An Improved Process of Obtaining Ammonia and Ammonia Salts from Nitrogenous Organic Matters.
Year: 1892

page_text: Date of Application, 28th Nov., 1892-Accepted, 14th Jan., 1893
[Communicated from abroad by Dr. LOTHAR STERNBERG, of Jersey City, New
Jersey, United States of America, Chemist.]
An Improved Process of Obtaining Ammonia and Ammonia Salts
from Nitrogenous Organic Matters.
I, HENRY HARRIS 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:-
My invention relates to a process of obtaining ammonia and ammonia salts from
nitrogenous organic matters.
It is a known fact that the nitrogen contained in nitrogenous organic materials
may be more or less completely transformed into ammonia by calcining such
substances in a retort or similar apparatus in an atmosphere of superheated steam.
The theoretical amount of steam necessary for the required chemical reactions is
not large, though of course different with different materials, but in all processes
founded on this fact, the quantity of steam required in practice, in order to obtain
a sufficient yield of ammonia from a given amount of nitrogenous organic matter, is
very considerable, being sometimes twenty to thirty times the amount of the sub-
stance to be treated. Such large excess of steam has heretofore been necessarily.
employed principally to dilute the ammonia as soon as formed, and to remove it as
quickly as possible from the retort or generating apparatus and from the effect of
the heat therein in order to protect it from decomposition. The necessity for this
dilution and quick removal of the ammonia arises partly from the small difference
which exists between the temperature at which the ammonia is formed and the
temperature at which it is again decomposed and also from the fact that such decom-
position takes place more easily and at a lower temperature if the ammonia is in a
more concentrated condition, than it does when the ammonia is highly diluted.
I have found that the quantity of steam can be reduced considerably and thus a
large economy secured by mixing with the steam, before its introduction into the
retort, a non-oxidating gas or mixture of gases, such as hydrogen, nitrogen, carbonic
oxide, carbonic acid, illuminating gas, water gas, and so on, these gases performing
the function of the excess of steam in protecting the ammonia, when formed, from
decomposition. Oxidating gases, such as air, on the contrary, are obnoxious if
present in any large amount, and will accelerate the decomposition of the ammonia.
In preference I use the gases which are generated in the process itself, and which
are similar in composition to the gas known as water gas, by introducing them again
into the generating retort after previously freeing them from ammonia by sulphuric
acid. If sufficient care be taken to prevent the condensation of the excess of steam
contained in the vapours from the retort there will require to be supplied of new
steam little more than the quantity of steam actually consumed in the production of
the ammonia and the other gases.
My process can be applied to any substance containing nitrogenous organic com-
pounds, for instance, to animal refuse, such as hair, wool, bones, skin, hides, blood
and the like or mineral matters, such as peat, bog, or other bituminous matters, or
refuse from manufacturing processes, such as waste-lye resulting from the extrac-
tion of sugar or the manufacture of alcohol from molasses, and the like.
In carrying out my invention I may use retorts of any suitable form and furnaces
of any known construction. I preferably conduct the process continuously, in
which case the steam and the non-oxidating gases enter the retort at the end
remotest from the fire and are conducted in the same direction as the nitrogenous
organic matter beyond the hottest spot in the retort. In this way the volatile
ID 7

page_text: nitrogenous bases, which in some cases may be generated in the colder parts of the
retort, will be transformed into ammonia when passing the glowing, porous, almost
exhausted material in the hottest parts of the retort.
The gases and vapors discharged from the retort are freed from the ammonia in
the usual manner by treatment with sulphuric acid and are immediately reintroduced
into the generating retort. When passing the absorbing solution, the hot gases
will take up so much steam by evaporation from the solution that the quantity of
steam so obtained will ordinarily be sufficient for the continuance of the process.
It will of course be understood that steam from some other source will be supplied
when the process is started as well as at any time thereafter when added.
Where the gases re-enter the retort a certain pressure will exist. To prevent
this pressure from becoming too high, an ordinary safety valve is provided and the
excess of gas that is generated in the retort may be conducted to a gasometer and
used for heating the retorts or for any other purpose.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed as communicated to me
by my foreign correspondent I declare that what I claim is :-
-
1. The method of extracting ammonia from nitrogenous organic matters by
calcining such matters in a retort in an atmosphere partially composed of steam and
partially of non-oxidating gas or gases.
2. The method of extracting ammonia from nitrogenous organic matters by
calcining such matters in a retort in an atmosphere partially composed of steam and
partially of hot non-oxidating gas or gases, and consisting of the residue of the
vapours discharged from the retort after said vapours have been freed from ammonia
by treatment with sulphuric acid in the usual manner.
Dated this 28th day of November 1892.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.