IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF AMMONIA
Year: 1874

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at tho
Office of the Commissioners of Patents, with his Petition, on the
14th December 1874.-A communication from abroad by Farnham
Maxwell-Lyte, of Paris, France.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MANUFACTURE OR PRODUCTION OF
AMMONIA," to be as follows:-
This Invention relates to the production of ammonia by synthesis of
its elements (hydrogen and nitrogen) in the proportion of, say, three
volumes of the former to one of the latter.
The Invention consists in passing the above mixture of hydrogen and
nitrogen in suitable proportions over one of the triatomic elements or
triads, or pentatomic elements or pentads in a divided or spongy
condition, or over a combination or mixture of one or more of these
clements in a similar condition. These matters may also be mixed with
an inert substance such as carbon, silica, or amianthus.

page_text: These elements are as follows:-Antimony, bismuth, vanadium, gold,
and those classed as pseudo triads, such as chromium, manganese, iron,
cobalt, nickel, uranium, cerium, lead, or tin, to which may be added
boron, phosphorus, and arsenic. The first of these last three would
however be very difficult of employment, while the two latter are
poisonous, volatile, and dangerous to use, but combinations of the same
might be made use of. Some of the above metals are practically excluded
owing to their rarity, their value, or the limited effect they produce.
All the above metals either alone or mixed with carbon or an inert
matter, such as silica or asbestos, possess the property when in a divided
or spongy condition of producing at moderate temperatures the synthesis
of the elements of ammonia, on subjecting the samo to the action of a
current of hydrogen and nitrogen with or without the presence of
oxygen, the mixture being made in the desired proportions. It is not
however necessary that the mixture should be exactly proportioned in
order that the synthesis may take place, as an excess of one or other of
the gases will not affect the reaction. The vapor of water either mixed
with the gases at the moment of their passage or alternated with the
same, much increases the production of the ammonia, and would even
seem to be essential to the production of this compound on a manu-
facturing scale. It would indeed appear to be impossible to produce in
this manner the compound Az H³, but that the presence of the vapor of
water is requisite to first produce the compound (Az H') 20, which is
immediately reduced to 2Az H³ + H2 O.
It is not absolutely necessary for the success of the operation that the
gases should be perfectly pure. The hydrogen may also be entirely or
partially replaced by a suitable proportion of volatile or gaseous hydro-
carbons. The hydride of methyl for instance, and many other volatile
hydrocarbons, including illuminating gas which is a mixture of volatile
and gaseous hydrocarbons may be employed.
The temperature varies with the kinds of metals employed, but a
temperature about that at which tin melts gives good results. By mixing
oxide of bismuth or of antimony with organic matters, such as pounded
charcoal, starch, or flour, and a binding material such as gum mucilage
or molasses, made up into balls which aro then heated to redness, I
obtain a spongy metallic charcoal which gives excellent results. I may
substitute therein the salts of the different metals above mentioned, or

page_text: saturate therewith porous bodies such as pumicestone or asbestos. The
sponge produced by the decomposition of their organic salts may also be
employed with advantage.
The gaseous mixture and vapor of water are injected either simul-
taneously or alternately upon the spongy matters heated to the desired
temperature. The use of aqueous vapor may also be dispensed with if
the gaseous mixture be otherwise saturated with moisture in any known
manner. The ammonia produced is condensed in the ordinary manner.
The portion of the gaseous mixture which escapes the reaction is
collected in a gas holder to be again passed over the spongy matter.
By these repeated passages an additional portion of ammonia being
obtained at each passage, which is in turn absorbed until the whole of
the mixture is converted into ammonia or there remains only tho excess
of hydrogen or of nitrogen which may have existed in the gaseous
mixture.