JP2008188491A - Adsorbent regeneration method using microwave - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an adsorbent regeneration method for obtaining a regenerated adsorbent, from which an adsorbed substance is almost perfectly removed, by treating a used adsorbent using microwave heating, especially capable of automatically treating the used adsorbent by utilizing the peculiar phenomenon of the change in temperature due to microwave heating to eliminate wasteful energy consumption. <P>SOLUTION: The adsorbent regeneration method using the microwave has a first process for irradiating the contaminated adsorbent 1 with a microwave and a second process for exposing the adsorbent 1 to hot air. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a filter for filtering impurities contained in gas, liquid and the like and a method for regenerating an adsorbent used as a gas adsorbing / separating material.

  An adsorbent is used as a filter in a path through which gas or liquid passes. Some adsorbents have a function of physically adsorbing micro substances by a physicochemical function in addition to a function of physically stopping dust and foreign substances by an external configuration such as a mesh. For example, activated carbon is adsorbed as an adsorbent in the middle of the air pipe to adsorb oil mist or silica gel to adsorb moisture.

  These adsorbents must be regenerated continuously because their adsorptive capacity is saturated when a certain amount of substances are adsorbed. Discarding used adsorbents with reduced adsorption capacity is not only economically undesirable, but may also cause secondary pollution, so reprocessing (specifically, contaminated contamination) Recycled after processing to discharge substances.

  Conventionally, such regeneration of the adsorbent has been performed by a method in which the collected used adsorbent is placed in a container and placed in an oven, and heated for a certain period of time by increasing the temperature. Or the method of blowing warm air into the container which put the used adsorbent for a fixed time was taken. Furthermore, an example using high frequency dielectric heating as a heating means is known.

  Patent Document 1 discloses an example in which the adsorbed moisture of a zeolite / silica gel mixed desiccant is dried by high-frequency dielectric heating. A general household microwave oven is used for high-frequency dielectric heating.

  Patent Document 2 discloses an example in which a zeolite desiccant is dried and regenerated by high-frequency irradiation. It is described that high-frequency irradiation can use a microwave oven for cooking.

  However, the used adsorbents such as zeolite, which are recovered, have different adsorbed components and adsorbed amounts for each recovery, and in many cases, the adsorbed components and adsorbed amounts cannot be specified. It is not possible to predict whether it is appropriate to heat for hours. If the heating temperature and heating time are insufficient, the substance adsorbed on the adsorbent remains, and the adsorbability of the regenerated adsorbent becomes insufficient. If the heating temperature and heating time are sufficient, the adsorbed substance will once desorb from the regenerated adsorbent, but will be adsorbed again.

  Further, in the regeneration of the used adsorbent, it is necessary to change the processing conditions such as the heating temperature, the heating time, or the amount of hot air for each regeneration processing lot, but there is no method for finding an appropriate condition. For this reason, it was performed by the operator's can, but in order to pursue certainty, in many cases, energy due to excessive heating was wasted.

JP-A-9-75727 JP 2002-85936 A

  The present invention has been made in order to solve the above-described problems. By treating a used adsorbent with microwave heating, adsorbent regeneration is obtained by obtaining a regenerated adsorbent from which the adsorbent has been substantially completely removed. It aims to provide a method.

  Furthermore, the inventor of the present invention has advanced research on the application of microwave heating to the regeneration of the adsorbent. When the amount of the residual material adsorbed on the adsorbent is changed by the microwave heating, the adsorbent has a characteristic temperature. It was found to show a change. Such a temperature change is a phenomenon peculiar to microwave heating, and an object of the present invention is to provide a method for regenerating an adsorbent that can be automatically processed by using this phenomenon, eliminating wasteful energy consumption.

  In order to achieve the above object, the method for regenerating an adsorbent using microwaves according to claim 1 of the present invention includes a first step of irradiating a contaminated adsorbent with microwaves, and the adsorbent. And a second step of exposing the substrate to hot air.

  Similarly, the adsorbent regeneration method using microwaves of the invention according to claim 2 of the claim is the method of the invention according to claim 1, wherein the first step and the second step are sequentially performed. Features.

  The microwave adsorbent regeneration method according to the invention of claim 3 is the method of the invention according to claim 1, wherein the first step and the second step are performed in the same container. And

  The method for regenerating an adsorbent using microwaves according to a fourth aspect of the present invention is the method according to the first aspect, wherein the first step and the second step are performed in a rotating container. To do.

  An adsorbent regeneration method using microwaves according to a fifth aspect of the present invention is the method according to the first aspect of the present invention, wherein the first step and the second step are performed in a rotating container, and the first step The rotation in is the rotation of the rotation shaft in the vertical direction, and the rotation in the second step is the rotation of the rotation shaft in the horizontal direction.

  The method for regenerating an adsorbent using microwaves according to a sixth aspect of the present invention is the method according to the first aspect of the present invention, wherein the first step measures the temperature of the adsorbent being irradiated with microwaves while measuring the temperature. The microwave irradiation amount is controlled by temperature data.

  The method for regenerating an adsorbent using microwaves according to a seventh aspect of the present invention is the method according to the first aspect of the present invention, wherein the first step measures the temperature of the adsorbent that is being irradiated with microwaves, and measures the temperature. When the temperature drops after rising and reaches a constant temperature range, the microwave irradiation is stopped.

  The method for regenerating an adsorbent by microwave according to an eighth aspect of the present invention is the method according to the first aspect of the present invention, wherein the adsorbent is activated carbon, silica gel, calcium oxide, zeolite, ceramic porous body, diatomaceous earth, bauxite, It is selected from bone charcoal, wood-based adsorbent, metal oxide-based adsorbent, and polymer-based adsorbent.

  The method for regenerating an adsorbent using microwaves according to a ninth aspect of the present invention is the method according to the first aspect of the present invention, wherein the adsorbent adsorbs a molecular substance having moisture or —OH groups. And

  The method for regenerating an adsorbent using microwaves according to the present invention includes placing a used adsorbent in a non-metallic container that is permeable to air inside a casing and irradiating microwaves while rotating the adsorbent from the used adsorbent. Is diffused and discharged through the exhaust means. Therefore, the adsorbed material from which the remaining adsorbed material is completely removed is regenerated without the adsorbed material adsorbed again by the adsorbent.

  By measuring the temperature of the adsorbent with the microwave adsorbent regeneration method of the present invention, the remaining amount of the adsorbent can be determined, and how much microwave should be irradiated or whether the adsorbent can be completely dissipated is accurate. Therefore, it is possible to irradiate without excess or deficiency. Therefore, useless energy consumption can be prevented.

  Furthermore, with the method of regenerating an adsorbent using microwaves according to the present invention, microwave irradiation can be controlled from temperature measurement data, and the adsorbent can be regenerated with an optimum amount of microwave irradiation unattended. Therefore, it is useful not only for energy saving but also for labor saving.

Preferred form for carrying out the invention

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings, but the scope of the present invention is not limited to these embodiments.

  FIG. 1 is an external front view of an embodiment of an apparatus for carrying out a first step (microwave irradiation) of an adsorbent regeneration method using microwaves to which the present invention is applied. The apparatus of the first step is provided with a magnetron 12 that oscillates microwaves from one side wall of a metal housing 10 whose front can be opened and closed by a door 13 into the chamber 8. The front door 13 covering the chamber 8 has a metal net for electromagnetic wave shielding covered with heat-resistant glass. A turntable 15 connected to a motor 14 that is a rotational drive source is disposed on the bottom surface of the housing 10. An exhaust cylinder 17 is installed on the ceiling portion of the housing 10 and opens to the outside via a fan (not shown). A metal net covers one place in the inner space of the exhaust cylinder 17 so as to ventilate but block electromagnetic waves.

  On the turntable 15, a plastic mesh tube container 20 in which the used adsorbent 1 to be recycled is placed is placed. It is a space 16 surrounded by a plastic mesh of a plastic mesh cylinder container 20 in a cylindrical shape. A metal sheath thermocouple thermometer 18 is inserted into the chamber 8 through the ceiling wall of the metal casing 10, and is inserted into the central space 16 of the cylindrical container 20. The conductor of the metal sheath thermocouple thermometer 18 is connected to the temperature input terminal of the control box 22 of the apparatus. In the control box 22, a temperature indicator 24, a remaining time indicator 25, a time setting knob 27, and an oscillation output setting knob 28 are arranged.

  FIG. 2 is an electric system block diagram of the above-described adsorbent recycling apparatus using microwaves. It comprises a temperature change detection circuit 30 connected to the metal sheath thermocouple thermometer 18, a motor power supply control circuit 31 connected to the temperature change detection circuit 30, and an oscillation power supply control circuit 32. The temperature change detection circuit 30 has a function of storing the temperature every moment inputted from the metal sheath thermocouple thermometer 18, detecting the change, and outputting an output signal. A motor power supply control circuit 31 connected to a power supply source, for example, a commercial power supply, is connected to the motor 14, and an oscillation power supply control circuit 32 is connected to the magnetron 12. A temperature indicator 24 and a remaining time indicator 25 are connected to the temperature change detection circuit 30.

  FIG. 3 is an external front view of an embodiment of a hot air exposure apparatus for carrying out the second step (hot air exposure) of the microwave adsorbent regeneration method to which the present invention is applied. In the apparatus of the second step, a cylinder 40 that blows out warm air from the bottom floor of the casing 37 whose front can be opened and closed by the door 35 into the chamber 38 is opened. The ejection cylinder 40 is connected to a warm air supply device (not shown). An exhaust pipe 41 is installed on the ceiling portion of the casing 37. A thermometer 42 is inserted into the chamber 38 through the side wall of the housing 37 and through the hollow of the shaft 19.

  The cylindrical container 20 in which the used adsorbent 1 to be regenerated is placed is the same as that used in the microwave irradiation apparatus for performing the first step shown in FIG. Both ends of the cylindrical container 20 are closed with caps 21. Each of the caps 21 has a rotation shaft 19 fixed thereto, and is supported on both side walls of the casing 37. A rotating shaft 19 penetrating one side wall is connected to a motor 34 so that the cylindrical container 20 rotates.

  This adsorbent regeneration apparatus is operated according to the procedure of the flowchart shown in FIG. 4 to implement the adsorbent regeneration method of the present invention.

  In the first step of Step 101, the used adsorbent 1 to be regenerated is placed in the cylindrical container 20, placed on the turntable 15 in the chamber 8, the door 13 is closed, the power is turned on and the motor 14 is rotated. The magnetron 12 is oscillated. Then, the used adsorbent 1 is heated in resonance with the microwave passing through the cylindrical container 20, and the residual adsorbed material is diffused and discharged through the exhaust cylinder 17. In step 102, the metal sheath thermocouple thermometer 18 and the temperature change detection circuit 30 are operated. In step 103, it is confirmed that the output temperature from the metal sheath thermocouple thermometer 18 has changed from rising to falling with the passage of time. When the temperature change detection circuit 30 detects that the temperature has become substantially constant in step 104, a command signal is issued to the motor power supply control circuit 31 and the oscillation power supply control circuit 32 in step 105, and the power supply is stopped. Thus, the first step is completed, and the residual adsorbing material such as moisture and oil is almost diffused from the used adsorbent 1.

  The used adsorbent 1 in the middle of regeneration is mounted on the hot air exposure device shown in FIG. Both ends of the cylindrical container 20 are closed with caps 21 and attached to the rotary shaft 19. And while rotating the motor 34, a warm air supply device is operated and a warm air is ejected in the chamber 38 through the ejection cylinder 40. As shown in FIG. The used adsorbent 1 in the tubular container 20 in the middle of regeneration is exposed to warm air while stirring, and the remaining adsorbed material such as oil is completely dissipated. Adsorption of the diffused oil or the like is discharged through the exhaust pipe 41.

  When the output temperature of the metal sheath thermocouple thermometer 18 shown in FIG. 1 becomes substantially constant, in order to confirm that impurities are substantially diffused from the adsorbent, that is, the operation from step 101 to step 104 is valid, The experiment was conducted.

  The used adsorbent was placed in a 100 cc crucible and processed by oscillating 2.45 GHz microwaves in the adsorbent regenerator. The adsorbent was taken out every 15 minutes and weighed precisely, and the temperature at that time was recorded.

  As a result of plotting the data, as shown by the solid line (left vertical axis) in FIG. 5, the temperature once increased with the lapse of time of the microwave oscillation, but when it further lapsed, it converged to a constant temperature. At the same time, as indicated by the dotted line (right vertical axis), with the lapse of time of microwave oscillation, the mass of the adsorbent decreased (impurity diffusion progressed) and eventually converged to a constant temperature. And the convergence time of both was substantially the same time.

  This fact indicates that when there are many impurities, the temperature rises due to the microwave, and when the impurities are diffused and reduced, the temperature decreases, and when there are no impurities, the temperature does not increase or decrease. Such a phenomenon is considered to be caused by an increase or decrease in heat generation due to a large amount of resonance substances (impurities) caused by microwaves.

It is an external appearance front view showing one embodiment of the device for carrying out the 1st process (microwave irradiation) of the adsorbent reproduction method to which the present invention is applied. It is an electric system block diagram of the adsorbent reproduction | regeneration apparatus by the microwave of FIG. It is an external appearance front view which shows one Embodiment of the warm air exposure apparatus for implementing the 2nd process (warm air exposure) of the adsorbent reproduction | regeneration method to which this invention is applied. It is a flowchart which shows the operation | movement procedure of the adsorbent reproduction | regeneration method to which this invention is applied. It is a graph which shows the time-dependent change of the apparatus internal temperature at the time of using the adsorbent reproduction | regeneration apparatus by the microwave of FIG. 1, and the mass of an adsorbent.

Explanation of symbols

  1 is a used adsorbent, 8 is a chamber, 10 is a metal housing, 12 is a magnetron, 13 is a door, 14 is a motor, 15 is a turntable, 16 is a central space, 17 is an exhaust tube, 18 is a metal sheathed thermocouple Thermometer, 19 is a rotating shaft, 20 is a cylindrical container, 21 is a cap, 22 is a control box, 24 is a temperature indicator, 25 is a remaining time indicator, 27 is a time setting knob, 28 is an oscillation output setting knob, 30 is Temperature change detection circuit 31 is a motor power supply control circuit, 32 is an oscillation power supply control circuit, 34 is a motor, 35 is a door, 37 is a housing, 38 is a chamber, 40 is an ejection cylinder, 41 is an exhaust cylinder, 42 is a thermometer , 101 is a first step microwave irradiation, 102 is a temperature measurement, 103 is a temperature rise → fall, 104 is a constant temperature, and 105 is a microwave irradiation first step end.

Claims (9)

  A method of regenerating an adsorbent using microwaves, comprising: a first step of irradiating a contaminated adsorbent with microwaves; and a second step of exposing the adsorbent to hot air.   The adsorbent regeneration method according to claim 1, wherein the first step and the second step are sequentially performed.   The adsorbent regeneration method according to claim 1, wherein the first step and the second step are performed in the same container.   The adsorbent regeneration method according to claim 1, wherein the first step and the second step are performed in a rotating container.   The first step and the second step are performed in a rotating container, the rotation in the first step is rotation of the vertical rotation shaft, and the rotation in the second step is rotation of the horizontal rotation shaft. The adsorbent regeneration method according to claim 1.   The said 1st process measures the irradiation amount of a microwave according to the temperature measurement data, measuring the adsorption material which is irradiating the microwave, The adsorption material reproduction | regeneration by a microwave of Claim 1 characterized by the above-mentioned. Method.   2. The first step of measuring the temperature of an adsorbent that is being irradiated with microwaves, and then lowering the measured temperature and then stopping the microwave irradiation when the temperature reaches a constant temperature range. A method for regenerating an adsorbent by microwaves as described in 1.     The adsorbent is selected from activated carbon, silica gel, calcium oxide, zeolite, ceramic porous body, diatomaceous earth, bauxite, bone charcoal, wood-based adsorbent, metal oxide-based adsorbent, and polymer-based adsorbent. Item 4. The adsorbent regeneration method according to Item 1.   The method for regenerating an adsorbent by microwave according to claim 1, wherein the adsorbent adsorbs a molecular substance having moisture or -OH groups.

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