FR2597881A1 - PROCESS AND INSTALLATION FOR GASIFYING MINOR QUALITY FUELS IN A FUSION METAL BATH - Google Patents

Abstract

THE INVENTION CONCERNS A PROCESS AND A PLANT FOR CARBONIZING MINOR-QUALITY FUELS IN A BATH OF FUSION METAL, IN PARTICULAR A BATH OF FUSION OF IRON. TO AVOID HEAT LOSS AND THE RISK OF SOLIDIFICATION OF THE BATH, AS IN KNOWN PROCESSES, RESPECTIVELY MINOR QUALITY AND HIGH QUALITY FUELS ARE INTRODUCED SEPARATELY IN TWO BEDROOMS 4, 5 OF A REACTOR 1, THESE BEDROOMS BEING SEPARATE FROM THEM. ONE OF THE OTHER BY A SEPARATING WALL 2 AS REGARDS THE VOLUMES OF GAS BUT BEING CONNECTED WITH RESPECT TO THE BATHS OF FUSED METAL THAT THEY CONTAIN THROUGH A PASSAGE OPENING 3. APPLICATION TO BURNING WASTE OF ALL NATURE.

Description

The present invention relates to a method and an installation

  process for the gasification of minor grade fuels in a bath of molten metal in a liquid state, especially a molten iron bath. When gasifying carbon-containing fuels and / or hydrocarbons in a liquid-state metal bath, such as in an iron bath, relatively high-grade fuels such as coal must be used. carbon anthracite, coal coke or lignite coke of sufficiently high calorific value to compensate for heat losses in the gasification plant and to be able to maintain the temperature of the iron bath at a value of constant. When the calorific value of the fuels to gasify decreases too much

  strongly, there may be a reduction in temperature and finally a solidification of the iron bath.

  This deficiency can be counteracted by operating with an oxygen content greater than the stoichiometric degree, ie, to maintain heat in the process, at least a portion of the rich final gas must be burned. in energy that is produced. However, this results in a decrease in the quality of the final gas produced. The disturbing elements consisting of CO 2 and H 2 O should, in the case of severe quality conditions imposed on the product gas, be subjected to a subsequent gas purification step or to a gas scrubbing which increases the gas content.

cost of operations.

  According to the German patent application DE-OS 31 680, there is known a process in which the final gas produced in the iron bath of a converter and essentially containing CO and H2, is sucked and partially burned in. the volume of the converter placed above the bath by means of an oxidation agent additionally injected onto the surface of the melt, for example oxygen or air, in which case the heat of combustion thus produced must to be transmitted to the iron bath. By the known method of gasification of carbon-containing fuels in an iron bath converter, attempts have been made to gasify low calorific qualities of coal without the addition of other energy-rich fuels, such as aluminum or aluminum. silicon. However, the product gas still contains a high percentage of CO2 and

  H20, which greatly reduces the quality of the gas.

  The aim of the invention is to create a method and an installation for carrying out the process for the gasification of fuels of minor value in a bath of molten metal in the liquid state, especially a molten iron bath. , in order to be able to produce a high gas

  quality by avoiding subsequent gas washes for CO 2 / H 2 O separation, involving measurements in the metallurgical field.

  With respect to the process, the problem is solved in that the minor grade fuels are introduced into a first reaction zone containing a bath of molten metal and high quality fuels are introduced into a second reaction zone containing a bath of molten metal, the gas volumes of the two reaction zones being kept separate from one another, and that the molten metal bath of the first zone of

  The reaction is mixed with the molten metal bath of the second reaction zone.

  Thanks to the separate introduction of the minor quality fuel into the first reaction zone and the high quality fuels into the second reaction zone, a number of advantages are obtained: the gas produced at the outlet of the second zone The reaction is a high quality gas that is not impure with CO 2 and H 2 O fractions. The energy-poor gas produced at the outlet of the first reaction zone and consisting mostly of the volatile constituents of the minor grade fuels is completely burned in part to introduce heat into the molten metal bath and partly for other functions and objectives within the whole process. Carbon passing into solution in the molten metal bath in the first reaction zone, by mixing the molten metal bath from the first reaction zone with the molten metal bath from the second reaction zone, in the zone of decarburization or gasification of the molten metal bath o, in the second reaction zone, the carbon dissolved in the metal will be partially oxidized by injection or insufflation of the gasification agent, for example oxygen or oxygen-enriched air, or oxygen-enriched gas from the first reaction zone, to produce carbon monoxide in gaseous form. The high quality final gas thus obtained, the carbon percentage of which comes from both the high grade fuel and the minor grade fuel, no longer requires

no further washing.

  In the practice of the invention, it is provided that the molten metal bath - in the first reaction zone is kept free of a slag layer, or that a slag is formed from ashes and non-burnable constituents of the minor grade fuels to be gasified are removed from the metal melt and slag former are introduced into the second reaction zone. In this way, it is ensured that in the first reaction zone good heat and material transmission can occur. The heat produced by combustion of the volatile constituents from the minor grade fuels can be absorbed by the molten metal bath without being impeded by a slag layer (having poor thermal conductivity). The transfer of materials or the dissolving of carbon from the minor grade fuel into the molten metal bath is not impeded by a layer of lnitier and can proceed in a sufficiently rapid manner, thanks to the movement of the bath of melting or the permanent exchange of materials of the liquid phase between the two reaction zones. The sulfur contained in the fuels of minor quality is put in solution for the most part in the melt of metal found in the first reaction zone and is fixed in the slag being formed under the action of the basic slag trainers , such as lime, which are introduced into the second reaction zone, so that in the final gas produced there is no longer any sulfur compound. The slag in the reaction zone is removed from time to time and

  is again formed by introducing lime.

  According to another aspect of the invention, it is intended to introduce into the first reaction zone containing a metal melt, as a minor quality fuel, lignite, coal of minor quality,

20 25 30 35

  peat, wood, sawdust, sawmills, straw, agricultural waste, tar, bitumen, pitch, oil, heavy oil, oily shale, garbage, combustible waste, plastics, clarification sludge, tires, used rubber or similar carbon-containing materials and hydrocarbons as well as mixtures of such materials in a corresponding disaggregated or agglomerated form. By means of the combination, provided according to the process of the invention, of two reaction zones which are separated with respect to the gas phase and which are connected with respect to the phase of the melt, very advantageously the field of minor quality fuels that can be used in the form indicated for the gasification in a bath of molten metal in the liquid state, in which case in the first reaction zone it is possible to use all the fuels of minor quality that can be envisaged. and reusing the gas thus produced to "filter" it into the metal bath in the second reaction zone.

  According to another feature of the invention, it is provided, with a view to simplifying the handling and standardization of quality of the fuels of minor value the most different, that the minor quality fuel is packed in containers for to be introduced in portions into the first reaction zone on the molten metal bath. When using containers for minor grade fuels, it is possible to use simple transport, handling or feeding systems, such as open conveyor belts, oscillating conveyors or cellular wheelhouses. . A mixture of minor grade fuels may consist of, for example, disintegrated or packaged oily shales, rubber or bitumen waste or packaged garbage, sawmill flour and waste oil. In this respect, it is advantageous to use as containers boxes, buckets, crates, casks, envelopes or bags which can

  be closed consisting of fusible and / or shiny materials.

  In this regard, the boxes, buckets or drums can be formed very advantageously for example sheet metal, which melts in the iron bath and which helps to compensate for the losses of iron dust discharged with the effluent gas or the gas of production. The boxes, envelopes or bags may for example be made of wood, plastic, paper or jute and they contribute by their combustion to introduce heat into the first zone

of reaction.

  According to another feature of the invention, it is intended to operate at least the first reaction zone under a pressure of 1 to 10 x 5 Pa, preferably under 3 x 105 Pa, and to introduce the containers.

  closed in this reaction zone using at least one gas-tight and pressure-proof airlock.

  By operating under pressure in the first reaction zone, the formation of dust and soot in the low energy gas produced in the first reaction zone is resisted. Under the effect of gas compression, more gas molecules, for example volatile constituents, which are available for combustion, occur in the same reaction volume;

  the heat capacity of the gas is increased and the introduc-

  heat generation in the metal melt is improved.

  According to another particularity of the invention, it is expected that, in the primary zone of reaction, the gaseous components recovering the fuel of minor quality, such as, for example, the volatile constituents and

  other pyrolysis products are reacted with the oxygen introduced or at least partially burned.

  Due to the combustion of the burnable gaseous constituents, the heat required to keep the temperature of the metal bath constant or to compensate for the temperature of the metal bath is very advantageously obtained in the first reaction zone.

heat losses.

  According to yet another feature of the invention, it is provided that the amount of gas leaving the first reaction zone is kept as small as possible and that the effluent gas is used in the second reaction zone after direct cooling. preferably by means of suspended heat exchange in the finely powdered coal gas and / or finely powdered limestone to form a stirring gas, or a solid transport gas to be introduced into the second reaction zone, such as for example coal, coke, lime and finely powdered slag from the first zone of

  reaction, and / or in the form of a gasification agent.

  The gas leaving the first reaction zone is recycled for the most part throughout the process since it may contain, for example, because of the direct contact with finely powdered coal during the heat exchange with suspension. in this gas, on the one hand substances still exploitable as for example CO, CH4, dust containing iron and carbon but also on the other hand sulfur components, soot and nitrogen oxides, which do not should not be discharged with the effluent gas into the atmosphere without taking measures

particular separation.

  The capital and operating costs for a sulfur and nitrogen removal and sulfur removal device may be minimized when, in accordance with the invention, the total amount of the effluent gas or the quantity of gas effluent to be discharged into the atmosphere are kept as small as possible. This result is obtained in a simple and advantageous manner by recycling most of the amount of effluent gas by injecting the gas from the first reaction zone back into the metal melt of the second reaction zone. in which case it is used, for example, in the form of a stirring gas to produce a directed flow in the melt, in the form of a carrier gas for discharging fuels in the form of particles as well as lime. or slag finely divided out of the first reaction zone, in the form of a

  agent for cooling the oxygen blowing nozzles or as an oxygen enriched gasification agent.

  According to another feature of the invention, it is provided that by a matched injection of the oxygen-containing gasification agent and high quality fuels into the second reaction zone as well as by a directed injection in correspondence of the combustion oxygen and / or a stirring gas in the first reaction zone, a horizontal flow of the liquid metal bath is produced between the two reaction zones. It is thus ensured that there is a constant exchange of the metal baths in the two reaction zones so that the carbon dissolved in the first reaction zone is partially oxidized by the oxygen in the second zone.

  reaction zone and that a high quality production gas is obtained and essentially containing CO and H2.

  Thanks to the exchange of the metal baths, it is also ensured that the temperature of the metal baths in the two reaction zones is

  constantly high and remains constant.

  According to another feature of the invntion, it is expected that the slag discharged from the first reaction zone is introduced at least partially into the second reaction zone. It is thus possible, on the one hand, to introduce dissolved sulfur into the molten metal bath in these slag fractions to near the saturation limit and, on the other hand, to the metal oxides still contained, if necessary, in the slurry. are reduced, the metal is recycled to the melt and thus the metal losses occurring at the outlet of the second reaction zone via the slag phase

unloaded are reduced.

  With regard to the installation, the problem which underlies the invention is solved in that a metal bath reactor is provided, in a central zone of which is disposed a separating wall which comprises at the bottom of the reactor at least one opening for the passage of the liquid metal and in that the two reaction chambers formed by the separating wall each comprise oxygen-containing fuel and gasification agent introduction members and each a discharge member. liquid slag and / or liquid metal, and in addition that the first reaction chamber comprises a discharge member of the low energy effluent gas while the second reaction chamber comprises a discharge member.

  production gas rich in energy.

  With the aid of the separating wall, the mixture of the two gaseous phases in the first and the second reaction chamber is excluded. The recycled gas from the first reaction chamber is converted into the second reaction chamber as high quality gaseous components. The sulfur is fixed in the slag, the oxides of nitrogen are reduced, the soot is burned and gasified; the CO2 and H2O components are reduced in the form of CO and H2, the excess oxygen reacts with the dissolved carbon

  in the bath of molten metal and also forms CO.

  Due to the connection, with separation as regards the gaseous phases, of the two reaction chambers, it is possible to introduce into the first reaction chamber all the materials and waste gasifiable that are usable (this part of the reactor "burns"). "everything") without a negative effect, for example an alteration of the quality of the final gas. The problem which is at the basis of the invention can be solved in another way by means of an installation for carrying out the process according to the invention, which comprises two separate reactors, one of 10 the other and provided with reaction chambers in each of which there are provided oxygen-containing fuel introduction and gasification agent delivery means, discharge devices for the produced gaseous effluent or production gas and discharge members 15 of liquid slag and / or liquid metal, said chambers being connected via at least one liquid metal flow conduit which is disposed in a zone

  lower side wall of the reaction chambers.

  This alternative embodiment comprising two reaction chambers which are connected by at least, and preferably by two ducts coated with refractory, represents another possibility for obtaining, during a separation of the gaseous bases, an exchange of the metal bath or else a

  compensation for carbon and sulfur concentrations in the metal phase.

  In this respect, it is particularly advantageous to provide in the passage or passageways of the liquid metal between the two reaction chambers respectively a

  shutter device, such as a drawer.

  Thus, when it is necessary to carry out work to improve the refractory masonry in only one reactor, the tubular connection can be closed and it is sufficient to discharge the metal bath of a reaction chamber. The other reactor, for example the one with the second reaction zone into which high quality fuel is injected, can continue to operate by filling the low energy effluent gas that is missing.

  by other gases, if any inert.

  In the installation according to the invention, provision is made for the feed member for introducing the containers provided with the fuels of minor quality into the first reaction chamber is arranged in the form of a cellular wheel lock or Uh sas double swing valve. In this way, the partial operative step can take place in the first chamber of

  reaction separately or at the same time as the partial process steps in the second reaction chamber at a necessary overpressure throughout the process.

  This problem can also be solved in an advantageous manner when the feed member of the minor quality fuels in the first reaction chamber is arranged in the form of a worm conveyor. According to another characteristic of the invention, it is provided that the effluent gas duct placed behind the first reaction chamber is arranged in the form of a gas suspension heat exchanger comprising a column a riser and a cyclone separator, in which case the riser comprises in a lower zone at least one feed member allowing the introduction of solids in the form of particles such as limestone, coal, oxides, etc. metal or metal powder. In this way, the low-energy effluent gas is cooled and the heat energy contained therein is exploited integrally, for example, in the gas-suspended heat exchanger. On the one hand, it is possible to preheat the solid materials in the form of particles to be injected to as high a temperature as possible; on the other hand, heat-consuming processes such as deacidification of limestone or degassing, and partly pyrolysis and / or coking of coal to gasify, or reduction of metal oxides, which have been introduced to compensate for the metallic losses in the reactor, can already take place in the heat exchanger by suspending gas, so that the fusion bath reactors are relieved from the point of view of the calorific balance or that 'iley has no heat extracted from them for

aforementioned reactions.

  According to another feature of the invention, it is provided that the liquid slag discharge members from the two reaction chambers are connected together or separately from one another, via a conduit placed under pressure, with a slag granulation device. This measure is necessary for carrying out the process with pressure operation, in which case the slag evacuated from the installation is obviously conditioned for subsequent application. In this regard, it is furthermore advantageous that the slag granulation device has a pressure-tight structure and consists of a water container having lateral water injection nozzles, a conveyor device discharging the fine-grained slag out of the water bath, for example a bucket apparatus, an inclined ring sorter or a worm conveyor, as well as a cellular wheel lock. In this way, the slag granulate can be removed from the pressure zone of the plant very simply and without having to involve a large water circulation path and to take water.

  important measures of purification of this water.

  Other features and benefits of

  the invention will be highlighted in the following description, given by way of non-limiting example, in

  1 is a longitudinal sectional view of an installation according to the invention for the gasification of fuels of minor quality, FIG. 2 is a plan view of another embodiment of the invention. Gasification plant according to the invention, Figure 3 is a sectional view, taken along line IIIIII, of the gasification plant shown in Figure 2, Figure 4 is another sectional view, taken along the line. IV-IV, of the gasification plant shown in FIG.

  Figure 5 is a schematic overview of an installation according to the invention for the gasification of S 5 fuels of minor quality.

  In FIG. 1 is designated by reference numeral 1 a reactor which comprises in its central zone a separating wall 2 which is provided at the bottom of the reactor 1 with at least one and preferably, however, two openings 3 for the passage of metal. liquid. The separating wall 2 may be equipped with a corresponding internal cooling device 17. The separating wall 2 forms in the reactor 1 two reaction chambers 4 and 5, each of which comprises at least one member 6, 7 for introducing the fuel-15 corresponding to gasify and at least one member 8, 9 for introducing the fuel. oxygen-containing oxidation or gasification agent, as well as a member 10, 10 ', 11 for discharging liquid slag and / or iron, the first reaction chamber 4 further comprising a tube 12 of evacuation of the low energy effluent gas while the second reaction chamber 5 comprises a tube 13 for discharging the

high energy production.

  The member 6 for introducing fuels of minor quality into the reaction chamber 4 is advantageously arranged in the form of a cellular wheel lock 14 which is gas and pressure tight, in particular when the reactor 1 has to operate in a range. of pressures understood by

5

  For example, between 1 x 10 Pa and 10 x 10 Pa. However, the introduction member 6 can also be arranged in the form of a double swing valve lock. The elements 7 and 9 for introducing the high quality fuel and the gasification agent containing oxygen into the reaction chamber 5 can be produced in the form of lances and / or in the form of nozzles 16 respectively in the case of a multi-channel structure. The oxygen nozzles 8, 16 are arranged in the side wall of the reactor 1

  in the reaction chamber 4 preferably at a distance of

  this, i.e., a distance of about 10 to 80 cm, above the surface 21 of the iron bath, and in the reaction chamber 5 preferably at a short distance, i.e. at a distance of about 10 to 60 cm. below the iron bath. Another tube 1M for introducing primary slag from the first reaction zone may be placed in the second reaction chamber 5 so as to open into the side wall of the reactor 1. On the opposite side of the reactor 1, provision is made for in the side wall of the reaction chamber 4 another nozzle 22 for introducing stirring gas. In the ceiling zone of the reaction chamber 4, it is furthermore provided

  a burner 19 directed towards the surface of the iron bath 21.

  When using the exemplary gasification reactor embodiment shown in FIG. 1 to effect gasification of minor grade fuels, these minor grade fuels, which have been previously packaged in correspondence and blended and which have Packaged in containers 20, such as paper bags or sheet buckets, are brought to the surface of the iron bath 21 by means of the airlock.

  cellular wheel 14 which is arranged in the ceiling zone or in the side wall of the reactor chamber 4.

  The metal bath in the reactor may, however, also be lead or liquid copper. The minor grade fuel has been preheated beforehand

  to a temperature of about 120 to 250 ° C using the heat contained in the low energy effluent gas.

  As soon as the minor quality fuel in the container 20 arrives via the cell wheel lock 14 into the reactor chamber 4, it is heated abruptly to the temperature of the iron bath, which is, for example from 1450 * C. Under the action of degassing and pyrolysis products escaping explosively, such as steam, volatile constituents and easily vaporizable hydrocarbons, the container bursts and burns.

  (plastic bag) or bottom (bucket sheet).

  The carbon contained in the minor grade fuel and also the sulfur are dissolved in the iron bath (indicated by C * and 5 * in Figure 1). The non-gasifiable or non-soluble constituents of the minor quality fuels are transformed into slag and are immediately discharged from the reactor chamber 4 via the discharge member 10. The energy-poor effluent gas occurring in the reactor chamber Reactor 4 is channeled through the discharge tube 12 into an effluent gas cooling device 10, not shown in detail in the drawing, and into a dust and water separation device.

  hot gas, which operates for example at a temperature of 400 ° C.

  The effluent gas quarter should, in accordance with the invention, be kept as small as possible and should be recycled for the most part. This problem is solved for example by the fact that the cooled and purified effluent gas is used as a stirring gas at a temperature of about 380.degree. C., by means of the stirring gas nozzle 22, in order to produce in the An iron flow is directed horizontally and passed through the discharge opening 3 in the separating wall 2 within the two reactor chambers 4 and 5. The nozzles 7, 8, 9 and 16 disposed in the Side wall of reactor 1 may also be oriented with a slight downward inclination to the horizontal so as to facilitate concentration balancing in the bath flow. In addition, a large portion of the low energy effluent gas is used as a carrier gas to inject the high quality fuels as well as lime and fine grain slag into the reactor chamber 5. Since the low-grade effluent gas is energy contains high percentages of CO2 and H2O, it can also be insufflated in the iron bath via nozzles 9 and 16, to which

  case it is used as a gasification agent.

  The SO-based components that are contained in the low-energy effluent gas are "filtered", i.e., reduced, in the second reaction zone or in the reactor chamber 5 inside the bath of iron, in which case the oxygen is fixed on the dissolved carbon while the sulfur is fixed in the slag. Any residue of the low energy effluent gas may be burned in other fires as an additional or auxiliary fuel gas. Through the introduction member 7, for example the blast lance 15 and / or the nozzles 9, 16, the high quality fuel and the gasification agent containing oxygen, are injected, if necessary with effluent gas from the first reaction zone, in the reactor chamber 5. In this chamber there is generally an excess of heat, which compensates by means of the iron bath flow producing inside the two reactor chambers the heat losses recorded in the first reaction zone. Through the discharge tube 13, a high-quality, high-energy production gas consisting mainly of CO 2 and H 2 is evacuated, substantially free of sulfur and channeled after cooling in an indirect heat exchanger 20. and after dedusting, to its place

of further use.

  In Figure 2 is shown another example

  embodiment of the installation according to the invention, the reference numbers already used in Figure 1 being adopted to designate identical parts.

  The fuels of minor quality are introduced into the reactor chamber 4 in the form of a pasty mixture, for example a mixture of heavy oil, tar, sawmill, refuse and clarification sludge, by through the feed member 6 disposed in the ceiling of the reactor 1 'and which is arranged in this

  case in the form of a worm conveyor 31.

  Through the feed member 8, which is constituted by a nozzle placed above the upper surface of the iron bath in the side wall of the reactor 1 ', oxygen or air Oxygen enriched is injected for the combustion of volatile constituents and other pyrolysis products from minor fuels. The energy-poor effluent gas thus obtained is discharged through the discharge tube 12, is cooled, dusted and is introduced again, at least partially, into the reactor 1. The two reactors are interconnected by the intermediate of two tubular ducts 30, 30 'coated with refractory In the event of an emergency, the ducts 30, 30' may be closed by closure devices 37, 37 ', for example shutter drawers, so that, during a possible disturbance for example in the reactor chamber 4, only this reactor chamber must be emptied while, in the reactor chamber 5, the separate gasification of high quality fuels, introduced via the nozzle 7 or the lance 15 can be continued because of the particular arrangement of the fuel supply and gasification agent organs 7, 8 and also of the stirring gas nozzle 22, we

  produced in the iron bath horizontally oriented flow between the two reactors 1 'and 1 ".

  The carbon dissolved in the reactor chamber 4 is gasified as carbon monoxide in the reactor chamber 5 and is discharged as a high-energy production gas through the discharge tube 13 placed therein. in the ceiling zone of the reactor 1. As intermediate or secondary products, the corresponding slags are discharged from the plant via the discharge members 10, 10 '. In keeping with the heat content, a burner 19 can be arranged in the side wall 30 of the reactor 1, which can advantageously be arranged in the form of a combined burner for heating gas burner and solid fuel (or oil and coal dust) and which can be supplied for example with energy-poor effluent gas which has been recycled, with Geulard gas and

coal dust.

  FIGS. 3 and 4 are cross-sectional views of the reactors 1 'and 1 "of FIG. 2. Here, above all, the passage openings 3, 3' of the conduits 30, 30 'between the reactors 1 ', 1 "and the worm conveyor 31 serving as a member 6 for introducing the fuel of minor quality into the reactor 1'. It is also possible to see the height arrangement of the fuel introduction member 7 and the stirring gas nozzle 22. The introduction member 7 and the agitation gas nozzle 22 essentially produce the iron bath flow propagating horizontally between the two reactors 1 'and 1 "through the openings.

passage 3 and 3 '.

  In accordance with the schematic overview of FIG. 5, minor grade fuels come in chunk form, such as garbage, waste, straw and automobile tires, in a disintegrating device. 50, such as a toothed crusher or a hammer mill, and they are then mixed in a divided form, if necessary with the addition of other fuels of minor quality, such as for example sawmilling flour. , pruning sludge and pitch (as indicated by arrows 55, 56) in a mixing and granulating device 51, for example a rotating drum, to be processed into aggregates or agglomerates. The mixture of different fuels of minor quality which has been packaged in this way can be introduced, with a pasty consistency, by means of a screw conveyor directly into the reaction chamber 4 of the reactor 1, or else is compacted in a briquetting machine 52, for example a roll press, and is transported into the reactor chamber 4 via a conveyor belt 53 and by means of the cellular wheel lock chamber 14. In the In the case where the minor grade fuels are to be fed to a gasification reactor 1 by being packaged in portions in containers, the packaged mixture is passed to a filling and packing station 54 prior to entering the liquid iron bath through the container. intermediary of the band

  conveyor 53 and the cellular wheel lock 14.

  The low-energy effluent gases which are produced by partial combustion of volatile constituents and other degassing and pyrolysis products in the reactor chamber 4 are channeled through a conduit 32 into a cyclone of separation 58 for separation of soot, dust and iron particles. These separated particles are mixed with the minor-grade fuels to be gasified and are returned to the reactor chamber 4. After the separator cyclone 58 is provided, for the cooling of the hot effluent gas, a heat exchanger is provided. in suspension in the gas 33, consisting of a riser 34 and a cyclone separator 35, two tubular ducts 57, 60 for introducing CaCO3 limestone powder and / or a coal granulate or many finely disaggregated finely graded fuels emerging at the lower end of the riser 34. In this advantageous manner, the effluent gas can be cooled to about 450 ° C and the thermal energy contained in this effluent gas can heating the solids

  introduced, it dissociates limestone as CaO and produces dehydration of carbon-containing materials (bound crystalline water), said materials being further degassed and coked.

  In the cyclone separator 35, the thermally treated particles are separated from the effluent gas stream. The burnt lime and the coke granulate produced are then injected, via the lance 15 or nozzles 7, 9, 16 into the reactor 5 for slag formation or sulfur fixation and drying. a gasification in the form of a high quality production gas. The low-energy effluent gas is completely purified at temperatures of about 300 ° C. in an electrofilter 61 placed afterwards and is partially recycled in the form of a preheated carrier gas, a gas

  stirring and a gasification agent in the reactor.

  Another part of the effluent gas may undergo a post-

  combustion and be discharged into the atmosphere.

  The slag produced in the reactor chamber 4 is transferred to a slag granulator 38 and is converted using at least one water nozzle 40 into a fine grain slag granulate (metallurgical sand). The slag granulates are discharged from the water container 39, subjected to the same pressure as the reactor 1, for example 5 × 10 5 Pa, using a conveying device 41, for example with the aid of a worm conveyor and via a pressure wheel lock 42. The slag discharged from the reactor chamber 4 can, when it still has sufficient sulfur fixing capacity, be recycled to the reactor chamber 5. The final slag discharged from the reactor chamber 15 is conditioned in a manner and can be used, for example, in road construction or

in the cement industry.

  With the gasification plant according to the invention, it is possible to convert all carbon-containing materials, in particular household waste or other carbon-containing wastes, into a valuable production gas, virtually free of carbon. sulfur, containing CO and H2 and which is cooled in a manner

  conventional for example in an indirect heat exchanger.

Claims (18)

  A process for gasifying minor grade fuels in a molten metal bath, in a liquid state, especially a molten iron bath, characterized in that the minor grade fuels are introduced into a first reaction zone containing a molten metal bath and high quality fuels are introduced into a second reaction zone containing a bath of molten metal, the gas volumes of the two reaction zones being kept separate from each other, and in that the molten metal bath of the first reaction zone is mixed   with the molten metal bath of the second reaction zone. -. 20 30 35   2. Method according to claim 1, characterized in that   the molten metal bath in the first reaction zone is kept free of a slag layer or a slag formed from ash and non-burnable constituents of the minor quality fuels to be gasified is removed from the bath of molten metal and that slag former is introduced into the second reaction zone.   3. Method according to one of claims 1 or 2,   characterized in that, as minor grade fuels, lignite, coal of minor quality, peat, wood, saw chips are introduced into the metal bath in the first reaction zone, sawmills, straw, agricultural waste, tar, bitumen, pitch, oil, heavy oil, oily shale, garbage, combustible waste, plastics, clarification sludge, tires, spent rubber or similar carbon-containing materials and hydrocarbons as well as mixtures of said materials in a corresponding disaggregated or agglomerated form.   4. Method according to any one of claims 1, 2 or 3,   characterized in that the minor quality fuel, packaged in containers, is introduced portion by portion into the first reaction zone on the bath of molten metal.   5. Process according to claim 4, characterized in that boxes, buckets, boxes, drums, envelopes or bags which can be closed and consist of a fusible and / or burnable material are used as containers.   6. Process according to any one of the claims   1, 2, 3, 4 or 5, characterized in that at least the first reaction zone operates at a pressure of 1 × 10 5 Pa at 10 × 10 5 Pa, preferably at 3 × 10 5 Pa and the closed containers are introduced into this reaction zone using   at least one gas and pressure tight airlock.   7. Method according to any one of claims 1   to 6, characterized in that in the first reaction zone the burnable gaseous constituents which are released from the minor quality fuel, such as volatile constituents and other pyrolysis products, are reacted with the reaction medium. oxygen introduced or are at least partially burned.   8. Process according to any one of claims 1   at 7, characterized in that the amount of effluent gas leaving the first reaction zone is kept as small as possible and the effluent gas after direct cooling, preferably by means of a heat exchange with suspension in the finely powdered coal gas and / or limestone is used in the form of a carrier gas for solids to be introduced into the second reaction zone, such as for example coal, coke, lime and fine-grained slag discharged from the first reaction zone, and / or in the form of a gasifier into the second reaction zone.   9. Method according to any one of claims 1   at 8, characterized in that, by a matched injection, the oxygen-containing gasification agent and high quality fuels in the second reaction zone as well as by an injection, oriented in correspondence, of combustion oxygen and / or 1, a stirring gas in the first reaction zone, a horizontal flow of the liquid metal bath is produced. between the two reaction zones.   10. Process according to any one of claims 1   at 9, characterized in that the slag discharged from the first reaction zone is recycled at least in part in the second reaction zone.   11. Installation for the implementation of the process of gasification of fuels of minor quality in   a liquid metal bath according to any one of claims 1 to 10, consisting of a reactor filled with metal   liquid, characterized in that there is provided in a central zone of the reactor (1) a separating wall (2) which comprises, at the bottom of the reactor (1), at least one opening (3) for the passage of the liquid metal and in that the two reaction chambers (4, 5) formed by the separating wall (2) each comprise at least one fuel introduction element (6, 7, 8, 9) and gasification agent containing oxygen and respectively a member (10, 11) for discharging liquid slag and / or metal, while in addition the first reaction chamber (4) comprises a tube (12) for evacuation of the effluent gas that is poor in energy and the second reaction chamber (5) comprises a tube (13) of   discharge of the production gas rich in energy.   12. Installation for carrying out the process of gasification of minor quality fuels in a bath of liquid metal according to any one of   Claims 1 to 10, characterized in that it comprises two reactors (1 ', 1 ") separated from each other and comprising reaction chambers (4, 5), which are each   provided with at least one oxygen-containing fuel and oxygen-containing gasification member (6, 7, 8, 9), respectively with a discharge gas discharge pipe (12, 13) produced or final gas, and respectively a member (10, 10 ', 11) for discharging liquid slag and / or liquid metal, and which are connected via at least one, and preferably two ducts (30, 30 ') of liquid metal passage which are arranged in a lower zone of the side wall of the chambers of reaction (4, 5).   13. Installation according to one of claims 11 or 12,   characterized in that the feed member (6) for introducing the containers (20) provided with the minor quality fuels into the first reaction chamber (4) is arranged in the form of a wheel lock.   cell (14) or a lock with double swing valve.   14. Installation according to any one of claims 11 or 12, characterized in that the member (6) for introducing fuels of minor quality in the first reaction chamber (4) is arranged as a carrier to worm (31).   15. Installation according to any one of revendica15 tions 11, 12, 13 or 14, characterized in that the effluent gas duct (12, 22) is placed behind the first reaction chamber (4) arranged in the form of a gas-suspending heat exchanger (33) having a riser (34) and a cyclone separator (35), the riser (34) being provided in a lower region with at least one supply member (59, 60) ensuring the introduction of solids under   Particle form, such as limestone, coal, minor grade fuels, metal oxides or metal powder.   16. Installation according to claim 12, characterized in that it is provided in the tubular conduit (s) (30, 30 ') of liquid metal passage between the   two reaction chambers (4, 5) respectively a closure device (37, 37 ').   17. Installation according to any one of claims 11 to 16, characterized in that the members (10, 10 ')   for discharging the liquid slag from the two reaction chambers (4, 5) are connected together or separately from each other, via a pressure line, with a granulation device. slag (38).   18. Installation according to any one of claims 11 to 17, characterized in that the device   granulating slag (38) is made pressure-tight and consists of a water container (39) provided with water nozzles (40), a conveyor device (41) discharging the fine-grained slag out of the water bath, such as a bucket mechanism, an inclined ring sorter or a conveyor auger, and an airlock with a cellular wheel (42).