Incineration plant and method for operating an incineration plant

Description

[0001] The present invention relates to an incineration plant and a method for operating an incineration plant. The incineration plant comprises a combustion chamber, in which a fuel, in particular a fuel of solid material is combusted. For example, waste or biomass as solid material may be combusted in the combustion chamber. An incineration plant with the features of the preamble of claim 1 is known from each of KR 2023 0153182 A and CN 218379390 U.

[0002] A combustion grate may be arranged within the combustion chamber for transporting the solid material and the residues of the combusted solid material (i.e. ash and slag) through the combustion chamber. The solid material and the residues of the combusted solid material form a so-called combustion bed during combustion on top of the combustion grate. The combustion grate is usually arranged within a lower section of the combustion chamber, wherein the combustion grate conveys the combustion bed from an end of a combustion material inlet shaft to a slag container downstream of the combustion grate. JP 2013 164227 A discloses an incineration plant with a combustion grate.

[0003] The combustion grate is preferably embodied as reciprocating grate, but it is also possible that the combustion grate is embodied in a different way, for example as vibrating grate, traveling grate or roller grate. Primary air as oxidant gas may be supplied from below the combustion grate to the combustion bed arranged on top of the combustion grate, so that the solid material arranged on the combustion grate is combusted with the primary air. For example, a wind box for supplying primary air may be arranged below the combustion grate for embodying the device, with which the oxidant gas is supplied to the combustion grate.

[0004] The main process steps on the grate (in the direction of travel of the solid waste) are: drying of the waste or biomass, devolatilization, combustion, afterburning of the solid residues (mainly ash and slags). Additionally, nozzles may be arranged above the combustion grate within the combustion chamber and / or within at least one path, with which nozzle(s) secondary air, tertiary air for afterburning or an oxygen-poor carrier gas can be provided to the combustion gases.

[0005] In an alternative to the before described grate firing, the combustion chamber may be embodied to produce a fluidized bed in which the combustion reaction occurs. In this case, the combustion chamber comprises a fluidizing bottom at the bottom of the combustion chamber, wherein an oxidant gas, for example primary air, is supplied through the fluidizing bottom as fluidizing agent. In this case, the device for supplying oxidant gas to the combustion process is embodied by the fluidizing bottom.

[0006] The combustion chamber may further have at least one fuel inlet above the fluidizing bottom, through which the to be fuel is supplied to the combustion chamber above the fluidizing bottom. In operation, the fluidizing agent fluidizes the fuel. Depending on the velocity of the fluidizing agent, the fluidized bed can be embodied as stationary, bubbling or circulating fluidized bed.

[0007] The incineration plant further comprises an auxiliary burner for igniting or supporting the combustion process of the solid material, wherein the auxiliary burner is operated with an auxiliary fuel.

[0008] It is an object of the present invention to provide an incineration plant and a method for operating an incineration plant, with which the carbon dioxide emission of the incineration plant can be reduced.

[0009] A possible solution for this problem is given with the incineration plant and the method for operating an incineration plant with the features of the respective independent claim. Further solutions and preferred embodiments are described in the preceding and following description as well as in the subclaims, wherein single features of the preferred embodiments can be combined in a technically meaningful manner. In particular, features disclosed with regard to the incineration plant can be applied to the method, and vice versa.

[0010] The problem is in particular solved by an incineration plant according to claim 1.

[0011] The problem is also in particular solved by a method for operating an incineration plant according to claim 8.

[0012] With other words: The present invention suggests to use ammonia as auxiliary fuel for operating the auxiliary burner, so that no carbon dioxide is produced by operating the auxiliary burner, whereby the CO 2 balance of the entire incineration plant is improved. Additionally, the ammonia is stored in a respective storage container, so that the ammonia can be periodically refilled, so that no stationary supply for a carbonaceous gas as auxiliary fuel needs to be embodied.

[0013] The incineration plant comprises a SCR or SNCR exhaust gas treatment system for reducing nitrogen oxides (NOx) wihin the combustion / flue gases.

[0014] In case of a SCR (selective catalytic reaction) system, ammonia may be applied to a carrier structure comprising a catalysator which is flown by the flue gases of the combustion gases, whereas in a SNCR (selective non-catalytic reaction) system gaseous ammonia is directly injected into the combustion / flue gases of the combustion process. SCR systems and SCNR systems as such are known from the prior art.

[0015] According to the invention, the storage container for the ammonia is connected with the exhaust gas treatment system and also with the auxiliary burner. Accordingly, only one storage container for ammonia is required in order to provide two separate systems (auxiliary burner and exhaust gas treatment system) with ammonia. It is therefore not necessary to provide two separate storage or supply systems in order to provide the respective operating gas to the auxiliary burner and to the exhaust gas treatment system.

[0016] The invention and the technical background will now be described with regard to the figure, which shows an incineration plant with grate firing in a schematic and exemplary way.

[0017] The incineration plant comprises a combustion chamber 60 at which bottom a combustion grate 10 is arranged. A so called combustion bed 70 consisting of solid material (fuel) and solid residues (such as ash and slag) of the combusted solid material is arranged on top of the combustion grate 10. The solid material bed 70 is advanced by the combustion grate 10 from an inlet side to an outlet 80 of the combustion chamber 60.

[0018] The incineration plant further comprises an auxiliary burner 20 for igniting or supporting the combustion process of the solid material within the solid material bed 70. The auxiliary burner 20 is connected to a storage container 30.

[0019] The auxiliary burner 20 is operated by combusting ammonia, wherein the ammonia is stored within storage container 30 connected to the auxiliary burner 20.

[0020] The incineration plant further comprises an exhaust gas treatment system 50, which is also connected to the storage container 30 for ammonia. Accordingly, only one storage container 30 is required in order to provide ammonia as operating agent to the auxiliary burner 20 as well as to the exhaust gas treatment system 50.

[0021] The exhaust gas treatment system 50 is based on the so-called and known selective non-catalytic reduction (SNCR) for which gaseous ammonia is added to the flue gases of the combustion reaction.Reference signs

[0022] 10combustion grate 20auxiliary burner 30storage container 40device for supplying combustion air 50exhaust gas treatment system 60combustion chamber 70combustion bed 80outlet

Claims

1. Incineration plant, comprising: - a combustion chamber (60), in which a fuel is combusted, - an auxiliary burner (20) for igniting or supporting the combustion process, wherein the auxiliary burner (20) is operated with an auxiliary fuel, - a storage container (30) for storing the auxiliary fuel for the auxiliary burner (20), wherein the auxiliary burner (20) is operated with ammonia as auxiliary fuel, wherein the incineration plant comprises a SCR or SNCR exhaust gas treatment system (50), wherein the storage container (30) for the ammonia is connected with the SCR or SNCR exhaust gas treatment system (50) and with the auxiliary burner (20).

2. Incineration plant according to claim 1, wherein the fuel is solid material and in particular waste or biomass.

3. Incineration plant according to any one of the preceding claims, wherein the auxiliary burner (20) is a support burner.

4. Incineration plant according to any one of the preceding claims, further comprising a combustion grate (10) for transporting the solid material through the combustion chamber (60).

5. Incineration plant according to any one of the preceding claims, further comprising a device (40) for supplying an oxidant gas to the combustion process.

6. Incineration plant according to any one of the preceding claims, wherein the oxidant gas is primary air.

7. Incineration plant according to any one of the preceding claims, wherein the storage container is a tank.

8. Method for operating an incineration plant, the method comprising: - Combusting a fuel in a combustion chamber (60), - Igniting or supporting the combustion process with an auxiliary burner (20), wherein the auxiliary burner (20) is operated with an auxiliary fuel, wherein ammonia as auxiliary fuel for the auxiliary burner (20) is stored in a storage container (30) and the auxiliary burner (20) is operated with ammonia as auxiliary fuel, wherein the incineration plant comprises a SCR or SNCR exhaust gas treatment system (50), wherein ammonia is supplied from the storage container (30) to the SCR or SNCR exhaust gas treatment system (50) and to the auxiliary burner (20).

9. Method according to claim 8, wherein the use of ammonia for operating the auxiliary burner (20) improves the CO2 balance of the incineration plant.

10. Method according to one of claims 8 or 9, wherein solid material is transported through the combustion chamber (60) on a combustion grate (10), wherein the solid material and its combusted residues form a combustion bed during combustion on the combustion grate (10).

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