CATION OF AMMONIA
Year: 1871

page_text: LETTERS PATENT to Thomas James Smith, of the Firm of Robertson,
Brooman, and Company, of 166, Fleet Street, in the City of London,
Patent Agents, for the Invention of "IMPROVEMENTS IN THE NITRIFI-
CATION OF AMMONIA," A communication from abroad by Cyrien
Marie Tessié du Motay, of Paris, France, Chemist.
-
PROVISIONAL SPECIFICATION left by the said Thomas James Smith
at the Office of the Commissioners of Patents, with his Petition,
on the 24th February 1871.
I, THOMAS JAMES SMITH, of the Firm of Robertson, Brooman, and
Company, of 166, Fleet Street, in the City of London, Patent Agents, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN
THE NITRIFICATION OF AMMONIA," to be as follows:-
This new process for the nitrification of ammoniacal gas is founded
upon the alternate or continuous employment of a mixture of oxygen or
air and ammoniacal gas passing over layers of manganates, perman-

page_text: ganates, bichromates, trichromates, and alkaline plombites, heated in
retorts or tubes or in any other closed vessel to a temperature between
650 to 1050 degrees Fahrenheit (300 to 500 degrees Centigrade). The
object of the pure oxygen or the oxygen of the air made use of mixed
with the ammoniacal gas, or alone, or with steam is either to bring about t
the immediate regeneration of the manganic, permanganic, and plombie
acids reduced by the hydrogen of the ammonia to the state of metallic
oxides, or to provide the nitric oxides with the necessary element for
their acidification.
The continuous regeneration by means of the oxygen, mixed or not 1
with steam, of the elements by which the nitrification of the ammonia
is brought about forms the characteristic feature of this Invention, for it
has long been known that ammonaical gas heated to between 650 to 1050
degrees Fahrenheit in contact with manganic, permanganic, chromic,
and plombic acids or their alkaline salts transforms partly into acids and 1
partly into oxygenated oxides of nitrogen.
I proceed to describe the process of nitrification, taking by way of
example manganate of soda as the nitrifying agent. I cause a mixture
of air and ammonaical gas to pass over manganate of soda heated to a
red heat in retorts in such proportions that the manganate of soda is 2
reoxidized in proportion to the transformation of ammonia into nitric
acid. In this transformation nitrate of soda and peroxide of manganese
are produced when the air or oxygen is in excess.
In the contrary caso nitrites and sesqui-oxide of manganese are
produced; it is therefore important that the proportion of oxygen 2
theoretically necessary to the nitrification of the ammonia should be at
least doubled. When the amount of the oxygen employed is sufficient
the proportion of the azoted acid united to the soda will scarcely amount
to 14 per cent, of the weight of the nitric acid formed, and the peroxide
of manganese will be all regenerated. When all the soda contained in 3
the manganate has been transformed by the process above. described
into nitrate the retorts in which are the mixture of nitrate or peroxide
of manganese are emptied. The mixture is lixiviated and the soluble
nitrate is separated from the demanganated peroxide, the latter combined
with a proportionate quantity of soda can serve for a fresh operation.
If on the contrary it is desired to obtain nitric acid a current, of air
and steam is caused to pass over a mixture of peroxide of manganese
"
3

page_text: and nitrate when at a dull red heat; the nitric acid distils and there remains
in the retorts regenerated manganate of soda which can be immediately
used for a new nitrification. In this operation the current of steam
should be kept constant and in excess, for in case of its failing the nitric
acid would decompose during the distillation and give off much nitrous
vapour. When on the other hand the operation is well performed the
distillation of the nitric acid is brought about with scarcely any loss,
and the quantity of nitrous acid formed is hardly raised to 5 per cent.
of the whole weight of the nitric acid.
Manganic acid and in consequence manganate of soda have been given
as types of the metallic acids united to alkaline bases suitable for
nitrifying ammonia, because of all those mentioned above they fulfil most
perfectly the conditions of the problem of the integral nitrification of
ammonia and the production of nitric acid without secondary products.
Bichromate and trichromate of potash upon which at a dull red heat a
mixture of air and ammoniacal gas is caused to pass, although producing
a continuous current of oxygenated acids of nitrogen, are far from
transforming the whole of the ammonia into nitric acid or hyponitric
acid; a certain quantity of protoxide of nitrogen is always produced
during the reaction of the mixture of air and ammonia upon this kind
of elements when decomposed, and when the temperature is raised a
little above a dull red heat water and nitrogen are formed, a circun-
stance which greatly raises the price of the nitric acid thus artificially
generated.
On the other hand the nitrous vapours produced in abundant
quantities should receive a special treatment in order to transform them
into nitric acid which augments the price of the latter.
Plombic acid and the plombites react almost in the same manuer as
chromates and trichromates upon mixtures of oxygen and ammonia.
For these causes I prefer to use for the practical nitrification of
ammonia manganates and permanganates of soda although the other.
elements mentioned are also applicable subject to the drawbacks
described.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas James Smith in the Great Seal Patent
Office on the 24th August 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
JAMES SMITH, of the Firm of Robertson, Brooman, and Company, of
166, Fleet Street, in the City of London, Patent Agents, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenth-fourth day of February, in
the year of our Lord One thousand eight hundred and seventy-one,
in the thirty-fourth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Thomas James Smith, Her
special licence that I, the said Thomas James Smith, my executors,
administrators, and assigns, or such others as I, the said Thomas James
Smith, my executors, administrators, and assigns, should at any, time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMESTS IN THE NITRIFICATION OF AMMONIA," (communicated to me
from abroad by Cyprien Maric Tessié du Motay, of Paris, France,
Chemist), upon the condition (amongst others) that I, the said Thomas
James Smith, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and scals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar months
next and immediately after the date of the said Letters Putent.
NOW KNOW YE, that I, the said Thomas James Smith, do hereby
declare the nature of my said Invention, and in what manner the samo
is to be performed, to be particularly described and ascertained in and
by the following statement thereof, that is to say :—
This new process for the nitrification of ammoniacal gas is founded
upon the alternate or continuous employment of a mixture of oxygen or
air and ammoniacal gas passing over layers of manganates, perman-
ganates, bichromates, trichromates, and alkaline plombites, heated in
retorts, or tubes, or in any other closed vessel to a temperature between

page_text: 570 and 950 degrees Fahrenheit (300 to 500 degrees Centigrade). The
object of the pure oxygen or the oxygen of the air made use of, mixed
with the ammoniacal gas, or alone, or with steam, is either to bring about
the immediate regeneration of the manganic, permanganic, and plombic
acids reduced by the hydrogen of the ammonia to the state of metallic
oxides, or to provide the nitric oxides with the necessary element for.
their acidification.
The continuous regeneration by means of the oxygen, mixed or not
with steam, of the elements by which the nitrification of the ammonia is
brought about forms the characteristic feature of this Invention, for it
has long been known that ammoniacal gas heated to between 570 and
950 degrees Fahrenheit in contact with manganic, permanganic, chromic,
and plombic acids or their alkaline salts transforms partly into acids and
partly into oxygenated oxides of nitrogen.
I proceed to describe the process of nitrification taking by way of
example manganate of soda as the nitrifying agent:-I cause a mixture
of air and ammoniacal gas to pass over manganate of soda heated to a
red heat in retorts in such proportions that the manganate of soda is
reoxidized in proportion to the transformation of ammonia into nitric
acid. In this transformation nitrate of soda and peroxide of manganese
are produced when the air or oxygen is in excess.
In the contrary caso nitrites and sesqui-oxide of manganese are
produced; it is therefore important that the proportion of oxygen
theoretically necessary to the nitrification of the ammonia should be at
least doubled. When the amount of the oxygen employed is sufficient
the proportion of the azoted acid united to the soda will scarcely amount
to 1 per cent. of the weight of the nitric acid formed, and the peroxide
of manganese will be entirely regenerated. When all the soda contained.
in the manganate has been transformed by the process above described
into nitrate the retorts in which is the mixture of nitrate or peroxide
of manganese are emptied. The mixture is lixiviated and the soluble
nitrate is separated from the demanganated peroxide; the latter combined
with a proportionate quantity of soda can serve for a fresh operation.
If on the contrary it is desired to obtain nitric acid a current of air
and steam is caused to pass over a mixture of peroxide of manganese
and nitrate, when at a dull red heat the nitric acid distils and there.
remains in the retorts regenerated manganate of soda, which can be
immediately used for a new nitrification. In this operation the current

page_text: of steam should be kept constant and in excess, for in case of its failing
the nitric acid would decompose during the distillation and give off much
nitrous vapor. When on the other hand the operation is well performed
the distillation of the nitric acid is brought about with scarcely any loss
and the quantity of nitrous acid formed is hardly raised to 5 per cent.
of the whole weight of the nitric acid.
Manganic acid and in consequence manganate of soda, have been given
as types of the metallic acids united to alkalino bases suitable for
nitrifying ammonia, because of all those mentioned above they fulfil most
perfectly the conditions of the problem of the integral nitrification of
ammonia and the production of nitric acid without secondary products.
Bichromate and trichromate of potash upon which at a dull red heat a
mixture of air and ammoniacal gas is caused to pass, although producing
a continuous current of oxygenated acids of nitrogen, are far from
transforming the whole of the ammonia into nitric acid or hyponitric
acid; a certain quantity of protoxide of nitrogen is always produced
during the reaction of the mixture of air and ammonia upon this class of
decomposed bodies, and when the temperaturo is raised a little abovo
a dull red heat water and nitrogen are formed, a circumstance which
greatly raises the price of the nitric acid thus artificially generated.
On the other hand the nitrous vapors produced in abundant
quantities should receive a special treatment in order to transform them
into nitric acid which augments the price of the latter.
Plombic acid and the plombites react almost in the same manner as
chromates and trichromates upon mixtures of oxygen and ammonia.
For these causes I prefer to use for the practical nitrification of
ammonia manganates and permanganates of soda or polass although the
other clements mentioned are also applicable-subject to the drawbacks
described.
And having now described the naturo of the said Invention, and in
what manner the same is to be performed, I declare that I claim,―
1st. The alternate or continuous employment of a mixture of oxygen
or air with ammoniacal gas passing over layers of manganates, perman-
ganates, bichromates, trichromates, and alkaline plombites, heated in
retorts or tubes or in any other closed vessel to a temperature between
570 and 950 degrees Fahrenheit (300 to 500 degrees Centigrade) for
obtaining nitrates, nitrites, and nitric or hyponitric acid.

page_text: 2ndly. The employment of oxygen or air in excess, and steam passing
over the nitrates formed by the oxidation of the ammonia in order to
disengage the whole of the nitric acid contained in the latter and to
regenerate the manganates and alkaline plombites.
In witness whereof, I, the said Thomas James Smith, have here-
unto set my hand and scal, this Twenty-second day of August, in
the year of our Lord One thousand eight hundred and seventy-
one.