EP1027407B1 - Method and device for producing combustible gas, synthesis gas and reducing gas from solid fuels - Google Patents

Description

The invention relates to a method and an apparatus for generating Fuel, synthesis and reduction gas from renewable and fossil fuels, other biomass, garbage or sludge, preferably for it manufactured pyrolysis products according to patent DE 44 04 673, when used of pyrolysis products as far as possible before they are fed into the reactor in solid and gaseous products, e.g. B. carbonization gas and charcoal, separated and fed separately to the reactor.

The device according to the invention is in the energy industry, chemical industry and metallurgy for the highly efficient production of fuel, synthesis and Reduction gas for engines, synthesis processes, ore reduction and Pig iron production can be used.

A process for the three-stage gasification of coal is known from FR 2177088, in which contains hydrogen and carbon oxides in a first process stage Synthesis gas generated and in the following process steps Methanation of this gas takes place. As possible in this procedure High methane fuel gas to be obtained from coal are high process pressures of at least 50 bar, but preferably 70 bar is necessary for the methanation.

In a first stage, synthesis gas and liquid slag are generated and added further fuel (coal, steam) to it in a second stage, being in addition to the formation of a methane, hydrogen and carbon oxides containing product gas while cooling the slag a coal-slag mixture is formed.

The resulting coal-slag mixture must then be in an additional Process stage either to be slurried with water vapor to still contain it separate trapped particles of charred material and these in a third stage of the process or by fluidization from the Fluid bed of a third process stage are removed.

In addition to the separation stage for the coal-slag mixture, which an additional This process requires energy expenditure, among other things disadvantageous that the molten slag by mixing cold Media, such as water vapor, gas or coal, can cool down, but not controllable agglomerations and caking occur.

In addition, this process requires a third process stage, in which the Reactants must be kept in a fluidized bed for an extended period of time.

Furthermore, there is a relatively large number of gasification processes that essentially the 3 large groups of fixed bed, fluidized bed and Allow traction gasification to be assigned. In the devices for gasification and especially in the devices for entrained-current gasification, where the inventive To classify device must make many compromises in energy Regarding and in need of gasification agent. Entrained flow gasifier with melting of the mineral components are mostly operated in one stage, d. H. all media involved in the gasification reaction fed to a reaction space. With this, all media are at the high level above the slag melting temperature of the mineral components of the Fuels raised. This is the case with reactors with refractory brick like also the case with the reactor wall lined with a cooling screen. With the reactors with Cooling screen, as is typical for the GSP entrained flow reactor (see literature [1, 2]), a significant proportion of the sensible heat of the gasification gas is transferred to the cooled wall dissipated. For DC reactors with water quenching of the gasification gas to water vapor saturation temperature, with or without cooled reactor wall, will continue to apply a very large amount of heat low exergy level devalued. For reactors with a cooled inner wall of the reactor, but also in countercurrent reactors in which the gasification gas after top and the liquid slag down the reactor must leave with additional heat or even with additional burners to keep the slag drain free become. These measures lead to a high oxygen demand, to reduce the calorific value of the gasification gas and thus too low exergetic efficiencies of the entire gasification. If you take this precaution not, then the function of a carburetor is disturbed because of the slag flow cannot be maintained.

Especially with entrained-flow reactors operated with oxygen as the gasifying agent there are very short residence times of the reactants. To avoid an oxygen breakthrough in the event of fuel failure is a very large measurement and Monitoring effort required.

Traction current reactors fed by a separate pyrolysis with fuel have the disadvantage that the pyrolysis products before being fed into the reactor to be cooled and, in addition to the heat losses, also a great deal of effort for gas processing and handling of liquid products.

The object of the invention to be solved is a simplified method and to propose a reactor that over the prior art an average lower temperature level with higher exergetic Work efficiency and produce a gasification gas that is free of Hydrocarbons and, chlorinated hydrocarbons (dioxins, furans), and while avoiding a separate separation stage that is used as fuel gas for electricity generation, as synthesis gas or as a reducing gas in a heat with ore reduction can be used.

The object is achieved with the features of claim 1. The further claims represent embodiments of the invention. The solution takes place in such a way that the reactor is constructed in such a way that the physical Heat at a high temperature level, with minimal losses remains and is used to increase the chemically bound heat. Here, fuel and / or gas is initially at the outlet at the firing temperature of the burner or at the entrance to the combustion chamber in rotation, what about this causes hot slag droplets to be thrown against the wall and flow down to a slag pan at the bottom of the combustion chamber.

Mixing of liquid slag with solid fuel is thus prevented. The combustion chamber wall is at such a temperature level held that a layer of solidified slag melt forms on it, on which the further slag runs, for which it is on the outside of the (reflected) gasification gas is washed around.

The combustion chamber floor has a central opening from which the Slag droplets freed gas as a submerged jet exits and into the entrained-flow gasifier reached. The slag running off the wall becomes the opening surrounding tub collected, preferably equipped with radial drainage channels is and flows parallel to the gas into the entrained flow gasifier. The gas leak is designed as a channel, whereby the gasification gas is laminarized becomes.

This accomplishes two things. For one, it stays down in the carburetor escaping gas received as a jet for a relatively long time, this above the water bath slowed down by compression effects and upwards is deflected (reflected) in order to then parallel to the immersion jet on the carburetor wall to ascend. in the descending gas jet is under reducing Conditions of carbon-containing fuel dust blown in, initially descending taken and then gets into the shell-shaped rising part of the gas, whereby the dimensioning of the device and the flow rate so are designed so that a sufficient dwell time results and thus a extensive gasification of the fuel dust takes place.

Around the gas outlet can prevent back mixing of the rising portion of gas with the emerging jet a jacket made of temperature-resistant Steel or ceramic can be arranged, through which through lances the fuel dust can be supplied.

The rising gas arrives e.g. via a guide device into an intermediate space between an outer shell of the device and the casing of the combustion chamber, causes a heat balance on this and leaves the device via the gasification gas outlet.

The device is provided with a heat protection lining and preferably chilled.

The resulting gas is of high quality and can be used directly.

Before the rising gas enters the heat equalization channel this by spraying water or cold gas, e.g. with unstable operating conditions, be quenched.

Based on the accompanying figure, the present invention is an exemplary embodiment explained in more detail.

A combination burner 1 is used, the hot, gaseous products the smoldering, including the vaporous components such as tar, oil, water and picks up dust at the inlet port of the carbonization channel 4 and passes into the combustion chamber 9 via the swirl device 33. In the smoldering product channel of the combination burner are pipes for the supply of residual coke, ashes and of aggregates 8 arranged in the reactor, so that in the combustion chamber 1 mineral components to be melted with twisted, heated and in the combustion chamber 1 are flung in liquid form to the wall. For the substoichiometric combustion to gasifying agent above the ash melting temperature the combination burner has 1 additional feed channels for oxygen 7 or air 3, in the same direction as the smoldering products via swirl devices 33 for rapid conversion with the smoldering products to gasifying agents and for melting the mineral components of the residual coke, the ash and, if applicable, the aggregates are introduced into the combustion chamber 1 become. In order to prevent critical heat input into uncooled Components become the pilot fuel supply necessary for starting and heating up 2, ignition air supply 5 and ignition device and ignition monitoring 6 with built into the combination burner where these elements differ from the others flowing media are protected during stationary gasification.

It is also possible to use a known swirl burner for coal fuel dust.

The combustion chamber 9 is operated above the melting temperature of the mineral components of the residual coke, the ashes and the additives. The wall of the combustion chamber 9 is thermally conductive, so that its slag solidifies to form a protective layer due to heat dissipation to the outside and liquid slag runs off due to the temperature in the combustion chamber 9. The bottom of the reaction chamber 10 is designed as a slag collecting trough with incorporated drainage channels 12 in such a way that a slag bath 13 can be formed which, due to the direct contact of the slag with the gasifying agent 11 and through the direct current with the gasifying agent 11, also through the gas outlet 34 through the slag flow always guaranteed. The gasification agent 11, which is produced under gasification conditions under the stoichiometry in the combustion chamber 9, serves because of its high CO ₂ and H ₂ O content as a gasification agent in the endothermic entrained flow gasifier 14. The sensible heat introduced with the gasification agent 11 is used to cover the heat requirement for the endothermic gasification reaction between fuel dust and gasification agent is used. Lances 15, 17 are therefore provided for the fuel dust in the reactor. The gasification agent 11 enters the endothermic entrained-flow gasifier 14 as an immersion jet 16 and accelerates the entrained slag droplets 18 so that they are introduced into the water bath 19 and solidify there to form granules which are resistant to elution. The slag discharge 22, the water inlet 21 and overflow 20 were provided for media removal and to supplement evaporated water. Together with the water bath 19, they form the lower end of the endothermic entrained flow reactor 14.

The immersion jet can also be stabilized and back-mixed with the reflected, Gas in the form of a jacket is prevented from rising parallel to the wall be when a jacket 35 made of heat-resistant below the gas outlet 34 Steel or ceramic is arranged through which the fuel lances 15 are passed are. Additional lances 17 can be located below.

The construction carried out ensures the supply of oxygen-free Gasification agent 11 and fuel dust to be gasified in the endothermic Entrained flow reactor 14 and through the high gasification temperature above 500 ° C that no oxygen breakthrough can enter cold reactor areas.

For heating the gasification gas cooled during endothermic gasification 23 is used for the heat compensation channel 26, in which, if appropriate Guides 24 are located. They give the gasification gas stream 23 a Vortex swirl, which is the removal of convective heat from the wall of the Combustion chamber 9 reinforced so that the inner combustion chamber wall under the Melting temperature of the slag is cooled and this creates a protective layer from solidified slag. In addition, the Cooling of the combustion chamber wall by the cooling device 27, which via coolant inlets and outlets 28, 29 is supplied. To lower the gasification temperature, which should be between 500 and 1200 ° C, the device 30 for quenching of the gasification gas is provided, to which quench nozzles 31 are mounted. about the gasification outlet leaves the refractory-lined gasification outlet 25 the reactor.

With the further design of the multi-stage reactor, an essential one Allows expansion of the application of the reactor. So by substitution the residual coke / ash and fuel dust lances 8, 15, 17, of parts of the Combination burner and the Qench nozzles 31 created the possibilities foreign mineral, possibly contaminated substances, but also Ores, melt down and gasify foreign fine-grained fuels, own Use fuel gas or foreign gas for dosing or with different Quench media such as water, steam or cold gas.

It is also the design of a pan to collect the from the combustion chamber 9 flowing melt provided in liquid form, which instead of the water bath 19 then the lower end of the endothermic entrained flow gasifier 14 forms.

The reactor is used for chemical and thermal protection with a refractory delivery 32 provided. But it is also with heat-resistant, corrosion-resistant Material and thermal external insulation designed for pressures up to 10 MPa.

To protect against a breakthrough of the combustion chamber 9 in the endothermic Entrained flow gasifier 14, the lower part of the heat compensation channel 26 is conical designed.

Literature:

[1] CARL / FRITZ: "NOELL CONVERSION PROCESS" EF publishing house for energy and Umwelttechnik GmbH 1994

[2] LUCAS et al. a .: "A comparison of coal gasification processes under pressure in the Airborne dust cloud "Chemische Technik 1988, No. 7, page 277-282

Reference list

1

Combination burner

2nd

Detonator

3rd

Combustion air

4th

Smoldering products

5

Pilot air

6

monitoring

7

O ₂

8th

Residual coke + ash

9

Combustion chamber

10th

Reaction space

11

Gasifying agent

12th

Slag pan

13

Slag bath

14

Endothermic Entrained flow gasifier

15

Brennstaublanze

16

Diving beam

17th

Brennstaublanze

18th

Droplets of slag

19th

water bath

20th

H ₂ O overflow

21

Water inlet

22

Schiackeatrag

23

Upward current

24th

Control device

25th

Gasification gas outlet

26

Heat compensation duct

27

Cooling device

28

Coolant inlet

29

Coolant leak

30th

Quench

31

Quench nozzles

32

Thermal insulation lining

33

Swirl device

34

Gas leak

35

coat

Claims (22)

1. Process for generating fuel, synthesis and reduction gas from renewable and fossil fuels, other biomasses, refuse or sludges by combustion in a combustor, admixing gaseous oxygen and/or oxygenaceous gases in substoichiometric ratios above the melting temperature of the inorganic portions into CO₂- and H₂O-containing gasifying agents, characterised in that

   fuel and/or gas is/are caused to spin when entering the combustion chamber, that the liquid mineral components forming during combustion are flung against the essentially vertical combustor wall and that they are separated from the gasifying agents forming in this process;

   the gasifying agent is guided through a central aperture at the bottom of the combustion chamber into a gasification reactor, forming an immersion jet in the process;

   the separated liquid components are discharged through the central aperture at the bottom of the combustion chamber, being entrained by the gasifying agent immersion jet as slag droplets, withdrawn parallel to the gas and accelerated towards the reactor floor, collected there and discharged by the latter;

   the gasifying agent is supplied with carbonaceous pulverised fuel in the gasifier, in the course of the ensuing gasification reaction carbon dioxide is reduced to carbon monoxide and water vapour to hydrogen;

   the gas immersion jet deflects above the reactor floor and the generated gasification gas in the upper portion of the reactor is discharged and processed to fuel, synthesis or reduction gas by subsequent dedusting and chemical cleaning.
2. Process according to claim 1, characterised in that the fuels are heated allothermally or autothermally at 300 to 800°C, the products being separated into gaseous and solid carbonaceous fuels, such as e.g. low temperature carbonisation gas and charcoal prior to being fed to the combustion chamber and being subsequently introduced separately to the process.
3. Process according to claim 1 or 2, characterised in that the solid carbonaceous fuels are ground to pulverised fuel.
4. Process according to any one of claims 1 to 3, characterised in that part of the heat requirement for the combustion is met by heat exchange with the gasification gas and/or the fuel, synthesis or reduction gas.
5. Process according to claim 4, characterised in that the gasification gas is guided through the chamber between the reactor wall and the exterior combustion chamber wall, absorbing a portion of the heat to be discharged from the combustion chamber.
6. Process according to claim 5 or 6, characterised in that the hot gasification gas is cooled prior to entry into the chamber or in the chamber between the reactor wall and the exterior combustion chamber wall.
7. Process according to any one of claims 1 to 6, characterised in that the slag is collected in a water bath on the reactor floor and is discharged therefrom.
8. Process according to claim 6, characterised in that cooling is performed directly by quenching with water, water vapour and/or cold gas or by means of a cooling surface connected to the reactor wall or its lining.
9. Process according to any one of claims 1 to 8, characterised in that extraneous mineral materials and/or ores are added to the carbonaceous solid fuels, being melt down during combustion.
10. Process according to any one of claims 3 to 9, characterised in that extraneous fuels of small particle size are admixed to the pulverised fuel.
11. Process according to any one of claims 1 to 10, characterised in that the pulverised fuel is injected into the immersion jet via one or more lances, preferably directly below the combustion chamber floor.
12. Process according to any one of claims 1 to 11, characterised in that the slag is collected on the floor of the combustion chamber in a slag collection trough, conveyed to the central aperture via drainage pipes.
13. Apparatus for performing the process according to claims 1 to 12, consisting of a combined fuel burner (1) as well as a combustion chamber (9) provided thereunder, comprising fuel and gas supplies (2, 3, 4, 5, 7, 8), characterised by the following features:

    a) at the top of the combustion chamber (9) a vortex means (33) is provided via which the fuels and gases from the combined fuel burner (1) are guided downwardly towards a gas outlet (34), provided centrally at the bottom of the said combined fuel burner;

    b) the gas outlet (34) is surrounded by a slag trough (12) at its upper end;

    c) an endothermic, entrained flow gasifier (14) comprising a slag trough (19) and a slag discharge means (22), into which the slag flows parallel to the gas, is provided underneath the gas outlet (34);

    d) pulverised fuel lances (15) are provided underneath the gas outlet (34) extending into the gasifier (14).
14. Apparatus according to claim 13, characterised in that the gas outlet (34) in the upper region of the endothermic, entrained flow gasifier (14) is surrounded by a jacket made of heat resistant material (35).
15. Apparatus according to claim 13 or 14, characterised in that upper (15) and lower pulverised fuel lances (17) are provided, the upper ones (15) passing through the jacket (35).
16. Apparatus according to any one of claims 13 to 15, characterised in that the endothermic, entrained flow gasifier (14) is enveloped by a heat protective lining (32).
17. Apparatus according to any one of claims 13 to 16, characterised in that the heat protective lining envelopes the combustion chamber (9) in spaced apart relationship, forming a heat compensating duct (26) in the form of an annular chamber.
18. Apparatus according to any one of claims 13 to 17, characterised in that the thermally protective lining (32) is provided with a cooling means (27) in the region of the combustion chamber (9).
19. Apparatus according to any one of claims 13 to 18, characterised in that guide means are provided in the annular chamber or the heat compensating duct (26).
20. Apparatus according to any one of claims 13 to 19, characterised in that quenching means (30) are provided in the upper region of the endothermic entrained flow gasifier (14) and/or in the heat compensating duct.
21. Apparatus according to any one of claims 13 to 20, characterised in that the slag trough is of conical design, comprising discharge channels for the slag.
22. Apparatus according to any one of claims 13 to 21, characterised in that the floor of the combustion chamber (9) is conical and that the entrained flow gasifier (14) comprises a counter cone as a safety means against flame breakthrough, surrounding the combustion chamber floor in spaced apart relationship.

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