FI120770B - Method and device for gasification of fuel in a fluidized bed reactor - Google Patents

Abstract

The invention relates to a method and apparatus for gasifying fuel in a fluidised bed reactor (1) containing fluidised solid material particles. The fuel (8) is introduced into the reactor bottom part, and product gas (10) formed in gasification is led from the reactor top to a separator, such as a cyclone (11), which separates solid particles from the gas for recirculation to the reactor. In accordance with the invention, a bubbling fluidised bed (2) containing coarser particles, and above this, a circulating bed containing finer particles are maintained in the reactor by recirculating the particles separated from the product gas to the reactor, to the top of the bubbling fluidised bed or above this. The reactor may comprise a lower part (2) for the bubbling fluidised bed and an upper part (4) larger in cross-section for the circulating fluidised bed, the speed of the ascending gas flow in the circulating bed being equal to or lower than that of the bubbling bed. The separating limit in the cyclone may be adjusted such that the discharged product gas flow entrains solid particles, which have a binding effect on tacky ash particles. The product gas is cooled in two successive heat exchangers (19, 20) before filtration of the gas. The method is suitable for gasification of biomasses and recycled fuels forming tars and/or containing chlorine, thus providing a solution to the problems of fouled and clogged gas ducts.

Description

The present invention relates to a process for gasifying fuel in an ascending gas stream from a reactor in a fluidized bed reactor containing solid fluidized material particles, in which a process is carried out in a fluidized bed reactor. , which are returned to the reactor. In addition, the invention relates to a gasification apparatus for applying the method.

10 Fuels suitable for gasification include finely divided biofuels and wastes such as sawdust, municipal waste, packaging materials and plastic waste. The resulting product gas can be utilized in power plants by replacing the plant's fuel, such as coal, oil or natural gas.

There are two main types of fluidized bed reactors, one of which is based on a stationary, bubbling fluidized bed (BFB = Bubbling Fluidized-Bed). The bubbling fluidized bed of relatively coarse-grained fluidized particles remains in place supported by the rising airflow blown into the reactor space. The air flow velocity is typically on the order of 1 m / s. The solids content of the gas stream above the well-defined bubbling fluidized bed is low. In a BFB reactor, it is possible to increase the temperature of the reactor space above the fluidized bed 20 by supplying additional air or: * ·. · Lowering it by injecting cooling water into the gas stream. To increase carbon conversion • «: * ··. the dust particles in the gas stream can be separated by a separate cyclone, from which • the particles are returned to the bottom of the reactor space. These types of so-called Winkler carburettors are described in DE 195 48 324 and 27 51911.

• · • · · 25 Another main type of fluidized bed reactor is the circulating bed reactor (CFB = Circulating

Fluidized-Bed), in which solid fluidized particles rise into the reactor with the blown air stream. The air flow velocity, typically of the order of 5 m / s, is higher and: ***: the size of the fluidized particles is smaller than in the BFB reactor. The fluidized particles are transported • • · with the product gas to a cyclone, where the particles and the carbon • · · 30 residue from the fuel are separated and returned to the bottom of the reactor space. In order to achieve the residence time required for the gasification reaction, the circulating bed reactors are made essentially BFB reactors. higher. Other typical features of a circulating bed reactor are a uniform temperature and a relatively uniform consistency of the solid suspension in the reactor space, without the clear fluidized bed characteristic of the BFB reactor. A typical CFB-2 reactor-based fuel gasification process is described in FI publication 62554,

With the gasification of finely divided biomasses and plastic-containing wastes by current methods and equipment, the abundant formation of tar-like compounds has proved to be a problem. Prior to combustion in the power plant, the product gas is filtered to remove ash and heavy metals with filters with an operating temperature in the range of 200 to 450 ° C. To this end, the gas from the reactor at a temperature of 800 to 1000 ° C has to be cooled by a heat exchanger, whereby tars condense on the surfaces of the gas ducts, the heat exchanger and the filter, causing blockages. Another cause of problems in current gasification processes is the chlorine contained in the fuel, which is abundant, especially in plastic waste and similar waste fuels. Chlorine reacts with the calcium used as fluidized particles or with the fuel to form compounds that also adhere to the gas ducts and heat exchangers, causing blockages in them. The phenomenon has been found to be at its maximum with the product gas cooling at a temperature in the range of about 720 to 780 ° C.

The above problems have been identified in the applicant's gasification tests of wood waste, such as sawdust, and plastic-rich waste in a BFB reactor. For both fuel types, tar formation was abundant despite fuel being fed into the bubbling fluidized bed. Some of the finely divided fuel rose without gassing with the air flow from the fluidized particles in the reactor space to the almost free top. Pyrolysis with plastic-containing fuel resulted in a large amount of heavy hydrocarbons, which do not have time to decompose in a relatively low leachate. These compounds rise from the reactor solids to the almost empty top, *** wherein the lack of catalytic particle surfaces prevents their decomposition. For this reason, the expansion of the flow ***** cross-section of the carburetor top and the high reactor height implemented in many known fluidized bed gasifiers are not a solution to the tar problem.

• · ·

In the experiments performed by the applicant, the reduction in tar content of the reactor fluidized particles at the empty top at 900 ° C with a delay of 10 seconds was less than 5%, and blockages in the product gas channels were found due to both condensed: ***: 30 tar and finely divided calcium / chlorine dust.

··· • · · • The applicant has also studied the gasification of the same fuels with a known CFB reactor. In these experiments, the tar problem of sawdust was alleviated by using limestone or dolomite as fluidized particles, which, after calcination to calcium oxide, catalyze the decomposition of tars. However, the problem is the lime grinding due to the high ** 35 flow rate and the consequent high lime consumption and dust increase. Chlorine-containing fuels had no significant effect on lime, presumably due to the deactivating reaction of HCl and the latter, which deactivated the lime particles. The problem of gas duct obstruction due to sticky calcium / chlorine compounds also remained. In a test with waste fuel, the product gas duct was almost completely blocked in a 30-hour run. Layer 5 was found to be rich in calcium and chlorine. The problem also does not depend on the fluidized material used, as the waste fuel itself contains enough lime to block the gas ducts. In U.S. Patent No. 5,658,359, the problem is solved by separately feeding a coarse carbon black, such as sand, into the product gas, but the disadvantages here are the cost of additional equipment and the abrasive effect of the coarse sand on the gas ducts and heat exchanger.

The applicant's previous FI application 981817 discloses a gasification method using a CFB rector, in which the bed material consists of a mixture of hard and coarse and easily grindable and porous material. The aim is to achieve a situation in which the sticky alkali metals in the ash bind to the fine calcium particles and rapidly pass through the circulating cyclone out of the carburetor. In the examples of the application, the velocity of the rising gas flow is 5 m / s typical for a CFB carburetor, and the dust separated by an efficient circulating cyclone is returned to the bottom of the bed inside a coarser sand bed. This enhances the rapid grinding of the circulating lime and good carbon conversion can be achieved even at a relatively low temperature, as the carbonaceous solids present in the 20 cycles are returned to the oxidizing zone at the bottom of the reactor. The described method is suitable for alkali-rich materials in which chlorine binds to the sodium or potassium of the fuel.

• · · * "j On the other hand, tests performed by the applicant have shown that materials with an excess of chlorine relative to sodium and potassium, as is the case in conventional waste incineration plants, show a strong formation of calcium and chlorine deposits in the cyclone. to the gas pipeline after.

m φ

The object of the invention is to provide a solution to the problems described above, in which the problem of fouling and clogging of gas ducts and heat exchangers due to tars and / or calcium / chlorine compounds can be prevented or substantially alleviated while the solid fluidized material consumption in the process remains reasonable **; · '. The process according to the invention is characterized in that a bubbling fluidized bed containing coarser fluidized material particles with a size of more than 0.2 mm and a maximum of 1.5 mm is maintained in the reactor by means of a gas flow, as well as finer fluidized material particles above it. the size is 50-300 pm, • · 35 containing a circulating bed, and that the recyclable particles separated from the product gas are returned to the top of the fluidized bed bubbling to or above the reactor.

4

The central idea of the invention is thus to maintain the bubbling fluidized bed and the rotating bed in the process in parallel, so that these beds operate substantially separately without mixing with each other. This achieves an optimal process where the advantages of both basic solutions, BFB gasification and CFB gasification, are combined.

In the invention, the bubbling fluidized bed at the bottom of the reactor requires a low gas flow rate, whereby a sufficient residence time is achieved in a reactor substantially lower than current CFB reactors. The fuel gasifies in a bubbling fluidized bed, from where the gas passes to an upper circulating bed where the circulating finely divided fluidized particles have a catalytic particle surface for tar decomposition. For the fluidization of the fine circulating particles 10, a low flow rate of the bubbling bed is sufficient, which provides a sufficient residence time and reduces the crumbling and dust formation due to the collision of the particles. A particular advantage of returning the circulating particles to or above the top of the bubbling fluidized bed is that the particles do not have to overcome the high pressure drop of the bubbling bed of the order of 50-200 mbar, as is the case in known BFB reactors.

Plastic-containing wastes and many biofuels are characterized by their high volatile matter content and / or the high reactive carbon residue they form. As a result, their fluidized bed gasification easily achieves the required 95% carbon conversion, and the most accurate separation of cyclone dust possible:. and returning to the fluidized bed is therefore not as central as e.g. above • · · ·. ·. : in said known Winkler carburetors. This makes it possible to adjust the separation limit of the separator so that the smallest solid particles in the product gas are not returned to the reactor as part of the circulating bed, but are left in a cooled product stream to substantially facilitate clogging due to calcium / chlorine compounds. . If the separator has a solids separation limit of about 50 to 70 μm, solid particles of 10 to 70 μm are obtained in the product gas stream, which reduce the proportion of sticky, sticky components in the gas solids, bind them and prevent the sticky substance from adhering to the gas ducts. : 30 for exchanger and gas filter. The particle size of the bubbling fluidized bed can be e.g.

• · · between 0.3 and 1.5 mm, and at said separation limit of the separator, a fraction with a particle size between 50 and 300 μm can be returned to the circulating bed. Particles of the latter size class rise in a gas flow having a velocity equal to or lower than in a bubbling bed and preferably e.g. 1 to 1.5 m / s. The upper part of the reactor space 35 containing the circulating bed can be made wider than the lower part containing the bubbling bed, so that the expansion compensates for the increase in the gas flow produced by the gasification and prevents the acceleration of the flow.

According to the invention, two different fluidized particle sizes can be fed to the reactor so that the coarser particles form a bubbling fluidized bed in the reactor and the finer particles form a circulating bed. The particles to be added, which may be e.g. sand, are then preferably located within the above-mentioned ranges of the bubbling bed and the rotating bed. Alternatively, however, the feed may consist only of coarse solid particles, e.g. of the order of 0.3-1.5 mm, the material of which is friable, whereby the material, after grinding in the bubbling bed 10, is transferred to the fluidized bed of the circulating bed. The finest fraction formed in the bubbling bed and the circulating bed further gives a solid fraction from the separator to the product gas stream, which prevents clogging of the gas ducts and the heat exchanger due to the sticky ash. Particularly suitable chopping fluid is lime, but magnesium oxide and kaolin, for example, can also be used.

To minimize clogging of the gas ducts, it is further advantageous to trace the cooling of the product gas in two successive stages with two different heat exchangers, the first cooling the gas to a temperature between 600 and 720 ° C and the second further to 450 ° C or below. The first heat exchanger 20 passes the critical temperature range of 720 to 780 ° C for gas blockages, so that the calcium and chlorine-containing ash components lose their adhesion and the risk of blockages in the second, lower temperature heat exchanger and gas filter. The first heat exchanger, on the other hand, is preferably dimensioned loosely so that the gas flow rate is low, and the gas pipes can be traced vertically, with the lowest risk of entrapment.

• · · • · ♦ • · «

An additional step by which the occurrence of blockages can be further introduced is the introduction of a sorbent, such as a suitable sodium, potassium or calcium compound, in or before the heat exchanger into the product gas stream to bind the ash particles.

• · • «· 30 The gasification apparatus according to the invention, applying the method described above, comprises. * ··. known as per se elements for producing a fluidized bed reactor, a fluidized material of solid particles, an ascending gas flow to the reactor, a fuel supply connection, a feed connection for adding the fluidized material to the reactor,

6

According to the invention, the apparatus is characterized in that a bubbling fluidized bed containing coarser fluidized material particles with a size of more than 0.2 mm and up to 1.5 mm can be traced into the reactor and a finer fluidized bed containing 50-300 μm particles above it. a circulating bed, wherein the return connection from the separator to the particles returning to the reactor terminates at or above the level of the top of the bubbling fluidized bed.

The reactor space preferably comprises a lower part for a bubbling fluidized bed and an upper part with a wider cross-section for a circulating bed. The ratio of the diameters of the upper and lower parts is preferably between 1.15 and 1.5. There may be a conically expanding part between the parts, the conical angle of which is gentle with respect to the vertical axis of the reactor space, preferably less than 10 ° and most preferably less than 7 °. The expansion allows the gas flow rate in the rotating bed not to increase higher than in the bubbling 15 beds.

The separator which separates the solid particles returning to the reactor circulating bed from the finer particles remaining in the gas stream is preferably a cyclone. A loose cyclone rated for a low flow rate, preferably less than 15 m / s, can be used with a low pressure drop, preferably less than 15 mbar. This facilitates the return of the par-20 particles of the circulating bed to the reactor, leaving solid particles in the product gas, which are able to soot the walls of the gas duct from dust and bind sticky, • ·! '·: Via ash components a.

• * »• · ·

The invention will now be described in more detail with reference to the accompanying drawing, which is an example of a gasification apparatus according to the invention comprising a bubbling fluidized bed and an upper rotary bed.

• · • a ·

The gasification apparatus according to the drawing comprises a fluidized bed reactor 1 consisting of a cylindrical lower part 2, a conically expanding part 3 above it and a cylindrical upper part 4, the upper part 4 being wider in cross-section than the lower part 2. In the reaction vessel 1, near its bottom, there is a grate 5, under which gasification air or steam is fed from the supply connection 6. In said lower part 2 of the reactor 1, a stationary · *** is maintained on the basis of an ascending air flow; a bubbling fluidized bed 7 consisting of solid, finely divided fluidized particles * «·. ·. with a size greater than 0.2 mm, preferably between about 0.3 and 1.5 mm. The gasifiable fuel in finely divided form, which may be biomass, such as sawdust, 7 or municipal or industrial waste, such as plastic waste, is fed from the joint 8 to the lower part 2 of the reactor, inside the fluidized bed 7. Gasification of the fuel takes place in the bubbling fluidized bed 7, whereby the generated gas is transferred to the rising gas flow in the reactor space while the ash 9 is removed from the bottom of the reactor.

In the conically expanding part 3 of the fluidized bed reactor 1 and in the upper cylindrical part 4, a circulating bed is maintained by means of a gas flow, in which the floating solids are smaller than in the lower bubbling fluidized bed 7, between 50 and 300. The conical expansion 3 of the reactor space is preferably dimensioned so that the increase in the cross-sectional area of the space corresponds to the increase in gas volume produced by fuel gasification, the rate of ascending gas flow in the bubbling bed in the narrower lower part 2 and the circulating bed in the upper part 4 is of the order of 1-1.5 m / s . Said operating parameters are controllable by means of gasification air and fuel supply, and it is possible that the gas flow rate in the circulating bed is even lower than in the bubbling bed.

From the upper end of the reactor space 1, the product gas stream is passed through the channel 10 to a separation cycler 11 which separates the circulating fluid particles for passing back through the channel 12 back to the fluidized bed reactor 1. According to the drawing, the return channel 12 joins the reactor space. The bubbling bed and the rotating bed are then separated from each other without mixing of the fluid particles between the beds. In practice, however, the height of the bubbling bed 7 may vary slightly, i.e. the upper edge of the bed. . may momentarily rise slightly above the end of return channel 12 or equivalent sink slightly below it. It is essential, however, that the circulating particles returning to the reactor 1 in the channel 12 only have to overcome the pressure drop in the gas flow in the circulating bed and the cyclone, but not in the bubbling bed much higher than in the bubbling bed, as would be the case if the circulating particles would be fed into or under the bubbling bed.

• · • · • ·

The drawing shows two fluid particle feed connections "13, 14" to be added to the process, so that the coarser particles of the bubbling bed 7 can be added to the fuel supply 8 and the finer particles of the circulating bed to the circulating flow return * ···: 30 channels can be added. eg sand fractions with a different particle size in the bubbling bed and in the circulating bed, on the other hand it is also possible to use a crumbling fluid material, such as lime, which, when finely divided in the bubbling bed 7, produces finer fluidized particles in the circulating bed. In this case, it may be sufficient to supply fluidized material only to the bubbling bed 7 of 13. The circulating bed may optionally be supplied with its secondary air-raising secondary air from 15 or 8 cooling water or steam from the combined 16 near the top of the reactor.

The function of the cyclone 11 is to separate the circulating fluidized particles returning to the reactor 1 from the product gas stream passing through the channels 17, 18 for cooling in two successive heat exchangers 19, 20. The temperature of the gas stream leaving the cyclone 11 to the channel 17 is typically in the order of 800-1000 ° C. It is cooled to a temperature in the range of 600 to 720 ° C. Cooling below the temperature range of about 720 to 780 ° C, which is problematic for the adhesion of the ash particles and the resulting blockages, takes place in pipelines of the heat exchanger 19 suitably arranged in a vertical position, dimensioned sufficiently loose and with a low gas flow rate, e.g. / s. When the particle separation limit in the cyclone 11 is about 50 to 70 μm, solid particles of 10 to 70 μm remain in the product gas stream, which are also essential as ash binders and anti-clogging agents. In addition, a total of 21 sorbents, such as calcium, sodium or potassium compounds reactive with chlorine, can be fed to the heat exchanger 19. If necessary, cooling water or steam can also be supplied to the gas stream of the heat exchanger 19. At the same time, the heat exchanger 19 acts as a separator which removes fly ash to the joint 22.

In the flow direction, in the second heat exchanger 20, the gas stream is cooled to a temperature of 450 ° C or below. The cooled product gas continues to filter 23, which has an operating temperature of 200-450 ° C and from which the final, purified product gas exits • · :: the duct 24 and the finest dust fraction separated in the outlet 2 5.

·· «• · · * 1 ·

It will be clear to a person skilled in the art that the applications of the invention are not limited to the examples given above, but may vary within the scope of the following claims. It is possible, for example, that the circulating flow return channel 12 merges into the reactor space above that shown in the drawing, e.g. so that the circulating particles are fed into the conically expanding part 3 of the reactor or even into the upper part 3 of the reactor. completely separate without • · · even momentary mixing of particles at the bed boundary.

it · • · · • · • · ··· • · • ·

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Claims (19)

9 A method for gasifying fuel in an ascending gas stream in a fluidized bed reactor (1) containing solid Lei material particles, wherein the fuel (8) is fed to the bottom of the reactor and the resulting product gas (10) is passed through a reactor (11) separated from the upper end of the reactor. ) to the reactor, characterized in that a bubbling fluidized bed (2, 7) containing coarser fluidized material particles larger than 0.2 mm and not more than 1.5 mm and finer fluidized material particles above it is maintained in the reactor (1) by means of a gas flow, with a size of 50 to 300 μm, containing 10 circulating beds (4), and that the recyclable particles separated from the product gas are returned to the reactor at or above the top of the bubbling fluidized bed. Method according to Claim 1, characterized in that the bubbling fluidized bed (7) contains particles of fluidized material with a size of between 0.3 and 1.5 mm. 3. The first of which is a patented product, which can be obtained from the product-25 gas (17) in the case of the product (11) without the use of a particle, which can be stored. it is 10 - 70 pm. • φ φφφ ... 4. Förfarande enligt nägot av föregäende patentkrav, kännetecknat av att gasens φ · · ** [/ flödeshastighet i circulationsbädden är den samma som eller lägre i den bub- * ··· '30 blande bädden. φ φ # a Method according to one of the preceding claims, characterized in that the product gas (17) leaving the separator (11) contains solid particles with a size of between 10 and 70 μm. Method according to one of the preceding claims, characterized in that the gas flow rate in the circulating bed is equal to or lower than in the bubbling bed. Method according to Claim 4, characterized in that the flow rate of the gas in the circulating bed is 1-1.5 m / s. Method according to one of the preceding claims, characterized in that coarser fluidized-particle particles (13) terminating in a bubbling fluidized bed and finer fluidized material particles (14) terminating in a circulating bed are added to the reactor. Method according to one of Claims 1 to 5, characterized in that particles of fluidizing material with a size of 0.3 to 1.5 mm and having a size of! 1 are added to the reactor (1). *** the material is friable, in which case the particles only move from the fluidized bed to the circulating bed as a result of the crumbling 9 # 9 • * 9 5. A patent according to claim 4 is disclosed in the invention. kulationsbädden is 1 - 1.5 m / s. φ · · φ φ φ # Φ # φ * * 35 6. A fitting according to the preceding patent, which comprises reacting with a knurled part (13) of a hammer and a bubble cord 12, as well as having a knurled part of the fluidized material (14) in the circulating part. 7. Förfarande enligt segot av patentkraven 1 - 5, kännetecknat av att reaktom (1) 5 tillförs virvlande particiklar, rod sticker is 0.3 - 1.5 mm and stem material is not coated, colors partiklama ovverförs frän den bubblande vvelbädden account circulationsbädden som en feljd av söndersmulning. 8. A patent according to claim 7, comprising a particle according to the form of a filter 10. Method according to Claim 7, characterized in that the par- * 9 * · ♦ · * particles to be added are lime. • 999 9 9 9 9 9. An embodiment according to the preceding claims, comprising a handle (8) and a bubble handle (7). 15. The first step is to apply a patented ring, which can be attached to a cyclone (11), and which is preferably 50 to 70. Method according to one of the preceding claims, characterized in that the fuel (8) is fed into the bubbling fluidized bed (7). 10 Method according to one of the preceding claims, characterized in that the separator is a cyclone (11) in which the separation limit of the solid particles is about 50 to 70 μm. 11. A method according to the preceding claims, comprising the product-20 gas (17) in a light-emitting diode (11), the LEDs having a color ratio (19), and the gas gas having a temperature in the range of 600 to 720 ° C, and having a subsequent temperature. and other colors (20), the gas mixture is cooled to a temperature of 450 ° C or • M ·: a white, varied product with a filter (23). • ♦ • ·· • · I • · · 25 12. A first version according to claim 11, which comprises a means (21) for producing a product and a solid color (19) according to a particle. • · · *** * ···! 13. Förfarande enligt nägot av föregäende patentkrav, kännetecknat av att bränslet (8) s scall förgasas är en finfördelad biomass, säsom trämassa. 30 Method according to one of the preceding claims, characterized in that the product gas (17) leaving the separator (11) is passed to a heat exchanger (19) in which the gas is cooled to a temperature in the range 600-720 ° C and then to a second heat exchanger (20). cooled to 450 ° C or below, after which the product gas is filtered (23). Method according to Claim 11, characterized in that a sorbent (21) is added to the product gas in the first heat exchanger (19) in order to bind the ash particles. Method according to one of the preceding claims, characterized in that the fuel to be gasified (8) is finely divided biomass, such as wood pulp. 14. The first of which relates to patent claims 1 to 12, which can be found in paragraphs (8) .. | .; som skall förgasas innehäller plast. • · Method according to one of Claims 1 to 12, characterized in that the fuel (8) to be gasified contains plastic. 15. A method according to claims 1 to 12, which comprises the markings (8) 35 in which the crystal is chlorinated. • · Method according to one of Claims 1 to 12, characterized in that the fuel (8) to be gasified is chlorine-containing. 16. The method of adjusting the requirements of the invention for a patented apparatus, a non-volatile reactor (1), and a solid material 13 for a particulate particle, and an inlet (6) for producing a gas stream in a reactor (1), for brand name (13, 14) for the production of the material to the reactor, in the gas channel (10) in the case of the reactor for the reaction of the product (5), for the separation of the reactants from the product-5 to the reactant, the same as the retractor (12) for the reticle of the particle of the reactant, the rotating part of the reactor (1) can be used in the form of a bubble cord (7) the outer part of the reactor, the stem is not more than 0.2 mm or 1 , 5 mm, velvet and ovanför virvelbädden placerad circulat-tionsbädd som innehäller finare virvlande partiklar, rod storlek är 50 - 300 μηι, 10 varvid returröret (12) för particiklar s retumeras frän avskiljaren account reaktom s lutar vid planet av den bubblande virvelbäddens övre del eller ovanför den. A gas suitable for a method according to any one of the preceding claims. . an apparatus comprising a fluidized bed reactor (1) for forming solid particles • · · | to produce an ascending gas flow to the feed connection (6) to the reactor (8), the fuel supply connection (8), the supply connection (13, 14) to add fluid material to the reactor, a degassing channel (10) starting at the top of the reactor, a separator * ** · (11) for separating solid particles from the product gas leaving the reactor and *: **: for returning the particles separated in the return connection (12) to the reactor, characterized in that coarser fluidized material particles can be traced in the reactor (1) with a bubbling fluidized bed with a size greater than 0,2 mm and not more than 1,5 mm; (7) and a rotating bed containing finer particles of fluidized material with a size of • •· | ... t 50-300 pm above it, whereby the return connection (12) from the separator to the reactor particles ends at the level of the top of the bubbling fluidized bed. or above. · * · • · · • · • φ. * · *. Apparatus according to claim 16, characterized in that the reactor comprises a lower part (2) for a bubbling fluidized bed (7) and an upper part (4) with a wider cross-section (4) for a circulating bed. • · • · * • · »π 17. An arrangement according to claim 16, which comprises reacting a part (2) for a bubble rod (7) as well as a part (4) for circulating a ring (4). 18. Anordning enligt patentkrav 16 or 17, kännetecknad av att avililjaren är en cyclone (11). Apparatus according to Claim 16 or 17, characterized in that the separator is a cyclone (11). Apparatus according to one of Claims 16 to 18, characterized in that it comprises two successive heat exchangers (19, 20) in the flow direction for the gradual cooling of the product gas discharged from the separator (11) and a filter (23) for filtering the cooled product gas. 10 1. Fertilizers for a branded or reactive reactor (1) in which the brandy is used in the presence of a gas stream (8) in which the reactants of the reactor product (10) are reacted for the account (11), for which the gas is used as a particulate matter, for a second time (12) account for the reactor (1) up to 15 (2, 7) of the gas strap (2, 7) virvirland partiklar, stems with a stem length of 0,2 mm and a height of 1,5 mm, velvet ovanför denna en circulationsbädd (4) innehällande finare virvlande partiklar, stems with a stake of 50-300 pm, and with the product being free from particulate matter ätereirku-leras account reaktom account den bubblande virvelbäddens Övre del eller ovanför denna. 20 • ♦ · .: * 2. For the purposes of claim 1, the reference number of the blanks is as follows: \ {(7) in the case of twisted particles, the stems being 0.3 to 1.5 mm long. φφφ • · · • · · ♦ 19. An arrangement according to claims 16 to 18, which comprises the use of a filter (23, 20) for the purpose of applying the filter (23) to the filter (23) for the filter (23). . ·! i nedkylda produktgasen. • · · • 1 • »· • 1 1 • · 25 • 1 • · • · · • · • • 1 # ·· f · · I · · * · 1 • · m · Φ · · •« · • · • · · * «» ··· ·