Improvements relating to the Manufacture of Ammonia and Gas.
Year: 1891

page_text: Date of Application, 8th Sept., 1891-Accepted, 10th Oct., 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by ALPHONSE HENNIN, Chemist, of Springfield,
Illinois, United States of America.]
Improvements relating to the Manufacture of Ammonia and Gas.
I, WILLIAM ROBERT LAKE of the firm of Haseltine, Lake & Co. Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 my invention is to simultaneously and continuously generate gas
and ammonia from bituminous coal, shale, or other suitable fuel, and, stated
broadly, I accomplish this result by introducing air and steam, or oxygen and
steam, the steam being preferably, though not necessarily, super-heated into the
incandescent portion of a body of fuel contained in any suitable vessel or generator,
regulating the amount of air or oxygen so as to maintain a zone of incandescence
or body of fire, of sufficient size and temperature to decompose steam and. reduce
carbon dioxide to carbonic oxide (CO, to CO) while also maintaining a sufficient
body of fuel at a lower temperature beyond such zone of combustion to allow of
the formation of ammonia, and causing the gases to pass off at a temperature
sufficiently low to prevent the disassociation of the ammonia.
In the accompanying drawings I have shown one form of apparatus which may
advantageously be used to carry out my process, and which I myself have used,
but I do not desire to be understood as limiting myself to this form alone, inasmuch
as any other suitable apparatus may be used if desired, provided it is capable of
carrying out the various steps of the process hereinafter described.
Figure 1 represents a vertical sectional view of the generator used in my process;
and Fig. 2 an enlarged view of the injector and washers.
A is the generator; B the grate; C the ash pit; D the feed hopper; E the
steam pipe coiled within the generator wall; F F a series of injecting tuyers with
adjustable reducing rings; G G poker holes ; H a pipe for the escaping gases;
and I a water main.
The generator A is made in any desired shape, preferably round, and of suitable
refractory material. It is provided with the well known bell and hopper D,
through which the fuel is fed, and holes G G through which the fuel may be
stirred and broken up as desired. At a point preferably a short distance above the
grate B, I construct a number of radial tuyers F; and into these tuyers I insert
steam injectors, as shown, provided with suitable cocks or valves to control the
admission of the steam. Steam is supplied to those injectors from any boiler by
means of a pipe E, which is preferably coiled within the walls of the generator, as
shown, in order to super-heat the steam by means of the radiant heat.
A pipe H is provided to carry off the gases produced and to conduct them to a
hydraulic main 1.
If the air is to be used with the steam, it is drawn in through the tuyers by
means of the injectors, and the same method is employed with a steam and oxygen
blast, the tuyers in this case being connected with any suitable oxygen supply not
shown.
By placing the injecting tuyers just above the grate I am enabled to introduce
the air or oxygen and steam to the hottest part of the fire, and to insure a more
uniform distribution and complete decomposition of the steam. I also avoid the
necessity of shutting off the blast when cleaning the grate and removing ashes, as
must be done when the blast is introduced into the ash pit, unless the inconvenient
plan of a water seal is adopted.

page_text: The water main I is connected with any suitable apparatus for condensing and
cleansing the gas and which, being well known, requires no further description.
Upon the injectors I mount adjustable reducing washers J J, made of any
suitable material and shown more particularly in Fig. 2. These washers are
formed with holes of different sizes, and when it is desired to control the amount of
air or oxygen admitted, one of the washers is pushed inwards, as shown at the right
hand of Fig. 1, and only so much air as can pass between the injector and the
washer is admitted. If it be desired to lessen this amount another washer, having
a smaller hole, is pushed inwards, and so on. This is, however, but one way of
regulating the air supply and any other suitable mechanism may be used as a
damper, the object of this part of my invention being merely to control the
supply of air or oxygen admitted to the fuel.
The apparatus being constructed as above described, my process is carried out in
the following manner :-
"
Bituminous coal, shale, or other suitable fuel is introduced through the hopper
and ignited, and allowed to burn until a bed of incandescent fuel five or six feet in
thickness is formed. At about the same time a blast of air or oxygen and super-
heated steam is admitted through the tuyers. The producer is then gradually
filled up until the coal reaches a depth of from ten to twelve feet, the upper
portion of this charge consisting of green coal drying and partially distilling. In
this portion, or zone, which I call the "black zone,' the temperature is not
allowed to rise above 350 deg. C., being regulated by feeding in fresh fuel as
required, and most of the liquid hydro-carbons of the fuel is here driven off.
Immediately below this zone lies a zone of a higher temperature, in which the
volatile matters of the coal are distilled. The temperature of this zone of dis-
tillation varies from 350 to 700 deg. C. Here, practically, all of the volatile
matters are distilled, and a percentage of ammonia formed equivalent to about
20 lbs. of sulphate per ton of coal consumed. Any steam arriving at this zone of
distillation is decomposed forming carbonic oxide (CO) carbon dioxide oxide (CO,)
and hydrogen (H), and the nascent hydrogen unites with the nitrogen of the coal
to form an additional amount of ammonia. The amount of carbonic oxide (CO)
formed in this zone is below 50% of the amount of carbon dioxide (CO2), since
the temperature, although sufficiently high to decompose steam, is too low to
convert all of the CO, into CO, which reaction commences at 550 deg. C., and is
only complete at a temperature of 1000 deg. C. Below this zone of distillation
lies a still hotter zone, the temperature whereof varies from 700 to 1000 deg. C.,
and which I call the zone of combustion. It is into this zone that the steam or
oxygen or air are introduced as above stated. In this zone a large amount of
steam is decomposed, half of the fixed carbon of the coal being thus oxidized
setting free an equivalent amount of hydrogen, and by then properly regulating
the supply of air or oxygen the remainder of the carbon is oxidized, raising the
All the
temperature to the point proper for the reduction of the CO, to CO.
nitrogen of the fuel is, by contact with the nascent hydrogen, set free from the fuel
and converted into ammonia. The hot zone in which these reactions occur does
not exceed, say, a few inches, and the ammonia formed there is instantly removed
by the action of the exhauster along with any steam remaining undecomposed to a
region already cooled by the reduction of CO, into CO, and mostly secured in the
upper zone, where decomposition of ammonia cannot occur owing to the low
temperature, and where all of the steam remaining is decomposed.
I have by means of this process, with very crude and imperfect means of
separating the ammonia from the gas, obtained ammonia equivalent to about half
of the nitrogen contained in the coal, and simultaneously therewith obtained a fuel
gas of the following composition :—

page_text: (Experiments at the time showed that still more ammonia was formed but escaped,
owing to the imperfect condensation.)
This gas is practically free from undecomposed steam and possesses the proper
qualities of a high grade of gas for heating and metallurgical purposes, one of the
5 main points of my process. As far as I am aware, I am the first to accomplish the
conversion of 50% or more of the nitrogen of the coal into ammonia, under
conditions which would allow of the reactions which take place in my process,
especially of the conversion of the CO, produced in the zone of combustion into CO,
and thus enabling me to produce simultaneously with the ammonia a gas very low
in carbonic acid (CO,) and high in carbonic oxide (CO).
The greatest care must be taken to regulate the temperature of the various
zones. If the temperature rises too high, no ammonia will be formed; or if formed,
will be immediately dis-associated by the heat.
The ammonia and gases are allowed to pass off at a temperature low enough to
prevent the dis-association of the ammonia. They pass through the pipe H into
the hydraulic main from whence they are drawn into any of the well known
apparatus for separating the ammonia, removing the tar and other impurities.
am aware that in previous gas processes air has been heretofore used to blow up
the fire, and that after a sufficient bed of incandescent fuel has been formed, the
air has been shut off and steam admitted to the fire and decomposed; and furthermore,
that air and steam have been simultaneously admitted to the fire; but in these
processes the gases that first pass off from the fuel are generally burned or used to
heat a separate chamber, to which the gases created by the decomposition of steam,
etc., are to be admitted, for the purpose of fixing or permanently combining them
through intense heat. As this is precisely what I desire to avoid, I use no super-
heating or fixing chamber; nor do I consume the gases first coming off the coal,
since I desire to preserve and utilize these gases, which are among the most useful
products of the distillation. I am thus able to secure all the gases contained in the
coal for fuel purposes, and hence my process will produce more gas per ton of
coal than any other now known.
The object of the former process has been to obtain a fixed combined gas for
illuminating and other purposes; and in order to do this, intense heat has been
necessary both in the generator and in the retort or fixing chamber, whereas, my
object being to simultaneously produce ammonia and gas, I dispense with any retort
or fixing chamber and, using merely the simple generator, I so control the
temperature at different points thereof as to first decompose the steam and reduce
the carbon dioxide (CO), second to allow the ammonia to form, and lastly prevent
its dis-association. If any ammonia has been made in the former processes for the
production of gas, other than the retort or illuminating gas process, it has been a
by-product produced unintentionally and almost accidentally, and has been at once
destroyed by the heat that was necessarily used to accomplish the purpose of the
inventions. Its formation was a thing rather to be avoided than sought, and if
formed, it must at once be destroyed.
In the majority of prior gas processes, ammonia could never be formed at all, and
if formed, it would last but an instant, and then be destroyed as above stated, so
that the operator would be in ignorance of its formation, and no advantage could be
taken of it.
In the ordinary process of making illuminating gas in closed retorts, a certain
percentage of the nitrogen of the coal combines with hydrogen and forms ammonia,
which is collected in the scrubbers and purifiers, but the larger portion of the
nitrogen still remains in the coke and is lost.
In all previous fuel gas processes, the ammonia has been neglected if not
altogether lost sight of. As stated before, it has either never been formed or at
once destroyed. I have however, discovered after careful investigation and
experiment the possibility of so controlling the operation of the generator that
ammonia can, not only be made simultaneously with the fuel gas and separated from
it without detriment to the quality of the gas, but that the nascent hydrogen of

page_text: the decomposed steam unites with most of the nitrogen, which would be lost in the
coke of the retort gas process. I am thus able to secure as a by-product from
three to four times as much ammonia per ton of coal consumed as is secured by the
retort gas process. The low temperature which I maintain in the coolest zone of
the generator, where the gases escape, also enables me to secure, at the same time
with the ammoniacal liquors, a considerable quantity of tar of a superior quality,
thus adding still further to the value of my by-products. The increased demand
for ammonia to be used as a fertilizer, and for other purposes, has increased
the price thereof, and consequently I am able to dispose of the ammonia I
manufacture at such a price as to greatly lessen the cost of the gas produced
therewith, inasmuch as it costs little if any more to produce both the ammonia and
the gas by my process, than it costs to produce ammonia or gas alone.
Although I have alluded to three zones, the zone of combustion, of distillation
and the black zone, it will be evident to any one skilled in the art that there can be
no well defined line between them; but that one must gradually fade into the other,
and that there may be considered to be one or more intermediate zones in which
part of the reaction of each of the principal zones may take place in a gradually
diminishing degree.
The operation being once commenced may be carried on as long as desired,―the
gas and ammonia being simultaneously produced throughout the operation.
Although I have shown and described the steam and oxygen or air as entering
at the same point, it will be evident that the steam blast may be admitted at one
point and the oxygen or air blast at another, provided they are simultaneously
introduced. By the use of a blast of oxygen, instead of air blast, I avoid the
introduction of atmospheric nitrogen, which is not only useless but positively
injurious to the gas; and I am thus able to produce a hydrogenized producer gas
of high calorific value, which is practically free from nitrogen and is all combustible,
consequently much more economically distributed and more efficient and valuable
for fuel purposes.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
The process of simultaneously and continuously making gas and ammonia which
consists in injecting air, or oxygen, and steam into a bed of incandescent fuel,
controlling the temperature of the generator, first by introducing such proportions
of steam and oxygen, or air, as to maintain a zone of combustion at a temperature
sufficient to reduce to carbonic oxide (CO) practically all the carbon dioxide (CO₂)
formed by the complete combustion of the fuel, and to decompose practically all
the steam so introduced in the blast, and second, by regulating the supply of fresh
fuel to maintain beyond the zone of combustion a zone of distillation, cool enough
not only to allow the formation of ammonia, but to prevent the dis-association of
that already formed, leading off the ammonia and gas and separating them by
condensers, washers or other suitable means, substantially as described.
Dated this 8th day of September 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., A gents for the Applicant.