IMPROVEMENTS IN THE PURIFICATION OF GAS AND IN THE PREPARATION OF MATERIALS TO BE USED IN THE SAID CATA PROVISIONAL SPECIFICATION
Year: 1875

page_text: LETTERS PATENT. to Frank Clarke Hills, of the Chemical Works,
Deptford, in the County of Kent, Manufacturing Chemist, for the
Invention of "IMPROVEMENTS IN THE PURIFICATION OF GAS AND IN THE
PREPARATION OF MATERIALS TO BE USED IN THE SAID
CATA
PROVISIONAL SPECIFICATION left by the said Frank Clarke Hills
at the Office of the Commissioners of Patents, with his Petition,
on the 24th May 1875.
I, FRANK OLARKE HILLS, of the Ohemical Works, Deptford, in the
3 County of Kent, Manufacturing Chemist, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN THE PURIFICATION OF GAS AND
IN THE PREPARATION OF MATERIALS TO BE USED IN THE SAID PURIFICATION," to be
as follows:-
'
In the Specifications of my former Patents, Nos. 1369, A.D. 1868,
and 934, A.D. 1874, I have described processes for purifying gas, more
or less, principally by means of purified gas liquor deprived of its car-
bonic acid and sulphuretted hydrogen by heat,
.

page_text: My present Invention consists, firstly, in separating the sulphuretted
hydrogen gas from the carbonic acid gas driven off from the gas liquor
while it is being purified by the said processes, and utilizing such
sulphuretted hydrogen gas to form sulphide of ammonium.
My Invention further consists in utilizing the sulphide of ammonium {
thus obtained for the purification of coal gas, more or less, from the
more fixed sulphur compounds (other than sulphuretted hydrogen)
generally known as bisulphide of carbon.
The sulphuretted hydrogen may also be used to form other sulphides,
some of which (e. g. sulphide of calcium) are also useful for purifying
gas from the said bisulphide of carbon.
According to my said Invention I proceed as follows:-To effect the
separation of the sulphuretted hydrogen gas from the carbonic acid gas I
use sulphide of sodium or sulphide of potassium, preferably made by
decomposing sulphate of soda or potash with excess of carbon in retorts:
or closed vessels at a red heat. Either of these sulphides, which as thus
prepared will contain excess of carbon, is reduced to a granulated state
or a state of coarse powder, and is placed on the shelves or trays of dry
lime purifiers, and the sulphuretted hydrogen and carbonic acid gases
driven off from the gas liquor during the patented process herein-before
referred to are then passed through the said purifiers so as to come into
contact with and pass through the sulphide material. The carbonic acid
will unite with the soda or potash of the sulphide, forming a rough or
impure carbonate, which is of commercial value, and the sulphuretted
hydrogen will escape at the exit pipe of the purifier, and is to be a
brought into contact with purified gas liquor in scrubbers or washers to
form sulphide of ammonium, which sulphide I use in any desired
quantity in scrubbers or washers through which the coal gas is passed
in order to purify it more or less from its bisulphide of carbon after it
has been deprived of its carbonic acid by the purified gas liquor. The 3
illuminating gas should afterwards be deprived of its ammonia by passing
it through water scrubbers.
Sulphide of sodium or potassium material may be used instead of
sulphide of ammonium in dry lime purifiers to purify gas more or less
from bisulphide of carbon.
The ordinary sulphuretted hydrogen in the gas is to be taken up in
the usual way by oxide of iron.
g

page_text: •
The sulphide of calcium herein-before referred to may be made by
passing the sulphuretted hydrogen aforesaid into lime in dry lime
purifiers or other similar vessels, and illuminating gas may be purified
more or less from its bisulphide of carbon by being passed through the
sulphide of calcium thus formed.
Sulphide of ammonium may also be made by passing the sulphuretted
hydrogen and carbonic acid gases driven off from the gas liquor as afore-
said through scrubbers, down which gas liquor is caused to pass.. Thẻ
carbonic acid will unite with the ammonia, and the sulphuretted
hydrogen may be taken into other scrubbers through which purified gas
liquor is caused to percolate to form sulphide of ammonium for purifying
gas from bisulphide of carbon.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Frank Clarke Hills in the Groat Scal Patent.
Office on the 20th November 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FRANK
CLARKE HILLS, of the Chemical Works, Deptford, in the County of
Kent, Manufacturing Chemist,, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-fourth day of May, in the
year of our Lord One thousand eight hundred 'and seventy-five, in the
thirty-eighth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said Frank Clarke Hills, Her special
license that I, the said Frank Clarke Hills, my executors, adminis-
trators, and assigns, or such others as I, the said Frank Clarke Hills,
my executors, administrators, and assigns, should at any time agrce
with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make;
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN THE PURIFICATION OF Gas and in' the PrePARATION OF
MATERIALS TO BE USED IN THE SAID PURIFICATION," upon the condition
(amongst others) that I, the said Frank Clarke Hills, my executors
or administrators, by an instrument in writing under my, or their,

page_text: or one of their hands and seals, should particularly describe and ascer-
tain 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 Frank Clarke Hills, do hereby
declare the nature of the 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:―
5
In the Specifications of my former Patents, Nos. 1369, A.D. 1868, 10
'and No. 934, A.D. 1874, I have described processes for purifying gas,
more or less, principally by means of. purified gas liquor deprived of its
carbonic acid and sulphuretted hydrogen by heat.
My present Invention consists, firstly, in separating the sulphuretted
hydrogen gas from the carbonic acid gas, both of which gases are driven 16
off from the gas liquor while it is being purified by the said processes,
and utilizing such sulphuretted hydrogen gas to form sulphide of
ammonium.
My Invention further consists in utilizing the sulphide of ammonium
thus obtained for the purification of coal gas, more or less, from the 20
more fixed sulphur compounds (other than sulphuretted hydrogen)
generally known as bisulphide of carbon.
The sulphuretted hydrogen may also be used to form other sulphides,
some of which, e. g. sulphide of calcium, are also useful for purifying gas
from the said bisulphide of carbon.
25
According to my said Invention I proceed as follows:-To effect the
separation of the sulphuretted hydrogen gas from the carbonic acid gas I
use sulphide of sodium or sulphide of potassium made by decomposing
sulphate of soda or sulphate of potash with excess of carbon in retorts
or similar closed vessels at a red heat. Either of these sulphides (which 30
as thus prepared will contain or be mixed with an excess of carbon, and
should be kept in air-tight vessels until required for use) must be
damped with water and reduced to a granulated state or a state of coarse
powder and placed on the shelves or trays of "dry lime purifiers," and
the sulphuretted bydrogen and carbonic acid gases driven off from the 35
.gas liquor during the patented processes herein-beforo referred to are

page_text: then passed through the said purifiers so as to come into contact with
and pass through the sulphide material. The carbonic acid will unite
with the soda or potash of the sulphide, forming a rough or impure
carbonate which is of commercial value, and the sulphuretted hydrogen
will escape at the exit pipe of the last of the series or purifiers, and is to be
brought into contact with purified gas liquor in scrubbers or washers
to form sulphide of ammonium, which sulphide I use in any desired
quantity in scrubbers or washers, through which the coal gas is passed
in order to purify it more or less from its bisulphide of carbon after the
said gas has been deprived of its carbonic acid by the purified gas
liquor. The illuminating gas should afterwards be deprived of its
ammonia by passing it through water scrubbers...
The sulphide of sodium or potassium prepared, as herein-bofore
described, may be used instead of sulphide of ammonium in "dry lime
purifiers" to purify gas more or less from bisulphide of carbon.
The sulphuretted hydrogen in the gas is or may be taken up in the
usual way by oxide of iron.
"
The sulphide of calcium herein-before referred to may be made by
passing the sulphuretted hydrogen, which has been separated from the
carbonic acid as aforesaid into lime, in "dry lime purifiers
or other
similar vessels, and illuminating gas may be purified, more or less, from
its bisulphide of carbon by being passed through the sulphide of calcium
thus formed.
.
'
Sulphide of ammonium may also be made by passing the sulphuretted
3 hydrogen and carbonic acid gases driven off from the gas liquor as
aforesaid through scrubbers, down which crude gas liquor is caused to
pass. The carbonic acid will unite with the ammonia, and the
sulphuretted hydrogen may be taken into other scrubbers through
which purified gas liquor is caused to percolate to form sulphide of
ammonium for purifying gas from bisulphide of carbon.
•
Having now described tho nature of my Invention, and the manner in
which the same is to be performed, I wish it to be understood that I do
not limit myself to the precise details hercin-before described, as the
same may be varied without departing from the, nature of my said
Invention; but I claim as my said Invention,-
Firstly. Separating in the ways herein-before described the sul-
phuretted hydrogen gas herein-before referred to from the carbonic acid

page_text: gas herein-before referred to, and thus obtaining sulphide of ammonium
or sulphide of calcium.
Secondly. Purifying coal gas more or less from its bisulphide of
carbon by means of the sulphide of ammonium, or of the sulphide of
calcium, made as heroin-before described.
Thirdly. Purifying coal gas more or less from its bisulphide of carbon
by means of the sulphide of sodium or of the sulphide of potassium,
made and used as herein-before described.
In witness whereof, I, the said Frank Clarke Hills, have here-
unto set my hand and seal, this Nineteenth day November, in
the year of our Lord One thousand eight hundred and seventy-
five.
Witness,
H. H. MURDOCH,
7, Staple Inn,
London.
F. C. HILLS. (L.S.)