JP2018095717A - Waste water treatment apparatus for use in twin tower gasification facility and twin tower gasification facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a waste water treatment apparatus of a simple structure for use in a twin tower gasification facility, capable of preventing the deterioration of efficiency while reducing the cost thereof without discharging waste water to outside, and a twin tower gasification facility.SOLUTION: The twin tower gasification facility comprises a gasification furnace 1 that gasifies a raw material charged into a fluidized bed of a fluid medium to produce a gasified gas and a combustible solid component, a combustion furnace 2 that burns the combustible solid component produced in the gasification furnace 1 and introduced from the gasification furnace 1 thereinto together with the fluid medium, a fluid-medium separation device 3 that separates the fluid medium from the flue gas introduced from the combustion furnace 2 and returns the separated fluid medium to the gasification furnace 1, a gasified gas purification device 4 that purifies the gasified gas produced in the gasification furnace 1, a concentrator 5 that heats the waste water discharged from the gasified gas purification device 4 with steam to concentrate the same, and a pump 6 that sends waste water concentrated in the concentrator 5 to the combustion furnace 2.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wastewater treatment apparatus for a two-column gasification facility and a two-column gasification facility.

  In general, in a two-column gasification facility equipped with a gasification furnace and a combustion furnace, wastewater treatment equipment for purifying wastewater generated in the process of gasification gas purification to a discharge standard suitable for the environment where the plant is installed Is going to be established.

  In addition, there exists patent document 1 as an example which shows the general technical level relevant to the two-column type gasification equipment provided with the said waste water treatment equipment.

JP 2014-24937 A

  However, the wastewater treatment apparatus disclosed in Patent Document 1 requires a sedimentation separation unit, an ammonia removal unit, an activated sludge tank, and the like, and has a large number of devices, and the initial cost and running cost increase while being consumed. The problem remains that the efficiency of the entire plant is reduced by the amount of energy required, and there is room for improvement.

  The present invention has been made in view of the above-described conventional problems, and wastewater treatment of a two-column gasification facility that can suppress the reduction in efficiency while reducing the cost without taking the wastewater out of the system with a simple configuration. An apparatus and a two-column gasification facility are to be provided.

In order to achieve the above object, the present invention provides a combustion furnace in which combustible solids produced in a gasification furnace are introduced from the gasification furnace together with a fluid medium to burn the combustible solids, and the gasification A wastewater treatment device for a two-column gasification facility equipped with a gasification gas purification device for purifying gasification gas generated in a furnace,
A concentrator for concentrating the waste water discharged from the gasification gas purifier by heating with steam;
And a pump for guiding the waste water concentrated by the concentrator to the combustion furnace.

  In the wastewater treatment apparatus for the two-column gasification facility, the steam used for heating the wastewater in the concentrator may be surplus steam produced by heat recovery in the two-column gasification facility.

  In addition, the concentrator may include a discharge unit that discharges moisture evaporated by steam heating to the atmosphere.

On the other hand, the two-column gasification facility of the present invention is a gasification furnace that gasifies a raw material charged into a fluidized bed of a fluidized medium to generate a gasified gas and a combustible solid content,
A combustion furnace in which combustible solids generated in the gasification furnace are introduced from a gasification furnace together with a fluidized medium to burn the combustible solids;
A medium separation device for separating a fluid medium from combustion exhaust gas introduced from the combustion furnace and returning the separated fluid medium to the gasification furnace;
A gasification gas purification apparatus for purifying the gasification gas generated in the gasification furnace;
A concentrator for concentrating the waste water discharged from the gasification gas purifier by heating with steam;
And a pump for guiding the waste water concentrated by the concentrator to the combustion furnace.

In the two-column gasification facility, the gasification gas purification device is
A tar reforming furnace for heating the gasified gas by supplying an oxidizing agent to reform tar contained in the gasified gas;
A boiler that generates heat by recovering heat from gasified gas whose tar has been reformed in the tar reforming furnace, and introduces the generated surplus steam into the concentrator;
A water scrubber for cooling the gasification gas can be provided by spraying the cooling water onto the gasification gas whose temperature has been recovered by heat recovery from the boiler.

Moreover, in the two-column gasification facility, the gasification gas purification device is:
A boiler that recovers heat from the gasified gas to generate steam, and introduces the generated surplus steam into the concentrator;
A water scrubber for cooling the gasification gas can be provided by spraying the cooling water onto the gasification gas whose temperature has been recovered by heat recovery from the boiler.

  According to the two-column gasification facility wastewater treatment apparatus and the two-column gasification facility of the present invention, it is possible to suppress a decrease in efficiency while reducing costs without discharging wastewater outside the system with a simple configuration. The effects can be achieved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole schematic block diagram which shows the Example of the waste water treatment equipment of the double tower type gasification equipment of this invention, and a double tower type gasification equipment. It is a general | schematic block diagram which shows an example (dry type) of the gasification gas refinement | purification apparatus in the Example of the waste water treatment equipment of the double tower type gasification equipment of this invention, and the double tower type gasification equipment. It is a general | schematic block diagram which shows the other example (wet) of the gasification gas refinement | purification apparatus in the Example of the waste water treatment equipment of the double tower type gasification equipment of this invention, and the double tower type gasification equipment.

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

  FIG. 1 shows an embodiment of a wastewater treatment apparatus for a two-column gasification facility and a two-column gasification facility according to the present invention.

  The two-column gasification facility of the present embodiment includes a gasification furnace 1, a combustion furnace 2, a medium separation device 3, and a gasification gas purification device 4. As a wastewater treatment device, a concentrator 5 and a pump 6 is provided.

  The gasification furnace 1 gasifies a raw material such as lignite charged into a fluidized bed of a fluid medium such as silica sand to generate a gasification gas and a combustible solid content. A fluidized bed of the fluidized medium is formed at the bottom of the gasification furnace 1 by introducing a gasifying agent such as water vapor.

  The combustion furnace 2 is configured such that the combustible solid content generated in the gasification furnace 1 is introduced from the gasification furnace 1 together with a fluidized medium, and the combustible solid content is combusted. By introducing air to the bottom of the combustion furnace 2, the combustible solid content is burned while blowing up the fluid medium and the combustible solid content.

  The medium separator 3 separates the fluid medium from the combustion exhaust gas introduced from the combustion furnace 2 and returns the separated fluid medium to the gasifier 1. Note that the high-temperature combustion exhaust gas from which the fluid medium has been separated by the medium separation device 3 is cooled to a set temperature by recovering heat in the boiler 7.

  The gasification gas purification device 4 is provided on the downstream side of the gasification gas generated in the gasification furnace 1 in the flow direction, and purifies the gasification gas.

  The concentrator 5 concentrates the waste water discharged from the gasification gas purification device 4 by heating with steam.

  The pump 6 is provided in the middle of a pipe connecting the concentrator 5 and the combustion furnace 2, and guides waste water concentrated by the concentrator 5 to the combustion furnace 2. The wastewater is burned.

  As shown in FIG. 2, the gasification gas purification apparatus 4 includes a tar reforming furnace 8, a boiler 9, a water scrubber 10, and a post-stage gas purification unit 11, as shown in FIG. ing.

  The tar reforming furnace 8 is provided on the downstream side of the gasification furnace 1 in the flow direction of the gasification gas, and heats the gasification gas to, for example, 1000 ° C. or more by supplying an oxidant such as oxygen or air. Thus, the tar contained in the gasification gas is reformed.

  The boiler 9 is provided on the outlet side of the tar reforming furnace 8, generates heat by recovering heat from the gasified gas whose tar is reformed in the tar reforming furnace 8, and generates the generated steam (surplus Steam) is introduced into the concentrator 5.

  The water scrubber 10 is composed of a spray tower or the like, is provided downstream of the boiler 9 in the gasification gas flow direction, and is heat-recovered by the boiler 9 to a temperature of about 300 to 600 [° C.]. The gasification gas is cooled to about 70 [° C.] by spraying cooling water of about 40 [° C.] onto the gasification gas. The cooling water is discharged from the water scrubber 10 as drainage.

  The latter-stage gas purification unit 11 is provided on the downstream side of the water scrubber 10 in the gasification gas flow direction, for example, a mist separator that removes mist from the gasification gas cooled by the water scrubber 10, It consists of a boiler or the like that generates heat by recovering heat from the gasified gas from which the mist has been removed by the mist separator.

  If the steam used for heating the wastewater in the concentrator 5 is steam produced by heat recovery in the two-column gasification facility, excess steam generated in the boiler 7 (see FIG. 1), or It is also possible to use surplus steam generated in a boiler (not shown) constituting the latter-stage gas purification unit 11.

  The concentrator 5 is provided with a discharge part 5a for releasing moisture evaporated to the atmosphere by steam heating.

  Next, the operation of the above embodiment will be described.

  In the state where a gasifying agent such as water vapor is introduced into the bottom of the gasification furnace 1 shown in FIG. 1 and a fluidized bed of a fluid medium such as silica sand is formed inside the gasification furnace 1, the raw material such as lignite is fluidized. When charged into the bed, the raw material is gasified to produce gasified gas and combustible solids.

  The combustible solid content generated in the gasification furnace 1 is introduced into the combustion furnace 2 together with the fluidized medium, and the fluid medium and combustible solid content are blown upward by the air introduced from the bottom of the combustion furnace 2. Meanwhile, the combustible solid content is combusted.

  The combustion exhaust gas generated by the combustion of the combustible solid content is introduced from the combustion furnace 2 to the medium separation device 3, and the fluid separation medium is separated from the combustion exhaust gas in the medium separation device 3, and the separated fluid medium is the gas Returned to the converter 1. The high-temperature combustion exhaust gas from which the fluid medium has been separated by the medium separation device 3 is recovered by the boiler 7 and cooled to the set temperature. Further, surplus steam is generated from the boiler 7.

  The gasification gas generated in the gasification furnace 1 is purified by the gasification gas purification device 4.

  Here, in the case of a dry type two-column gasification facility, as shown in FIG. 2, in the tar reforming furnace 8 constituting the gasification gas purification apparatus 4, first, by supplying an oxidant such as oxygen or air, The gasification gas is heated to, for example, 1000 ° C. or more, and tar is reformed.

  Subsequently, the gasified gas whose tar has been reformed in the tar reforming furnace 8 is guided to the boiler 9 to recover heat, and then introduced into a water scrubber 10 constituted by a spray tower or the like. Steam (surplus steam) generated in the boiler 9 by heat recovery from the gasified gas is introduced into the concentrator 5.

  In the water scrubber 10, cooling water of about 40 [° C.] is sprayed on the gasified gas that has been heat-recovered by the boiler 9 and has reached about 300 to 600 [° C.]. It is cooled to about 70 [° C.] and guided to the subsequent gas purification unit 11.

  For example, after the mist is removed by a mist separator, the gasified gas led to the subsequent gas purification unit 11 is further recovered by a boiler to be a purified gasified gas.

  And the cooling water which cooled the gasification gas with the said water scrubber 10 is introduce | transduced into the concentrator 5 as waste_water | drain, and it heats with the vapor | steam (surplus steam) which generate | occur | produced in the said boiler 9, and the water | moisture content in waste_water | drain drains and is concentrated. The Incidentally, the volume of the waste water is concentrated to about 1/10. The waste water concentrated by the concentrator 5 is guided to the combustion furnace 2 by the pump 6 and subjected to combustion treatment.

  For this reason, the wastewater discharged | emitted from the water scrubber 10 of the said gasification gas refiner | purifier 4 can be combusted inside the double tower type gasification equipment, without going out of the system.

  In the case of the present embodiment, it is only necessary to install the concentrator 5 and the pump 6 inside the two-column gasification facility. Unlike the waste water treatment device disclosed in Patent Document 1, the sedimentation separation unit and the ammonia removal No part, activated sludge tank, etc. are required, the number of equipment is small, the initial cost and the running cost can be reduced, and the consumed energy can be reduced and the overall efficiency of the plant can be suppressed. Incidentally, in the case of the two-column gasification facility shown in FIG. 1, the generation of purified gasification gas is a main process, and power generation using the combustion exhaust gas is not taken into consideration, so that it occurs in the boiler 7 and the boiler 9. Although a part of the steam is used inside the facility, the remaining steam is simply discarded as surplus steam. However, in this embodiment, as shown in FIG. 2, surplus steam generated in the boiler 9 of the gasification gas purification apparatus 4 is effectively utilized for concentration of waste water, so that waste is eliminated and the efficiency of the entire plant is improved. Connected.

  Further, since the tar contained in the gasification gas is reformed in the tar reforming furnace 8 of the gasification gas purification apparatus 4 and the tar is not contained in the waste water discharged from the water scrubber 10, the concentrator 5 and the pump No tar adheres to 6 and the drainage is concentrated stably.

  In this way, it is possible to suppress the reduction in efficiency while reducing the cost without discharging the wastewater outside the system with a simple configuration.

  FIG. 2 shows the gasification gas purification device 4 in the case of a dry two-column gasification facility, but in the case of a wet two-column gasification facility, the gasification gas purification device 4 is shown in FIG. The tar reforming furnace 8 as shown in FIG. 3 is not provided, but as shown in FIG. 3, a boiler 9, a water scrubber 10, and a rear gas purification unit 11 are provided. In FIG. 3, the boiler 9 recovers heat from the gasification gas generated in the gasification furnace 1 to generate steam, and introduces the generated steam (surplus steam) into the concentrator 5. The water scrubber 10 and the rear gas purification unit 11 have the same configuration as that shown in FIG. In the wet two-column gasification facility shown in FIG. 3 as well as in the case of the dry two-column gasification facility shown in FIG. A reduction in efficiency can be suppressed. In the case of the wet two-column gasification facility shown in FIG. 3, since the wastewater discharged from the water scrubber 10 of the gasification gas purification device 4 contains tar, the wastewater concentrated by the concentrator 5. However, the high-concentration tar can be combusted together with waste water in the combustion furnace 2.

  And in the case of a present Example, the vapor | steam used for the heating of waste_water | drain with the said concentrator 5 is made into the surplus vapor | steam manufactured by heat recovery with the said two tower type gasification equipment. If comprised in this way, the surplus steam which was only thrown away can be utilized effectively for the concentration of waste water, the efficiency of the whole plant can be improved without waste.

  The concentrator 5 is provided with a discharge part 5a for releasing moisture evaporated to the atmosphere by steam heating. If comprised in this way, it will be effective in aiming at simplification of a waste-water-treatment apparatus only by releasing the water | moisture content evaporated by steam heating to air | atmosphere from the discharge | release part 5a, and it is not necessary to provide a special apparatus.

  Further, in this embodiment, a gasification furnace 1 that gasifies a raw material charged into a fluidized bed of a fluidized medium to generate a gasification gas and a combustible solid content, and a combustibility generated in the gasification furnace 1. A combustion furnace 2 in which a solid content is introduced from a gasification furnace 1 together with a fluidized medium to burn the combustible solid content, a fluidized medium is separated from the combustion exhaust gas introduced from the combustion furnace 2, and the separated fluidized medium The medium separator 3 for returning the gas to the gasification furnace 1, the gasification gas purification apparatus 4 for purifying the gasification gas generated in the gasification furnace 1, and the waste water discharged from the gasification gas purification apparatus 4 This is a two-column gasification facility provided with a concentrator 5 for heating and concentrating with steam, and a pump 6 for leading waste water concentrated by the concentrator 5 to the combustion furnace 2. If comprised in this way, efficiency reduction can be suppressed, aiming at cost reduction without taking out waste_water | drain with the simple structure which only has the concentrator 5 and the pump 6 as a waste water treatment apparatus.

  In the case of the two-column gasification facility, the gasification gas refining device 4, as shown in FIG. 2, heats the gasification gas by supplying an oxidant to reform the tar contained in the gasification gas. A reforming furnace 8, a boiler 9 for generating steam by recovering heat from the gasified gas whose tar has been reformed in the tar reforming furnace 8, and introducing the generated surplus steam into the concentrator 5; A water scrubber 10 for cooling the gasification gas can be provided by spraying the cooling water onto the gasification gas whose temperature has been recovered by the boiler 9 and whose temperature has dropped. With this configuration, the two-column gasification facility becomes a dry-type facility, and the tar contained in the gasification gas is reformed in the tar reforming furnace 8 of the gasification gas purification device 4 and discharged from the water scrubber 10. Since tar is not contained in the wastewater to be discharged, tar does not adhere to the concentrator 5 and the pump 6, and the concentration of the wastewater can be performed stably.

  In the case of the two-column gasification facility, as shown in FIG. 3, the gasification gas purification device 4 recovers heat from the gasification gas to generate steam, and the generated surplus steam is converted into the concentrator. And a water scrubber 10 that cools the gasified gas by spraying the cooling water onto the gasified gas that has been heat-recovered and reduced in temperature by the boiler 9. If comprised in this way, since the said 2 tower | column type | formula gasification installation turns into a wet installation and tar contains in the waste_water | drain discharged | emitted from the water scrubber 10 of the said gasification gas refiner | purifier 4, it concentrates with the said concentrator 5 The discharged wastewater contains a high concentration of tar, and the high concentration tar can be burned together with the wastewater in the combustion furnace 2.

  Note that the two-column gasification facility wastewater treatment apparatus and the two-column gasification facility of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention. Of course, it can be added.

DESCRIPTION OF SYMBOLS 1 Gasification furnace 2 Combustion furnace 3 Medium separation apparatus 4 Gasification gas refinement apparatus 5 Concentrator 5a Discharge part 6 Pump 8 Tar reforming furnace 9 Boiler 10 Water scrubber

Claims (6)

Combustion furnace in which combustible solids generated in a gasification furnace are introduced from the gasification furnace together with a fluid medium to burn the combustible solids, and gas for purifying the gasification gas generated in the gasification furnace A wastewater treatment device for a two-column gasification facility equipped with a gasification gas purification device,
A concentrator for concentrating the waste water discharged from the gasification gas purifier by heating with steam;
A wastewater treatment apparatus for a two-column gasification facility, comprising: a pump for guiding wastewater concentrated by the concentrator to the combustion furnace.   The wastewater treatment apparatus for a two-column gasification facility according to claim 1, wherein the steam used for heating the wastewater in the concentrator is surplus steam produced by heat recovery in the two-column gasification facility.   The wastewater treatment apparatus for a two-column gasification facility according to claim 1 or 2, wherein the concentrator includes a discharge unit that discharges moisture evaporated by steam heating to the atmosphere. A gasification furnace that gasifies a raw material charged into a fluidized bed of a fluidized medium to generate gasified gas and combustible solids;
A combustion furnace in which combustible solids generated in the gasification furnace are introduced from a gasification furnace together with a fluidized medium to burn the combustible solids;
A medium separation device for separating a fluid medium from combustion exhaust gas introduced from the combustion furnace and returning the separated fluid medium to the gasification furnace;
A gasification gas purification apparatus for purifying the gasification gas generated in the gasification furnace;
A concentrator for concentrating the waste water discharged from the gasification gas purifier by heating with steam;
A two-column gasification facility comprising: a pump that guides the wastewater concentrated by the concentrator to the combustion furnace. The gasification gas purification device comprises:
A tar reforming furnace for heating the gasified gas by supplying an oxidizing agent to reform tar contained in the gasified gas;
A boiler that generates heat by recovering heat from gasified gas whose tar has been reformed in the tar reforming furnace, and introduces the generated surplus steam into the concentrator;
The double-column gasification facility according to claim 4, further comprising: a water scrubber for cooling the gasification gas by spraying the cooling water onto the gasification gas whose temperature has been recovered by the boiler and whose temperature has been lowered. The gasification gas purification device comprises:
A boiler that recovers heat from the gasified gas to generate steam, and introduces the generated surplus steam into the concentrator;
The double-column gasification facility according to claim 4, further comprising: a water scrubber for cooling the gasification gas by spraying the cooling water onto the gasification gas whose temperature has been recovered by the boiler and whose temperature has been lowered.

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