IMPROVEMENTS IN OBTAINING AMMONIA, TARRY MATTERS, AND COMBUSTIBLE GASES FROM COAL OR OTHER COMBUSTIBLE NITROGENOUS SUBSTANCES"
Year: 1883

page_text: LETTERS PATENT to Ludwig Mond of Winnington Hall Northwich in the
county of Chester for an Invention of "IMPROVEMENTS IN OBTAINING
AMMONIA, TARRY MATTERS, AND COMBUSTIBLE GASES FROM COAL OR OTHER
COMBUSTIBLE NITROGENOUS SUBSTANCES"
PROVISIONAL SPECIFICATION left by tlie said Ludwig Mond at the Office
of the Commissioners of Patents on the 13th August 1883.
LUDWIG MOND of Winnington Hall, Northwich, in the County of Chester
"IMPROVEMENTS IN OBTAINING AMMONIA, TARRY MATTERS, AND COMBUSTIBLE
GASES FROM COAL OR OTHER COMBUSTIBLE NITROGENOUS SUBSTANCES."
Numerous inventors have attempted to obtain ammonia by burning coal or
other nitrogenous substances with a limited supply of air in the presence of steam.
They have generally supposed that the steam and fuel ought to act upon each
other at high temperature, so that the incandescent carbon should decompose the
steam and produce nascent hydrogen, which it was believed would combine with
the nitrogen present in the gases, and produce ammonia, and have therefore
invariably worked their furnaces at a bright red heat. I have demonstrated by a long
series of experiments that nascent hydrogen and nitrogen do not form any ammonia
under those circumstances, that all the ammonia obtained by the treatment
proposed is derived from the nitrogen existing in the fuel, and that only a small
proportion of this nitrogen, say from one seventh to one fifth can thus be obtained
in the form of ammonia. I have however found that if the fuel be burned at a
low temperature, say a dull red heat, in the presence of steam, practically the
whole of the nitrogen contained in the fuel is easily obtained as ammonia. In
this case the tarry products are also of higher value, while the combustible gases
obtained do not suffer in heating power.
In order to maintain this low temperature throughout the furnaces or gas
producers in which the fuel is treated, I introduce with the limited supply of air a
large amount of steam, or I load this air with water atomized by spray apparatus,
or 1 may use both steam and atomized water.

page_text: The gas formed by this mode of working differs considerably from any producer
gases hitherto obtained; it contains a comparatively small amount of carbonic
oxide and large quantities of carbonic acid and hydrogen, which have been
produced by the action of the carbonic oxide upon the vapour of water. As the
carbonic oxide is atom for atom replaced by hydrogen, the heating power of this
gas does not suffer but is slightly increased.
In order to collect the ammonia and tarry substances, the gases are passed
through cooling and condensing apparatus in the usual way. I prefer to use the
solutions of chloride of calcium or of magnesium or sulphuric acid for absorbing
the ammonia, as these allow the ammonia to be absorbed, from the gases without
complete cooling.
It is also possible to keep the temperature of the burning nitrogenous substances
sufficiently low by the use of air partly deprived of its oxygen, such as chimney
gases or a mixture of such or other inert gases with air, and in this case only a
small amount of water or steam is required to obtain nearly all the nitrogen of
the fuel in the form of ammonia.
The gases resulting from this treatment are however very poor in combustible
constituents and consequently of little value.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ludwig Mond in the Patent Office on the 13th February 1884.
LUDWIG MOND, of Winnington Hall, near Northwich, in the county of Chester.
"IMPROVEMENTS IN OBTAINING AMMONIA, TARRY MATTERS, AND COMBUSTIBLE
GASES FROM COAL OR OTHER COMBUSTIBLE NITROGENOUS SUBSTANCES"
Numerous inventors have attempted to obtain ammonia by burning coal or
other nitrogenous substances with a limited supply of air in the presence of steam.
They have generally supposed that the steam and fuel ought to act upon each other
at high temperature, so that the incandescent carbon should decompose the steam
and produce nascent hydrogen, which it was believed would combine with the
nitrogen present in the gases and produce ammonia, and have therefore invariably
worked their furnaces at a bright red heat. I have demonstrated by a long series
of experiments that nascent hydrogen and nitrogen do not form any ammonia
under those circumstances; that all tho ammonia obtained by the treatment
proposed is derived from the nitrogen existing in the fuel, and that only a small
proportion of this nitrogen, say from one seventh to one fifth can thus be obtained
in the form of ammonia. I have however found that if the fuel be burnt nearly
the whole of the nitrogen contained in the fuel is easily obtained as ammonia if the
fuel is burnt in the presence of steam at so low a temperature that the aminonin
once formed is not dissociated again, namely at a dull red heat. In this case the
tarry products are also of higher value, while the combustible gases obtained do
not suffer in heating power.
In order to maintain this low temperature throughout the furnaces or gas
producers in which the fuel is treated, I introduce with the limited supply of air a
large amount of steam, or preferably I load this air with water atomized by spray
apparatus, or I may use both steam and atomized water.
The gas formed by this mode of working differs considerably from ordinary
producer gases; it contains a comparatively small amount of carbonic oxide and
large quantities of carbonic acid, and hydrogen which have been produced by the
action of the carbonic oxide upon the vapour of water. As the carbonic oxide is
atom for atom replaced by hydrogen, the heating power of this gus does not suffer
but is slightly increased.
In order to collect the ammonia and tarry substances, the gases are passed through
cooling and condensing apparatus in the usual way. I prefer to use the solutions
of chloride of calcium or of magnesium or sulphuric acid for absorbing the
ammonia, as these allow the ammonia to be absorbed from the gases without
complete cooling.
It is also possible to keep the temperature of the burning nitrogenous substances
sufficiently low by the use of air partly deprived of its oxygen, such as chimney
gases or a mixture of such, or other inert gases with air, and in this case only a
small amount of water or steam is required to obtain nearly all the nitrogen of the
fuel in the form of ammonia.
The gases resulting from this treatment are however very poor in combustible
constituents and consequently of little value.
In place of steam or atomized water or of air deprived of its oxygen, I may mix
with the air a portion of the cooled combustible gases produced by the process,
but while this plan will be found very effective when properly carried out it is so
liable to accident that I prefer at the present time the use of atomized water with
the limited supply of air.
In conclusion I am well aware that water or steam has been admitted into gas

page_text: producers for many years past so as to make use of the surplus hent given off by
the combustion of carbon into carbonic oxide, and that it has been also known
that this steam aids the production of ammonia, inoreasing the quantity produced.
But I believe no one prior to my application for this patent ever proposed to carry
on the entire operation of converting carbonaceous fuel into combustible gases by
means of air so largely charged with water, steam or indifferent gases that the
temperature of combustion should not exceed the temperature of dissociation of
the ammonia formed, namely a dull red heat, and therefore I claim as my invention
to be protected under the Letters Patent :-
1st. The improvemont in obtaining ammonia, tarry matters and combustible
gases from coal or other nitrogenous combustible substance, which consists in
converting of the entire combustible matter into gases at one operation, by passing
through such fuel air mixed with such a largo excess of steam or water, or steam
and indifferent gases, as to maintain the temperature of combustion at a dull red
heat throughout the mass of burning fuel, whereby a greatly increased yield of
ammonia is obtained.
2nd. The improvement in the manufacture of ammonia, tarry matters and
combustible gas from nitrogenous combustible material, which consists in passing
into the fuel air strongly charged with water spray or atomized water, substantially
as described,
_ In witness whereof I the said Ludwig Mond have hereunto set my hand and
seal this first day of February in the year of our Lord one thousand eight hundred
and eighty four