JP2633678B2 - Method for transporting fine or dusty fuel into a gasification reactor under elevated pressure - Google Patents

Description

The present invention relates to a fuel to be gasified in a tank with a lock gate in order to feed fine or dusty fuel into a gasification reactor under elevated pressure. To the gasification pressure by pressure loading with gas, from here via the metering tank,
The present invention relates to a method in which a carrier gas stream is supplied to a burner of a gasification reactor, and in that case, a tank with a lock gate is alternately pressurized and depressurized again.

[Conventional technology]

The above-mentioned process has been known for a long time for transporting fine or dusty fuels into a gasification reactor under pressure. In this case, the entire system is conventionally operated, inter alia, with the use of inert gases, in particular nitrogen. Furthermore, from DE-A 28 31 208, an alternative to this method is known, in which the pressure loading of a tank with a lock gate is carried out using nitrogen or industrial carbon dioxide, and the discharge from a metering tank. A flammable gas, which may be the gas from the original generator, is used as a carrier gas for feeding the fuel to the burner of the gasification reactor. The method described in European Patent No. 0101 098 works similarly,
In this case, syngas or residual gas from hydrocarbon synthesis is used as the combustible gas.

In this case, due to the fact that the tanks with locking gates are pressure-loaded with inert gas and the metering tanks are pressure-loaded with flammable gas, these tanks are supplied from these tanks in addition to the inert gas component during the filling process. Is expelled. Therefore, the continued use of this gas in the coal processing plant is made difficult by the safety measures required in this case. Emission of this gas into the atmosphere is not easily possible for safety reasons. The high content of inert gas components also makes it virtually impossible to discard or utilize this gas by combustion without the use of auxiliary fuel.

[Problems to be solved by the invention]

The problem underlying the present invention, therefore, is that a method of the type mentioned at the outset avoids the disadvantages mentioned above and at the same time allows a complete return of all gases expelled from the tank during the filling process. It is to develop to become.

[Means for solving the problem]

According to the present invention, a method which helps to solve this problem is that the fuel is transported from the processing unit using an inert carrier gas into a cyclone filter having an extended separation chamber, from which the tank with the lock gate is moved by gravity flow. Flammable gas having an inert gas content of not more than 1% by volume, for the pressure loading of the tank with lock gate and the metering tank and for the supply of fuel to the burners of the gasification reactor. It is characterized by the following.

That is, in the method of the present invention, the gas range that is inert and hardly pressurized is clearly separated from the combustible gas range,
The use of flammable gas here is also provided for the pressure loading of the tank with the lock gate, and the inert gas is used only within a range that is hardly pressurized. Therefore, in the working method according to the invention, depending on the pressure used in each case, only a very small amount of inert gas enters the metering vessel from the tank with the lock gate, so that the metering between the individual filling steps takes place. The purging of the tank can be abandoned. Due to the low inert gas content, it is also possible to return the gas purged from the container during the filling process to the process. How this is done depends on the type of use of the partial oxidizing gas generated in the gasification reactor.

In principle, two methods are possible for carrying out the process according to the invention: In the first, the partial oxidizing gas generated in the gasification reactor is converted into syngas by the following gas treatment. . In this case, the dried carbon dioxide is used no dust as an inert carrier gas, the carbon dioxide cases necessary to synthesis gas generation may be filed are from the partial oxidation crude gas of CO ₂ cleaning . In this case, the carbon dioxide used exits the cyclone filter and is discharged into the atmosphere in the corresponding purifying liquid. Alternatively, the gas discharged from the tank with the lock gate and the metering tank during the filling process is returned to the process and added to the generated partially oxidized crude gas before its gas treatment. In this case, it is generated particularly as a combustible gas for the pressure load of the tank with the lock gate and the metering tank, and for supplying fuel to the burner,
It is possible to use a partial stream of syngas which has no already dried dust. However, for this purpose, the residual gas from, for example, ammonia synthesis can also be used. For example, such as SO ₂ and CO ₂ containing residual gas from the gas treatment
As long as the SO ₂ -containing residual gas is present, it must be kept at a temperature clearly above the dew point in order to avoid corrosion.
Unlike the above-mentioned working method, in this case by adding directly to the burner gas is returned to the method that decreases reliably and completely in the reaction zone of the gasification reactor by fuel SO ₂ content It can be advantageous.

In the second method, the partially oxidized gas generated in the gasification reactor is used as a fuel gas for a gas turbine of a gas / steam turbine power plant to be connected. In this working method,
It is important not to remove the load from the inert ballast gas in the gasification process, but to reduce the compressor output for the gas required in the system. Thus, in this case, nitrogen is used as the inert carrier gas. This nitrogen is particularly produced as a by-product in the air separation unit which supplies the oxygen required for gasification. It may be relatively impure nitrogen with an oxygen content of 3-5% by volume. Nitrogen used as an inert carrier gas, after transporting and separating the fuel into a cyclone filter,
The gas is supplied to a gas turbine of a gas / steam turbine power plant to be connected together with the pressure-released gas from the tank with the lock gate and the discharge tank. In this case, purified partial oxidizing gas and / or residual gas can be used as a combustible gas for pressure-loading the tank with the lock gate and the metering tank and for supplying fuel to the burner.

Other details of the method according to the invention are evident from the second and subsequent claims and will now be described with reference to the system diagram shown in the accompanying drawings.

〔Example〕

In the flow sheet shown in FIG. 1, fine or dusty fuel is supplied from a storage bunker 1 of a processing plant to a conduit 2.
With carbon dioxide as an inert carrier gas
It is fed into the cyclone filter 3 by air at a low pressure of ４4 bar. In this case, cyclone filter 3
Has an expanded separation chamber 4. The carbon dioxide required for transportation is introduced into the system by the conduit 5 and flows out of the cyclone filter 3 operating under almost no pressure by the conduit 6. After passing through the filter 7 or the molecular seal, the gas can be vented to the atmosphere. Separation chamber 4
The fuel, which is collected almost unpressurized therein and is replenished by a continuous supply, enters a nearly unpressurized tank 9 with a lockgate via conduit 8 by gravity flow. In order to avoid a bridging phenomenon at the outlet of the separation chamber 4, additional carbon dioxide is blown into the outlet area via a conduit 10. During the filling process, there is no actual overpressure in the lockgate tank 9. However, this tank with a lock gate is filled with combustible gas flowing out of the conduit 11 after being barged by the falling fuel. This barged gas enters the gasometer 13 operating at a slight overpressure via the post-purification conduit 12 in the filter 65. Of course, this overpressure is always the working pressure in the cyclone filter 3 in order to ensure that the flammable gas never enters the separation chamber 4 and the cyclone filter 3 connected thereto from the lock gate tank 9 in countercurrent to the fuel. Must be slightly lower. However, contamination of up to 25% by volume of carbon dioxide by the combustible gas system withdrawn via conduit 11 is permissible.

After the lock gated tank 9 is filled to the required extent with fuel, the fuel supply is interrupted by closing the valve 14 in the conduit 8 and at the same time the valve 15 in the conduit 11 is closed. Thus, the tank 9 with the lock gate is brought into a pressure balanced state with the metering tank 16. This is done by supplying flammable gas via conduits 17 and 18. What kind of combustible gas can be used has already been described above. As can be seen from the drawing, this gas is blown simultaneously from above and below into the tank 9 with the lock gate. In this case, the conduit 17 has several outlet holes which are distributed evenly around the circumference in the region of the hopper-shaped taper and open into the locking gated tank 9. The gas supply via conduits 17 and 18 can be controlled by valves 19 and 20. Due to this gas supply, the gas is present in the lock gate-equipped tank 9 after the completion of the non-pressurized filling step. The gas mixture, which may still contain up to 25% by volume of OC ₂ , is strongly diluted by the supplied flammable gas and the inert gas content is finally reduced to 1% by volume at normal working pressures in the process. not big. As soon as the pressure in the locking gate tank 9 substantially matches the pressure in the metering tank 16, the valve 19 in the conduit 17 is closed and the valve 20 in the gas supply conduit 18 and the valve 21 in the gas discharge conduit 22 cause Perform a fine balance of control.

To exhaust the lock gated tank 9, the valve 23 in the conduit 24 is opened. Similarly, the valve 25 in the pressure balance pipe 26 is opened, so that gas can flow into the lock gated tank 9 in response to fuel outflow. As soon as the valves 23 and 25 are open and the fuel flows out of the lock gated tank 9, the valve 64 in the conduit 63 is also opened, so that additional flammable gas flows through this conduit from the lock gated tank 9. The cross-linking phenomenon when fuel flows out can be avoided. In this case, this gas increases the apparent density of the fuel-gas mixture by 10 to 20.
It works by decreasing%. But in principle, gas supply is
It is limited so that fluidized bed-like disaggregation of fuel is avoided.

The fuel flowing under the influence of gravity into the metering tank 16 barges the combustible gas present above the fuel deposits in the metering tank, and the gas escapes from the metering tank 16 via conduit 27. Can be issued. A major amount of the expelled gas is introduced into the lock gated tank 9 by means of a pressure balance pipe 26, a small part of which enters the conduit 22 when the valve 28 is opened, from which it can enter the buffer tank 29. . Gas existing in the tank 9 with the lock gate after the pressure increase and the pressure balance pipe 26
Mixing with the gas stream supplied by the dispensing tank
The inert gas content (CO ₂ content) in the flammable gas present above the fuel deposits in 16 decreases to some extent by only about 0.5% by volume after the filling step of the metering tank. After the tank 9 with the lock gate is completely discharged, the valves 20, 23,
Valves 25 and 64 are closed, and at the same time valve 21 is opened to release tank 9 with lockgate into buffer tank 29. Before releasing the pressure from the tank 9 with the lock gate, a pressure corresponding to about 15% of the pressure in the tank with the lock gate exists in the buffer tank 29. Due to the pressure relief, the pressure in the lockgate tank 9 drops to, for example, 9 bar even if it drops by about 66%. Therefore, at high pressure levels, most of the flammable gas from the lock gated tank 9 is recovered and the conduit 30 provides a buffer tank.
Can be taken from 29. After being compressed correspondingly in the compressor 31, the gas is added via line 32 to the partially oxidized crude gas before the gas treatment 33. As a final step of the pressure release of the tank 9 with the lock gate, the valve 15 in the conduit 11 is opened, and the residual gas mainly containing the flammable gas component is introduced into the gas meter 13 through the filter 65 and the conduit 12. Filter 65
The fuel dust separated therefrom is returned to the lock gated tank 9 by a partial stream of carbon dioxide supplied by conduit 34 from conduit 5. To do this, when the lockgate tank 9 is just unpressurized before filling,
Valve 37 in 36 is temporarily opened. The gas collected in the gasometer 13 can be removed by a conduit 38 and supplied to a compressor 39 which rotates coaxially with the compressor 31. Subsequently, this gas is added to the gas stream in conduit 30 by conduit 40. Optionally, the gas withdrawn via conduit 38 may be fully or partially available for other use by conduit 66, for example, as a fuel gas.

The fuel present in the metering tank 16 is added via line 41 to the fuel in the gasification reactor 42. In this case, the addition is not under the influence of gravity, but rather in the metering tank 16 and the gasification reactor.
This is done by means of a pressure difference between 42 and which determines the mass flow.
This pressure difference is generated by supplying the combustible gas into the metering tank via lines 43, 44 and 45, with the valves 46, 47 and 48 being opened accordingly. In this case, conduit 44
Cover about 2/3 of the required volume. In this case, the introduction into the metering tank 16 is effected by several outlet holes which are evenly distributed over the entire circumference in the area of the taper on the hopper and open into the metering tank 16.
The gas flow in the conduit 45 serves, inter alia, to avoid bridging phenomena when the fuel flows out of the metering tank 16. This gas flow also achieves a reduction in bulk density, in which case fluidized bed dissociation of the fuel is avoided. The amount of gas supplied by the conduit 43 serves, first of all, to balance the volume of withdrawal of fuel from the metering tank 16 when a corresponding amount of fuel from the locking gate tank 9 does not flow simultaneously. In this case, valve 46 in conduit 43 will generally remain closed. Valve 46 in connection 50 connecting the metering tank 16 with the conduit 41
Is of course open during the removal of fuel from the metering tank 16.

The partial oxidizing gas generated in the gasification reactor 42 is cooled in a waste heat boiler 51 forming one unit with the gasification reactor 42, and then, via a conduit 52, the partial oxidizing gas is converted into syngas. The individual steps of the gas treatment 33 where the conversion takes place are entered. Since this step is known per se and is a step commonly used in industry, it need not be described in detail. The generated syngas is withdrawn via conduit 53 and is subsequently used. In this case, this partial stream of gas can be branched off by a conduit 54. This partial stream is brought to the required pressure by stepwise compression in compressors 55 and 56 and subsequently reaches conduit 58 via conduit 57, from which conduits 17, 18, 63, 64, 44 and 45 have departed.

Also, the SO ₂ and CO ₂ -containing residual gas from the gas treatment unit 33 can be supplied to the compressors 55 and 56 via the conduit 59, and then returned to the method as described above. in this case,
The heat exchanger 60 is used for necessary temperature control of the returned gas stream. Via the conduit 61, the oxygen or the oxygen / steam mixture required for the gasification is introduced into the gasification reactor. The burner of the gasification reactor 42 is adjusted so as not to allow backflow of oxygen or oxygen / steam mixture into the conduit 41. The details of the gasification reactor 42 need not be described in detail, as it can also be of a known construction. In particular, a reactor of the type in which the gasification takes place in the cloud of dust is selected.

No syngas or residual gas, carbon dioxide is usually utilized during the start-up of the apparatus. In this case, the supply of the lock gate system is effected temporarily using nitrogen supplied by conduit 62. In this case, the gas supply to the gasometer 13 and the buffer tank 29 is stopped during the initial phase, and the pressure-released gas is discharged.

In the flow sheet of FIG.
It is not shown that a filter for removing entrained fuel particles from the depressurized gas may be arranged in the gas path between the gas and the buffer tank 29. In this case, the filter is again free to be washed again when the pressure is increased by the flammable gas flowing into the tank 9 with the lock gate next. In addition, if a large gasification reactor with a throughput of> 10 t / hr is used in the flow sheet, two or several tanks 9 with lock gates are optionally provided, which are shifted in time from one another. It is not shown that filling and discharging can also take place. As a result, the fuel supply to the metering tank 16 becomes uniform, and only one metering tank is provided in this case, similarly to the gas meter 13 and the buffer tank 29.

FIG. 2 shows a flow sheet of a method in which the generated partially oxidized crude gas is used as a fuel gas for a gas turbine of a gas / steam turbine power plant to which the gas is attached. This flow sheet largely corresponds to the flow sheet of FIG. 1 and the same reference signs will of course represent the same in both flow sheets. Therefore, the detailed description of this flow sheet can be abandoned with reference to the above description. In this case, it is important not to remove the load from the inert ballast material in the gasification method but to reduce the output of the compressor. In this case, nitrogen as the inert carrier gas is supplied into the system by the conduit 5. You. This nitrogen may be impure nitrogen with an oxygen content of 3-5% by volume, which is produced as a by-product in an air separation plant supplying the oxygen required for gasification. By means of this nitrogen, the fuel is pneumatically sent from the storage bunker 1 by a conduit 2 to a cyclone filter 3, where oxygen is separated from the fuel. In this case, the nitrogen withdrawn through conduit 6 enters gasometer 13 without being discharged to the atmosphere. If the tank with lockgate 9 is to be filled by means of the conduit 11, the flammable gas then enters the cyclone filter 3 and is introduced together with nitrogen into the gasometer via the conduit 6. From here, the gas mixture is withdrawn by conduit 38. After the gas mixture has been compressed correspondingly in the compressors 31 and 39, the mixture is piped together with the gas withdrawn from the buffer tank 29.
By 32, it is supplied to the combustion chamber of the gas turbine of the gas / steam turbine power plant that is directly connected. The generated partial oxidizing gas which is taken out by the conduit 53 following the gas treatment device 33 also flows into the combustion chamber. In this case, the steam generated in the waste heat boiler 51 may be heated,
It can be used in a steam turbine of a steam turbine power plant.

[Brief description of the drawings]

The accompanying drawings show an embodiment of the method of the present invention. FIG. 1 is a flow sheet of an embodiment in which a generated partial oxidation crude gas is further processed into a synthesis gas. Gas that is followed by crude gas
5 is a flow sheet of another embodiment used as a fuel for a gas turbine of a steam turbine power plant. 1 .... Storage bunker, 2 ... Conduit, 3 ... Cyclone filter, 4 ... Separation chamber, 5,6 ... Conduit, 7 ... Filter,
8 ... conduit, 9 ... tank with lock gate, 10, 11, 12 ...
... Conduit, 13 ... Gasometer, 14,15 ... Valve, 16 ... Dispensing tank, 17,18 ... Conduit, 19,20,21 ... Valve, 22 ... Conduit, 23 ... Valve, 24 ... ... conduit, 25 ... valve, 26 ... pressure balance pipe, 27 ... conduit, 28 ... valve, 29 ... buffer tank, 30
... conduit, 31 ... compressor, 32 ... conduit, 33 ... gas treatment device, 34, 36 ... conduit, 37 ... valve, 38 ... conduit, 39 ...
Compressor, 40, 41 ... conduit, 42 ... gasification reactor, 43, 44, 45 ... conduit, 46, 47, 48, 49 ... valve, 50 ... connecting pipe, 51 ... waste heat boiler , 52,53,54 …… Conduit, 55,56 ……
Compressor, 57, 58, 59 ... conduit, 60 ... heat exchanger, 61, 62, 63
…… Conduit, 64 …… Valve, 65 …… Filter.

Claims (8)

(57) [Claims] 1. The fuel to be gasified is brought to the gasification pressure by pressure loading with gas in a tank with a lockgate, from which it is fed via a metering tank using a carrier gas stream to the burner of a gasification reactor. In this process, the tank with the lock gate is alternately pressurized and released again, in a method for transporting fine or dusty fuel into a gasification reactor under elevated pressure, wherein the fuel is inertly transported. It is sent from the treatment equipment by means of a gas into a cyclone filter with an extended separation chamber, from where it enters by gravity flow into a tank with a lockgate, due to the pressure loading of the tank with a lockgate and the metering tank and the gasification reaction. 1% by volume inert gas content for the supply of fuel to the burner of the vessel
Using a flammable gas of no greater size to transport fine or particulate fuel into a gasification reactor under elevated pressure. 2. The use of syngas and / or residual gas for the pressure loading of the tank with lock gate and the metering tank and for the supply of fuel to the burner.
The described method. 3. The flammable gas used is obtained from a partially oxidized crude gas generated during gasification.
The described method. 4. The method according to claim 1, wherein the temperature above the dew point is maintained when the SO ₂ -containing residual gas is used as the combustible gas. 5. The volume flow supplied to the lock-gate tank and the metering tank is exclusively adapted to pressure increase, supply of fuel to the gasification reactor and pressure maintenance, and is carried out in the lock-gate tank and the metering tank. 5. A method as claimed in any one of claims 1 to 4 for preventing a fluidized bed-like disaggregation of fuel deposits. 6. The method according to claim 1, wherein dry carbon dioxide having no dust is used as the inert carrier gas, and the gas is discharged to the atmosphere after transporting and separating the fuel in the cyclone filter. Or the method of claim 1. 7. The method according to claim 1, wherein carbon dioxide used as an inert carrier gas is separated from the partially oxidized crude gas generated during gasification. 8. The use of nitrogen as an inert carrier gas which, after the supply and separation of the fuel into the cyclone filter,
6. The method according to claim 1, wherein the gas is supplied to a gas turbine of a gas / steam turbine power plant together with the gas under pressure.