JPH0631349B2 - Method and apparatus for separating synthesis gas / fly ashes mixture - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention relates to a method and apparatus for separating a syngas / fly ash mixture.

BACKGROUND OF THE INVENTION When producing synthesis gas by incomplete combustion of coal,
Fly ash often occurs as a by-product. Fly ash must be removed from the resulting synthesis gas before it can be used as a raw material for the production of organic compounds or for other uses.

It is known to carry out the operation of separating most of the synthesis gas from fly ash using a cyclone separator, one or more reactors or a combination thereof. However, this known separation method cannot perform sufficient separation. A considerable amount of synthesis gas consisting almost entirely of CO and H ₂ remains in the fly ash, so there is a risk of a significant explosion due to the H ₂ remaining in the fly ash, and also in the fly ash. There is also a risk that human health will be impaired due to residual CO. Therefore, it is important to separate substantially all syngas from the fly ash before placing it in contact with the atmosphere.

OBJECT OF THE INVENTION It is therefore an object of the present invention to provide a novel method for separating a syngas / fly ash mixture. According to the method of the present invention, H ₂ and CO ₂ are no longer substantially present in the fly ash after carrying out this separation operation, so that even if the fly ash is placed in contact with the atmosphere, H ₂ and There is little or no explosion or deterioration of human health due to the presence of CO, respectively.

Another object of the invention is to provide a device used for carrying out the method of the invention.

SUMMARY OF THE INVENTION The present invention provides a synthesis gas / fly ash mixture to be separated by carrier gas to a separator; contacting the synthesis gas / fly ash mixture with an inert gas in the separator; The active gas / syngas mixture is passed through the first of the separators.
And a fly ash through a second tube of the separator, and a method for separating a synthesis gas / fly ash mixture.

The present invention also provides a separator for use in the method for separating a synthesis gas / fly ash mixture, comprising: a separator; a feed pipe for the synthesis gas / fly ash mixture attached to the separator; It has a supply pipe, an inert gas / syngas mixture discharge pipe, and a fly ash discharge pipe, the synthesis gas / fly ash mixture supply pipe is provided with a carrier gas supply pipe, and these pipes are provided in these pipes. Pipe closing means are provided, and the inert gas supply pipe and the inert gas / syngas mixture discharge pipe are provided with means for preventing or limiting the flow of fly ash into these pipes. And the syngas /
It also relates to a device for separating fly ash mixtures.

As mentioned above, the conventional method of producing synthesis gas by gasification of coal has a serious problem, and although this problem has been solved by the present invention, the present invention is never the product of coal gasification. It is not limited to processing only, and the solution of the above problem can be applied to a wider range of fields. That is, no matter how the synthesis gas / fly ash mixture is made, the separation can be reliably carried out in accordance with the present invention, that is, the above separation can be carried out with such a high degree of separation that the above-mentioned object can be sufficiently achieved. It can be carried out.

As used herein, the term "inert gas" means a gas or gas mixture that does not react with each of the above components when the method of the present invention is carried out under the specified conditions.
The presence of CO and / or H ₂ in the inert gas is generally accepted, that although the CO or H ₂ is not necessary to remove, syngas by CO and / or H ₂ is present in the inert gas It will be quite clear that the separation operation of the / fly ash mixture is not improved. Therefore, in a preferred embodiment of the present invention, an inert gas containing no CO or H ₂ is used. Any inert gas can generally be used, so long as the inert gas meets the above definition. However, in a preferred embodiment of the present invention, an inert gas such as N ₂ or CO ₂ that remains in fly ash without risk of health deterioration or explosion.
Is used.

In a preferred embodiment of the invention, the syngas / fly ash mixture and the inert gas are contacted under a pressure of 0.5-30 bar (more preferably atmospheric pressure). The temperature can be varied within wide limits, for example 0-
The temperature may be 200 ° C. In a preferred embodiment of the invention, the operation is carried out at a temperature comparable to ambient temperature (ie room temperature).

The process according to the invention can be carried out continuously, semicontinuously or discontinuously. In a preferred embodiment of the invention, the syngas / fly ash mixture is continuously contacted with an inert gas and then the inert gas / syngas mixture and the fly ash are continuously removed.

The contact operation between the synthesis gas / fly ash mixture and the inert gas is carried out as follows: that is, the fly ash is allowed to stand or move, or is brought into contact with the inert gas in the form of a fluidized bed. It is advantageous. When the synthesis gas / fly ash mixture is contacted with an inert gas, the fly ash can be brought into a fluid state and kept in this state, in which case the inert gas is very advantageous as a fluid medium. Can be used.

After fully removing syngas from the fly ash,
The fly ash can be further processed, stored, dumped, or shipped.

The resulting inert gas / syngas mixture can be further processed or placed in a combustion furnace to remove the CO present in the gas.
And H ₂ can be removed by combustion.

If a large amount of synthesis gas has to be separated from a relatively small amount of fly ash, it is synthesized using a cyclone separator, one or more reactors or a combination thereof according to known methods before carrying out the process of the present invention. Most of the gas should be removed from the fly ash. This is called preliminary separation. The advantage here is that most of the synthesis gas is obtained in a non-mixture with the inert gas. In addition, the benefit is that the required amount of inert gas is relatively low. This preliminary separation is 5-4
It can be carried out under a pressure of 0 bar.

The process according to the invention can in principle be carried out using any separator known in the art as a separator for fine dust particles and gas.

Suitable separation devices for carrying out the process according to the invention include a separator, a feed line for the synthesis gas / fly ash mixture attached thereto, a feed line for the inert gas, and a discharge for the inert gas / syngas mixture. A pipe and a fly ash discharge pipe, these conduits being provided with pipe closing means, said inert gas supply pipe and said inert gas / syngas mixture discharge pipe being connected to the inside of the pipe. Separation device characterized in that means for blocking or limiting the inflow of fly ash is attached.

In a preferred embodiment of the invention, the feed pipe for the synthesis gas / fly ash mixture and the discharge pipe for the synthesis gas / inert gas mixture are connected to the separator at a relatively high location, and the other two said conduits are connected relatively well. Connect to the separator at a low place. In another preferred embodiment, the fly ash exhaust is connected to the bottom of the separator and the inert gas / syngas mixture exhaust is connected to the top of the separator. The connection location of the other two conduits can be appropriately determined within the scope of the above teaching depending on the size and form of the separator and the arrangement condition of each device for processing.

As already mentioned, the process according to the invention can be carried out continuously, semicontinuously or discontinuously.

A case where the operation is performed discontinuously will be described. Fly ash and synthesis gas are fed to the separator via the feed pipe, but the other conduits are closed at this time. Then, close the supply pipes for fly ash and synthesis gas, open the supply pipe for the inert gas, supply the inert gas to the separator to keep the inside of the separator at high pressure (30 bar or less), and then the inert gas. The supply pipe of is closed again. The syngas and inert gas outlets are then opened, if desired after some time. Since the inside of the separator is kept at a high pressure, the syngas / inert gas mixture leaves the separator and is discharged out of the system. After that, the following operations are carried out in order: the syngas / inert gas mixture exhaust pipe is closed and the fly ash exhaust pipe is opened to remove the fly ash. If desired, fly ash can be removed with the aid of a carrier gas, which carrier gas is preferably of the same type as the inert gases mentioned above (eg N ₂ or CO ₂ ). After closing the fly ash exhaust pipe and opening the fly ash / syngas mixture supply pipe, the process according to the invention can be carried out again, that is to say the new raw material fly ash / syngas mixture can be processed. When the synthesis gas is not sufficiently separated from the fly ash, the above-mentioned separation operation can be repeated once or several times for the fly ash and the residual synthesis gas. This can be done in one of two ways: The first way is to instead re-contact the fly ash and residual syngas with the inert gas in the same separator instead of exhausting it from the separator. A second method is to discharge the fly ash and residual syngas from the separator and then place it in another one or more separators to carry out the separation process again. It will generally be sufficient to repeat the above method for about 10 times. It is often the case that good results are obtained by repeating the method about 3 to 6 times.

When the method of the present invention is carried out semi-continuously, synthesis gas /
The fly ash mixture is fed to the separator, while the other conduits are closed. Then the syngas / fly ash mixture supply pipe is closed, after which the inert gas supply pipe and the inert gas and synthesis gas discharge pipe are opened,
The inert gas is then continuously passed through the fly ash and the inert gas / syngas mixture is evacuated, and this operation is continued until the syngas is well separated from the fly ash. After closing the open conduit, the fly ash is discharged through its discharge pipe. This discharge can be carried out with the aid of the carrier gas already mentioned, if desired.

As described above, the method of the present invention is preferably carried out continuously, which will be described in detail. The fly ash / syngas mixture and the inert gas are fed simultaneously and continuously to the separator via feed lines. This supply pipe is installed for the above purpose. Then, the inert gas / synthesis gas mixture and the fly ash are continuously discharged through the discharge pipe. This discharge pipe is installed for the above purpose. The flow rate of the inert gas through the separator can be varied within wide limits. This is because the flow rate of the inert gas depends on the passage speed of the fly ash and the synthesis gas in the separator, the amount of the synthesis gas to be separated from the fly ash, the size of the separator, and the like.

The pressure should be kept constant when operating semi-continuously or continuously, as opposed to operating discontinuously.

When the synthesis gas / fly ash mixture is contacted with an inert gas, the fly ash is stationary as described above.
It can be kept in the form of a fluidized bed with kinetic or inert gas. In a preferred embodiment of the invention, a fluidized bed is used, i.e. dust particle fluidization means are attached to the separator according to known techniques and inert gas is used to fluidize and maintain the fly ash.

As mentioned above, fly ash / syngas mixtures containing relatively large amounts of syngas can be subjected to a pre-separation operation prior to contact with an inert gas. The composition of the fly ash / syngas of the mixture is different before and after the pre-separation operation. This is because a large part of the synthesis gas is separated during the pre-separation operation.

In order to feed the syngas / fly ash mixture obtained by the pre-separation operation to the separator, the feed pipe of the syngas / fly ash mixture (the feed pipe connected to the separator) is pre-separated by means of a cyclone. Separator, one or more devices or combinations thereof).

The pre-separation operation can be carried out under a pressure of 5-40 bar.
Since contacting the synthesis gas / fly ash mixture with the inert gas is carried out at a relatively low pressure, the pressure must be reduced before this contacting. For this purpose, according to the invention, a means for reducing the pressure inside the separator can be attached to the separator. The pressure reducing means may be known per se. In a preferred embodiment, this pressure reduction means is installed between the pre-separation means and the separator in the separation device of the present invention. Examples of pressure reducing means that can be used include the separate vessels known per se, which are suitable for pressure reduction. Furthermore, elongated, preferably coiled and perforated pipes can also be used as pressure reducing means. In the preferred embodiment of the invention, a separation vessel is used. After the pressure has been reduced, the synthesis gas / fly ash mixture can be fed to the separator, which feeding can be carried out via the feed line of the synthesis gas / fly ash mixture with the aid of a carrier gas.

Furthermore, it is also advantageous to provide the device according to the invention with a suitable container for the storage of the fly ash / syngas mixture.
This storage container is preferably arranged between and connected to the pressure reducing means and the cyclone separator, the vessel or a combination thereof. As already mentioned, the separation method and the separation device according to the invention are particularly suitable for separating the fly ash / syngas mixture obtained by the coal gasification operation.

Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic tubing diagram of an example of a separator for a synthesis gas / fly ash mixture according to the present invention.

Syngas obtained by gasification of coal under a pressure of 5-40 bar is piped together with fly ash which is a by-product.
It is supplied to a container (2) via (1), and according to a known method, a cyclone separator, one or more separators or a combination thereof (these devices are schematically shown in the drawings as a container (2)). Most of the synthesis gas is separated by. This is called preliminary separation. The synthesis gas separated here is discharged via the pipe (3) and then further processed,
Or used for other purposes. The fly ash, together with the residual syngas, is introduced into a storage container (also called "collector container") (5) via a pipe (4). Container (2) and Container (5)
Is kept under the same pressure as during the coal gasification step.

Storage container with sufficient amount of fly ash / syngas mixture
Once fed to (5), this mixture is immediately introduced via tube (6) into vessel (7), where the pressure is reduced to atmospheric pressure. This fly ash / syngas mixture is then continuously separated with a carrier gas supplied via tube (9).
Supply to (10). The separator (10) has means for bringing the fly ash into and keeping it in a fluid state. This fluidization is carried out with the aid of a continuous inert gas stream supplied from the pipe (11). Synthetic gas and inert gas are continuously removed via the pipe (12) and fly ash is removed via the pipe (13).

The fly ash obtained by this is H ₂ or C
Can be further processed or transported without the risk of explosions or harm to humans or animals due to the presence of O respectively,
Alternatively it can be stored.

The amount of synthesis gas in the synthesis gas / fly ash mixture after the above-mentioned pretreatment is 10 Nl or more (expressed as the amount of synthesis gas per 1 kg of fly ash). By carrying out the process according to the invention, this amount can be reduced to a small amount of less than 0.01 Nl (indicated by the amount of synthesis gas per kg of fly ash).

Various embodiments of the present invention will be apparent to those skilled in the art from the description herein and accompanying drawings. It is to be understood that these embodiments are also within the scope of the invention as claimed.

[Brief description of drawings]

FIG. 1 is a schematic tubing diagram of an example of the device of the present invention. 1 ... Syngas / fly ash mixture supply pipe; 2 ...
… Separation container for preliminary separation; 3 …… Syngas exhaust pipe; 4
...... Exhaust pipe for fly ash and residual synthesis gas; 5 ……
Storage container (also referred to as “collector container”); 7 ... Pressure reducing container; 9 ... Carrier gas supply pipe, 10 ...
... Separator; 11 ... Inert gas supply pipe; 12 ... Syngas and inert gas exhaust pipe; 13 ... Fly ash exhaust pipe.

Claims (15)

[Claims] 1. A synthesis gas / fly ash mixture to be separated is sent by a carrier gas to a separator; said synthesis gas / fly ash mixture is contacted with an inert gas in said separator; and subsequently an inert gas. A method for separating a synthesis gas / fly ash mixture comprising: removing a synthesis gas mixture through a first tube of the separator and removing fly ash through a second tube of the separator; 2. Process according to claim 1, characterized in that the inert gas is N ₂ or CO ₂ . 3. Process according to claim 1 or 2, characterized in that the synthesis gas / fly ash mixture and the inert gas are contacted under a pressure of 0.5-30 bar. 4. The method according to claim 3, wherein the contact operation is performed under atmospheric pressure. 5. A method of continuously contacting a synthesis gas / fly ash mixture with an inert gas, and then continuously removing both the inert gas / syngas mixture and fly ash. The method according to any one of claims 1 to 4. 6. The method according to claim 1, wherein when the synthesis gas / fly ash mixture and the inert gas are brought into contact with each other, the fly ash is kept in a fluid state. The method according to any one of 1. 7. The method according to claim 6, wherein the fly ash is kept in a fluidized state with the aid of an inert gas. 8. Syngas / contacted with an inert gas
A fly ash mixture (referred to as "Mixture A") was obtained from another fly ash / syngas mixture having a different fly ash / syngas composition (referred to as "Mixture B"), ie, Mixture A A mixture B obtained after a separation operation using a cyclone separator, one or more reactors or a combination thereof to separate most of the synthesis gas from the fly ash. The method according to any one of items 1 to 7. 9. A synthesis gas / fly ash mixture (referred to as "mixture A") to be contacted with an inert gas to another mixture (referred to as "mixture B") having a different fly ash / syngas composition. 9. Cyclone separator, obtained by carrying out a separating operation under a pressure of 5-40 bar using one or more transoilers or a combination thereof. The method described. 10. A separator, a syngas / fly ash mixture supply pipe attached to the separator, an inert gas supply pipe, an inert gas / synthesis gas discharge pipe, and a fly ash A discharge pipe, the supply pipe of the synthesis gas / fly ash mixture is provided with a supply pipe of a carrier gas, and these pipes are provided with pipe closing means, and the supply pipe of the inert gas and the inert gas / synthesis are provided. The gas mixture discharge pipes are provided with means for preventing or limiting the flow of fly ash into these pipes.
Equipment for separating fly ash mixtures. 11. A synthesis gas / fly ash mixture supply pipe and an inert gas / syngas mixture discharge pipe are connected to a separator at a relatively high place, and the other two pipes are connected at a relatively low place. The device according to claim 10, characterized in that 12. Apparatus according to claim 10 or 11, characterized in that the separator is provided with means for keeping the fly ash in a fluidized state. 13. A feed line for a syngas / fly ash mixture (referred to as "Mixture A") is connected to a cyclone separator, one or more reactors or a combination thereof, the separation means comprising fly ash. Claim 11 characterized in that it is suitable for separating the majority of the syngas from another syngas / fly ash mixture of different syngas composition (referred to as "mixture B"). -A device according to any one of clause 12. 14. A means suitable for reducing the pressure, characterized in that it is arranged between and connected to a cyclone separator, a transponder or a combination thereof and a separator. 14. The device according to claim 13, wherein 15. A container suitable for the storage of the fly ash / syngas mixture, that is, the container is arranged between a cyclone separator, a vessel or a combination thereof and a pressure reducing means, The device according to claim 14, which is connected to these.