OA20314A - Reactor and process for gasifying and/or melting of feed materials. - Google Patents

Abstract

This invention relates to a method and a reactor for gasifying a carbonaceous feedstock material. The method includes the steps of choke-feeding a carbonaceous feedstock material into a pyrolysis zone of the reactor to form a discharge bed; heating the discharge bed to initiate pyrolysis of the feedstock material to form a pyrolysis product; providing a lower lying upper oxidation zone; gasifying the pyrolysis product to form a bed of char; converting thermal energy into chemical energy in an upper reduction zone; providing a lower lying lower oxidation zone; collecting any metal slag and/or slag melts in the lower oxidation zone; and discharging hot reducing gases having a temperature of at least 1300°C and a CO/CO2 ratio of ≥ 5, more preferably ≥ 15.

Description

REACTOR AND PROCESS FOR GASIFYING AND/OR MELTING OF FEED MATERIALS

FIELD OF THE INVENTION

This invention relates to a method and a reactor for gasifying and/or melting substances. In particular, the invention relates to the material and/or energy recovery of any waste, for example, but not exclusively household waste, used tires, hazardous waste, asbestos, hospital waste, coal or coal dust. The reactor and the method are also suitable for the gasifying and melting of feed materials of any composition or for the génération of energy through the use of waste and/or coal.

BACKGROUND TO THE INVENTION

For some time now, solutions hâve been sought for the thermal disposai of various types of waste and other materials. In addition to combustion processes, various gasification processes are known, the main aim of which is to achieve results with a low pollutant load on the environment and to reduce the cost of treating the feed materials, but also the gases produced in the process. However, the known processes are characterized by a complex technology that is difficult to master and the associated high disposai costs for the feed material or waste to be treated.

For instance, EP 1 261 827 B1 discloses a reactor for the gasifying and/or melting of feed materials. This reactor does not follow the approach of the previously frequently used circulating gas process. In contrast, the disclosed reactor opérâtes according to the co-current principle. The complété élimination of conventional recirculation gas management avoids many of the problems associated with the condensation of pyrolysis products and the formation of unwanted deposits. Furthermore, EP 1 261 827 B1 discloses that already in the upper part of the reactor a partial conglomération of the feed materials takes place due to the shock-like heating of the bulk material (bulk column), whereby adhérences to the inner wall ofthe reactor are largely excluded. In EP 1 261 827 B1 it is disclosed that a réduction section is formed between two injection means through which ail gases flow before extraction, thereby reducing them to a large extent.

Although the reactor disclosed in EP 1 261 827 B1 largely reduces the feed materials, the gas discharged from the reactor cannot be used without further heating for use in the metallurgical reactors for réduction melting due to the outlet températures from the reactor.

OBJECT OF THE INVENTION

It is accordingly an object of the présent invention to provide a novel reactor for and method of gasifying and/or melting substances which overcomes, at least partially, the abovementioned disadvantages and/or which will be a useful alternative to existing reactors for and methods of gasifying and/or melting substances

SUMMARY OF THE INVENTION

According to a first aspect of the présent invention, there is provided a method of gasifying a carbonaceous feedstock material to generate hot reducing gases using a reactor, the method including the steps of:

feeding a carbonaceous feedstock material via a sluice to form a discharge bed in a pyrolysis zone of the reactor;

heating the discharge bed in the pyrolysis zone to initiate pyrolysis in the carbonaceous feedstock material and to form a pyrolysis product;

providing a lower lying hot upper oxidation zone in the reactor by supplying a source of oxygen at a température of at least 800°C to the reactor at a location beneath the pyrolysis zone;

gasifying the pyrolysis product and remaining un-pyrolyzed carbonaceous feedstock material, if any remains, in the hot upper oxidation zone to form a char bed in an upper réduction zone of the reactor, the upper réduction zone being located beneath the hot upper oxidation zone;

converting thermal energy into Chemical energy in the upper réduction zone; providing a lower lying hot lower oxidation zone in the reactor by supplying a source of oxygen at a température of at least 800°C to the reactor at a location beneath a lower réduction zone of the reactor;

collecting any métal and/or slag melts présent in the lower oxidation zone;

removing the métal and/or slag melts présent in the lower oxidation zone; and discharging hot reducing gases having a température of at least 1300°C and a CO/CO2 ratio of s 5 which hâve been generated in the upper réduction zone through a gas outlet located in a gas outlet section of the reactor, the gas outlet section being located between the upper réduction zone and the lower réduction zone ofthe reactor

The source of oxygen may be air or pure oxygen.

The métal and/or slag melts présent in the lower oxidation zone may be removed from the lower oxidation zone by tapping the métal and/or slag melts.

There is provided for the hot reducing gases which are being discharged to hâve a CO/CO2 ratio >15.

The method may include the additional step of providing hot gases (e.g. preheated air or combustion gases, which are supplied via burners or nozzles) to the pyrolysis zone to initiate pyrolysis in the carbonaceous feedstock material and to form the pyrolysis product.

There is provided forthe heating ofthe discharge bed in the pyrolysis zone to be done gradually to a température of at least 700°C, the température being increased gradually to prevent breakup of the carbonaceous feedstock material and pyrolysis product. Advantageously, this prevents the formation of fine or powder carbonaceous feedstock material, pyrolysis product and char which may choke the reactor. Therefore, the method and reactor can be operated at a lower pressure than a case where fine or powder carbonaceous feedstock material, pyrolysis product and char are formed. As an example, the method and reactor can be implemented and/or operated at a pressure of 50 kPa.

The volumétrie flow rate ofthe hot gasses may be controlled to heat the discharge bed in the pyrolysis zone gradually.

The method may include the additional step of drying the carbonaceous feedstock material prior to choke-feeding the carbonaceous feedstock material to the reactor.

The volumétrie flow rate of the source of oxygen to the lower oxidation zone may be controlled to prevent the accumulation of char fines in the lower oxidation zone. To increase the consumption rate of char fines in the lower oxidation zone, the volumétrie flow rate of the source of oxygen to the lower oxidation zone may be increased.

The method may, further, include the step of preheating and pre-drying the carbonaceous feedstock material in a buffer zone ofthe reactor, the buffer zone being located above the pyrolysis zone of the reactor.

By feeding the carbonaceous feedstock material in the pyrolysis zone, a discharge bed having a discharge cône may be formed and the cross-section ofthe pyrolysis zone may be enlarged with respect to the cross-section of the buffer zone.

There is provided for the method to include the additional step of pyrolyzing and drying the carbonaceous feedstock material in an intermediate zone of the reactor, the intermediate zone being located beneath the pyrolysis zone.

The method may include the still further step of discharging hot reducing gases having a température of at least 1300°C which hâve been generated in a co-current section of the reactor from the at least one gas outlet of the reactor, the co-current section may comprise:

- a plénum zone of the reactor, the plénum zone comprising:

o the feed zone of the reactor;

o the buffer zone of the reactor;

o the pyrolysis zone of the reactor; and o the intermediate zone of the reactor;

the upper oxidation zone of the reactor; and the upper réduction zone of the reactor.

There is provided for the method to include the step of discharging hot reducing gases having a température of at least 1300°C which hâve been generated in a countercurrent section of the reactor through the gas outlet located in the gas outlet section of the reactor, the countercurrent section may comprise the lower oxidation zone and lower réduction zone ofthe reactor.

The volume ratio of the upper oxidation zone volume to the plénum zone volume may be a ratio of 1 :N volume units, wherein 4 < N < 20.

The volume ratio ofthe upper oxidation zone volume to the total volume ofthe upper réduction zone and the plénum zone volume may be a ratio of 1:N volume units, wherein 7 < N < 25.

The volume ratio ofthe countercurrent section volume to the total volume ofthe reactor may be a ratio of 1:N volume units, wherein 1 < N < 10.

By supplying at least 800°C hot oxygen and/or air below the intermediate zone, a hot upper oxidation zone is created having a température above 1800° C in a particular area of the lining and températures between 2000° C and 4000° C in the bed. The pyrolysis products and parts ofthe feedstock material burn, crack and/or melt in this hot upper oxidation zone, whereupon further coking ofthe not yet converted feedstock material takes place. In the subséquent upper réduction zone, thermal energy is then converted into Chemical energy. The conversion of Chemical energy in thermal energy is partially achieved by reducing CO2 to CO. Here, the CO/CO2 gas volume ratio at the gas outlet may be greater than 10 or even greater than 15. For example, the CO/CO2 gas volume ratio may be between 10 and 1000, 15 and 10000 and even between 15 and 10⁷ (essentially CO2-free).

The gas may flow in the co-current section from the feed zone to the gas outlet in cocurrent.

A hot zone having températures between 1800°C and 4000°C may also be created in the conical lower oxidation zone by providing at least 1000°C hot oxygen and/or air. Métal and/or slag melts may also be collected in this lower-arranged hot lower oxidation zone. These slag melts and/or métal melts may be tapped off via the tapping (e.g. in molds) or run out continuously (e.g. to a slag granulation) as required. In the conical lower oxidation zone and in the conical lower réduction zone, hot gases having a température above 1000°C and up to 2000° C may also be generated which flow upwards (in countercurrent) in the direction ofthe gas outlet. The thermal energy may also be converted into Chemical energy in the lower réduction zone, in part by reducing CO2 to CO. This ensures that the CO/CO2 gas volume ratio is greater than 10 or even greater than 15 when the gas outlet is reached. For example, the CO/CO2 gas volume ratio is between 10 and 1000, preferably between 15 and 10000 and in particular preferably between 15 and 10⁷ (essentially CO2-free). The gases from the co-current section (from top to bottom) and the gases from the countercurrent section (from bottom to top) are discharged from the gas outlet section through at least one gas outlet. The gases from the co-current section and the gases from the countercurrent section hâve températures between 1500°C and 1750° C, preferably between 1600°C and 1750° C.

The method steps essentiel for the invention may be advantageously further developed by exhausting the gases produced in the co-current section and the gases produced in the countercurrent section by suction. For this purpose, gas suction means may be used. The suction may create a négative pressure in the reactor. The use of négative pressure in the reactor may allow maintenance of the reactor during operation, as air may be sucked in when the gasifier is opened, but no gas can escape.

According to a second aspect of the présent invention, there is provided a reactor for use in a method of gasifying a carbonacious feedstock material, the reactor comprising:

a co-current section comprising:

o a plénum zone comprising:

a feed zone with a sluice, wherein feed materials are introduced into the reactor from above via the feed zone;

a buffer zone;

a refractory lined pyrolysis zone that adjoins the bottom of the buffer zone while providing a cross-sectional enlargement; and a refractory lined intermediate zone that adjoins the bottom of the pyrolysis zone;

o a refractory lined upper oxidation zone that adjoins the bottom of the intermediate zone and comprises tuyeres in at least one plane; and o a refractory lined upper réduction zone that adjoins the bottom of the upper oxidation zone;

a refractory lined gas outlet section comprising at least one gas outlet; and a refractory lined countercurrent section comprising:

o a conical lower réduction zone adjoining said gas outlet section; and o a conical lower oxidation zone adjoining the conical lower réduction zone and comprising at least one tuyere and a tapping, wherein the volume ratio of the refractory lined upper oxidation zone volume to the plénum zone volume is a ratio of 1 :N volume units, wherein 4 < N < 20.

The volume ratio of the refractory lined upper oxidation zone volume to the total volume of the refractory lined upper réduction zone volume and the plénum zone volume may be a ratio of 1 :N volume units, wherein 7 < N < 25.

The volume ratio of the refractory lined countercurrent section volume to the total volume ofthe reactor may be a ratio of 1:N volume units, wherein 1 < N < 10.

There is provided for at least one refractory lined portion of the reactor to consist of at least two lining sections arranged one above the other, wherein a tongue-and-groove connection is formed between the lining sections arranged one above the other, wherein one ofthe lining sections has the groove on the side facing the reactor interior and the other lining section has the tongue on the side facing the reactor interior, wherein the tongue-and-groove connection has a temperature-dependent gap opening between the groove and the tongue.

A circumferential water-cooled console may be arranged between the at least two lining sections.

The upper lining section may hâve the groove and the lower lining section may hâve the tongue.

The at least two lining sections may hâve one refractory inner lining and an outer lining encasing the inner refractory lining.

The inner refractory lining may be a lining made of fired bricks or a monolithic lining.

The circumferential water-cooled console may consist of black or stainless Steel.

The tuyeres of the refractory lined upper oxidation zone and/or refractory lined conical lower oxidation zone may consist out of ceramic.

In an alternative embodiment, the tuyeres ofthe refractory lined upper oxidation zone and/or refractory lined conical lower oxidation zone may consist out of copper or Steel, wherein an inner ceramic pipe is arranged in each of the tuyeres, and wherein a compressible and temperature-resistant layer is arranged between the ceramic inner pipe and the respective tuyere.

The refractory lined upper oxidation zone may hâve a cône angle of between 5° and 30°.

The refractory lined upper réduction zone may be arranged above the refractory lined gas outlet section so that the refractory lined gas outlet section adjoins the bottom of the refractory lined upper réduction zone while providing a cross-sectional enlargement.

A portion of the refractory lined upper réduction zone may be arranged in the refractory lined gas outlet section and the refractory lined gas outlet section may hâve a crosssectional enlargement with respect to the refractory lined upper réduction zone.

The refractory lined conical lower réduction zone and the refractory lined conical lower oxidation zone may hâve a cône angle of between 50° and 70°.

A gas supply means may be arranged in the région of the cross-sectional enlargement of the refractory lined pyrolysis zone.

The tuyeres of the refractory lined upper oxidation zone may be arranged in a plurality of planes.

There is provided for at least one further tuyere to be arranged in a further plane of the refractory lined conical lower réduction zone or one further tuyere to be arranged in a further plane of the refractory lined conical lower réduction zone and at least one additional tuyere to be arranged in the refractory lined upper réduction zone.

At least one further tuyere may be arranged in a further plane of the refractory lined conical lower oxidation zone.

In order that hot gases with températures greater than 1500°C, for example between 1600°C and 1750°C, can be discharged from the gas outlet, it is provided that the reactor is designed in such a way that températures above 1800°C in the peripheral area of the bulk material (or the bed) and between 2000°C and 4000°C in the center of the bulk material (or the bed) can be reached at least in the refractory lined upper oxidation zone. These high températures cause the refractory lining (e.g. brick lining) to expand axially, tangentially and radially up to 20 mm per lining meter, creating stresses in the lining which in turn affect the outer Steel Shell of the reactor in a radial direction.

In order that the stability of the reactor is not impaired by these high températures and the resulting stresses in the lining, it is provided in accordance with the invention, that at least one refractory lined portion ofthe reactorconsists of at leasttwo lining sections arranged one above the other. The at least one refractory lined portion can be the refractory lined pyrolysis zone, the refractory lined buffer zone, the refractory lined upper oxidation zone, the refractory lined upper réduction zone, the refractory lined gas outlet section, the refractory lined countercurrent section, or a combination thereof.

Here it can be conceived that the refractory lining of the reactor has a further lining section every 2 to 4 height meters.

For reactors which hâve a gas outlet température of 1500°C to 1600°C, it may be provided that the refractory lining has a further lining section every 3 to 4 height meters. For reactors which hâve a gas outlet température of 1600°C and 1750°C, it may be provided that the refractory lining has an additional lining section every 2 to 3 height meters.

Since particularly high températures (températures between 1800°C and 4000°C) are generated in the lined upper oxidation zone and the lined lower oxidation zone, it may be provided that the lining sections arranged one above the other are arranged in such a way that exactly one lining section is arranged in each of the lined upper oxidation zone and the lined lower oxidation zone. Furthermore, it may be provided that a further lining section is arranged below and above the oxidation zones. This ensures that the hot oxidation zones each are composed of only one lining section, wherein each of the lining sections can expand in the direction of the respective further lining section, such that in these zones there is no need for further consoles or other fixations, which can be damaged at these high températures.

In order that no hot gases or high températures continue to escape outside via the région between the at least two lining sections, it is also be provided that a tongueand-groove connection is formed between the refractory lining sections arranged one above the other, wherein one of the refractory lining sections has the groove on the side facing the reactor interior and the other lining section has the tongue on the side facing the reactor interior. The tongue-and-groove connection is designed in such a way that even when the reactor is at a standstill, the tongue in the groove is arranged in a positive-locking manner, whereby the vertical outerwall of the tongue is connected to the vertical wall of the groove, but a vertical gap opening remains between the groove and the tongue. This is an advantage in ensuring that despite the gap opening no gas can escape during start-up or high heating of the reactor. Furthermore, it may be provided that the gap opening between the groove and the tongue is a temperaturedependent gap opening. The temperature-dependent gap opening between the groove and the tongue can be for example 50 mm. As described above, the lining can expand at high températures, where the tongue can expand into the groove due to the tongueand-groove connection.

Furthermore, it is provided that a circumferential water-cooled console for holding the refractory lining and stabilizing the lining during heating up and cooling down of the reactor is arranged between the at least two lining sections arranged one above the other. This circumferential water-cooled console can be produced by bending of hollow cylindrical pipes with square or rectangular cross-sections without welding seams. It can be advantageously provided here that the water-cooled console has a high heat flow, which is achieved by flow velocities of the cooling water from 2 m/s to 25 m/s, which is supplied via a connection flanges. These high flow velocities of the cooling water are advantageous for maintaining the thermal and mechanical stability of the circumferential console when it is arranged in areas with high températures (> 1500°C).

The arrangement described above of at least two superimposed tongue-and-groove refractory lining sections and a circumferential water-cooled console may be arranged in the co-current section and/or the gas outlet section and/or the countercurrent section. Each section can also hâve several arrangements of two refractory lining sections arranged one above the other with tongue-and-groove connection and circumferential water-cooled console.

The co-current section of the reactor according to the invention comprises a partially lined plénum zone, a lined upper oxidation zone, and a lined upper réduction zone.

The partially lined plénum zone comprises a feed zone with at least one sluice, a buffer zone, a lined pyrolysis zone, and a lined intermediate zone.

Via the feed zone with a sluice, feed materials such as waste, toxic or biological waste, water, used tires, biomass, wood, coal, automotive shredder residues, aggregates or the like can be fed into the reactor from above. The sluice ensures that the uncontrolled entry of ambient air and the discharge of gases from the reactor are avoided as far as possible. It is intended that the sluices may hâve hydraulic, pneumatic or electrically operated hatches. These hatches can preferably be designed in such a way that the hatches are additionally closed in the event of unintentional overpressure in the reactor and no gas can escape unintentionally.

The plénum zone also includes a buffer zone for buffering and pre-drying the feed material volume. The température of the buffer zone is preferably adjustable. For example, a set température of approx. 100°C to 200°C can be provided for the predrying of waste.

In addition, a refractory lined pyrolysis zone is provided in the plénum zone, which is connected to the bottom of the buffer zone by creating a cross-sectional enlargement being preferably abrupt. Preferably, the cross-section increases at least twice. The cross-sectional enlargement ensures that the sinking speed of the feed materials is reduced and that a cone-shaped discharge area (discharge cône) made of bulk material forms within the gas space of the reactor. The discharge cône is supplied centrally with the pre-dried feed materials (from the buffer zone).

Hot gases (e.g. combustion gases, temporarily stored or recirculated excess gases, or inert combustion gases provided by combustion) can be supplied to the discharge cône in the refractory lined pyrolysis zone via burners, nozzles, wall openings or other devices. The bed is shock-heated by the hot gases at the surface, whereby sticking of the feed materials with the lining (e.g. brick lining or castable lining) is prevented as far as possible. Shock heating can be achieved, for example, by means of burners directed radially at the bed. Alternatively, or additionally, shock heating can also be achieved by means of a ring-shaped channel in which a flame rotâtes. This rotation can be achieved constructively by blowing the hot gas tangentially to the discharge cône and burning it.

The plénum zone also includes a refractory lined intermediate zone located below and adjacent to the refractory lined pyrolysis zone. In the intermediate zone, the heat from the pyrolysis zone and the waste heat from the refractory lined upper oxidation zone below are used for final drying and complété pyrolysis ofthe feed materials. It may be advantageously provided that the intermediate zone comprises a lined (e.g. brick lined or castable lined) Steel shell, wherein the liner can be of a thickness similar to that of other zones. This embodiment simplifies the commissioning (starting up) ofthe reactor, as high températures can also occur in the intermediate zone. It may be advantageous to provide for a tapered cross-section in the lower area ofthe intermediate zone, which changes the rate at which the feed material sinks.

Below the refractory lined intermediate zone in the zonally refractory lined co-current section there is a lined upper oxidation zone in which tuyeres are arranged. These tuyeres are arranged on at least one level (height or vertical distance from the reactor bottom). Since the reactor, as described above, has a circumferential water-cooled console and two lining sections arranged one above the other and having tongue-andgroove connection, the température in the upper oxidation zone in the région of refractory lining can be increased to more than 1800°C and the température in a center of bulk material (bed) can be increased to a value in between of 2000°C and 4000°C by providing at least 1000°C hot oxygen and/or air without compromising the stability of the reactor.

Ail materials can be converted in an inorganic gas such as carbon monoxide (CO), hydrogen (H2), water (H2O), carbon dioxide (CO2), hydrogen sulphide (H2S), ammonia (NH3), nitrogen dioxide (NO2) or sulphur dioxide (SO2), liquid métal or liquid slag, coke or carbon (C) by these hot températures.

Below the upper oxidation zone, a lined upper réduction zone is arranged in the lined co-current section, into which essentially no organic components enter.

It can be advantageously provided that the lined upper réduction zone has a crosssectional enlargement compared to the upper oxidation zone, which changes the sinking rate ofthe feed materials and increases the résidence time at the same level. In the lined upper réduction zone, the gas flows through the coked fixed bed in cocurrent and thermal energy is converted into Chemical energy, producing carbon monoxide (CO) and hydrogen (H2). In particular, carbon dioxide (CO2) is converted into carbon monoxide (CO) and water (H2O) into hydrogen (H2), whereby the carbon still contained in the bed is further gasified. Réduction of CO2 to CO can be achieved in the reactor in such a way that the CO/CO2 gas volume ratio is greater than 10 or even greater than 15. For example, the CO/CO2 gas volume ratio is between 10 and 1000, preferably between 15 and 10000 and in particular preferably between 15 and 10⁷ (essentially CO2-free).

As they pass through the upper réduction zone, the gases are simultaneously cooled, for example to températures between approx. 1000 °C and approx. 1600 °C. As ail material flows necessarily flow through the upper oxidation zone and cannot be returned, there is no longer any contact with the unreacted materials above the oxidation zone after they hâve passed through the upper réduction zone. In this way, ail cleanly cracked and/or melted, exclusively inorganic substances reach the gas outlet section without anew contamination.

As ail material flows necessarily flow through the upper oxidation zone and cannot be returned, there is no longer any contact with the unreacted materials above the oxidation zone after they hâve passed through the upper réduction zone. In this way, ail cleanly cracked and/or melted, exclusively inorganic substances reach the gas outlet section without anew contamination in the lined gas outlet section. The gases of the upper oxidation zone are cooled as they pass through the lined upper réduction zone. It can be provided that the gases produced in the lined upper oxidation zone are so hot that passing through the upper réduction zone leads to a cooling to a température between 1500 °C and 1750 °C, wherein after the cooling these hot gases reach the gas outlet.

It is provided that the gas outlet section comprises at least one gas outlet. It is also conceivable thatseveral (e.g. four) gas outlets are arranged all-round, preferably radial distributed.

Below the lined gas outlet section there is a substantially conical lined countercurrent section. This comprises a conical lower réduction zone to convert the thermal energy of the gas from the conical lower oxidation zone into Chemical energy (mainly CO) and to generate the countercurrent. This conical lower réduction zone is connected to the lined gas outlet section. Below the conical lower réduction zone, a conical lower oxidation zone is arranged with the eut tip of the cône pointing downwards. In the conical lower oxidation zone, the residual coked material is converted into gas. In the conical lower oxidation zone at least one tuyere is arranged in at least one plane, via which at least 1000°C hot air and/or oxygen can be introduced, which in turn cause températures between 1800°C and 4000°C in the bed of the lower oxidation zone. These high températures allow the slag and the metals to leak out in liquid form via at least one tapping for collection and discharge.

The generated gas flows in countercurrent through the conical lower réduction zone to the gas outlet section, where the gases cool to températures between approx. 1500 °C and approx. 1750 °C. Here it can be provided, that the gases generated in the lower oxidation zone are so hot that passing through the lower réduction zone leads to cooling ofthe gases to a température between 1500°Cand 1750°C or between 1600°C and 1750°, which are then discharged through the gas outlet réduction zone.

Since according to the invention, the reactor has both a réduction zone in the countercurrent section and an upper réduction zone in the co-current section, the total réduction zone volume (sum ofthe volumes ofthe upper and conical lower réduction zones) can be considerably largerthan the one réduction zone of known reactors. As an example, reference is made to EP 1 261 827 B1, in which only a réduction zone is arranged in the area ofthe gas outlet section.

Thus, according to the invention, the reactor achieves a simple, inexpensive and environmentally friendly material and/or energetic utilization of feed materials. In addition, employing ofthe reactor described herein enables increase in capacity and yield of a Chemical and a thermal energy.

It is provided in one embodiment of the reactor that the upper lining section has the groove and the lower lining section has the tongue.

This can cause the lining to expand upwards when exposed to hot températures.

A further embodiment of the reactor provides, that each of the at least two lining sections comprises at least one refractory inner lining and an outer lining encasing the refractory inner lining, wherein the refractory inner lining is a brick lining made of fired bricks or a monolithic (e.g. castable) lining.

Furthermore, it may be provided that the lining sections, comprising a refractory inner lining and an outer lining, are arranged in a stabilizing Steel shell.

It may also be advantageous that at least one further insulating layer is arranged between the outer lining and the Steel shell. The additional insulating layer may consist of cardboard, high-temperature felt, or high-temperature foams.

This embodiment ensures that the Steel shell is better insulated. For example, the additional insulating layer can be designed in such a way, that thermal heat loss through the Steel shell is improved by more than 2% compared to reactors without an additional insulating layer and as a resuit thereof the outside température of the Steel shell is also reduced. For example, this design allows the outside température of the Steel shell to remain below 60°C during reactor operation, which means that no contact protection is required. Furthermore, the insulating layer can be used to compensate a possible radial thermal expansion of the inner lining and/or the outer lining.

In order to reduce the wear of the refractory inner lining, it may also be provided that the inner lining consists of bricks consisting of spinel corundum, chromium corundum, or carbides. It can be provided that the thermal conductivity of these stones is > 3 W/mK.

Furthermore, it may be provided that the bricks in the hotter areas (températures > 1500 °C) of the reactor are protected against Chemical and/or thermal conditions by slag freezing.

In order to enable this slag freezing, the outer lining can consist of thermally conductive materials, whereby sufficient heattransfer ofthe cooling medium (e.g. a pipe coil with cooling water) to the inner lining can be achieved.

Here it is conceivable that the outer lining is formed from bubble refractory (e.g. bubble aluminia), whereby the bubble refractory can be cast, whereby a positive connection between a cooling medium (e.g. a pipe coil with cooling water) and the inner lining can be achieved. For the hotter areas (températures > 1500 °C) ofthe reactor, it can also be provided that the bubble refractory consists of spinel corundum or aluminum corundum. Alternatively, it may be provided that the outer lining consists of free-flowing cast masses with higher stability, but due to this, less insulating properties.

For the less hot areas (températures < 1500 °C), the outer lining may be made of a cast insulating bubble refractory with a thermal conductivity of < 1 W/mK in order to reduce heat loss. This design ensures that slag fur formation is favored by the more thermally conductive material in the hotter areas and heat loss is reduced by the less conductive material in the less hot areas. This is particularly advantageous as the less hot areas cover a much larger area of the reactor than the hotter areas.

Another advantageous embodiment ofthe invention is that the circumferential watercooled console is made of black Steel or stainless Steel.

Whether black Steel orstainless Steel is used dépends on the use and operation ofthe reactor. Black Steel is cheaper and has a higher thermal conductivity than stainless Steel. However, stainless Steel is thermally and chemically more stable than black Steel. Finite element thermal simulation can help détermine which material should be used for the intended application.

An embodiment of the invention provides, that the tuyeres (of the upper and conical lower oxidation zone) are made of copper or Steel. In addition, it may be provided that one of the tuyeres has a ceramic inner pipe, or each of some of the tuyeres has a respective ceramic inner pipe, or each of the tuyeres has a respective ceramic inner pipe. This embodiment ofthe tuyeres (with a ceramic inner pipe) enables the tuyere to be protected against melting ofthe métal by adding oxygen and/or air, whereby oxygen and/or air can also be preheated (e.g. to températures > 1000°C). It can also be advantageous that a compressible and temperature-resistant layer is arranged between the ceramic inner pipe and the tuyere, whereby thermally induced mechanical stresses can be compensated. This compressible and temperature-resistant layer consists, for example, of high-temperature felt, high-temperature cardboard or hightemperature foam.

An alternative embodiment ofthe invention provides that, the tuyeres (ofthe upper and conical lower oxidation zones) may be completely made of ceramic. Through this embodiment it can be achieved, for example, that the oxidation zone can be operated with a supply of hot air and/or oxygen having température more than 1000°C and thus a bed température of more than 2000°C, since ceramics can withstand higher températures than metals.

The inevitably necessary cooling of metallic tuyeres is not necessary for tuyeres made entirely of ceramics, whereby the heat loss can be reduced by more than 5 %. The Chemical load caused by melting without cooling and the high thermal stress can be achieved for these tuyeres by a combination of ceramics with good thermal conductivity (e.g. Silicon Carbide with e.g. 85 W/mK) and slag freezing, followed by insulating ceramics (e.g. spinel corundum with less than 4 W/mK).

It can also be advantageous for the reactor that the cône angle (a) of the lined upper oxidation zone is between 5° and 30°.

This conical shape ofthe upper oxidation zone allows itto be advantageously achieved that a part of the slag remains on the surface of the lining, whereby the formation of a slag fur in this area is achieved.

For a further embodiment of the reactor it is intended that the lined upper réduction zone is arranged above the gas outlet section, wherein the gas outlet section adjoins the lower part of the lined upper réduction zone by creating a cross-sectional enlargement. Here it could be conceived, that the cross-sectional enlargement is abrupt.

Preferably, the cross-sectional area ofthe gas outlet section increases by at leasttwice

605 that ofthe cross-sectional area ofthe upper réduction zone.

This embodiment ensures that the bed widens conically thereby increasing the surface area or discharge area of the bed. The surface or discharge area of the bed essentially corresponds to the outer surface for a truncated cone-shaped design.

An embodiment provides that the cross-sectional enlargement is such that the discharge area of the bed is at least 3 times larger than the cross-sectional area of the upper réduction zone. Furthermore, the cross-sectional enlargement can be so large that the discharge area of the bed is at least 7 times or even at least 9 times larger than the cross-sectional area of the upper réduction zone.

For this or a further embodiment, it may also be provided that the cross-sectional enlargement of the gas outlet section is such that the discharge area of the bed is increased by at least 5 times the cross-sectional area of the upper oxidation zone. Furthermore, the cross-sectional enlargement can be so large that the discharge area of the bed is at least 9 times larger than the cross-sectional area of the upper oxidation zone.

The advantage of the above-mentioned embodiments is that the gas flow velocity (through the gas outlet) is reduced proportionally to the increased discharge area of the bed (compared to known reactors)- so that the dust entrainment from the bed can be reduced to minimized.

Alternatively, it may be provided for the reactor that at least a portion of the lined upper réduction zone arranged in the co-current section is arranged or inserted in the gas outlet section.

This embodiment may also provide for the gas outlet section to hâve a larger crosssection than the upper réduction zone.

With this embodiment, the co-current section with a part ofthe upper réduction zone is introduced or partially inserted into the gas outlet section. For example, the lining (e.g. brick lining or castable lining) ofthe upper réduction zone protrudes into the gas outlet section. Since the gas outlet section has a larger cross-sectional area than the upper réduction zone and the at least one gas outlet is located in the edge portion of the gas outlet section, the gas produced in the co-current section must bypass the lining (e.g. brick lining or castable lining) extending out into the gas outlet section in orderto reach the gas outlet, whereby less dust enters the dust séparation. This embodiment allows the overall height of the reactor to be reduced, wherein at the same time the dust séparation can be improved, since the gas and the entrained dust must additionally flow upwards in order to achieve at least one gas outlet.

It may also be provided that the lining (e.g. brick lining or castable lining) of the upper réduction zone extending out into the gas outlet section is formed as a hollow cylindrical shape. The hollow cylindrical shape may be made as a Steel holder construction, which is lined on both sides which is protected by water cooling against high thermal and consequently mechanical stresses.

For a further embodiment of the invention, it is provided that the volume ratio of the upper oxidation zone volume to the plénum zone volume is a ratio of 1 : N volume units, wherein N is a number greater than or equal to (s) 4 and less than or equal to (<) 20.

Thus, the upper oxidation zone volume is many times larger compared to previously known reactors, whereby a considerably higher capacity can be achieved. Here it is further conceivable that 5 is < N < 15 or even 6 < N < 11.

In a reactor embodiment, it is provided that the volume ratio of the upper oxidation zone volume to the total volume of the upper réduction zone volume and the plénum zone volume is a ratio of 1 : N volume units, wherein N is a number greater than or equal to (>) 7 and less than or equal to (<) 25.

A further embodiment provides that the volume ratio of the upper oxidation zone volume to the total volume ofthe upper réduction zone volume and the plénum zone volume is a ratio of 1 : N volume units, wherein 8 < N 15 or even 9 < N < 14.

This embodiment of the reactor is advantageous in that a larger capacity is achieved with a fictitious same height of the reactor. This is possible because the plénum zone volume compared to the oxidation volume has a smaller ratio than in known reactors.

Afurther embodiment ofthe reactor provides thatthe volume ratio ofthe countercurrent section volume to the total volume ofthe reactor is a ratio of 1 : N volume units, where N is a number between 1 and 10 (1 < N < 10). Here it is further conceivable that 2 < N < 7 or even 3 ί N < 5.

Due to the cross-sectional enlargement of the gas outlet zone and the countercurrent section, the discharge cône area in the conical lower réduction zone is also enlarged, whereby smaller gas flow velocities flow out of the bed and less dust is entrained.

Another advantageous embodiment of the reactor is that the cône angle of the conical lower réduction zone and the cône angle of the conical lower oxidation zone are between 50° and 70°. Due to this embodiment, the slag, which is kept liquid at sufficiently high températures in the conical lower oxidation zone and the conical lower réduction zone, drains off better, since the walls run at an angle of approx. 50°-70°, preferably approx. 60°C, from the horizontal or at an angle of 20° to 40° from the vertical.

A further embodiment of the reactor provides that gas supply means are arranged in the area of the cross-sectional enlargement in the pyrolysis zone. This embodiment ensures that hot gases (e.g. preheated air or combustion gases) are supplied to the discharge cône.

In one embodiment of the invention, it is also provided that the tuyeres of the upper oxidation zone are arranged on several levels (heights). This is particularly advantageous because a better distribution of the gas is achieved with uniform heating of the bed. In addition, this embodiment ensures that local overheating of the lining (e.g. brick lining or castable lining) is avoided as far as possible.

Another advantageous embodiment of the reactor is that at least one tuyere is arranged on a level (height) of the conical lower réduction zone.

The further tuyere additionally supplies air and/or oxygen in a defined way, so that no CO2 is produced, but almost exclusively CO. Furthermore, it can be achieved through this embodiment that the throughput can be increased. Furthermore, this embodiment enables a throughput increase and an increase in a gas outlet température at the gas outlet above 1500°C without impairing the quality ofthe gas.

For applications that prefer thermal energy over Chemical energy it may be further advantageous that at least one additional tuyere is arranged in the upper réduction zone. Through this embodiment it can be advantageously achieved that Chemical energy (CO, H2) is turned back to thermal energy by oxidizing the CO to CO2 and H2 to H2O.

A further embodiment provides that at least one other tuyere is arranged on a further level (height) ofthe conical lower oxidation zone. The tuyere atthe next level is located preferably above the tapping.

By arranging the tuyere above the tapping, the melting can be facilitated in the area of the tapping, as the heat is generated in the area where the melt is to run off liquid. At the same time, the arrangement of the tuyere above the tapping ensures that the solidified melt desired on the opposite side of the tapping (so-called slag freezing, which protects the lining as, e.g. brick lining) is not liquefied and therefore does not flow off.

According to a third aspect of the présent invention, there is provided for the use of the reactor according to the second aspect of the présent invention for providing gases having températures between 1500°C and 1750°C and a CO/CO2 ratio >15, wherein the gases are introduced into a metallurgical reactor for réduction melting. The gases preferably hâve a température of between 1600°C and 1750°C. Furthermore, it is provided that the gases may be introduced into a metallurgical reactor for réduction melting. The CO/CO2 gas volume ratio of the gases introduced into the metallurgical reactor for réduction melting may be greater than 10 or even greater than 15. For example, the CO/CO2 gas volume ratio is between 10 and 1000, preferably between 15 and 10000 and in particular preferably between 15 and 10⁷ (essentially CO2-free).

According to a fourth aspect of the présent invention, there is provided for a System comprising a reactor according to the second aspect of the présent invention and a metallurgical reactor connected to the reactor for réduction melting. It is conceivable here that the reactor is operated with the process described above, so that the CO/CO2 gas volume ratio in the région (connecting section) between the reactor and the metallurgical reactor for réduction melting is greater than 10 or even greater than 15. For example, the CO/CO2 gas volume ratio is between 10 and 1000, preferably between 15 and 10000 and in particular preferably between 15 and 10⁷ (essentially CO2-free).

The metallurgical reactor for réduction melting may be any reactor or blast furnace capable of reducing metals from ores.

According to a fifth aspect ofthe présent invention, there is provided for the use ofthe reactor according to the second aspect of the présent invention to provide a hot gas for a process for the smelting of a metalliferous feedstock material. The process for the smelting of a metalliferous feedstock material may be the process described in Dutch priority founding patent application number 2023109 entitled “Process for the smelting of a metalliferous feedstock material” in the name of African Rainbow Minerais Limited.

According to a sixth aspect of the présent invention, there is provided for the use of the reactor according to the second aspect of the présent invention in the method according to the first aspect of the présent invention.

Further advantages, details and developments resuit from the foilowing description of the invention, with reference to the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 shows a simplified cross-sectional view of a reactor according to the invention.

Fig. 2 shows a cut-out of a simplified cross-sectional view of the reactor according to the invention with two lining sections and tongue-and-groove connections.

Fig. 3 shows a perspective view of the circumferential water-cooled console, which can be placed between two lining sections and in the area of the tongue-and-groove connection.

DETAILED DESCRIPTION OF THE DRAWINGS

Like-numbered éléments in these figures are either identical or fu If il I the same function. Eléments previously discussed are not necessarily discussed in later figures if the function is équivalent.

In the following, Figure 1 describes a substantially cylindrical reactor 100 according with the invention. In connection with the explanation ofthe details ofthe reactor, the method steps that take place during the treatment of feed materials and the génération of gas températures above 1500°C at a gas outlet are also specified.

By using other feed materials, modifications of the reactor and/or method may be useful. In general, different feed materials (for instance low-grade coal) can also be combined, for example by adding feed materials with a higher energy value (e.g. organic waste, contaminated waste wood, car tires or the like) during the gasifying/melting of non-organic feed materials.

The reactor 100 shown in Fig. 1 has three sections. A partially lined co-current section 110, a refractory lined gas outlet section 120 and a refractory lined countercurrent section 130. The co-current section 110, the gas outlet section 120 and the countercurrent section 130 are arranged substantially concentrically to each other (represented by the vertical dash-dot line passing substantially through the center of the reactor). As shown, several circumferential water-cooled consoles 400 are shown in the co-current section 110 and in the counter-current section 130. The circumferential water-cooled consoles 400 are arranged between at least two refractory lining sections arranged one above the other (not shown) in the area of the tongue-and-groove connections (not shown). In the co-current section a non-lined plénum zone 111, a refractory lined upper oxidation zone 116 and a refractory lined upper réduction zone 118 are arranged. The plénum zone 111 comprises a feed zone with a sluice 112, whereby feed materials such as waste, water, car tires, additives or other feed materials are fed into the reactor from above via the feed zone. The material flow ofthe solids is shown as a dashed arrow from top to bottom. A downstream buffer zone is arranged below the pyrolysis zone 114 for buffering and pre-drying the feed material volume, which adjoins the bottom ofthe bufferzone thereby creating a crosssectional enlargement. In the pyrolysis zone 114, a discharge cône can form from feed materials (represented by the oblique dashed lines; between 114 and 119). Pyrolysis can therefore take place on the surface of the bed. The pyrolysis zone can also be made inert with combustion gas or any other low oxygen gas (e.g. N2 or CO2), therefore flammable gases moving to the sluice 112 burn safely. Below the pyrolysis zone 114 there is a lined intermediate zone 115 which is equipped for final drying and complété pyrolysis. A refractory lined upper oxidation zone 116 adjoins the refractory lined intermediate zone 115, wherein in the upper oxidation zone 116 tuyeres are arranged circumferentially in a plurality of planes as shown. At least 1000°C hot oxygen and/or air is supplied via the tuyere 117, which increases the température above 1800°C and up to 4000°C such that ail substances are converted into inorganic gas, liquid métal, coke, carbon and/or minerai slag. In the refractory lined upper réduction zone 118, which adjoins the lined upper oxidation zone 116 and which is arranged substantially above a subséquent lined gas outlet section 120, the endothermie conversion of thermal energy into Chemical energy takes place. At the same time, the gas co-current (represented by a dotted arrow running from top to bottom), which is generated from the plénum zone to the upper refractory lined réduction zone 118 from top to bottom, is generated here and introduced into the refractory lined gas outlet section 120.

As shown, the refractory lined gas outlet section 120 is connected to the refractory lined upper réduction zone 118, thereby creating a cross-sectional enlargement. The gas produced is - approximately in cross-flow to the bed - discharged in the gas outlet section 120 through at least one gas outlet 121 (shown by a dotted arrow running from left to right). It may be provided, for example, that four or more gas outlets 121 are radially distributed around the circumference (not shown), so that the gas produced in the co-current section and in the countercurrent section can be diverted radially in the cross-flow. The discharged gas has a CO/CO2 gas volume ratio between 10 and 1000, preferably between 15 and 10000 and particularly preferably between 15 and 10⁷ (essentially CO2-free).

Below the gas outlet section is the refractory lined conical lower réduction zone 138. In the refractory lined conical lower réduction zone 138 the conversion of thermal energy into Chemical energy also takes place.

Below the lined conical lower réduction zone there is, as shown, a lined conical lower oxidation zone 136 in which at least one tuyere 137 and a tapping 131 are arranged. The tuyere 137 introduces at least 1000°C hot air and/or oxygen to oxidize the remaining coked material and prevents the melt from solidifying. The collection and discharge of métal melts and slag melts takes place in the tapping 131.

The gas generated in the conical lower oxidation zone and in the conical lower réduction zone also flows in countercurrent with the solid’s flow through the bed (represented by a dotted arrow running from bottom to top) to the refractory lined gas outlet section 120, where it is discharged via at least one gas outlet 121.

The reactor according to the invention can hâve the following internai volumes, for example:

Table 1

Reactor	Example 1 [m3]	Example 2 [m3]
Co-current section:	19,80	118,70
Feed zone with sluice	2,70	3,20
Buffer zone	4,00	6,00
Pyrolysis zone	4,70	41,60
Intermediate zone	4,00	20,40
Upper oxidation zone	1,50	9,90
Upper réduction zone	2,80	37,70
Gas outlet section:	3,20	32,20
Countercurrent section:	6,80	59,50

870

Fig. 2 shows a cut-out of a simplifiée! cross-sectional view of the refractory lined intermediate zone 115 of the reactor according to the invention with two lined sections 200, 300 and a circumferential tongue-and-groove connection. As shown as an example for the lined intermediate zone 115, where each other lined portion can also 875 hâve at least two lined sections 200, 300 with circumferential tongue-and-groove connection, this lined portion of the reactor has at least two lined sections 200, 300 arranged one above the other. Each of the at least two lined sections 200, 300 comprises at least one inner refractory liner 202, 302 and an outer liner 203, 303 enclosing the inner refractory liner. It is conceivable that the inner refractory liner 202, 880 302 is a liner made of fired bricks or a monolithic (e.g. cast) liner. As shown further in

Fig. 2, a tongue-and-groove connection is formed between the lining sections 200, 300 arranged one above the other, one of the lining sections 200 has a groove 201 on the side facing the reactor interior and the other lining section 300 has a tongue 301 on the side facing the reactor interior. As shown here, it can be provided that the upper 885 lining section 200 has the groove 201 and the lower lining section 300 has the tongue

301. Furthermore, the tongue-and-groove connection has a (vertical) temperaturedependent gap opening 400 between the groove 201 and the tongue 301. As further shown, a circumferential water-cooled console 400 is arranged between the at least two lining sections 200, 300 arranged one above the other.

890

The circumferential water-cooled console 400 for holding the brick lining and stabilizing the brick lining during high heating and cooling of the reactor is shown in perspective view in Fig. 3. This circumferential water-cooled console 400 is manufactured by bending, without welding seams, of hollow cylindrical pipes with square or rectangular 895 cross-sections and is made of black Steel. Cooling water can be supplied to and drained from the water-cooled console 400 by means of the connection flanges 401 as shown.

Claims (11)

1. A method of gasifying a carbonaceous feedstock material to generate hot reducing gases using a reactor, the method including the steps of:

choke-feeding a carbonaceous feedstock material via a sluice to form a discharge bed in a pyrolysis zone ofthe reactor;

heating the discharge bed in the pyrolysis zone to initiate pyrolysis in the carbonaceous feedstock material and to form a pyrolysis product;

providing a lower lying hot upper oxidation zone in the reactor by supplying a source of oxygen at a température of at least 800°C to the reactor at a location beneath the pyrolysis zone;

gasifying the pyrolysis product and remaining un-pyrolyzed carbonaceous feedstock material in the hot upper oxidation zone to form a char bed in an upper réduction zone ofthe reactor, the upper réduction zone being located beneath the hot upper oxidation zone;

converting thermal energy into Chemical energy in the upper réduction zone; providing a lower lying hot lower oxidation zone in the reactor by supplying a source of oxygen at a température of at least 800°C to the reactor at a location beneath a lower réduction zone ofthe reactor;

collecting any métal and/or slag melts présent in the lower oxidation zone;

removing the métal and/or slag melts présent in the lower oxidation zone; and discharging hot reducing gases having a température of at least 1300°C and a CO/CO2 ratio of > 5 which hâve been generated in the upper réduction zone through a gas outlet located in a gas outlet section ofthe reactor, the gas outlet section being located between the upper réduction zone and the lower réduction zone of the reactor.

2. The method of claim 1, wherein the hot reducing gases which are being discharged hâve a CO/CO2 ratio of > 15.

3. The method of claim 1 or claim 2, wherein the heating of the discharge bed in the pyrolysis zone is done gradually to a température of at least 700°C, the température being increased gradually to prevent breakup of the carbonaceous feedstock material and pyrolysis product.

4. The method of any one of the preceding daims, including the step of providing hot gases to the pyrolysis zone to heat the discharge bed in the pyrolysis zone to initiate pyrolysis in the carbonaceous feedstock material and to form the pyrolysis product.

5. The method of claim 4, including the step of controlling the volumétrie flow rate of the hot gases which are being fed to the pyrolysis zone so as to heat the discharge bed in the pyrolysis zone gradually to a température of at least 700°C, the température being increased gradually to prevent breakup of the carbonaceous feedstock material and pyrolysis product.

6. The method of any one of the preceding daims, including the step of drying the carbonaceous feedstock material prior to choke-feeding the carbonaceous feedstock material to the reactor.

7. The method of any one of the preceding daims, including the step of preheating and pre-drying the carbonaceous feedstock material in a buffer zone of the reactor, the buffer zone being located above the pyrolysis zone of the reactor.

8. The method of claim 7, wherein by feeding the carbonaceous feedstock material in the pyrolysis zone, a discharge bed having a discharge cône is formed, the cross-section of the pyrolysis zone being enlarged with respect to the crosssection of the buffer zone.

9. The method of any one of the preceding daims, including the step of pyrolyzing and drying the carbonaceous feedstock material in an intermediate zone of the reactor, the intermediate zone being located beneath the pyrolysis zone.

10. The method of claim 9, including the step of discharging hot reducing gases having a température of at least 1300°C which hâve been generated in a cocurrent section of the reactor from the at least one gas outlet of the reactor, the co-current section comprising:

a plénum zone of the reactor, the plénum zone comprising:

o the feed zone of the reactor;

o the buffer zone of the reactor;

o the pyrolysis zone of the reactor; and o the intermediate zone of the reactor;

- the upper oxidation zone of the reactor; and — the upper réduction zone of the reactor.

11. The method of any one of the preceding claims, wherein the method includes the step of discharging hot reducing gases having a température of at least 1300°C which hâve been generated in a countercurrent section ofthe reactorthrough the

85 gas outlet located in the gas outlet section of the reactor, the countercurrent section comprising the lower oxidation zone and lower réduction zone of the reactor.