JP2016112547A - Adsorption tower and method for recycling adsorbent - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling adsorbent and an adsorption tower, which enable processes from adsorption and removal of impurities, elution of the impurities, dehydration of adsorbent, to the recycling of the adsorbent, to be performed in a closed system.SOLUTION: An adsorption tower 1 includes: a main body 2; one or more stages of adsorbent storage bodies 3 disposed inside the main body 2; an inlet 7 where gas to be treated is introduced; an air outlet 8 where gas after adsorption is exhausted; a supply port 9 where eluent 14 is supplied into the main body; a discharge port 10 where the eluent 14 is discharged; a heater 5 for heating and drying activated carbon 15 and/or heating the eluent; and so on. Impurities (arsine gas, etc.) adsorbed on the activated carbon 15 are eluted into the eluent 14, and then the activated carbon 15 containing the eluent 14 is heated and dried by the heater 5 disposed in the main body 2, thus regenerating the activated carbon 15.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an adsorption tower and an adsorbent regeneration method, and more particularly to an adsorption tower and an adsorbent regeneration method that can easily and safely regenerate the adsorbent.

In smelting of non-ferrous metals, such as copper electrolytic refining, metals such as copper, arsenic, antimony, bismuth, and nickel increase in the electrolytic solution as the electrolytic refining progresses. (Patent Document 1). However, since the exhaust gas generated in the electrolyte cleaning process contains a highly harmful arsine gas (hydrogen arsenide (AsH ₃ )) or the like, it is necessary to surely remove them.

  For example, in order to remove arsine gas, there are known a method of adsorbing to an adsorbent in addition to a method of oxidizing and dissolving by passing through a trap solution in which an oxidizing agent is dissolved, a method of absorbing in an alkali (Patent Document 2).

  In the method of absorbing in the liquid, the gas is absorbed in the liquid, so the contact area and the reaction rate are important. Therefore, it is highly effective for removing a relatively high concentration of arsine gas. However, the effect is not so high when the concentration is lower than the detection limit. In addition, in order to process a large amount of gas, it is necessary to make a large contact area with the liquid, so that the equipment tends to be enlarged.

  Therefore, adsorption removal with an adsorbent is generally used to remove low-concentration arsine gas. That is, it is a method of introducing an exhaust gas containing an arsine gas into an adsorption tower having an adsorbent packed bed filled with an adsorbent and adsorbing the arsine gas on the adsorbent. Then, after a certain period of use, the adsorbent is reused by purging the hydrogen arsenide component adsorbed on the adsorbent.

  In the removal process of impurities by such an adsorbent, various adsorbents are used. For example, activated carbon is an inexpensive adsorbent having high adsorption performance (Patent Document 3). As other adsorbents, highly functional resins and porous materials whose functions are enhanced by chemical treatment have been proposed (Patent Document 4).

JP-A-9-78284 Japanese Patent No. 2549415 JP 2011-16070 A JP 56-89837 A

  When performing adsorption removal of impurities with an adsorbent, it is necessary to periodically remove the adsorbed impurities. In particular, when impurities are highly harmful substances such as arsine gas, if the arsenic component is eluted by passing the eluent through the adsorption tower in this process, there is a risk that the arsenic component will leak out of the system. Can be suppressed.

  However, the adsorbent after the impurities are eluted with the eluent can be used again as it is, but if the moisture remains on the surface of the adsorbent, the adsorption performance cannot be fully exhibited.

  In this case, the adsorbent after elution from the adsorption tower may be taken out and replaced, or the taken out adsorbent may be heated and dried. However, the arsenic component which is an impurity adsorbed on the adsorbent is removed. Since it is not completely removed by the eluent, it cannot be denied that the arsenic component desorbed in the heating and drying process causes problems such as effects on the human body, environmental pollution, and equipment damage. Therefore, special drying equipment is required when the adsorbent is dried by heating.

  In addition, although water adhering to the adsorbent can be removed by passing a water-soluble organic solvent such as alcohol or acetone through the adsorbent after the arsenic component is eluted with the eluent, it contains the arsenic component. However, this is not a realistic method because a new problem of organic solvent treatment will occur.

  Therefore, as a result of intensive studies to solve the above problems, the present inventors have provided an adsorbent cleaning means and an adsorption removal of impurities by providing a heating and drying means for regenerating the cleaned adsorbent. The present invention has been completed by conceiving an adsorbent regeneration method and an adsorption tower capable of performing the process from the elution of impurities to the drying of the adsorbent to the recycle of the adsorbent in a closed system.

  In order to solve the above-mentioned problems, the present invention according to claim 1 introduces impurities contained in a gas into an airtight main body of an adsorption tower, and in one or more stages in the middle of the gas flow path. In an adsorption tower that performs the adsorption treatment of the impurities with the adsorbent accommodated in the adsorbent accommodating body, the impurities adsorbed on the adsorbent by supplying the eluent into the main body are contained in the eluent. And the adsorbent after elution of the impurities is heated and dried by a heating device disposed in the main body to regenerate the adsorbent.

  In order to solve the above problems, the present invention according to claim 2 is an adsorption tower for adsorbing and removing impurities contained in a gas by using an adsorbent, and containing an adsorbent containing an airtight main body and an adsorbent. An adsorbent containing body arranged in one or more stages inside the main body, an inlet for introducing a gas to be processed into the main body, and the adsorbent for adsorbing the impurities. An exhaust port for exhausting the gas after being broken, a supply port for supplying an eluent that elutes the impurities adsorbed on the adsorbent into the main body, an exhaust port for discharging the eluent, and the adsorbent And a heating device that is disposed in a lower part of the container and that heats and drys the adsorbent after discharging the eluent and / or heats the eluent introduced into the main body. Features.

  In order to solve the above-mentioned problems, the present invention described in claim 3 is characterized in that in the adsorption tower according to claim 1 or 2, the adsorbent holder is formed so as to be removable.

  In order to solve the above-mentioned problem, the present invention according to claim 4 is the adsorption tower according to any one of claims 1 to 3, wherein the introduction port is disposed on a lower side of the main body, and the exhaust port is provided. Is arranged on the upper side of the main body, and the adsorbent holder is located in the middle of the gas flow path.

  In order to solve the above-mentioned problem, the present invention according to claim 5 introduces impurities contained in a gas into an airtight main body of an adsorption tower, and forms one or more stages in the middle of the gas flow path. In the method for regenerating an adsorbent after the adsorption treatment of the impurities by the adsorbent accommodated in the adsorbent accommodating body, the adsorbent is adsorbed to the adsorbent by supplying an eluent into the main body. Provided is a method for regenerating an adsorbent characterized in that impurities are eluted in the eluent and the adsorbent after the impurities are eluted is heated and dried by a heating device disposed in the main body.

  In order to solve the above-mentioned problem, the present invention according to claim 6 is the adsorbent regeneration method according to claim 5, wherein the eluent supplied into the main body is reduced to 50 ° C. or less by the heating device. It is characterized by heating.

  In order to solve the above-mentioned problem, the present invention according to claim 7 is the adsorbent regeneration method according to claim 5 or 6, wherein the gas is an exhaust gas containing hydrogen arsenide generated in a cleaning step of the electrolytic solution. It is characterized by being.

  According to the adsorption tower and the adsorbent regeneration method of the present invention, the impurities contained in the gas are removed, the impurities adsorbed on the adsorbent are eluted, and the adsorbent after the impurities are eluted is dried and recycled. There is an effect that it is possible to perform a series of steps until the utilization is performed in the closed system facility. As a result, there is an effect that the risk of leakage to the outside can be greatly reduced even when the impurities are highly harmful such as arsine gas. In addition, there is an effect that the risk of workers exposed to hydrogen arsenide is greatly reduced.

It is explanatory drawing which shows one preferable embodiment of the adsorption tower which concerns on this invention. It is a flowchart which shows one preferable embodiment of the regeneration method of the adsorbent which concerns on this invention. It is explanatory drawing explaining the adsorption | suction operation | movement of an adsorbent.

  The adsorbent regeneration method and adsorption tower according to the present invention will be described in detail below with reference to the drawings. First, a preferred embodiment of the adsorption tower according to the present invention will be described, and then a preferred embodiment of the adsorbent regeneration method according to the present invention will be described. FIG. 1 is an explanatory view showing an embodiment of an adsorption tower according to the present invention.

  The illustrated adsorption tower 1 generally includes a main body 2 having an internal space, adsorbent containers 3 and 3 arranged in two upper and lower stages inside the main body 2, and impurities contained in the gas to be processed (for example, , Arsine gas: hydrogen arsenide) activated carbons 15 and 15 (only a part of which is shown in FIG. 1) are evenly thickened (= height) in the two-stage adsorbent containers 3 and 3. The adsorbent packed layers 4 and 4 (in this case, two layers) formed by housing, the heating device 5 installed below the lower adsorbent housing 3 in the main body 2, and steam to the heating device 5 A steam generator 6 to be supplied, an inlet 7 for introducing a gas to be processed into the main body 2 attached to the side wall of the main body 2 below the heating device 5, and activated carbon stored in the adsorbent containers 3 and 3 15 and 15 are exhaust ports for exhausting the gas after the impurity adsorption processing is performed. A supply port 9 for supplying an eluent 14 for eluting impurities adsorbed on the activated carbon 15 into the main body 2, a discharge port 10 for discharging the eluent 14 from the supply port 9 to the outside of the main body 2, and elution A tank 11 for storing the liquid 14, a pump 12 for feeding the eluent 14 in the tank 11 to the supply port 9, a steam generator 6 and a controller 13 for controlling the pump 12 are provided.

[Main unit]
The main body 2 is a container into which a gas to be processed is introduced, and is formed in a substantially cylindrical shape having a predetermined internal space. The main body 2 is preferably formed of a material that can withstand corrosion caused by the introduced gas, for example, a metal material such as stainless steel. Moreover, the ceiling part of the main body 2 is shaped to bulge upward, and an exhaust port 8 is provided at the top. Although not shown, piping is connected to the introduction port 7 and the exhaust port 8. The main body 2 is formed with airtightness.

[Adsorbent container]
The adsorbent accommodating bodies 3 and 3 are containers for accommodating the activated carbon 15 that is an adsorbent, are formed in a tray shape from a metal material, and are arranged inside the main body 2. The bottom surfaces of the adsorbent accommodating bodies 3 and 3 are formed in a vent hole such as a punching hole or a wire mesh shape, so that the gas to be processed introduced into the main body 2 is accommodated in the adsorbent accommodating bodies 3 and 3. Impurities are adsorbed by the activated carbons 15 and 15 by passing through the adsorbent packed layers 4 and 4 formed by the activated carbons 15 and 15, and into the adsorbent containers 3 and 3 for the eluent 14 and the drying air. Is allowed to pass. Each of the adsorbent accommodating bodies 3 and 3 can be put into and out of the main body 2 by an opening / closing door (not shown) provided on a side wall at a position to be accommodated in the main body 2. The activated carbons 15 and 15 accommodated in the bodies 3 and 3 can be exchanged. Note that the attachment and removal of the adsorbent containers 3 and 3 into the main body 2 is not limited to this, and the upper portion of the main body 2 is formed in a lid shape, thereby enabling attachment and removal from the upper portion of the main body 2. You can also. In the present embodiment, the adsorbent containers 3 and 3 are arranged in the upper and lower stages in the main body 2, but three or more stages may be arranged, or only one stage may be arranged.

[Adsorbent packed bed]
The adsorbent packed layers 4 and 4 are formed by accommodating activated carbons 15 and 15 in respective predetermined thicknesses in adsorbent containers 3 and 3 arranged in two upper and lower stages. In the present embodiment, the adsorbent packed layers 4 and 4 have an equal thickness, but the present invention is not limited to this. For example, the thickness of the lower adsorbent packed layer 4 through which the introduced gas passes first. And the thickness of the upper adsorbent packed layer 4 may be made thinner, or vice versa. Further, the interval between the upper and lower adsorbent packed layers 4, 4, that is, the space volume is also appropriately determined depending on the shape and size of the main body 2, the amount of gas to be processed, and the like. Further, the frequency of replacement of the activated carbons 15 and 15 is also adjusted as appropriate according to the capacity of the adsorbent and the operation conditions.

  Here, although the adsorbent is activated carbon 15 in the present embodiment, any adsorbent that is porous and has a function of adsorbing hydrogen arsenide can be used as appropriate, and is not limited to activated carbon 15. In addition to the activated carbon, for example, a functional resin, a chemically treated porous material, and the like can be used. However, the activated carbon 15 is suitable as an adsorbent because it is inexpensive and easy to dispose of.

[Eluent supply and discharge ports]
The main body 2 has a supply port 9 for supplying an eluent 14 for eluting impurities adsorbed on the activated carbon 15 into the main body 2, and a discharge port 10 for discharging the eluent 14 from the supply port 9 to the outside of the main body 2. Although provided, in this embodiment, the supply port 9 is provided in the lower part of the main body 2, and the discharge port 10 is provided in the upper part of the main body 2. Either the supply port 9 or the discharge port 10 may be arranged on the upper side, but when the supply port 9 is at the bottom and the discharge port 10 is at the top, the adsorbent packed layers 4 and 4 are submerged by the eluent 14. Therefore, the impurities adsorbed on the activated carbon 15 can be reliably eluted. Of course, the supply port 9 and the discharge port 10 may be reversely arranged. In this case, it is necessary to prevent the eluent 14 from flowing out of the discharge port 10 by a valve or the like. . Moreover, both the supply port 9 and the discharge port 10 may be provided in the lower part, and it is also possible to make the supply port 9 have the function of the discharge port 10.

[Heating device]
The heating device 5 regenerates the function as an adsorbent by drying the activated carbon 15, 15 from which impurities have been eluted by the eluent 14, and heats the eluent 14 supplied into the main body 2. The structure and material of the heating device 5 are not particularly limited, but the material shown in the present embodiment as the heating device 5 that needs to use a material that is not easily attacked by the eluted impurities is the heating supplied from the steam generator 6. The heat exchanger is configured by meandering pipes into which steam flows in a coil shape. Here, the steam generator 6 is, for example, a boiler, and generates steam 16 using thermal power or electric power as a heat source. In addition, the waste heat of the other equipment collect | recovered with the heat exchanger different from the steam generator 6 can also be utilized. In this case, there is an advantage that the equipment cost can be reduced. The heating capacity of the heating device 5 is optimized depending on the size of the adsorption tower 1 and the type of activated carbon 15 or 15 used. With such a configuration, the activated carbon 15, 15 can be made efficient by heating and venting the main body 2 by introducing air into the main body 2 from the inlet 7 in the process of drying the activated carbon 15, 15 as the adsorbent after elution. Can be dried. Furthermore, if the eluent 14 is heated with the eluent 14 supplied in the main body 2, the eluent 14 is heated and circulated in the main body 2 by thermal convection, and two effects of promotion of impurity elution and stirring are obtained. be able to. Furthermore, when the outside air temperature is low, activated carbon 15 and 15 may dew at the time of adsorbing and removing the arsine gas and the adsorption capacity may be reduced. Therefore, the exhaust gas introduced into the main body 2 is heated to prevent the occurrence of dew condensation. Therefore, the heating device 5 can also be used.

[Eluent]
The eluent 14 is a liquid for eluting impurities adsorbed on the activated carbons 15 and 15 to regenerate the activated carbons 15 and 15. The optimal eluent 14 is selected depending on the nature of the impurities, but water is used if the impurities are arsine gas or the like. Further, when the eluent 14 is heated, the elution performance improves as the temperature increases. In the present embodiment, the temperature of the eluent 14 is heated to 50 ° C. or lower in consideration of heating costs and load of equipment such as piping.

[Operation of adsorption tower]
Next, the adsorbent regeneration method according to the present invention will be described with reference to FIGS. 1 to 3 together with the operation of the adsorption tower 1 described above. Here, FIG. 2 is a flowchart showing a preferred embodiment of the adsorbent regeneration method according to the present invention, and FIG. 3 is an explanatory view for explaining the adsorbing operation of the adsorbent. As electrolytic purification progresses in copper electrolysis equipment, metals such as arsenic, antimony, bismuth, nickel, etc., generated in the electrolytic solution increase. For this reason, an operation of appropriately cleaning and removing the electrolytic solution is performed, but the exhaust gas generated when the electrolytic solution is cleaned contains a highly harmful arsine gas or the like. Therefore, this exhaust gas is introduced into the adsorption tower 1 to remove harmful substances.

  First, an operator throws a predetermined amount of activated carbon 15 into each adsorbent container 3, 3, and disperses them uniformly. Then, the adsorbent containing bodies 3 and 3 are arranged in two upper and lower stages in the main body 2 of the adsorption tower 1 to form the adsorbent packed layers 4 and 4. Next, as shown in FIG. 3A, the exhaust gas 17 generated during the cleaning of the electrolytic solution is introduced into the main body 2 from the introduction port 7. In addition, it is preferable to remove the mist in advance from the exhaust gas 17 to be introduced by a demister. The exhaust gas 17 passes through the adsorbent filling layers 4 and 4 and is discharged from the exhaust port 8. In this process, arsine gas or the like in the exhaust gas 17 is adsorbed by the activated carbons 15 and 15 constituting the adsorbent packed layers 4 and 4. In the case where there is a possibility that the adsorption capacity of the activated carbon 15 or 15 may be reduced due to condensation, as described above, the exhaust gas 17 is heated by the heating device 5 to prevent condensation of the activated carbon 15 or 15. A decrease in adsorption capacity can be prevented. As a result, the exhaust gas 18 after the adsorption treatment is discharged from the exhaust port 8.

[Cleaning treatment of activated carbon]
When the treatment of the exhaust gas 17 is completed and the performance of the activated carbons 15 and 15 deteriorates and the cleaning start timing comes, cleaning for regeneration of the activated carbon 15 using the eluent 14 is performed (step S1). First, the steam generator 6 is operated to generate water vapor (step S2). Next, as shown in FIG. 3B, the steam 16 generated by the steam generator 6 is supplied to the coiled pipe of the heating device 5 (step S3). When the heating device 5 is sufficiently heated, as shown in FIG. 3C, the eluent 14 is supplied from the supply port 9 into the main body 2 by the pump 12 (step S4). Note that the eluent 14 may be supplied before the heating by the heating device 5 is started. The eluent 14 supplied into the main body 2 gradually increases the water level and finally reaches the height position of the discharge port 10 and elutes while maintaining this water level. The eluent 14 is heated in advance or heated by the heating device 5. At this time, the water temperature of the eluent is preferably 50 ° C. or less in consideration of the heating cost and the load of equipment such as piping. The eluent 14 flows through the main body 2 by heating the eluent 14.

  In the process in which the eluent 14 flows through the main body 2, the eluent 14 comes into contact with the activated carbon 15, 15 as an adsorbent, and the arsine gas adsorbed on the activated carbon 15, 15 is washed away in the eluent 14 and discharged. It is discharged from the outlet 10 together with the eluent 14. These are sent to a wastewater treatment facility (not shown) where arsenic components are recovered and finally disposed in a stable form. The elution is generally performed by sequentially passing the liquid as described above, but it is also possible to perform the elution with the eluent 14 filled in the main body 2 in a batch manner.

  When cleaning of the activated carbons 15 and 15 with the eluent 14 is completed (step S5), the operator stops the steam generator 6 and the pump 12 (step S6). Thus, the cleaning process using the adsorbent packed layers 4 and 4 is completed. Since the activated carbon 15 and 15 are wetted by the eluent 14 by this washing treatment, it is necessary to dry them sufficiently before the next use. Therefore, the following drying process is executed (see FIG. 3D). When starting the drying process (step S7), instead of the exhaust gas 17, dry air is supplied from the introduction port 7 using an air blower (not shown) (for example, an air pump), discharged from the exhaust port 8, and dried. Is executed (step S8). The drying air supplied into the main body 2 is heated using the heating device 5. Thereby, regeneration of activated carbon 15 and 15 is promoted in a short time, and it can prepare for the next operation immediately. In addition, the drying air can be heated in the main body 2 by heating the drying air supplied to the introduction port 7 by using a separately prepared electric heater or the like in addition to the heating device 5. When the drying process is completed (step S9), the supply of dry air to the inlet 7 is stopped (step S10). Thus, the drying process of the activated carbons 15 is completed.

The operation conditions in each process are as follows.
Exhaust gas supply volume: Space velocity 4200h ^-1
Activated carbon: derived from coconut shell Activated carbon: “Kuraray Coal” manufactured by Kuraray Co., Ltd.
Cleaning time: 3 to 4.5 hours Cleaning temperature: about 45 ° C. Drying temperature: 11 days at 45 ° C. or 22 days at 30 ° C. Air flow rate: 60 m ³ / min

[Effect of the embodiment]
According to the adsorption tower and adsorbent regeneration method according to the present embodiment, as shown in FIGS. 2 and 3, the adsorbent (activated carbon) is removed from the removal of impurities in the exhaust gas by the heating device 5 and the adsorbent packed layers 4 and 4. As a result, it is possible to perform a series of steps in the closed system equipment until the impurities adsorbed in 15, 15) are further dried and the adsorbent after the impurities are eluted are dried and reused. For example, even if the impurities are highly harmful such as hydrogen arsenide, there is an effect that the fear of leakage to the outside can be greatly reduced. In addition, there is an effect that the risk of workers exposed to hydrogen arsenide is greatly reduced.

  Furthermore, since a series of processes are performed in the heating tower 5 and the adsorbent packed beds 4 and 4 in the adsorption tower 1, there is no need to install special equipment, and there is an effect that it is very advantageous in terms of operation cost.

  As described above, the preferred embodiment of the present invention has been described in detail. However, the present invention is not limited to the specific embodiment, and within the scope of the gist of the present invention described in the claims, Needless to say, various modifications and changes are possible.

DESCRIPTION OF SYMBOLS 1 Adsorption tower 2 Main body 3 Adsorbent container 4 Adsorbent packed bed 5 Heating device 6 Steam generating device 7 Inlet 8 Exhaust port 9 Supply port 10 Discharge port 11 Tank 12 Pump 13 Controller 14 Eluent 15 Activated carbon 16 Steam 17 Exhaust gas 18 Exhaust gas after adsorption treatment

Claims (7)

Impurities contained in the gas are introduced into the gas-tight main body of the adsorption tower, and the impurities are absorbed by the adsorbent contained in the adsorbent containing body arranged in one or a plurality of stages in the gas flow path. In an adsorption tower that performs adsorption treatment,
By supplying an eluent into the main body, the impurities adsorbed on the adsorbent are eluted into the eluent, and the adsorbent after the impurities are eluted is heated by a heating device disposed in the main body. An adsorption tower, wherein the adsorbent is regenerated by heating and drying. In the adsorption tower that adsorbs and removes impurities contained in the gas with an adsorbent,
An airtight main body;
An adsorbent container in which an adsorbent is accommodated, wherein the adsorbent container is disposed in one or more stages inside the main body;
An inlet for introducing a gas to be processed into the main body;
An exhaust port for exhausting the gas after the adsorption treatment of the impurities by the adsorbent;
A supply port for supplying an eluent into the main body to elute the impurities adsorbed on the adsorbent;
A discharge port for discharging the eluent;
A heating device that is disposed below the adsorbent container and that heat-drys the adsorbent after discharging the eluent and / or heats the eluent introduced into the main body;
An adsorption tower characterized by comprising: In the adsorption tower according to claim 1 or 2,
The adsorption tower, wherein the adsorbent holder is formed to be removable. The adsorption tower according to any one of claims 1 to 3,
The introduction port is disposed on the lower side of the main body, the exhaust port is disposed on the upper side of the main body, and the adsorbent holding body is positioned in the middle of the gas flow path. Adsorption tower. Impurities contained in the gas are introduced into the gas-tight main body of the adsorption tower, and the impurities are absorbed by the adsorbent contained in the adsorbent containing body arranged in one or a plurality of stages in the gas flow path. In the regeneration method of the adsorbent after the adsorption treatment,
By supplying an eluent into the main body, the impurities adsorbed on the adsorbent are eluted into the eluent, and the adsorbent after the impurities are eluted is heated by a heating device disposed in the main body. A method for regenerating an adsorbent characterized by heating and drying. In the regeneration method of the adsorbent according to claim 5,
The adsorbent regeneration method, wherein the eluent supplied into the main body is heated to 50 ° C. or less by the heating device. In the regeneration method of the adsorbent according to claim 5 or 6,
The method for regenerating an adsorbent, wherein the gas is an exhaust gas containing hydrogen arsenide generated in a cleaning step of an electrolytic solution.

Images