DE1915248C3 - Process for purifying gases containing sulfur - Google Patents

Description

2. The method according to claim I, characterized gejedoch shown that in practical use we In view of the necessary extensive investment and the high operating costs, it is not economical are.

Furthermore, procedures have already been ent where the sulphurous gases are discharged after combustion and gasification of the fuel will. However, this again involves complex systems and / or high operating costs connected.

In the German patent specification 413 680 is a method for burning carbon fuel, in which the fuel and oxygen be introduced into a molten iron bath beneath its surface, so that the carbon from the fuel can react with the oxygen, carbon monoxide and from the present Impurities create a slag. In this process, the fuel is in block

,. "·""" I " ^ul "'. UUUUIiIi gc- Dci iiicscni vciiariicii iicgi uer Drennsioil in tJlock-

Indicates that the carbon fuel * ° forms before, which inevitably has a low carbon

with a KnrnimHi · «.. <r>.«; .. ·. · ι._ -ι- ■. ·. ■ -. · -. . '

with a grain size of no more than about 3,175 mm is used.

ο σ D «.mi.,. VJi ₁ -

Concentration in the iron bath has the consequence, so that when performing this process with sulfur-containing Carbon fuels and sulfur dioxide

other harmful gases are formed.

U.S. Patent 1592860 describes a

. Verfrhre.1, in which carbon fuel is

The invention relates to a method for purifying molten iron bath for the formation of carbon from gases, which is introduced by burning sulfur monoxide and dioxide, whereby also .... ι carbon fuel with oxygen under a slag is created. However, the description gives

Carbon monoxide are obtained under 3o no indication, as in the case of the burning of pigs molten iron bath, under fuselage fuels to avoid formation

of sulfur dioxide is to be dealt with.

According to this, the object on which the present invention is based can be seen in a To propose methods of purifying gases produced by burning sulfur-containing carbon fuel can be obtained, with the sulfur already during the combustion in more economical Way is removed. This object is achieved according to the invention in the fact that in the process assumed to be known at the outset, the carbon fuel in reduced form is dissolved in the iron bath in such an amount that in this the carbon content kept at a sufficiently high level to prevent the formation of sulfur dioxide avoid, and that the iron bath is mixed with lime

_{β e} - Mt.v.iiv.11 «-laciiuaucs, unier

the surface of which the fuel and oxygen are introduced into the bath.

The burning of solid carbon fuels by implementing the same with a limited The amount of oxygen used to produce carbon monoxide is well known. For this Implementation can either be pure oxygen or air can be used. As combustion products carbon monoxide and also hydrogen, some carbon dioxide, water and get nitrogen. The hydrogen is created from the hydrocarbons present in the fuel, whereas the nitrogen results from the air for the conversion, if air is used for combustion is used. However, nitrogen can also be contained in the fuel itself. carbon dioxide can result from the reaction of water vapor with carbon monoxide.

»« ..., 1.ICIIIVIW ₁ IICMIIIIII-IICIi ICMCTl

Carbon fuels contain sulfur. If these fuels are now reacted with air or Oxygen is burned and gasified, so are the other combustion products too Free sulfur-containing gases, which generally contain predominantly sulfur dioxide. These turn out to be combustion products The resulting sulfur-containing gases are, however, often undesirable for many reasons, mainly because such sulfur-containing gases are highly toxic and at release in the atmosphere cause a not inconsiderable air pollution.

Numerous attempts have already been made to remove the sulfur from the sulfur-containing Remove fuels before burning these fuels with air or oxygen will. Some of these attempts at sulfur removal have been relatively successful: it has worked

. .-ww ·. ■■ * * kwii «* f.l.1LL £ l

and the calcium sulfide-containing slag formed is removed will. In order to maintain the desired high carbon concentration in accordance with the invention de in iron bath it proves to be expedient to use the carbon fuel with a con size of not to use more than about 3.175 mm.

In the method according to the invention, the carbon contained in the fuel is from the Iron bath is absorbed where it meets the oxygen, which is supplied in the form of air and is preheated can be, preferably converted to carbon monoxide, which is then passed through the iron bath above rises. The sulfur contained in the fuel is also absorbed by the molten iron, however, by the presence of more chemically active carbon in a reaction with the Air or the oxygen hindered. In this context it should be noted that the carbon content of the molten iron bath must always be maintained at a sufficiently high level must in order to ensure that there is no

«Development comes from sulfur dioxide or iron oxide. This can easily be achieved in that the Introduction of carbonaceous fuel relative to the introduction of air or oxygen is controlled in such a way that there is always a sufficiently high concentration of carbon in the iron bath. In addition, certain chemical agents can also be added to the iron bath the chemical activity of carbon moderate process is not necessary to comminute or pulverize the fuel to such an extent that it is in the form of a finely ground powder. However, it should preferably have a grain size that is no coarser than about 3.175 mm.

The lime is introduced into the vessel 10 above the iron bath 12, see that on the surface of the iron bath 12 forms a melt layer of lime-containing slag 13. With the name "lime"

chejnische the activity of the carbon relative to _e _. ...

those of sulfur and / or iron to increase. ^l0 in this context is calcium oxide, calcium on the surface of the molten iron bath carbonate (limestone) or dolomite (a mixture of

Calcium and magnesium carbonate or oxide) kikb id bi dr in the vessel

a molten layer of calcareous slag is maintained according to the invention, the two Purposes. First of all, it acts as a flux for the ashes; H. it forms together with the incombustible Leftovers from the fuel are a melted mixture. Furthermore, it reacts by learning from the melted one Iron absorbed sulfur in such a way that calcium sulfide was formed. To form a such slag becomes the layer of slag floating on the surface of the molten iron bath Lime added.

means. The calcium carbonate is converted into calcium oxide at the temperature in the vessel 10.

»5 walks.

Preheated air is introduced into the iron bath 12 through the line 16. Upon contact with the melted Iron dissolves the carbon contained in the fuel in the iron and is exposed to it

oxygen from the air to carbon monoxide around. The sulfur contained in the fuel is absorbed by the iron and therefore cannot get along with it convert the oxygen.

The carbon monoxide thus formed migrates

Part of the slag is continuously withdrawn

gen, so that in this way a continuous decline

guidance of the sulfur from the iron bath is given. as through the slag layer 13 upwards and leaves

The incineration. Carbon- the vessel 10 through line 14. As below

gas mixture containing non-oxide is collected and explained in detail, the carbon

and can then be further burned for synthesis purposes, for layering monoxide, and with it

development in hydrogen or as a reactant for an- carbon dioxide, whereby additional

whose purposes are used. But it can also 30 before heat is generated, which in turn is a series

be mixed with additional air or oxygen, the carbon monoxide being mixed with the oxygen with the formation of carbon dioxide and heat, which are made industrially usable can be supplied by uses. From the incombustible residues of the Ashes form fuel, which rises to the surface of the iron bath 12 and through the lime in this way

will come. The carbon dioxide and other gases 35 is slagged that a molten calcareous

can then simply be discharged into the outside air without any air pollution associated therewith would.

The from the surface of the molten iron slag layer 13 is created. This slag layer 13 also removes (as calcium sulfide) that from the molten one Iron bath 12 absorbed sulfur. The fact that in the vessel 10 is continuously sulfur

bath continuously removed slag is introduced and on the other hand continuously parts of the cools, processed into granules, wetted and coated with a cohesive lacquer layer 13 via a discharge line 15 are withdrawn, the sulfur is also continuously removed from the iron bath 12.

far away. The extracted slag contains ash, lime

brought into contact with fuel dioxide. The carbon dioxide reacts with the in the presence of water

calcium sulfide contained in the slag in the .- "^.

Way that hydrogen sulfide and calcium carbonate (including the unconverted limestone) bonat educates. The resulting hydrogen sulfide and calcium sulfide.

Fig. 2 shows how carbon monoxide and other gases from the vessel 10 through the line 14 withdrawn and into the combustion chamber of a

can then be further processed and implemented in such a way that pure sulfur is finally obtained will. c-o

The process according to the invention is conducted in the drawing boiler 17, where the carbon deposits Illustrates in which identical oxides are converted into carbon dioxide by reaction with air Parts or pre-ranks are converted with the same elements. The air is blown by a fan

18 introduced into the combustion chamber of the boiler 17. By the fact that the carbon monoxide with converts the oxygen from the air into carbon dioxide, heat is released and this Heat as well as part of the heat content of the combustion products passing through the boiler 17 transferred to the water in the boiler 17,

Fig. 1 shows a combustion vessel 10, 60 whereby this is converted to steam. The one there a molten iron bath 12 contains. In with obtained combustion products get over

~ '- ■ · a line 19 from the boiler 17 and into the heat

exchanger 20, where further heat is used to feed the steam boiler

Parts or processes are each designated with the same reference numerals. It shows

1 shows a schematic representation of a combustion vessel suitable for the purposes of the invention and

Figure 2 is a schematic representation of an embodiment of one for carrying out the invention suitable device.

the lower part of this iron bath 12 is crushed sulfur-containing carbon fuel introduced through a line 11, which is in the form of a

preheat water-cooled supply line or another suitable feed water, which is

lieten device can be formed. device 31 into the boiler 17 and via a line 52

Otherwise, in this context, betner- got into the steam boiler 41. From heat exchange

k.en. that in order to carry out the inventive step 20, the thus cooled combustion

tion products through a line 21 and they can from there easily into the atmospheric ambient air be drained without the risk of air pollution.

The molten slag withdrawn from the vessel 10 through the discharge line 15 is subjected to a comminution or granulating device 22 is supplied, in which it is processed into solid granules. There are a number of commercially available slag reduction devices that in which the slag is cooled so far that it solidifies, whereby it is crushed at the same time. at Such devices can be a rotating one for cooling and crushing the slag or a reciprocating disk, a water jet, or any other suitable means may be used. With a view to the fact that commercially available devices can be used for this purpose, a detailed description of the granulator 22 is not necessary.

The hot solid granular slag is from the granulator 22 via a line 23 into a cooling shaft 24 headed. In this cooling shaft 24, the slag is cooled in such a way that air from below is passed up through the duct, the introduction of the air into the duct 24 below With the aid of a fan 25 takes place. The hot air that collects in the cooling duct 24 is over a line 26 is fed to the line 16, through which it, as described above, into the vessel 10 got. In this connection it should be noted that the cooling of the slag also takes place on different levels Other ways can be done, for example, by passing the slag through a water bath or it is simply left to stand in the air, so that it gradually gains its warmth releases into the outside air. The cooling shaft 24 is for carrying out the method according to the invention not absolutely necessary, and preheated from another source can also be present in the line 16 Air can be introduced.

The cooled slag coming from the cooling shaft 24 is passed through a line 28 into a desulfurization device 27 initiated. If the slag is not sufficiently wet, it will be before hers Entry into the desulfurization device 27 wetted with water, which is stirred into the line 28 can be. While the wet slag passes down the desulfurization device 27, it comes into contact with the carbon dioxide, which in turn moves upwards. A part of Combustion products can be used as a carbon dioxide source for the desulfurization device 27 to be needed. For this purpose a pump 29 is used, which feeds some of the combustion products brings into a line 30, which in turn is connected to the desulfurization device 27.

In the presence of water, the carbon dioxide contained in the combustion products settles with the calcium sulphide of the slag in such a way that potassium carbonate unu Weäscrstoiisu! fid arises. At the same time there is also a conversion between the carbon dioxide and the lime in the slag, which also creates calcium carbonate.

The hydrogen sulfide obtained in this way arrives together with some unreacted carbon dioxide residues in the desulfurization device 27 upwards and enters the line 33. The already converted slag that collects in the lower region of the desulfurization device 27 contains unreacted calcium oxide, calcium carbonate, ash and some calcium sulfide and gets into the pipe 34 brought. A part of the slag can again enter the combustion chamber via line 35 10 can be initiated. However, in order to avoid excessive ash formation, a part must

ίο this slag discharged through line 34 and be taken away.

The hydrogen sulfide and the unconverted carbon dioxide arrive through line 33 a three-way valve 36, which is set so that about a third of the gases to a burner 37 and two thirds get into a line 44. The burner 37 is supplied with air by a pump 38 and the hydrogen sulfide is burned, thus producing sulfur dioxide and water vapor develop. In order to ensure the combustion in the burner 37, it may be necessary through a pipe 39 still to introduce natural gas. Along with other combustion products and carbon dioxide the sulfur dioxide and water vapor get there

»5 through a line 40 which runs within a boiler 41 runs. The heat released by the combustion process is absorbed by the walls of the pipe 40 forwarded and thus reaches the water in the boiler 41, so that from this Steam is produced. The steam generated in this way is in turn discharged from the boiler 41 through a line 42 and combined with the steam formed in the boiler 17 and flowing through the line 43. This steam stream formed from the two substreams can now be used as a heat source for any Another method for driving power turbines in a power plant or for one Any number of other purposes which will be readily apparent to those skilled in the art can be employed.

After passing through the line 40, the sulfur dioxide, the carbon dioxide, the water vapor and the other gases generated in burner 37 with the hydrogen sulfide and carbon dioxide streams brought together in line 44.

The stream composed in this way then passes into line 45 and from there into the conversion tank 46. The reaction vessel 46 contains a catalyst, preferably bauxite, which becomes effective in such a way that the implementation between

see the sulfur dioxide and the hydrogen sulfide to form pure sulfur vapor and Accelerated water vapor. This is a reaction well known to those skilled in the art, the can be controlled so that a high yield of elemental sulfur is obtained. A more accurate one Description of this reaction is therefore unnecessary.

The elemental sulfur obtained in this way (present in vapor form) leaves the reaction vessel 46

through a line 47 and then enters a condenser £ 48. In this condensation device 48 can be used as a coolant either water or air, so that the the gases passing through the device so far

be cooled so that the sulfur vapor condenses. This condensed sulfur comes along with Carbon dioxide, water and other vapors through a line 49 into the sulfur collection tank

50, in which the sulfur is accumulated. The rest of the carbon dioxide, the water and others Vapors leave this container 50 through a line 51 and from there can simply be released into the outside air, be forwarded.

In the preceding description, for the sake of illustration, reference has been made to the use referred to by steam boilers, but understands

it is for the expert that the by the inven proper combustion process of Brennstof fen generated heat for numerous other Ver Application purposes can be used in denei hot combustion products as the reaction medium can be used, but that they can also be used there as well as a heat and energy source men. where carbonaceous fuels are available.

For this purpose 2 sheets of drawings

Claims (1)

Patent claims: 1. Method of purifying gases produced by burning sulfur-containing carbon fuel with oxygen to form carbon monoxide can be obtained using of a molten iron bath, under the surface of which the fuel and oxygen in the bath is introduced, characterized in that the carbon fuel in crushed Form is dissolved in the iron bath in such an amount that in this the carbon content kept at a high enough level to prevent the formation of sulfur dioxide to avoid, and that the Eisenoad is mixed with lime and the calcium sulfide-containing Slag is removed.