GASIFICATION SYSTEM

Abstract

GASIFICATION SYSTEM One aspect of the invention relates to a gasification system comprising a fuel injection (5) comprising at least one fuel injection point (11) arranged above a primary air injection inlet (4), the primary air injection inlet (4) being arranged in such a way that a gasification air flow (F1) is injected into the reactor (2) in a direction substantially tangential to the wall (3) of the reactor (2), the wall (3) comprising a substantially cylindrical upper portion (6), a substantially frustoconical lower portion (7), the primary air injection (4) and the fuel injection point (11) being arranged through the lower portion (7) of the wall (3). Figure to be published with the abstract: Figure 1

Description

Title of the invention: GASIFICATION SYSTEM TECHNICAL FIELD OF THE INVENTION

[0001] The invention relates to the general technical field of heat generation installations for industrial processes, and more specifically to solid fuel gasification installations, in particular in cement processes. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0002] Gasifiers are conventionally used to produce combustible gases from solid fuels, typically plant biomass, coal, or alternative solid fuels for recovering combustible waste. Organic materials are converted into gases during a pyrolysis operation, by heating the solid fuel in the presence of a small amount of oxygen and water vapor, depending on the type of fuel being converted. Long-chain hydrocarbon molecules are split in a phenomenon based on the splitting of long-chain molecules which thus release volatile compounds, including hydrogen, methane and carbon oxides, producing a combustible gas mixture, according to known methods.

[0003] Classically, the main phenomena at work in a gasification process involve the following transformations: - drying of the fuel, during which the fuel is subjected to temperatures between 100°C and 160°C, causing the water contained in the fuel to evaporate; - pyrolysis, taking place at temperatures between 120°C and 600°C, during which the fuel is gradually heated in the absence of oxygen, decomposes and results in the formation of by-products, including carbon, carbon oxides, methane, tars and volatile compounds; - oxidation, taking place at temperatures between 1200°C and 1500°C, during which oxygen is injected to react with the gases formed during pyrolysis, releasing energy so as to reach the temperatures necessary for the various gasification reactions and forming carbon dioxide and water vapor; - reduction, taking place at temperatures between 800°C and 1200°C, during which the carbon obtained by pyrolysis reduces water vapor and carbon dioxide, forming dihydrogen and carbon monoxide.

[0004] Conventionally, three main categories of gasifiers are known: fixed bed gasifiers, fluidized bed gasifiers, and entrained bed gasifiers.

[0005] Fixed bed gasifiers typically comprise a vertical reactor. Inside the reactor is a mass, called a "bed", formed by the solid fuel, the char produced by the pyrolysis of the solid fuel and the ash, which descends by gravity as the fuel is transformed. This type of gasifier can be downdraft or updraft.

[0006] In fixed bed gasifiers with upward draft, or counter-current, the solid fuel is injected from the top of the reactor. It then reacts with a gasification flow (air and / or oxygen, steam) which rises from the bottom of the reactor, counter-current to the direction of solid fuel feed. The solid fuel undergoes a pyrolysis process which transforms it into a solid mass of carbonaceous material which moves downward. In the carbonaceous mass, gasification reactions occur until the carbon mass is reduced to a residue combined with ash, inert materials, etc. The ash is removed from the bottom of the reactor, powdery or in the form of slag. The gas produced, rich in tar and loaded with dust, must be purified before use. This type of gasifier accepts relatively non-uniform biomass with a high moisture content better than others.On the other hand, the synthesis gas obtained is humid, and loaded with tars and particles.

[0007] In downdraft, or co-current, fixed-bed gasifiers, the gasification flow is introduced into the reactor from the top, in the same direction as the fuel. For the gasifier to operate, the upper part of the bed can be heated simply by conduction from the high-temperature reaction zones, by burning small amounts of fuel, or by using an external heat source. The tar produced must pass through a high-temperature coal bed, and then the synthesis gas produced is cleaner than that obtained in countercurrent gasifiers, other conditions remaining unchanged. In addition, the moisture content is also lower. On the other hand, the gasifier only accepts fuel with optimal uniformity characteristics, small sizes, and low initial water content, and therefore typically uses plant biomass.

[0008] Fixed bed gasifiers are also generally limited in power, typically of the order of 10 MW, and are therefore not suitable for industrial applications requiring high power, such as in cement works.

[0009] In fluidized bed gasifiers, the solid fuel is generally introduced into the lower part of the reactor in the form of small particles, of the order of 5 mm. A fluidization medium is also introduced into the vertical part of the reactor, typically small solid particles, either inert (sand) or catalytic (olivine, dolomite), conveyed by a high-speed air carrier flow. The bed then behaves like a fluid, exhibiting a large homogeneity of temperature and concentration of reactants. Unlike the fixed bed, fluidization allows the use of more varied fuels, including ASF type fuels (Alternative Solid Fuel, a type of fuel mainly prepared from combustible waste to be burned).

[0010] On the other hand, the gas produced is heavily loaded with particles, requiring the implementation of treatments before its recovery, making its implementation complexity unsuitable for low-power installations.

[0011] In entrained bed gasifiers, the fuel is sprayed into the gaseous flow of gasifying agent and kept in suspension until complete consumption. The reaction zone can be heated to high temperatures (1300°C to 2000°C). At these temperature levels, the reactions are very rapid, of the order of a few seconds, promoting the formation of CO and H2 as well as the steam reforming of methane and the destruction of tars. The ash passes into the liquid state. A fraction of the molten ash particles is recovered on the walls of the reactor, or can be partially separated from the gas stream by inertial separation. A portion of the carbonaceous solid can be entrained by the gas. This technology eliminates the problems posed by the use of a fluidizing material and promotes the production of CO and H2 as well as the reforming of methane and the destruction of tars.

[0012] However, this technology requires finely pulverized fuel, typically with a particle size of less than one millimeter, which requires significant fuel preparation upstream.

[0013] However, in a context of research for industrial solutions that consume less fossil fuels, the use of alternative fuels, particularly ASF type fuels, presents itself as an interesting alternative. However, the gasifiers of the prior art have drawbacks that degrade the efficiency of the gasification of ASF type fuels.

[0014] Fixed bed gasifiers do not allow this type of fuel to be gasified efficiently, fluidized bed gasifiers involve regularly replacing and treating the fluidization medium, and fluidized bed gasifiers involve using a fuel with a very restrictive particle size which excludes the use of ASF type fuels due to fuel preparation being too energy-intensive.

[0015] There is therefore a need for gasification solutions that can efficiently transform solid alternative fuels. Summary of the invention

[0016] For this purpose, the invention proposes a gasification installation comprising a reactor comprising a substantially cylindrical wall extending along a vertical axis and externally delimiting a cavity configured to contain a gasification reaction, the reactor comprising: - a primary air injection inlet, - a fuel injection comprising at least one fuel injection point arranged above the primary air injection inlet, the primary air injection inlet being arranged in such a way that a gasification air flow is injected into the reactor in a direction substantially tangential to the wall of the reactor, - the wall comprising a substantially cylindrical upper portion, a substantially frustoconical lower portion, for injecting primary air and the fuel injection point being arranged through the lower portion of the wall.

[0017] Such an installation therefore makes it possible to generate a mixing flow in the reactor preventing the fuel bed from falling back by gravity, and thus making it possible to improve the residence time of the fuel in the reactor, making it possible to improve the transformation of the fuel. The separate injection of air and fuel makes it possible to admit a greater variety of fuels, therefore making it possible to use ASF type fuels and to transform them efficiently.

[0018] Optionally but advantageously, the following characteristics may complete the invention, taken alone or in combination:

[0019] - the at least one fuel injection point is provided on the lower portion of the wall so as to inject a gasification air flow into the reactor in an injection direction at the fuel injection point, the injection direction having an inclination relative to a radius of the reactor at the fuel injection point, so as to give the gasification air flow a tangential displacement component at the fuel injection point; this makes it possible to improve the generation of a circulation of the mixing flow in an upward helical trajectory in the reactor, which makes it possible to improve the homogenization of the temperatures in the reactor;

[0020] - the primary air injection inlet comprises a plurality of injection points of fuel distributed regularly according to an annular section of the lower portion of the wall; this makes it possible to homogenize the distribution of fuel in the reactor and to improve the temperature homogeneity in the reactor;

[0021] - the installation comprises a lift injection configured to inject a lift flow in the reactor so as to oppose the gravity fall of the fuel, the lift injection comprising at least a first stage of injection points arranged above the primary air injection and below from the fuel injection point; this improves the drive of the fuel towards the upper part of the reactor, limiting its fall by gravity, which increases the residence time of the fuel in the reactor and improves the reaction of the fuel;

[0022] - the installation further comprises a secondary air injection comprising at least one secondary injection stage comprising a plurality of injection openings provided through the upper part of the wall, configured to inject gasification air into the reactor; this makes it possible to inject the gasification air in a distributed manner at several points in the reactor, which makes it possible to improve the control of the reaction at different points in the reactor;

[0023] - the fuel injection comprises a fuel supply circuit comprising a vertical pipe opening onto each fuel injection inlet; this allows the fuel to be injected into the reactor at a reduced speed, improving its drive by the mixing flow, while limiting the consumption of the fuel supply circuit;

[0024] - the installation comprises a separation device configured to separate suspended particles of the combustible gas formed in the reactor, the separation device connected to the reactor by means of a channel extending between an upper portion of the separation device and the upper portion of the reactor; this makes it possible to obtain a quality syngas at the outlet of the installation, allowing it to be used as soon as it is produced;

[0025] - the installation further comprises a recovery device configured to reinjecting the incompletely reacted fuel particles from the separation device into the reactor; this improves the quantity of fuel used compared to the quantity of fuel injected into the reactor;

[0026] - the channel opens into the reactor in a substantially tangential direction configured to be substantially tangent to the circulation of the mixing flow at the channel; this allows the channel to face the circulation of the mixing flow and thus limit its deviation to redirect it towards the separation device, which makes it possible to improve the channeling of the mixing flow from the reactor to the separation device. BRIEF DESCRIPTION OF THE FIGURES

[0027] The figures are presented for information purposes only and in no way limit the invention.

[0028] [Fig.l] represents an overall view of a gasification installation according to the invention.

[0029] [Fig.2] represents a sectional view from above of a gasification installation according to the invention.

[0030] [Fig.3] represents a sectional side view of a gasification installation according to the invention.

[0031] [Fig.4] represents a sectional side view of a gasification installation according to the invention, more precisely focused on the recovery device. DETAILED DESCRIPTION

[0032] The invention relates to a gasification installation 1, shown in [Fig.l], comprising a reactor 2 configured to contain a gasification reaction of a fuel. The reactor 2 comprises a substantially cylindrical wall 3 extending along a vertical axis Y under normal conditions of use of the installation, and externally delimiting a cavity configured to contain the gasification reaction. The geometric concepts, in particular top, upper, bottom, lower, take as reference the normal conditions of use of the installation, and the references relating to axial, radial and tangential relate to a cylindrical reference frame along the vertical axis Y. The concepts of upstream and downstream refer to the circulation of gases in the installation under normal conditions of use.

[0033] The reactor 2 comprises a primary air injection inlet 4 configured to convey into the reactor 2 a gasification air flow F1 intended to start the gasification reaction of the fuel, and a fuel injection 5 arranged above the primary air injection inlet 4, the fuel injection 5 being configured to introduce fuel into the reactor 2. The wall 3 of the reactor 2 comprises an upper portion 6 having a substantially cylindrical geometry, and a lower portion 7 having a substantially frustoconical geometry widening as it flows from the bottom to the top.

[0034] The primary air injection inlet 4 is arranged on the lower portion 7 of the wall 3 in such a way that the gasification air flow F1 is injected into the reactor 2 in an injection direction at the primary air injection inlet 4. The injection direction advantageously has an inclination relative to a radius of the reactor at the primary air injection inlet 4. The inclination may be between 30° and 90°, so as to give the gasification air flow F1 a tangential displacement component at the primary air injection inlet 4, so as to generate a highly turbulent mixing flow F2 circulating in an upward helical trajectory in the reactor 2. Alternatively, the gasification air flow F1 is introduced into the reactor 2 in a radial injection direction.The gasification air flow F1 is introduced into the reactor at a first speed configured to prevent the fuel from falling back. The upwardly flaring truncated cone shape of the lower portion 7 of the reactor 2 guides the gasification air flow F1 so as to generate a circulation of the mixing flow F2 according to a . ascending helical trajectory in the reactor 2, the mixing flow F2 gradually slowing down until reaching a second speed at the upper end of the lower portion 7, the second speed being configured to allow sufficient residence time for the mixing flow in the upper portion 6 of the reactor 2. The introduction of the gasification air flow F1 in a substantially tangential direction makes it possible to promote the guidance of the mixing flow F2 by the frustoconical lower portion 7.

[0035] Preferably, the half-angle at the apex of the lower frustoconical portion 7 is between 15° and 20°. Such a circulation of stirring flow F2 in the reactor 2 makes it possible to drive the fuel particles towards the core of the reactor 2, so as to prevent the fuel particles from falling back towards a lower part of the reactor 2 and to improve the reaction of the fuel. This stirring of the fuel bed makes it possible to accelerate the gasification reaction and to prevent the bed from forming a mass in the center of the reactor 2, which makes it possible to homogenize the temperatures in the reactor 2, and thus to avoid temperature peaks which can cause a problem of melting and sticking of the liquid ash. As in a fluidized bed, the drying, pyrolysis, oxidation and reduction reactions take place in the same zone of the reactor 2, in which the temperature is homogeneous.This limits the formation of tars, particularly those obtained during the pyrolysis phase.

[0036] Injecting the primary air without needing it to transport the fuel makes it possible in particular to use fuels whose particle size is more permissive, typically ASF type fuels, the treatment of which is complex to achieve a very fine particle size. This therefore makes it possible to increase the compatibility of the gasification installation 1 with the different types of fuels available.

[0037] Furthermore, such a configuration of the mixing flow F2 makes it possible to limit the need to use a fluidization medium to set the fuel bed in motion. Avoiding the use of an additional fluidization medium injected with the gasification air flow F1 makes it possible to significantly limit the wear of the installation, as well as to promote the control of the temperature of the reactor 2. Indeed, by limiting the heated mass to only the reactants, the thermal inertia of the bed is thus greatly reduced, and it is thus possible to more precisely control the temperature of the bed by varying the flow rate of the gasification air flow F1. The flow rate of the reactor 2 is further increased compared to a solution using a fluidization medium, because it is possible to assign the total mass capacity of the reactor 2 to reactants.

[0038] Furthermore, the mixing flow F2 has an upward velocity component which prevents the phenomenon of ash falling back towards the bottom of the reactor 2.

[0039] The fuel injection 5 is supplied by means of a fuel supply circuit 8, comprising a conveying device 9 arranged to supply fuel to a vertical pipe 10 connected to the fuel injection 5. Thus, the fuel supply to the reactor 2 is carried out by gravity, the fuel being injected into the reactor 2 through the fuel injection 5 with a low horizontal speed. This ensures that all of the fuel is effectively entrained by the mixing flow F2 circulating in a helical trajectory along the wall 3 of the reactor 2.

[0040] The fuel injection 5 comprises two fuel injection inlets 11, arranged through the lower part 7 of the wall 3 and positioned relative to each other in a diametrically opposite manner relative to the vertical axis Y, each being connected to a respective vertical pipe 10, the conveying device 9 being arranged to uniformly supply the two vertical pipes 10. Such a configuration makes it possible to distribute the fuel injection at several points, so as to promote the homogenization of the entrainment of the fuel particles by the mixing flow F2.

[0041] Advantageously, the reactor also comprises a lift injection 12, configured to allow the injection into the reactor 2 of a lift flow F3 configured to blow the fuel bed of the reactor and prevent it from falling by gravity towards the bottom of the reactor 2.

[0042] Advantageously, the lift injection 12 comprises a stage of injection points 13, comprising a plurality of injection points arranged through the lower part 7 of the wall 3 and arranged in a straight section normal to the vertical axis Y, at an intermediate height between the primary air injection 4 and the fuel injection 5. Preferably, the stage of injection points 13 is located close to the fuel injection inlets 11.

[0043] The reactor may also comprise a secondary air injection comprising a secondary injection stage 14, and advantageously a second secondary injection stage 15, or several stages of additional injection points, each secondary injection stage respectively comprising a plurality of injection openings arranged through the upper part 6 of the wall 3. The secondary air injection 14 is configured to distribute the injection of gasification air along the reactor 3 so as to modulate and control the gasification air factor and therefore the temperature level as a function of the type of fuel, so as to produce a syngas of optimal quality.

[0044] The installation may advantageously comprise a separation device 16 in fluid connection with the reactor 2 by means of a channel 17. The separation device 16 is configured to allow the suspended particles to be separated from the gas in the flow leaving the reactor 2 through the channel 17. The separation device 16 comprises an extraction pipe 18 configured to evacuate the gases resulting from the gasification, typically the synthetic gas (syngas) comprising hydrogen, carbon monoxide, and methane, from the separation device 16 to a network for consumption or elimination of the gas produced.

[0045] In the embodiment shown, the separation device 16 has a substantially cylindrical geometry, comprising a substantially cylindrical upper portion 19 extending along a second vertical axis Y', and a frustoconical lower portion 20 extending along the second vertical axis Y'. The channel 17 extends between the upper portion 6 of the reactor 2 and the upper portion 19 of the separation device 16. The extraction pipe 18 comprises an upstream portion 21 which extends along a vertical axis, here along the second vertical axis Y', from an inlet section 22 located in the upper portion 19 of the separation device 16, through an upper end 23 of the separation device 16. The inlet section 22 is advantageously located at a height lower than that of the channel 17 under normal conditions of use.

[0046] Thus, the gases and gasification products generated in the reactor 2, carried by the mixing flow F2 and the lift flow F3, circulate through the channel 17 arriving at an upper end of the reactor 2. They enter the separation device 16 and fall by gravity towards the lower portion 20. The most volatile compounds, typically the gaseous products, rise and are evacuated through the extraction pipe 18. The relative position of the inlet section 21 of the recovery pipe 20 with respect to the channel 17 makes it possible to prevent the ash and slag from the gasification from being able to circulate directly from the channel 17 to the extraction pipe 18. These solid products fall by gravity towards the lower portion 20 of the separation device 16.

[0047] Advantageously, the channel 17 extends from an upper end of the reactor and the upper end 23 of the separation device 16, and is configured so as to promote the circulation of the mixing flow F2 through the channel 17. The mixing flow F2 circulating along a helical trajectory along the wall 3 of the reactor 2, the channel 17 opens into the reactor in a tangential direction facing the circulation of the mixing flow F2, so as to limit as much as possible the bend made by the flow circulating in the reactor 2 when it enters the channel 17. In this way the flow circulating in the reactor 2 is efficiently channeled towards the separation device 16, with minimal disturbance to the flow direction of the mixing flow F2.

[0048] Advantageously, the channel 17 opens into the separation device 16 in a direction tangential to the second vertical axis Y'. Thus, the flow emerging from the channel 17 maintains its speed by flowing along a helical trajectory, this time descending due to the gravity acting on the flow. This makes it possible in particular to eject the particles carried by the flow against the walls of the separation device, and to confine the flow evolving at high speed against the walls of the separation device 16. This thus makes it possible to limit mixing and turbulence in the central part, around the second vertical axis Y', and to prevent the particles from rising towards the inlet section 22 due to excessive mixing.

[0049] Advantageously, the separation device 16 comprises a recovery device 24 located at a lower end of the lower portion 20, configured to recover the solid products of the gasification, typically the ash, the slag, and the fuel residues which have not completely reacted. This makes it possible to avoid the accumulation of these particles in the separation device 16, which could lead to the evacuation of particles in the recovered gas through the extraction pipe 18.

[0050] The recovery device 24 advantageously comprises a sorting module 25 and a reinjection module 26. The sorting module 25 is configured to separate the ash from the unburned fuel particles, and to evacuate the material that can no longer gasify, typically the ash. The reinjection module 26 is configured to reinject into the reactor 2 the particles that have not been evacuated by the sorting module 25. This makes it possible to recycle the fuel particles that have not been completely consumed and thus to optimize the conversion of the carbon fraction of the fuel into gas. This is particularly advantageous for fuels whose gasification is slower, typically ASF type recovery fuels.

[0051] The reinjection module 26 is advantageously connected to the lower part 7 of the reactor 2, and opens at a height greater than that of the fuel injection 5. The reinjection module 26 is arranged in such a way that the recycled particles are injected into the reactor 2 by gravity. In such a way, the recycled particles are efficiently entrained by the mixing flow F2 and the lift flow F3 and are reintegrated into the fuel bed.

[0052] The sorting module 25 is advantageously equipped with a draining device 27 for removing particles that are not recycled by the reinjection module 2. The draining device 27 may, for example, comprise an endless screw for removing the waste, and upstream of the endless screw an airlock comprising two valves configured to open alternately so as to allow the circulation of the waste while maintaining a seal between the sorting module 25 and the endless screw.

[0053] Advantageously, the recovery device 24 comprises a fluidization injection 28, arranged to inject a fluidization flow F4 configured for fluidize the particles collected in the recovery device 24 and facilitate their circulation, thus avoiding occlusions. The fluidization injection 28 advantageously comprises an upstream injection point 29 and a downstream injection point 30. The upstream injection point 29 is positioned at the inlet of the recovery device 24, in the direction of circulation of the particles in the recovery device 24. It is advantageously configured to blow the particles towards the recovery device 24, so as to impart an initial flow movement to the particles. The downstream injection point 30 is advantageously located in a lower part of the recovery device 24, and configured to inject the fluidization flow F4 into the particles in such a way that they behave like a fluid.

[0054] In the embodiment shown, the sorting module 25 of the recovery device 24 comprises a separation pipe 31 generally forming a “U” extending between the lower end of the lower portion 20 of the separation device 16, and the reinjection module 26. In the embodiment shown, the reinjection module 26 comprises a reinjection pipe 32 extending along a downward slope between the separation pipe 31 and the reactor 2, in the direction of circulation of the particles. The upstream injection point 29 of the fluidization injection 28 is located at an upstream end of the separation pipe 31. The separation pipe 31 comprises from upstream to downstream a first substantially vertical segment 311, a second substantially horizontal segment 312 and a third substantially vertical segment 313. The second segment 312 therefore connects the lower ends of the first segment 311 and the third segment 313.The downstream injection point 30 is located at the level of the second segment 312. Such a configuration makes it possible to avoid the return of higher pressure gas circulating in the reactor 3 to a lower pressure zone located in the lower part of the separation device 16.

[0055] Thus, the particles blown towards the first segment 311 by the upstream injection point 29 accumulate in the second segment 312 and are fluidized by the fluidization flow F4, and are therefore distributed in the second segment 312. By accumulation, the level of the accumulating particles rises along the first section 311 and third section 313, in the manner of a communicating vessel thanks to the fluidization flow F4. When the level of the particles reaches that of the reinjection pipe 32, the particles circulate by gravity towards the reactor 2, and are recycled. The fluidization allows the least dense phase, therefore all of the largest particles, to “float” on the densest phase, composed of ash of very small particle size. An opening equipped with a filter can be positioned at the level of the second segment 312 to prevent the accumulation of ash and prevent it from being recycled.

[0056] The fluidization flow F4 may comprise an inert gas, such as nitrogen, or carbon dioxide or water vapor, or a mixture of these gases, in order to avoid secondary combustion of the residual carbon contained in the ash and a reactant contained in the gas, which could result in the formation of a magma of molten ash leading to occlusion of the pipe.

[0057] Advantageously, the gasification installation 1 also comprises a control unit configured to control and pilot the various operating parameters of the gasification installation 1. The control unit is advantageously capable of piloting the flow rate of the gasification air flow F1 so as to adjust the circulation speed of the mixing flow F2, which makes it possible to control the gasification reaction speed.

[0058] Advantageously, the control unit is also capable of controlling the temperature of the gasification air flow FL. This makes it possible to modulate the speed of the gasification reaction. The gasification air flow FL is heated to a temperature between 300°C and 800°C.

[0059] Advantageously, the gasification air flow FL comes at least in part from a hot air flow originating from a production process, typically when implemented in a cement production unit, the hot air originating from the cooling elements can be redirected to supply the gasification air flow FL

[0060] Advantageously, the gasification flow F1 comprises water vapor, or oxygen, which makes it possible to improve the quality of the gas produced by the gasification.

[0061] Advantageously, the gas recovered by means of the extraction pipe 18 can be used to reheat the gasification flow F1 by means of a heat exchanger, and can be used in part to supply a burner configured to bring the gasification flow to the desired temperature. This makes it possible to limit the need for external energy input to supply the gasification reaction.

[0062] The implementation of safety devices, particularly at the gasifier level, following an Analysis of Failure Modes, their Effects and their Criticality (AMDEC) and the drafting of the voluntary / safety / emergency start-up and shutdown sequences:

[0063] Advantageously, the upper portion 6 and the separation device 16 are equipped with vents (not shown), configured to allow circulation of the internal gases to the outside when the pressure of the gases in the reactor 2 or the separation device 16 exceeds a predefined threshold. This makes it possible in particular to limit the internal pressure in the event of an accidental explosion, in particular during transient phases such as the start-up or shutdown of the installation.

[0064] Advantageously, the upper portion 6 of the reactor 2 is equipped with an injection rod (not shown) configured to inject water into the reactor in the event of a need to rapidly reduce the temperature of the reactor 2. Advantageously, the injection rod is retractable so as to be located outside the reactor when it is not in use.

[0065] Advantageously, the reactor 2 comprises an injection of inert gas (N2 or CO2) at the level of the lower portion 7 so as to purge the gasification unit in the event of a critical situation (emergency shutdown, fire).

Claims

Claims

1. Gasification installation (1) comprising a reactor (2) comprising a substantially cylindrical wall (3) extending along a vertical axis (Y) and externally delimiting a cavity configured to contain a gasification reaction, the reactor (2) comprising: - a primary air injection inlet (4), - a fuel injection (5) comprising at least one fuel injection point (11) arranged above the primary air injection inlet (4), the primary air injection inlet (4) being arranged in such a way that a gasification air flow (F1) is injected into the reactor (2) in a direction substantially tangential to the wall (3) of the reactor (2),, - the wall (3) comprising a substantially cylindrical upper portion (6), a substantially frustoconical lower portion (7), primary air injection (4) and the fuel injection point (11) being arranged through the lower portion (7) of the wall (3).

2. A gasification plant according to claim 1, wherein the at least one fuel injection point (11) is provided on the lower portion (7) of the wall (3) so as to inject a gasification air flow (Fl) into the reactor (2) in an injection direction at the fuel injection point (11), the injection direction having an inclination relative to a radius of the reactor (2) at the fuel injection point (11), so as to impart to the gasification air flow (Fl) a tangential displacement component at the fuel injection point (11).

3. Gasification installation according to one of claims 1 or 2, in which the primary air injection inlet (4) comprises a plurality of fuel injection points (11) distributed regularly along an annular section of the lower portion (7) of the wall (3).

4. Gasification installation (1) according to claim 10 or claim 2, further comprising a lift injection (12) configured to inject a lift flow (F3) into the reactor (2) so as to oppose the fall by gravity of the fuel, the lift injection (12) comprising at least a first stage of injection points (13) arranged above the primary air injection (4) and below the fuel injection point (11).

5. Gasification installation according to one of claims 1 to 4, further comprising a secondary air injection comprising at least one secondary injection stage (14) comprising a plurality of injection openings provided through the upper part (6) of the wall (3), configured to inject gasification air into the reactor (2).

6. Gasification installation (1) according to any one of the preceding claims, in which the fuel injection (5) comprises a fuel supply circuit (8) comprising a vertical pipe (10) opening onto each fuel injection inlet (11).

7. A gasification plant (1) according to any preceding claim, further comprising a separation device (16) configured to separate suspended particles from the combustible gas formed in the reactor, the separation device (16) connected to the reactor (2) by means of a channel (17) extending between an upper portion (19) of the separation device (16) and the upper portion (7) of the reactor (2),

8. A gasification plant (1) according to claim 6, further comprising a recovery device (24) configured to reinject the incompletely reacted fuel particles from the separation device (16) to the reactor (2).

9. Gasification plant (1) according to claim 7 or claim 8, wherein the channel (17) in the reactor (2) in a substantially tangential direction configured to be substantially tangent to the circulation of the mixing flow (F2) at the channel (17).

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