JP5088535B2 - Fuel gasification equipment - Google Patents

Description

  The present invention relates to a fuel gasification facility.

  2. Description of the Related Art Conventionally, development of a fuel gasification facility that generates a gasification gas using a solid fuel such as coal, biomass, waste plastic, or various hydrated wastes as a fuel has been advanced.

  6 and 7 show an example of a conventional fuel gasification facility. The fuel gasification facility has a fluid medium (eg, sand, limestone, etc.) using steam and a reaction gas for flow such as air or oxygen. A gasification furnace 2 that generates gasified gas and combustible solids by gasifying solid fuel (coal, biomass, etc.) that is input after forming the fluidized bed 1, and is generated in the gasifier 2. Combustion furnace 5 in which a combustible solid content is introduced from an introduction pipe 3 together with a fluid medium and a fluidized bed 4 is formed by a reaction gas for flow to burn the combustible solid content. Generated in the gasification furnace 2, and a medium separation device 8 such as a hot cyclone that separates the fluidized medium from the exhaust gas introduced through the exhaust gas and supplies the separated fluidized medium to the gasification furnace 2 through the downcomer 7. Hot separating the fluidized medium from the gasified gas A medium separating device 9, such as a cyclone, has provided comprising constituting a collecting container 10 for collecting the fluidized medium separated by said medium separating device 9.

  In FIGS. 6 and 7, 11 is a dispersion plate for uniformly blowing steam introduced into the bottom of the gasification furnace 2 and flowing reaction gas into the fluidized bed 1, and 12 is the inside of the gasification furnace 2. A partition wall for preventing the fluid medium in the fluidized bed 1 from flowing out directly to the introduction pipe 3 by covering the part to which the introduction pipe 3 is connected in such a way that only the lower part is opened; 5 is a dispersion plate for uniformly blowing the flowing reaction gas into the fluidized bed 4, 14 is a hopper for storing the solid fuel, and 15 is a screw feeder for cutting out the solid fuel stored in the hopper 14. , 16 is a fuel supply pipe to which the solid fuel cut out by the screw feeder 15 is guided and connected to a position higher than the upper surface of the fluidized bed 1 on the side surface of the gasification furnace 2.

  In the fuel gasification facility as described above, in the gasification furnace 2, the fluidized bed 1 is formed by the reaction gas for flow such as steam and air or oxygen, and the coal, biomass, etc. stored in the hopper 14 here. When the solid fuel is cut out by the screw feeder 15 and introduced from the fuel supply pipe 16, the solid fuel is partially oxidized and gasified to generate gasified gas and combustible solids, which are generated in the gasifier 2. The combustible solid content is introduced from the introduction pipe 3 together with the fluid medium into the combustion furnace 5 in which the fluidized bed 4 is formed by the flow reaction gas, and the combustible solid content is combusted. The exhaust gas from the exhaust gas is introduced into a medium separator 8 such as a hot cyclone through an exhaust gas pipe 6. In the medium separator 8, the fluid medium is separated from the exhaust gas, and the separated fluid medium is Returned to the gasification furnace 2 through a Nkama 7, it is circulated.

Here, the inside of the gasification furnace 2 is maintained at a high temperature in the presence of steam supplied to the bottom of the gasification furnace 2 or moisture evaporated from the solid fuel itself, and is generated by pyrolysis of the solid fuel. When gas or its residual fuel reacts with steam, water gasification reaction [C + H ₂ O = H ₂ + CO] or hydrogen conversion reaction [CO + H ₂ O = H ₂ + CO ₂ ] occurs, and H ₂ , CO, etc. A combustible gasification gas is produced.

  The gasified gas generated in the gasification furnace 2 is separated into a fluid medium by a medium separator 9 such as a hot cyclone, and the fluid medium separated by the medium separator 9 is recovered in a recovery container 10.

For example, Patent Document 1 discloses an apparatus configuration similar to the fuel gasification facility shown in FIGS. 6 and 7.
JP 2006-207947 A

Incidentally, in the conventional fuel gasification system such as described above, wherein the gasification gas generated in the gasification furnace 2 also contains CO _2, the CO ₂ contained in the gasification gas, the product Although it is finally separated from flammable gases such as H ₂ and CO, it has not been said that it has been fully utilized effectively.

In view of such circumstances, the present invention can effectively utilize CO ₂ gas finally separated from combustible gas such as H ₂ and CO as a product for supplying solid fuel to a gasifier, An object of the present invention is to provide a fuel gasification facility that can stably supply fuel to a gasification furnace.

The present invention comprises a gasification furnace that gasifies a solid fuel containing biomass that is input by forming a fluidized bed of a fluidized medium with a fluidizing reaction gas and generates gasified gas and combustible solids,
An O ₂ separator that separates air into O ₂ and N ₂ ;
High temperature reformer for performing reforming tar and lower hydrocarbons as a mixture of o _2, wherein the relative gasification gas produced in the gasification furnace is separated by the O ₂ separator,
CO ₂ gas separation and circulation means for separating CO ₂ gas from gasification gas downstream of the high-temperature reforming furnace and introducing the solid fuel to the gasification furnace supply system. And
The CO ₂ gas separation / circulation means is constituted by a CO ₂ separator provided in a preceding stage of an ammonia synthesizer for producing ammonia by mixing H ₂ in a gasification gas with N ₂ separated by the O ₂ separator. ,
A fuel supply pipe is connected to a position lower than the upper surface of the fluidized bed on the side surface of the gasification furnace, and the solid fuel is supplied from the fuel supply pipe into the fluidized bed.
A flow gas pipe is connected in the vicinity of a connection portion of the fuel supply pipe to the gasification furnace, and the CO ₂ gas separated by the CO ₂ separator is separated from the flow gas pipe by the solid fuel containing the biomass. The present invention relates to a fuel gasification facility which is configured to be introduced as a flowing gas for stably supplying into a fluidized bed so as not to be melted and fixed to a connecting portion of a fuel supply pipe .

  According to the above means, the following operation can be obtained.

When configured as described above, the CO ₂ gas separated from the gasification gas is effectively used for supplying the solid fuel to the gasification furnace, so that the solid fuel is stably supplied to the gasification furnace and the gasification is performed. C + CO ₂ → 2CO, one of the gasification reactions in the furnace
Reaction will be promoted, leading to improved gasification efficiency.

In the fuel gasification facility, a spray tower for dedusting and removing trace components from the gasification gas reformed in the high-temperature reforming furnace, and a gasification in which dust removal and trace component removal has been performed in the spray tower A desulfurization tower that removes sulfur from the gas and a precision remover that removes trace components such as light tar from the gasification gas from which sulfur has been removed in the desulfurization tower can be further provided .

On the other hand, in the fuel gasification system, the CO ₂ gas separated by the CO ₂ gas separating circulating means, be introduced into the hopper solid fuel is stored, the solid fuel is dried, the solid fuel CO ₂ This is effective for pumping and steady supply with gas.

According to the above configuration, compared with the case where the solid fuel is supplied from the fuel supply pipe onto the fluidized bed of the gasification furnace, the solid fuel fine particles do not scatter and are in sufficient contact with the fluid medium. , The thermal decomposition of solid fuel is reliably completed, the amount of gas heat obtained, that is, the efficiency of cold gas is increased, the C conversion rate and the H conversion rate are also increased, and the tar in the gasification gas can be reformed. Become. Here, if the fuel supply pipe is connected to a position lower than the upper surface of the fluidized bed on the gasifier side surface and the solid fuel is supplied from the fuel supply pipe into the fluidized bed, biomass is used as the solid fuel. In this case, since the biomass has a higher volatile content than coal and is easily gasified, at the connection portion of the fuel supply pipe to the gasifier, the biomass is heated to several hundred [° C.] and melted. Although it is conceivable that the fuel supply pipe is clogged, in the case of the configuration as described above, CO ₂ gas is supplied as a flowing gas from the flow gas pipe connected to the fuel supply pipe, and the flow of the solid fuel is promoted. Therefore, even if biomass is used as the solid fuel, the melted biomass does not adhere to the connecting portion of the fuel supply pipe, and there is no fear that the fuel supply pipe is clogged.

According to the fuel gasification facility of the present invention, the CO ₂ gas finally separated from the combustible gas such as H ₂ or CO that is the product can be effectively used for supplying the solid fuel to the gasification furnace, An excellent effect that the solid fuel can be stably supplied to the gasification furnace can be obtained.

  Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIGS. 1 and 2 are reference examples for carrying out the present invention. In the figure, the same reference numerals as those in FIGS. 6 and 7 denote the same components, and the basic configuration is shown in FIG. 7 is similar to the conventional one shown in FIG. 7, but the feature of the illustrated example is that, as shown in FIGS. 1 and 2, CO ₂ gas is extracted from the gasification gas generated in the gasification furnace 2. A CO ₂ gas separation / circulation means for separating and leading to the supply system of the solid fuel to the gasification furnace 2 is provided.

In the case of this example,
An O ₂ separator 17 for separating air into O ₂ and N ₂ ;
(Not shown in FIG. 1, see FIG. 6) the generated in the gasification furnace 2 medium separator 9 O ₂ where the fluidized medium is separated by the relative separated gasification gas O ₂ separator 17 A high temperature reforming furnace 18 for mixing and reforming tar and lower hydrocarbons;
A spray tower 19 for dedusting and removing trace components from the gasified gas reformed in the high-temperature reforming furnace 18;
A desulfurization tower 20 for removing sulfur from the gasification gas that has been dedusted and trace components removed in the spray tower 19;
A precision remover 21 for removing trace components such as light tar from the gasification gas from which sulfur has been removed in the desulfurization tower 20;
A CO ₂ separator 22 for separating CO ₂ from a gasified gas (H ₂ , CO, CO ₂ ) from which trace components such as light tar have been removed by the precision remover 21;
FT for producing H ₂ and CO as liquid fuel by performing a Fischer-Tropsch synthesis reaction in which the H ₂ / CO ratio in the gasified gas from which CO ₂ has been separated by the CO ₂ separator 22 is adjusted to about 2. And the CO ₂ gas separation / circulation means is constituted by a CO ₂ separator 22 provided in the preceding stage of the FT synthesizer 23.

Then, CO ₂ gas separated by the CO ₂ separator 22 as the CO ₂ gas separating circulating means, as shown in FIG. 2, a supply system to the gasification furnace 2 of a solid fuel and solid fuel reservoir The hopper 14 is configured to be introduced.

  Next, the operation of the illustrated example will be described.

In the case of the reference example shown in FIG. 1, the gasification gas generated in the gasification furnace 2 and separated from the fluidized medium in the medium separation device 9 (not shown in FIG. 1, see FIG. 6) O ₂ separator 17 are mixed separate O ₂ reforming of tar and lower hydrocarbons is carried out, dedusting from reformed gasification gas in the hot reformer 18 in a spray tower 19 as well as in Trace component removal was performed, sulfur was removed from the gasification gas in which dedusting and trace component removal was performed in the spray tower 19 in the desulfurization tower 20, and sulfur was removed in the desulfurization tower 20 in the precision remover 21. From the gasification gas (H ₂ , CO, CO ₂ ) from which the trace components such as light tar are removed from the gasification gas and the trace components such as light tar are removed by the precision remover 21 in the CO ₂ separator 22. ₂ are separated, FT synthesis H ₂ and CO as a liquid fuel by the CO ₂ separator 22 with CO ₂ is a Fischer-Tropsch synthesis reaction to adjust the H ₂ / CO ratio of about 2 gasification gas separated is carried out at 23 are produced, the CO ₂ gas separated by the CO ₂ separator 22 as the CO ₂ gas separating circulating means, as shown in FIG. 2, is introduced into the hopper 14 the solid fuel is stored.

As described above, when the CO ₂ gas is introduced into the hopper 14, the solid fuel is dried in the hopper 14, and the solid fuel is pumped by the CO ₂ gas, so that the solid fuel is constantly supplied. Is possible.

Further, when the CO ₂ gas is supplied from the hopper 14 through the screw feeder 15 and the fuel supply pipe 16 to the gasification furnace 2, C + CO ₂ → 2CO, which is one of gasification reactions.
Reaction will be promoted, leading to improved gasification efficiency.

Incidentally, it is possible to introduce N ₂ gas, steam, or the like into the hopper 14, but if N ₂ gas is introduced into the hopper 14, an inert gas is mixed into the gasification furnace 2, thereby generating While the amount of heat of the gasified gas is reduced, if steam is introduced into the hopper 14, extra steam is required, and the efficiency of the entire system is reduced accordingly. However, in this illustrated example, since CO ₂ finally separated from the combustible gas such as H ₂ or CO that is the product is circulated and used, the calorific value of the gasification gas as in the case of using N ₂ gas. There is no concern that the efficiency of the entire system will be reduced as in the case of using steam.

Thus, the CO ₂ gas finally separated from the combustible gas such as H ₂ or CO that is the product can be effectively used for supplying the solid fuel to the gasification furnace 2, and the solid fuel is supplied to the gasification furnace 2. It can be supplied stably.

  FIG. 3 is a main part configuration diagram showing a modified example of the gasification furnace 2, in which the parts denoted by the same reference numerals as in FIGS. 1 and 2 represent the same thing, and the basic configuration is shown in FIG. 1 and FIG. 2, but the feature of this illustrated example is that the fuel supply pipe 16 is connected to a position lower than the upper surface of the fluidized bed 1 on the side surface of the gasifier 2 as shown in FIG. The solid fuel is supplied from the fuel supply pipe 16 into the fluidized bed 1.

  As described above, when the fuel supply pipe 16 is connected to a position lower than the upper surface of the fluidized bed 1 on the side surface of the gasification furnace 2 and the solid fuel is supplied from the fuel supply pipe 16 into the fluidized bed 1, FIG. As in the example, compared with the case where the solid fuel is supplied from the fuel supply pipe 16 onto the fluidized bed 1 of the gasification furnace 2, the solid fuel fine particles are not scattered and are sufficiently in contact with the fluid medium. , The thermal decomposition of solid fuel is reliably completed, the amount of gas heat obtained, that is, the efficiency of cold gas is increased, the C conversion rate and the H conversion rate are also increased, and the tar in the gasification gas can be reformed. Become.

FIG. 4 is a main part configuration diagram showing another specific example of the gasification furnace 2 in the reference example (see FIG. 1) of the embodiment of the present invention. In the figure, the same reference numerals as those in FIGS. 1 and 3 are used. The attached parts represent the same thing, and the basic configuration is the same as that shown in FIGS. 1 and 3, but the feature of this illustrated example is that the CO ₂ gas separation and circulation means serves as the CO ₂ gas separation and circulation means. Instead of introducing the CO ₂ gas separated by the _two separators 22 (see FIG. 1) into the hopper 14 in which the solid fuel is stored, as shown in FIG. 4, as a supply system of the solid fuel to the gasifier 2 of connecting the connecting portion fluidizing gas pipe 24 in the vicinity for the gasification furnace 2 of the fuel supply pipe 16, separated by the CO ₂ separator 22 as the CO ₂ gas separating circulating means to flowable gas pipe 24 the CO ₂ gas, the fluidizing gas for supplying solid fuel stably into the fluidized bed It lies in that is configured to introduce.

Here, as in the examples shown in FIGS. 3 and 4, the fuel supply pipe 16 is connected to a position lower than the upper surface of the fluidized bed 1 on the side surface of the gasification furnace 2, and the solid fuel is fed into the fluidized bed 1 from the fuel supply pipe 16. When configured to supply, especially when biomass is used as a solid fuel, the biomass has a higher volatile content than coal and is easily gasified. Therefore, at the connection portion of the fuel supply pipe 16 to the gasification furnace 2, several hundred [° C.] If the fuel is heated and melted and is fixed, the fuel supply pipe 16 may be clogged. However, in the example shown in FIG. 4, the flow gas connected to the fuel supply pipe 16 from the tube 24 CO ₂ gas is supplied as a fluidizing gas, since the flow of the solid fuel is promoted, even with the use of biomass as a solid fuel, without biomass was melted causes sticking to the connection portion of the fuel supply pipe 16 There is no worry about clogged fuel supply pipe 16.

In the example shown in FIG. 4, similarly to the example shown in FIG. 3, the CO ₂ gas separated by the CO ₂ separator 22 as CO ₂ gas separating circulating means (see FIG. 1) is a solid fuel is stored Needless to say, it may be introduced into the hopper 14.

FIG. 5 is a first example of an embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same components, and the basic configuration is the same as that shown in FIG. However, as shown in FIG. 5, the feature of this illustrated example is that the CO ₂ gas separation and circulation means is an ammonia synthesizer that produces ammonia by mixing H ₂ in the gasification gas with N ₂ . 25 is constituted by the CO ₂ separator 22 provided in the preceding stage.

For this illustrated example, the CO ₂ in the CO ₂ separator 22 is provided with of H ₂ separator 26 which separates and H ₂ from gasification gas separated, separated by the H ₂ separator 26 H ₂ is introduced into the ammonia synthesizer 25 for reaction during the production of ammonia, and the CO from which H ₂ has been separated by the H ₂ separator 26 is gasified gas from which CO ₂ has been separated by the CO ₂ separator 22. It is trying to return to.

  Even when the system configuration shown in FIG. 5 is adopted, as a specific example of the gasification furnace 2, any of the formats shown in FIGS. 2, 3, and 4 can be used as in the case of FIG. The same effect can be obtained.

  The fuel gasification facility of the present invention is not limited to the above-described illustrated examples, and various modifications can be made without departing from the scope of the present invention.

It is a block diagram which shows the system configuration | structure of the reference example of embodiment which implements this invention. It is a principal part block diagram which shows the specific example of the gasification furnace in the reference example of embodiment which implements this invention. It is a principal part block diagram which shows the modification of the gasification furnace shown in FIG. It is a principal part block diagram which shows the other specific example of the gasification furnace in the reference example of embodiment which implements this invention. It is a block diagram which shows the system configuration | structure of the 1st example of embodiment which implements this invention. It is a whole schematic block diagram which shows an example of the conventional fuel gasification installation. It is a principal part block diagram which shows the gasification furnace in an example of the conventional fuel gasification equipment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluidized bed 2 Gasification furnace 3 Introducing pipe 5 Combustion furnace 7 Downcomer 8 Medium separator 10 Recovery container 11 Dispersing plate 14 Hopper (supply system)
15 Screw feeder 16 Fuel supply pipe (supply system)
19 Spray tower
20 Desulfurization tower
21 Precision remover 22 CO ₂ separator (CO ₂ gas separation and circulation means)
23 FT Synthesizer 24 Gas Pipe for Flow 25 Ammonia Synthesizer

Claims (3)

A gasification furnace that forms a fluidized bed of a fluidized medium with a fluidizing reaction gas and gasifies a solid fuel containing biomass and generates gasified gas and combustible solids;
An O ₂ separator that separates air into O ₂ and N ₂ ;
High temperature reformer for performing reforming tar and lower hydrocarbons as a mixture of o _2, wherein the relative gasification gas produced in the gasification furnace is separated by the O ₂ separator,
CO ₂ gas separation and circulation means for separating CO ₂ gas from gasification gas downstream of the high-temperature reforming furnace and introducing the solid fuel to the gasification furnace supply system. And
The CO ₂ gas separation / circulation means is constituted by a CO ₂ separator provided in a preceding stage of an ammonia synthesizer for producing ammonia by mixing H ₂ in a gasification gas with N ₂ separated by the O ₂ separator. ,
A fuel supply pipe is connected to a position lower than the upper surface of the fluidized bed on the side surface of the gasification furnace, and the solid fuel is supplied from the fuel supply pipe into the fluidized bed.
A flow gas pipe is connected in the vicinity of a connection portion of the fuel supply pipe to the gasification furnace, and the CO ₂ gas separated by the CO ₂ separator is separated from the flow gas pipe by the solid fuel containing the biomass. A fuel gasification facility configured to be introduced as a fluidized gas for stably supplying into a fluidized bed so as not to be melted and fixed to a connecting portion of a fuel supply pipe . A spray tower for dedusting and removing trace components from the gasified gas reformed in the high temperature reforming furnace;
A desulfurization tower for removing sulfur from the gasification gas that has been dedusted and trace components removed in the spray tower;
The fuel gasification facility according to claim 1, further comprising a precision remover that removes trace components such as light tar from the gasification gas from which sulfur has been removed in the desulfurization tower. The fuel gasification facility according to claim 1 or 2, wherein the CO ₂ gas separated by the CO ₂ separator is introduced into a hopper in which solid fuel is stored.

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