A Method of and Apparatus for Obtaining_Ammonia from Atmo- spheric Nitrogen and the Hydrogen of Decomposed Steam.
Year: 1889

page_text: Date of Application, 24th Dec., 1889-Accepted, 8th Feb., 1890
A Method of and Apparatus for Obtaining_Ammonia from Atmo-
spheric Nitrogen and the Hydrogen of Decomposed Steam.
A communication from abroad by THE AMERICAN AMMONIA MANUFACTURING
COMPANY, of Alexandria, State of Virginia, United States of America.
I, JOHN CORRY FELL, of the Firm of Fell & Wilding, of 1, Queen Victoria Street,
London, E.. Patent Agents, do hereby declare the nature of this invention 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 to obtain ammonia by a simple and economical
method from atmospheric nitrogen and the hydrogen of decomposed steam; and it
consists in the matters hereinafter described and particularly pointed out.
In the accompanying drawings, which illustrate an apparatus adapted to carry out
the present process:-
Figure 1 is a vertical, and Figure 2 a horizontal section on line a - - - a.
Figure 3 is a plan.
Figure 4 is a front elevation.
Figure 5 is in part a vertical section, and in part an elevation of a modified form of
the apparatus, and
Figure 6 is a horizontal section of the furnace, forming part of the same.
A is an ammonia-generating furnace adapted for the use of gaseous fuel, in which B
is the combustion chamber; CC, and D D, pipes for the supply of gas and air
respectively; E, a hopper provided with a feeder, m; F, shelves or bafflers; and G a
steam-pipe.
H is a supplementary furnace for superheating steam and air, and contains the air
superheater, I, and steam superheater, J, both opening into the ammonia-generating
furnace, A.
The mode of operation is as follows:-
We admit suitable volumes of gas and air through the pipes C and D respectively,
to the ammonia-generating furnace, A, and having ignited the gas, force or draw it,
duly mixed with a suitable volume of air or of steam and air mixed, through the
furnace, A, from which they escape through a flue or chimney not shown. The
incandescent gases are, for the present, used solely for the purpose of heating the
furnace, but as soon as we commence to make ammonia from the nitrogen of these
gases, the chimney or other outlet through which they were at first permitted to
escape is closed, and they are directed through condensers, scrubbers, and other
apparatus suitable for the collection of the ammonia with which they are charged.
Having brought the furnace to a working heat, we feed a suitable volume of
pulverized carbon and alkali into the ammonia-generator, A. The fall of this
pulverized carbon and alkali is retarded by the shelves, F, and the carbon and alkali
become intensely heated by the actively incandescent gas with which the furnace is
filled, and unite with the nitrogen in the flame to form alkaline cyanides or cyanates
or a mixture thereof, according as the volume of incandescent gas contains oxygen in
greater or less quantity.
If it is found, upon examination, that the compounds of cyanogen produced in the
furnace are cyanates, we decompose them by means of a suitable volume of steam
admitted to A through the pipe J, and produce ammonia, oxides of carbon, hydrogen,
and alkaline compounds.
While it is not actually necessary to do so, it is advantageous to superheat the
steam admitted through the pipe, J, and thereby prevent to a great extent, the
cooling of A; and promote the decomposition of the cyanates, and production of
ammonia.

page_text: If, however, it appears that the compounds of cyanogen produced are cyanides,
an increased volume of air is admitted through the pipes, D, or, preferably, a
supplementary air supply is admitted through the superheating-pipe, I.
We are careful to admit the air through the pipe, I, at such a point in the furnace,
and at such distance above or before the steam-pipe, J, that the oxygen of the air
admitted through I shall have sufficient time to act upon the cyanides, to ensure their
conversion into cyanates before they are subjected to the action of the steam admitted
through J. In the furnace shown in the drawings this is effected by introducing a
supplementary air supply into A, at a point higher than that at which the steam is
introduced.
The action of this supplementary air supply in reference to its chemical effect is
subsequent to the production of cyanides, though this production of cyanides and
their conversion into cyanates is continuous, and the air is supplied through the
pipe, I, simultaneously with the introduction and ignition of gas at the top of the
furnace, and in a like sense, the introduction of steam though pipe, J, is subsequent
to the supplying of air to oxidize the cyanides, the present method being distinguished
from those prior methods which introduce these agents simultaneously or together into
a retort (and therefore in such manner that the gases or reagents are not able to act
upon each other successively) and substantially as herein described.
By the present improvement, air and gas are introduced and the latter burned in
the presence of the moving solids, thus heating them and the furnace more directly,
and more highly than practicable by the use of final products, generated outside of the
furnace, or by the use of superheated gases; and further, all extraneous steam, or all
steam except such inconsiderable portion as may be generated from the moisture in
the solids, is excluded until after the production of cyanides has been effected, and air
is introduced in excess to convert the evanides into cyanates.
The steam supply decomposes both the gaseous products of the prior steps of the
operation and the solid cyanides, and this steam, as well as the air and gases, moves
in the same direction and intermingles with the solids to secure an intimate contact
and to afford time for the required reactions.
Free oxygen derived from any source will serve the purpose of converting cyanides
into cyanates, and also a sufficient supply of this element in the incandescent furnace
gases is capable of effecting this result even without a secondary air supply, though
such secondary or supplementary supply is preferred, owing to the difficulty of
regulating the oxygen when solely supplied with the furnace gases.
Referring to Figures 5 and 6 of the drawings, A is the furnace used for the
combustion of solid, liquid, or gaseous fuel, and consists of the fire-place, b, shown
partly filled with coal, the vertical flue, c, provided with an air inlet, d, and the
ammonia-generator proper, e, provided with suitable shelves or bafflers, f, and with
the steam superheater, g, and an outlet, h, connected with a chimney or aspirator not
shown in the drawings.
B is a collector, in which the solid matter escaping from A becomes separated from
the gaseous product, and C is a condenser wherein the gas is cooled preparatory to
the separation from it of the ammoniacal and other alkaline matter which it contains.
D is a scrubber by means of which the alkaline matter, other than ammonia, is
intercepted and collected. This scrubber, D, may represent a series of scrubbers used
at this point of the process for separating from the ammonia soluble alkaline salts
present in the ammoniacal liquor; for, by repeated scrubbing, using the same liquor
over and over again, we obtain a highly concentrated solution of these salts accom-
panied by a little ammonia. By transferring this solution to the boiler, E, and
heating it, the ammonia present will be driven off through the pipe, m, and carried to
join the gas .entering the scrubber, F, which, in turn, represents a scrubber or series
of scrubbers wherein the ammoniacal liquor is collected and concentrated as in
ordinary gas works.
F is a scrubber for collecting the ammonia. G and H are tanks for the liquor from
the condensers and scrubbers.
The mode of using this furnace, which differs mainly from the method above

page_text: described in that no distinct provision is made for a supplementary air supply to
oxidize cyanides, is as follows:
A fire is built in 6, and the fuel ignited and burned. The supply of air admitted to
the fuel is preferably so limited that the products of combustion will be producer gas;
so called, composed largely of carbonic oxide mixed with nitrogen. These pass up
through the flue, c, and receive an additional supply of air through the pipe, d, and
enter the ammonia-generator in a state of intense combustion, and passing downwards
through e, escape at its outlet, h.
The interior of e will thus become intensely heated, and the gases escaping at h, if
the air supply be properly adjusted, will be truly the waste products of combustion,
and the fuel consumed will serve the double purpose of heating the furnace, e, and
furnishing highly incandescent nitrogen for the production of ammonia.
If oil or gas, natural or manufactured, is the fuel used, the fire-place, b, and the
vertical flue, c, may be dispensed with, and these substances may be advantageously
burned in the top of the ammonia-generator, e, itself, or in a suitable combustion
chamber formed therein.
Having brought the ammonia-generator to a working heat, and having closed its
outlet,, the products of combustion are forced or drawn through the apparatus, to
the outlet, j, of the scrubber, F. At the same time there is discharged into the
bottom of the ammonia-generator, through the pipe, k, a volume of steam which partly
cools the incandescent gases, and helps to settle the dust or other solid matter suspended
in the gases passing through the dust-catcher, B.
We also pass into e, through the superheater, g, a suitable volume of steam which
decomposes the cyanides formed in the upper part of e, with the production of
ammonia, fuel gas, and alkali; and at the same time furnishes a gaseous envelope for
the protection of the ammonia from contact with the heated walls of the furnace, and
also a cooling medium whereby the intense, and otherwise destructive, heat of the
incandescent gases may be moderated. While ordinary live steam will suffice for this
purpose, it is most desirable to superheat the steam before adimitting it into e, as, by
this means, a larger volume may be used without lowering the temperature of e and
of the contained gases to a degree insufficient for the rapid decomposition of the
cyanides.
At this stage we feed a suitable quantity of pulverized carbon and alkali into the
ammonia-generator, e, through which its fall or passage is retarded by the shelves, f,
and in which the alkalized carbon soon becomes intensely heated, and by contact with
the incandescent nitrogenous gas combines with the nitrogen thereof to form alkaline
cyanides, which are, in turn, decomposed by the steam admitted through the super-
heater, g. with the production of ammonia, fuel gases, and alkali; this last chiefly in
a state of combination.
In no prior process has a mixture of carbon and alkali been heated by burning gases
moving in the same direction therewith to produce cyanogen or cyanides, and in none
has steam been introduced and mingled with such mixture of carbon and alkali after
it has been subjected to the action of burning gases, and then caused to move in the
same direction and in intimate mixture therewith.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The process herein described of making ammonia, consisting in first introducing
incandescent gases and air in excess of the quantity required to burn said gases in the
presence of a moving mixture of pulverized carbon and alkali, conducting these fluids
and solids together in the same direction, thereby affording time for heating the solids
and effecting desired reactions and producing alkaline cyanides and cyanates, and
subsequently introducing steam to decompose these alkaline compounds and producing
ammonia and other products, substantially as described.
2. In the process of making ammonia, the steps consisting in first introducing
incandescent gases and air in excess of the quantity required to burn said gases in the

page_text: presence of a moving mixture of pulverized carbon and alkali, then conducting these
fluids and solids together in the same direction, thereby affording time for heating the
solids and effecting desired reactions, and subsequently introducing oxygen to convert
alkaline cyanides into cyanates, substantially as described.
3. In the process of making ammonia, the steps consisting in causing such
cyanides to combine with oxygen and to form evanates; second, subsequently
decomposing the cyanates so formed by steam, producing ammonia, oxides of carbon,
hydrogen gas, and alkaline compounds, substantially as described.
4. In the process of making ammonia, the step consisting in supplying air in excess
of the amount required for the combustion of gases and production of cyanides, to
convert the latter into ammonia, substantially as described.
5. The process herein described of producing ammonia, consisting in first intro-
ducing incandescent gases and air to burn said gases into the presence of a moving
mixture of pulverized carbon and alkali; conducting these fluids and solids together
in the same direction, thereby affording time for heating the solids and effecting
desired reactions, and producing alkaline cyanides and cyanates, and subsequently
introducing steam to decompose these alkaline compounds and producing ammonia
and other compounds, substantially as described.
6. In the process of making ammonia, the steps consisting in first introducing
incandescent gases and air to burn said gases in the presence of a moving mixture of
pulverized carbon and alkali, then conducting these fluids and solids together in the
same direction, thereby affording time for heating the solids and effecting desired
reactions, substantially as described.
7. In the process of making ammonia, the step which consists in introducing steam
into the presence of cyanides and other solid and gaseous substances produced by
incandescent gases acting upon mingled carbon and alkali, and conducting these
several fluid and solid substances in the same direction in an intermingled state to
decompose the cyanides and cyanates, substantially as described.
8. In the process of making ammonia, the steps which consist in causing the
nitrogen of incandescent nitrogenous furnace gases to combine with carbon and
alkali and to produce alkaline cyanides and cyanates, by passing burning gases in
the same direction with said solids, and in subsequently decomposing the cyanides
and cyanates so produced by steam, producing ammonia, fuel gases, and alkali;
scrubbing the gases thus produced, and separating the ammonia from the dissolved
alkalies and salts by heat, substantially as described.
9. The combination of the ammonia-generator furnace, A, having its combustion
chamber, B, placed at its upper part, and provided with a gas inlet, C, air inlet, D,
and a hopper for supplying solids, with the superheater, H, and the steam-pipe passing
through said superheater and communicating with the furnace below its combustion
chamber, substantially as described.
10. In an ammonia-generator furnace, A, the supplementary air-pipe, I, suitably
placed between the combustion-chamber, B, and steam-pipe, J, and constructed and
operated substantially as described.
11. In an apparatus for producing ammonia, the combination of the hopper and
feeder with the combustion-chamber, B, placed in the upper part of the ammonia-
generator, A, and the steam and air pipes, J and I, constructed and operated
substantially as described.
12. In an apparatus for producing ammonia, the combination of the ammonia-
generator, A, provided with a combustion-chamber at its upper part, and with the
shelves, F, and with the steam and air pipes, J, I and G, constructed and operated
substantially as described.
FELL & WILDING,
1, Queen Victoria Street, E.C., Agents for the Applicant.