LU83579A1 - METHOD FOR DESULFURATION IN GAS PRODUCTION IN THE IRON BATH REACTOR - Google Patents

Description

KLÖCKNER-WERKE AKTIENGESELLSCHAFT Klöckncrstrasse 29, 41 Duisburg 1

Desulphurization process for gas generation in an iron bath reactor _; _

The invention relates to a process for desulfurization in gas generation in an iron bath reactor, wherein in the reactor vessel the reactants fuel in solid and / or liquid form, below the bath surface in the iron melt and oxidizing gas, for example oxygen, oxygen-enriched air or air, below or below and above the iron bath level.

Methods are known to convert fuels, in particular coal, together with oxygen or oxygen-containing gases in an iron bath and to produce a reaction gas which consists essentially of CO and H ^. A particular advantage of the gas ore in the iron bath reactor is that the sulfur present in the fuel is largely absorbed by a slag.

DE-Auslegeschrift 25 20 883 describes a process for the continuous gasification of coal or carbon-containing fuels in an iron bath reactor, in which the fuel and substances or oxygen or oxygen-containing gases, the latter before / 1 • · · / »t - 2 - ··· '· · ·· .. ·.

»

Hydrocarbons are encased and fed into the melt via nozzles below the bath surface. The slag formers, preferably lime dust with or without admixture of limestone or dolomite, are charged to the oxygen flow or blown into the bath together with the fine-grained coal.

ji DE patent ent publication 25 20 58 ^ describes a process for the gasification of sulphurous egg-containing coal in an iron bath reactor, in which a part of the sulfur-containing slag is continuously withdrawn in the liquid state, ready for descaling and returned to the iron bath reactor in liquid j. Especially with regard to the heat balance at

This process proves to be advantageous in the gasification process.

The known methods show different ways of gasifying carbon-containing fuels in an iron bath reactor and thereby generating largely sulfur-free reaction gases. However, all known methods use lime or limestone, possibly with a mixture of MgO or dolomite, to adjust a deslagging agent. The use of lime as a slag-forming agent proves to be disadvantageous in two ways. On the one hand the costs for the lime have to be used and on the other hand you have to the lime can be heated to the bath temperature. For example, to gasify .1 t coal, approx. 100 kg CaO with a Scliwefelye- j! of about 1%. The price for 1 t lime dust is

Time about DM 100, and to stain this lime you still need about DM 65 as energy costs. If you use cheaper i 'limestone, then the energy costs for heating and removing! acidify in the iron bath reactor so high that this method of operation is even less favorable.

left

The invention has set itself the task of developing a process to b t that the desulfurization during coal gasification in the egg. senbadrealctor in a particularly economical way.

'' • 4.-.

• · · • Μ * $ - 3 -

According to the invention, this object is achieved in that the steelworks slag resulting from the steel position are used as dewaxing sludges in the iron bath reactor.

The steel mill slag can be added to the iron bath reactor in various ways. The slag can e.g. be charged in pieces onto the surface of the iron bath, or they are blown into the iron bath x'ealctor in powder form below and / or above the bath surface. The powdery slag can also be mixed with the fuel, for example the coal to be gasified.

• In a particularly advantageous and economical manner, the

Steel aluminum silicates as base supports for the desulphurization in the iron bath reactor are fed to the reactor vessel / liquid. This mode of operation can always be easily achieved if an iron bath reactor for coal gasification is operated at a short distance from a steel mill. This is e.g. the case in an iron and steel works with an integrated power plant. In the power plant, e.g. burn the gas generated by the process according to the invention in the boiler system.

The use of steel slags according to the invention saves considerable costs, since these slags, for which there is generally only a limited usability, are available at low cost. In addition, there is a further advantage of the better usability of the slags after they have acted as desulfurization slags in the iron bath reactor and their composition has been changed by the absorbed IC hollow bag. They then have a composition similar to that of conventional blast furnace slag and, like this, can be widely processed in the cement or building materials industry.

The slags produced in a steel plant, for example when refining low-phosphorus pig iron, according to the various converter hairdressing methods using oxygen, have approximately »®fso hot as possible, in particular - 4 -» · • * the following composition: $ 0% CaO, 10? £ SiO ,,, 30% FcO, 0.1 S, ό the remaining constituents are essentially Alo0, MgO, HnO and Po0_.

J -

The process according to the invention for desulfurization in the gas: | jj generation in the iron bath reactor uses these slags because their output i; Sulfur content is low at approx. 0.08 to 0.12% and therefore one! : * jj high sulfur absorption capacity up to sweat contents of approx. 10; j exists- It is advantageous to reduce the sulfur content of the slags to i »*. t Ü ’to limit approx. 3 9 °, because it is in the range of the usual high ij I; 'Remain slag and can be used in a similar way.

Boron use of steel slags, for example from a | Steel production converter, for desulfurization in the iron bath reactor j, also brings about the irritcil that the iron oxide content 'from | this slag is reduced and thus an additional iron is obtained in the gasification unit. This iron can be extracted in portions from the

The liquid iron bath reactor is withdrawn and fed to the steel production. The operation of an iron bath reactor, for example for coal gasification in an iron and steel works, also has a favorable effect here.

. The method according to the invention makes it possible to bind the sulfur dioxide, for example of a coal to be gasified, almost completely in the metallurgical slag which is located on the iron bath in the gasification unit. The sulfur content of the first I.

j produced gases is very low. It is in the range of approx. 10 ppm.

| This means that more than 99% of the sulfur in the Schlak 'ko is bound. . '\ i |

The use of the process according to the invention brings particularly economic advantages when gasifying cabbages with high sulfur or odor ash contents. Would you, as usual, Λ A.

• »· • - 5 - *

Add lime to the slag formation / so high quantities are necessary that the economy of the process suffers and it may also be necessary to add energy to the bath, because these types of coal with the high lime scale must no longer be autothermally gasified.

It is within the meaning of the invention to add water to the iron bath reactor in order to increase the hydrogen concentration in the gas produced. Preferably in the gasification of high-energy coal types in which the gasification process takes place with excess energy, the free heat can be used to split water into hydrogen and oxygen. As the hydrogen escapes from the melt, the oxygen reacts with the carbon of the. Iron bath to CO.

The water can be added directly in liquid form or as water vapor. Of course, it can also be supplied as a secondary in suspension with a carrier gas. Furthermore, it can also be mixed with the coal to be gasified or introduced in the form of an increased moisture content of the coal. For example, it has proven useful to use the coal without drying with a constant water content or to only partially dry the coal to be gasified in order to set a defined moisture content, with which it is then introduced into the iron bath of the reaction vessel.

H·

The use of steelworks slags according to the invention for desulfurization in gas generation in the iron bath reactor thus proves to be particularly advantageous and economical in several directions. In terms of its composition, it is well suited as a deslagging slag in coal gasification and also saves Enerc when it is added to the gasification unit, which is otherwise required to heat up the slag formers. Furthermore, the steel slag is changed in composition after its use in the iron bath reactor in such a way that it is suitable for use in cement production and construction. In addition to the resulting economic advantages, "the storage and the problems resulting therefrom are eliminated with unpredictable results." * ', (- 6 - i »i is reduced in the iron bath reactor, and pig iron is produced, which can be processed into steel in the steel works.

j; The desulfurization process according to the invention in the Gaserzou- [. In an iron bath reactor, gasification proves to be i; types of coal or fuels containing carbon at’Ein- j | The energy-saving liquid slag is advantageous because I have a higher energy component for the reduction of the iron oxide in the egg-bath reactor. It also lies in the sense of the invention to use excess energy for iron production 1 from iron ore or pre-reduced iron ore.

s (; An iron bath reactor can be included with the present

Operate the invention for example as follows: i

120 t liquid iron with a carbon content of approx. 4% is initially charged into a converter-like vessel with an internal volume of 3 ’about 150 m. 30 t of liquid slag from the LD process are also added. In this iron bath reactor, 50 t of coal of the composition 'C 78.3%, H2 5.0%, 02 6.7%., Ash 5.0%, Hu 7510. kcal / kg are gasified per hour. The ! Coal is introduced below the bath surface and with acid

Material that is also blown through the floor gasifies. At the same time, 30 tons of ore, e.g. as fine-grain ore, through nozzles in the lower part of the converter or in the form of lumpy ore or pellets from above. After an operating time of 4 hours, sth! 50 t of slag and 210 t of iron with a carbon content of about I 2% accumulated, j

At this point, the slag is stuck out of the converter, possibly completely and approx. 90 t of iron. After the further addition of liquid LD slag in the amount mentioned, the process is continued in the same way. The gas generated is fed to its use via a gas meter. The capacity of a conventional gasometer is generally large enough to continue supplying customers during the interruption period for emptying the slag and steel and filling the new slag, which is approximately 5 minutes.

The liquid iron from the coal gasification vessel has a sulfur content of approx. 0.3% and a phosphorus content of approx. 0.1%.

After desulfurization, it can be carried out in a known manner, e.g. in a converter, to be freshened to steel. i U '· * \ t

Claims (9)

3. The method according to claim - 1; characterized in that the steelworks slag enters the iron bath reactor in powder form below and / I ’j or above the bath surface! is blown. i i j 4) Method according to claims 1 and 3, characterized thereby! net that the steelworks slag in pieces on the Eisonbad- | · Surface is charged. j '”3) Method according to claims 1 to 4, characterized in that the steel works slag has approximately the following composition: $ 0% CaO, 10% S1O2, 30% FeO, 0.1% S, the remaining constituents are essentially MnO, I Al ^ Oo and MgO. f ^ as hot as possible, especially Ir '-9- 6. The method according to one or more of claims 1 to 5, characterized in that the basicity (CaO / SiC ^) of the steel works slag is 3 to 5. 7. The method according to one or more of claims 1 to 6f, characterized in that the desulfurization slag in the iron bath reactor is changed to a basicity of 1 to 2 by the fuel axis. 8. The method according to one or more of claims 1 to 7, characterized in that the desulfurization slag in the iron bath reactor has a final sulfur content of at most 10%, preferably below 3%. 9. The method according to one or more of claims 1 to 8, characterized in that water and / or water vapor is introduced below the bath surface in the iron bath reactor. 10. The method according to claim 9, characterized in that the water comes from the water content of the coal used as fuel. 11. The method according to one or more of claims 1 to 10 / characterized in that iron 'is produced in the iron bath reactor by reducing the iron oxide content of the steelworks slag. 12. The method according to one or more of claims 1 to 11 / characterized in that iron ore and / or pre-reduced iron ore is reduced in the iron bath reactor. 13. The method according to one or more of claims 1 to 12 / characterized in that liquid iron is withdrawn in portions and / or continuously from the iron bath reactor and fed to a steelmaking process. (! \ A \ u,