IMPROVEMENTS IN PURIFYING COAL GAS AND OBTAINING AMMONIA FROM COAL GAS PRODUCTS
Year: 1868

page_text: LETTERS PATENT to Alexander Roll son, of Number 123, Pembroke
Road, in the Parish of Clifton, in the City and County of Bristol,
Chemist, for the Invention of "IMPROVEMENTS IN PURIFYING COAL GAS
AND OBTAINING AMMONIA FROM COAL GAS PRODUCTS."
Sealed the 16th February 1869, and dated the 20th August 1868.
PROVISIONAL SPECIFICATION left by the said Alexander Rollason at
the Office of the Commissioners of Patents, with his Petition, on
the 20th August 1868.
I, ALEXANDER ROLLASON, of Number 123, Pembroke Road, in the
Parish of Clifton, in the City and County of Bristol, Chemist, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN PURIFYING
COAL GAB AND OBTAINING AMMONIA FROM COAL GAS PRODUCTS," to be as
follows:-
1st. I take peat bog or any other decomposed vegetable matter, and
having disintegrated it I mix with it strong sulphuric acid in about the
proportion of one part of the latter to three parts of the former, after
which I subject it to a slow heat until it has become charged by the

page_text: sulphuric acid, or after the peat bog or any decomposed vegetable matter
has been disintegrated I subject it to a heat sufficient to dry but not
carbonize it, and then add the acid.
2ndly. I take clay, mud, or similar siliceous matter, and after burning
them so as to expel the carbonic acid they contain, and having dis-
integrated or ground the burnt matter I mix with it sulphuric acid in
the same way and proportion as with the peat bog or any decomposed
vegetable matter.
3rdly. Either of the foregoing first and second products I put into
ordinary coal gas purifyers, and the gas passing through them is deprived
of its ammonia, which these products fix, forming sulphate of ammonia.
4thly. Either of the foregoing first and second products may be mixed
with ordinary coal gas water containing ammonia, which water would be
subsequently evaporated until the material was saturated with sulphate
of ammonia, or hydrochloric or nitric acid may be used instead of sul-
phuric acid in obtaining the first or second products so far as relates to
its being used for coal gas water, in which case muriate, or nitrate, or
sulphate of ammonia would be produced.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Rollason in the Great Seal Patent Office
on the 20th February 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
ROLLASON, Chemist, 123, Pembroke Road, Clifton, City and County of
Bristol, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of August, in the year
of our Lord One thousand eight hundred and sixty-eight, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Alexander Rollason, Her special licence that
I, the said Alexander Rollason, my executors, administrators, and assigns,
or such others as I, the said Alexander Rollason, my executors, adminis-
trators, and assigns, should at any time agree with, and no others, from
time to time and at all times thereafter during the time therein
expressed, should and lawfully might make, use, exercise, and vend,

page_text: within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN PURIFYING
COAL GAS AND OBTAINING AMMONIA FROM COAL GAS PRODUCTS,"
upon the
condition (amongst others) that I, the said Alexander Rollason, my
executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Alexander Rollason, do hereby
declare the nature of my said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say:-
I take peat bog or other similar decomposed vegetable matter, and
having disintegrated it I mix with it sulphuric acid of the specific gravity
of 1 840 or 1 845 in about the proportion of one part of the latter to two
(2) or three parts of the former, and if the peat bog or other decomposed
vegetable matter requires to be artificially dried before the acid is added,
care must be taken not to burn or char it. The product of this part of
my Invention is designed to be used in an ordinary gas-purifying box
apart from the other purifying boxes, and the gas should pass through it
first after it leaves the scrubber, so that any ammonia which the scrubber
has failed to work out of the gas is arrested as it passes through it, forming
sulphate of ammonia. When the gas passing through it turns red litmus
paper blue it is spent and should be replaced by fresh. I now wash the
sulphate of ammonia from the spent product; or I use as an artificial
manure in the state in which it leaves the purifying box; or I subject
it to a moderate heat to drive off the tarry matter and smell which
clings to it; or I evaporate upon it neutralized ammoniacal liquor, which
deprives it of the said tarry matter and smell, and adds any desired
proportion of ammoniacal salt to it.
Second. I use the said decomposed vegetable matter and also clay,
mud, and such like siliceous substances either burnt or not, and all
these either separate or combined, and also sawdust, as an absorbent for
gas water or ammoniacal liquor, which liquor when mixed with any of
these is to be evaporated either on the retort benches, on a kiln heated
by the waste fire of the retort's furnace, or by any other suitable means;

page_text: and to fix the ammonia which is contained in the said liquor I either add
sulphuric, nitric, or muriatic acid to them, or I neutralize the liquor
itself with either of these acids before adding it to them, and as
evaporation proceeds more neutralized liquor or more acid (when the
liquor is not neutralized) is added until any desired quantity of liquor
has been evaporated, taking care in either case that the acid used shall
be in sufficient quantity to neutralize the ammoniacal liquor. I do not
confine myself to the precise proportions here indicated.
Having now described the nature of my said Invention, and the manner
of performing the same, I would have it understood that I claim as my
Invention,―
First. The use of decomposed vegetable matter mixed with sulphuric
acid as a means of depriving gas of its ammonia, and then to be otherwise
treated, as herein-before described.
And; secondly. The use of decomposed vegetable siliceous matters
and sawdust as absorbents of gas liquor, as herein-before described.
In witness whereof, I, the said Alexander Rollason, have hereunto
set my hand and seal, this Twentieth day of February, in the
year of our Lord One thousand eight hundred and sixty-nine.