Improvements in the Treatment by the Claus Process of Gases Containing Sulphuretted Hydrogen, and Recovery of Valuable Products therefrom.
Year: 1890

page_text: Date of Application, 30th Dec., 1890
Complete Specification Left, 8th Sept., 1891-Accepted, 10th Oct., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Treatment by the Claus Process of Gases
Containing Sulphuretted Hydrogen, and Recovery of Valuable
Products therefrom.
I, CHARLES WILLIAM HEATON, of 44 Woodstock Road, Bedford Park,
London, W., Analytical Chemist, do hereby declare the nature of this invention
to be as follows:-
My invention has reference to improvements in the treatment by the Claus
process of gases containing sulphuretted hydrogen, the object being to enable a
large percentage of sulphur to be economically recovered, whilst at the same time
obviating the nuisance that is liable to result from the carrying on of the Claus
sulphur recovery process as heretofore usually practised. According to my inven-
tion the gases containing sulphuretted hydrogen are heated in a Claus kiln as
heretofore usual for effecting the separation of the sulphur; the sulphur vapour
and gases therewith pass from the said kiln, a large proportion of the sulphur is
condensed and collected, then the cooled gases with their contained sulphur are
mixed with air in quantity sufficient, or more than sufficient, to oxidize all the
unoxidized sulphur and convert into sulphurous acid and water the sulphuretted
hydrogen that escaped from the sulphur recovery apparatus; then the mixed gases
are passed into a chamber hereinafter referred to as the supplementary Claus kiln,
which chamber resembles the well known Claus kiln, but, as there may not be
sufficient unoxidized sulphur or sulphuretted hydrogen to generate by oxidation a
sufficient degree of heat to keep the supplementary kiln in an active state, I make
provision whereby there can, when required, be applied to this kiln, additional heat
from some convenient source, it may be heat produced from burning coke or other
fuel, or heat generated in the Claus kiln. Thus by my invention the free sulphur
(if any), and the sulphuretted hydrogen are entirely oxidized even when present
in small proportion.
As will be evident, in carrying out my invention different plans can be adopted so
long as the interior of the supplementary Claus kiln be kept at a temperature
sufficient for its continuous action. Thus for example the supplementary Claus
kiln can be constructed over and in close proximity to a furnace in which coke or
other suitable fuel can be consumed; and the exit gases from the kiln may be dis-
charged separately, or be allowed to mingle with the gases produced by the
combustion of the fuel; or the supplementary Claus kiln might be arranged over or
under or in close proximity to, and so as to be supplied with heat from the ordinary
Claus kiln in which a great degree of heat is generated that heretofore has not
usually been utilized.
In some cases I utilize the sulphurous acid in the exit gases of the supplementary
Claus kiln to produce valuable sulphur compounds.
For this purpose a series of towers or scrubbers is provided each of which is
packed with limestone or chalk in blocks, or with flint or some other neutral
material. Each tower is furnished at the top with a distributor by which water or
other liquid can be passed down it. The liquid is pumped in succession to the top
of each tower and meets, as it descends, the exit gases from the supplementary
Claus kiln which ascend each tower in succession in an opposite direction to that in
which the liquid is travelling.
If the towers are packed with limestone or chalk, water is admitted to the top of
the tower farthest from the tower where the gases first enter.
In this case the water before it leaves the towers will have become a solution of
sulphite of lime strong enough to possess commercial value.
D

page_text: If the towers are packed with flint or other neutral material they may be washed
as before with water, in which case a solution of sulphurous acid is obtained, or
with a solution of carbonate of soda, in which case a solution of sulphite of soda is
obtained, or with any other alkaline solution.
Dated this 30th day of December 1890.
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Treatment by the Claus Process of Gases
Containing Sulphuretted Hydrogen, and Recovery of Valuable
Products therefrom.
I, CHARLES WILLIAM HEATON, of 44 Woodstock Road, Bedford Park,
London, W., Analytical 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 :—
My invention has reference to improvements in the treatment by the Claus pro-
cess of gases containing sulphuretted hydrogen, the object being to not only enable
a large percentage of sulphur to be economically recovered as heretofore, but at
the same time to obviate the nuisance that is liable to result from the carrying on
of the Claus sulphur recovery process as heretofore usually practised. According
to my invention the gases containing sulphuretted hydrogen are treated in a Claus
kiln as heretofore usual for effecting the separation of the sulphur; the sulphur
vapour and gases therewith pass from the said kiln, a large proportion of the free
sulphur is condensed and collected, then the cooled gases with their contained
sulphur (free or combined) are mixed with air in quantity sufficient, or more than
sufficient, to oxidize all the unoxidized sulphur and convert into sulphurous acid
and water, the sulphuretted hydrogen that escaped from the sulphur recovery
apparatus; then the mixed gases are passed into an apparatus constructed with a
chamber or chambers charged with some substance that will cause the oxidation of
sulphuretted hydrogen, as for example oxide of iron, to the action of which the
gases are subjected as in the well known Claus kiln, and which apparatus is there-
fore hereafter called for distinction the supplementary Claus kiln, but as there may
not be sufficient unoxidized sulphur or sulphuretted hydrogen to generate by
oxidation a sufficient degree of heat to keep the contents of the said chamber or
chambers sufficiently hot, I make provision whereby there can, when required, be
applied to the chamber or chambers additional heat from some convenient source.
Thus by my invention the free sulphur (if any), and the sulphuretted hydrogen are
oxidized even when present in small proportion.
As will be evident, in carrying out my invention different plans can be adopted
so long as the interior of the supplementary Claus kiln be kept at a temperature
sufficient for its continuous action. Thus for example the supplementary Claus
kiln can be constructed in close proximity to a furnace in which coke or other
suitable fuel can be consumed; and the exit gases from the kiln may be discharged
separately, or be allowed to mingle with the gases produced by the combustion of
the fuel; or in some cases it might be found convenient to arrange the supple-
mentary Claus kiin so as to be supplied with heat from the ordinary Claus kiln, in
which a great degree of heat is generated that heretofore has not usually been
utilized; but the first of these arrangements and of which an example is herein-
after more fully described will I believe usually be found preferable.
In some cases I utilize the sulphurous acid in the exit gases of the supplementary
Claus kiln to produce valuable sulphur compounds.
For this purpose a tower or series of towers or scrubbers is provided, which
tower or each of which towers if there be a series, is packed with limestone or
chalk in blocks, or with flint or some other neutral material; and also is

page_text: furnished at the top with a distributor by which water or other liquid can be
passed down it. The liquid is pumped to the top of the tower or to the top
of each tower in succession, as the case may be, and meets, as it descends, the
exit gases from the supplementary Claus kiln which ascend the tower or each
tower in succession in an opposite direction to that in which the liquid is
travelling.
If the tower or towers be packed with limestone or chalk, water is admitted to
the top of the tower or the top of that tower of the series which is farthest from
the tower where the gases first enter.
In this case the water before it leaves the tower or towers will have become a
solution of sulphite or bisulphite of lime.
If the tower or towers be packed with flint or other neutral material it or they
may be washed as before with water, in which case a solution of sulphurous acid is
obtained, or with a solution of carbonate of soda, in which case a solution of
sulphite of soda is obtained, or with any other alkaline solution.
Such being the nature of my invention I now proceed to describe a way in
which it has been carried into successful practical effect, for which purpose
reference is had to the accompanying sheet of illustrative drawings.
Figs. 1 and 2 shew respectively in front elevation and partly in side elevation
and partly in section an apparatus such as hereinbefore referred to as the supple-
mentary Claus kiln,—and
Fig. 3 is a vertical section of a wash tower.
Referring to Figs. 1 and 2, A is a furnace with combustion chamber B traversed
by inclined tubes or chambers arranged in two series C and C¹. E is an end box
with connection F to a suitable cooling apparatus such as a wash tower which in
turn is in connection with the sulphur-depositing chambers of the ordinary Claus
kiln the upper ends of the inclined tubes or chambers C are open to the end
box E. G is another end box with internal horizontal partition G whereby it is
divided into two compartments connected by a bent pipe H. The lower ends of the
tubes or chambers Care open to the upper compartment and those of the tubes C¹
to the lower compartment. I is an end box in communication by pipe K with the
wash tower represented in Fig. 3,-or it might be with the first tower of a series.
The upper end of the tubes or chambers C₁ are open to the end box I.
The chambers C C¹ are filled or nearly filled with pieces of oxide of iron, an
oxide of manganese, or other material suitable for the purpose hereinabove referred
to as will be readily understood by chemists.
By combustion of solid fuel in the furnace sufficient external heat is supplied to
give to the gases in the chambers C C₁ a suitable temperature say about from 600°
to 800° Fahrenheit in order to convert the H2S into SO, and H₂O.
Although I have shewn a furnace for burning solid fuel and designed to be
regulated by a damper or dampers, it will be evident the apparatus might be
constructed to use liquid or gaseous fuel. It will be understood that the gases
escaping from the sulphur-depositing chambers of the Claus kiln ordinarily used in
carrying out the Claus process-and which gases consist mainly of inert gases with
small but varying quantities of H2S or SO, but usually both (according to the
manner in which the Claus process is worked)-are according to my invention
cooled, mixed with sufficient air to oxidize any H2S they may contain; and then
the mixture of gases and air is caused to pass through what I have hereinabove
called the supplementary Claus kiln, i.e. through the packed chambers C C¹ in the
example illustrated for the purpose already mentioned.
From this apparatus the gases pass to a tower such as that represented in Fig. 3
which is suitably packed. The gases enter by the pipe K the chamber L, passing
through the perforations in the false bottom M and ascending through the material
with which the tower is packed, whilst water from the distributor N trickles
down.
If the tower be packed with limestone, the wash liquor may be allowed to run
away; but the SO, may be absorbed by carbonate of soda, or caustic soda, or any

page_text: other alkaline liquid; and sulphites of soda or other bases be thus produced that
will be of commercial value.
Exit gases containing sulphuretted hydrogen may, after admixture with sufficient
air, be heated by external heat such as that of a coke fire and then be passed
through a supplementary Claus kiln which in this case need not be otherwise
heated or the exit gases as aforesaid may be mixed with hot air and then be passed
into a supplementary Claus kiln.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The hereinabove described process of oxidizing the exit gases containing
sulphuretted hydrogen, the said gases with their contained sulphur (free or com-
bined) being mixed with air in quantity sufficient, or more than sufficient, to
oxidise all the unoxidised sulphur and convert into sulphurous acid and water the
sulphuretted hydrogen that escaped from the sulphur recovery apparatus, and the
mixed gases being then treated in a supplementary Claus kiln (with application of
heat when necessary) in such a manner as to oxidize the free sulphur (if any) and
the sulphuretted hydrogen as set forth.
a
2. The hereinabove described treatment of the exit gases containing sulphuretted
hydrogen by mixing the cooled exit gases with air, then treating the mixture in
supplementary Claus kiln (with application of heat when necessary) in such a
manner as to oxidize the free sulphur (if any) and sulphuretted hydrogen, and
effecting the absorption of the sulphurous acid produced in the supplementary
Claus kiln either by a tower or towers containing limestone or chalk down which
water is trickling or by a tower or towers packed with neutral material down which
an alkaline liquid is trickling.
Dated this 8th day of September 1891.
CHARLES WILLIAM HEATON.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicant.