Improvements in the Purification of Coal Gas.
Year: 1886

page_text: Date of Application, 5th June, 1886.
Complete Left, 5th Mar., 1887.
Complete Accepted, 20th May, 1887
PROVISIONAL SPECIFICATION.
Improvements in the Purification of Coal Gas.
I, CARL FRIEDRICH CLAUS, of Merton Road, South Wimbledon, in the County
of Surrey, Chemist, do hereby declare the nature of this invention to be as
follows:-
In the specifications of applications for Letters Patent bearing even date herewith
and numbered respectively 7580 and 7584 I have described processes of purification
of coal gas in which ammonia gas or ammonia liquor is introduced into scrubbers,
the liquor being caused to circulate through a series of scrubbers as in the said
specifications respectively set forth. One result of the treatment described in either
case is, that a portion of the bisulphide of carbon is removed.
Now according to my present invention I introduce into one or more of the
scrubbers in which bisulphide of carbon is to be removed from the coal gas, solid
sulphur in excess of the quantity that can be dissolved by the sulphide of ammonium
present in such scrubber or scrubbers.
W. LLOYD WISE,
Per F. J. Brougham,
46, Lincoln's Inn Fields, London, W.C.,
Agent for the Applicant.

page_text: Improvements in the Purification of Coal Gas.
I, CARL FRIEDRICH CLAUS, of Merton Road, South Wimbledon, in the County
of Surrey, Chemist, 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 :-
In the specifications of applications for Letters Patent bearing even date herewith
and numbered respectively 7580 and 7584 I have described processes of purification
of coal gas in which ammonia gas or ammonia liquor is introduced into scrubbers,
the liquor being caused to circulate through a series of scrubbers as in the said
specifications respectively set forth. One result of the treatment described in either
case is that a portion of the bisulphide of carbon is removed.
Now according to my present invention I introduce into one or
more of the
scrubbers in which bisulphide of carbon is to be removed from the coal gas, solid
sulphur in excess of the quantity that can be dissolved by the sulphide of ammonium
during its passage in contact with the said solid sulphur. For introducing the solid
sulphur into the scrubber, it is convenient to first finely grind the sulphur, which
may be done by well-known means (such as edge runners) and then to mix (and
agitate) it with water or ammoniacal liquor in a tank or vessel, whence it can be fed
to the scrubber, as I will now describe by aid of the annexed sheet of illustrative
drawings, whereof Fig. 1 is a vertical section and Fig. 2-a plan shewing so much
of a scrubber with special apparatus connected thereto as is needful to a clear
understanding of this method of carrying my present invention into practical
effect.
A is a tank of a capacity sufficient to hold the quantity of mixed sulphur and water
or ammoniacal liquor required for, say, one day's work to feed solid sulphur into the
scrubber. In the said tank is an agitator B, to maintain a uniform mixture of the
sulphur with the liquid; the tank is also provided with a false bottom C, which may
be either of perforated plate or wire gauze, the apertures in either case being smaller
than the apertures in the distributor of the scrubber. This false bottom acts as a
strainer.
The mixture of sulphur and water, or of sulphur and ammoniacal liquor, is pumped
to the scrubber in which the solid sulphur is to be used, and enters together with the
ordinary ammoniacal liquor supplied to the said scrubber through the distributor, or
it might be introduced through a special distributor. The powdered solid sulphur is
deposited upon the coke or other material with which the scrubber is filled, and
gradually dissolves in the sulphide of ammonium contained in the liquor. The
resulting sulphurised liquor absorbs the bisulphide of carbon from the coal gas
during its passage through the scrubber, and may be pumped through one or more
additional scrubbers. The amount of sulphur required will of course vary with the
amount of impurity in the gas to be purified, but usually about two pounds will be
sufficient for the purification of the gas from one ton of coal. This quantity of

page_text: sulphur may be diffused through one gallon of water or ammoniacal liquor as a
vehicle for enabling it to be pumped into the scrubber.
As will be evident, the solid sulphur might be introduced in lumps or powder
directly into the scrubber without the aid of a liquid vehicle, but this mode of working
would obviously entail inconveniences that are obviated by the method abovo
described. It will be understood that by so proportioning the supply of sulphur to
the quantity of liquor flowing through in a given time as to maintain in the scrubber
a reserve or quantity of solid sulphur in excess of that which will be taken up by the
sulphide of ammonium contained in such liquor, not only will the sulphide of
ammonium be charged with a sufficient proportion of sulphur to enable it to remove
bisulphide of carbon from the gas, but furthermore the loss of sulphur to which the
liquor is subjected during the subsequent operations will be compensated in an
automatic manner, so that the process of purification will be made practically
continuous, the liquor being kept sufficiently charged with sulphur.
In carrying out my invention the amount of sulphur dissolved by the liquor should
be such as will yield at the outlet of the first scrubber (that is to say, at the outlet of
the scrubber that the gas first enters) a liquor of distinctly yellow colour, but an
excess of sulphur should be avoided, because it will be prejudicial to the subsequent
treatment of the liquor in the manner described in my Specifications No. 7580 and
No. 7584.
Having now particularly described and ascertained the nature of the said invention,
and in what manner it is to be performed, I declare that I am aware that it
has been proposed to prepare a special liquor for the purpose of removing bisulphido
of carbon from coal gas by concentrating the ordinary ammoniacal liquor by
distillation, and afterwards saturating the said concentrated liquor with sulphur, and
to this I lay no claim, but by my present invention not only is such concentration as
just referred to dispensed with, but I am enabled to sulphurise the ammoniacal liquor
sufficiently to remove bisulphide of carbon without impairing its officiency in the
removal of other impuritiés.
What I claim is :-
In the purification of coal gas, causing ammoniacal liquor to be sulphurised without
previous distillation by contact with solid sulphur preparatory to use for removing
bisulphide of carbon from the coal gas in a scrubber, substantially in the manner
hereinabove set forth.
Datad this 4th day of March 1887