JP2011212516A - Activated carbon regeneration apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an activated carbon regeneration apparatus using no electric power energy and requiring no special steam generator.SOLUTION: The activated carbon regeneration apparatus II is constituted so as to adsorb and remove a harmful substance in the exhaust gas from a waste treatment furnace 11 to activate deteriorated activated carbon lowered in adsorption capacity to regenerate the same and has a solar heat collection device 23, an activated carbon activation device 21 for heating the deteriorated activated carbon by the solar heat collected by the solar heat collection device 23 to activate the same under an activating reaction gas atmosphere, a gas heater 22 for receiving at least one of the treated exhaust gas subjected to detoxification treatment from the waste treatment furnace 11 and steam produced in a waste heat boiler 12 by the exhaust gas from the waste treatment furnace 11 and heating the same by the solar heat from the solar heat collection device 23 to supply the heated treated exhaust gas or steam to the activated carbon activation device 21 as activating reaction gas and an activating reaction produced gas return means 26 for returning the gas produced by activating reaction into the waste treatment furnace 11 from the activated carbon activation device 21.

Description

  The present invention activates and regenerates activated carbon that has been used in an activated carbon adsorption device that adsorbs and removes harmful substances in exhaust gas discharged from a waste treatment furnace that incinerates or gasifies and melts waste, thereby reducing adsorption performance. The present invention relates to an activated carbon regenerator.

  As a waste disposal technology, there are stoker-type incinerators and fluidized-bed incinerators that supply waste such as municipal waste and shredder dust onto a grate, burn the waste, and discharge ash from the combustion residue. There are a method of using and a method of using a gasification melting furnace in which waste is pyrolyzed to generate a combustible gas, and the pyrolysis residue is melted and discharged as slag. In the present invention, the waste incinerator and the waste gasification melting furnace are collectively referred to as a waste treatment furnace.

  In any system, exhaust gas discharged from the waste treatment furnace is completely burned in the secondary combustion chamber to decompose harmful substances generated in the waste treatment furnace. In many cases, waste heat of exhaust gas after combustion in the secondary combustion chamber is utilized and heat is recovered as steam by a boiler or economizer for effective use. In some cases, a turbine generator is provided to generate power using this steam. In order to make the exhaust gas harmless, the exhaust gas discharged from the economizer is cooled in advance by a temperature reducing device to a temperature suitable for acid substance removal and filtration type dust collection performed later. The cooled exhaust gas is supplied with alkaline chemicals to remove HCl and SOx in the exhaust gas, and then the reaction products and dust of the alkaline chemicals in the exhaust gas with HCl and SOx are collected by a filtration dust collector (bag filter). Be collected.

  Furthermore, dioxins in the exhaust gas discharged from the filtration dust collector are removed by adsorption using an activated carbon adsorption device. Patent Document 1 describes an activated carbon adsorption device used for exhaust gas treatment, and dioxins in the exhaust gas are adsorbed and removed while the exhaust gas passes through the adsorbent layer of the activated carbon adsorption device filled with activated carbon.

JP 2000-272914 A

  When exhaust gas treatment for introducing and removing dioxins by introducing exhaust gas into an activated carbon adsorption device is performed, the adsorption performance of activated carbon gradually decreases. In Patent Document 1, when a predetermined adsorption removal performance cannot be maintained, deteriorated activated carbon is taken out from the activated carbon adsorption device, and new activated carbon is introduced. Since the cost of processing the deteriorated activated carbon and the cost of purchasing the activated carbon increase, it is originally desirable to activate and regenerate the deteriorated activated carbon and reuse it. However, the regeneration of activated carbon has the following problems.

In order to activate the activated carbon, it is necessary to supply a gas containing a high temperature of about 1000 ° C. and water vapor in order to cause the following reaction. Conventionally, an electric heater is used to heat the gas to a high temperature, but conversion of the energy source is required from the viewpoint of reducing carbon dioxide emissions. In addition to this electric heater, a device for generating water vapor and its heat source are also required.
C + H ₂ O → CO + H ₂

Further, there is a need for an apparatus for treating CO, H ₂ generated by the activation reaction of activated carbon, and harmful substances adsorbed and desorbed in the pores of the activated carbon.

The present invention has been made to solve such problems, and an activated carbon regenerator that activates and regenerates activated carbon that has been used in an activated carbon adsorber used for exhaust gas treatment discharged from a waste treatment furnace and has reduced adsorption performance. In order to obtain a gas containing heat and water vapor necessary for the activation reaction of activated carbon, no power energy is used, and no special apparatus for generating water vapor is required. It is an object of the present invention to provide an activated carbon regenerator that does not require an apparatus for treating CO, H ₂ , and desorbed harmful substances generated in the process.

  The activated carbon regeneration apparatus according to the present invention is a deteriorated activated carbon whose adsorption performance is reduced by being used in an activated carbon adsorption apparatus for adsorbing and removing harmful substances in exhaust gas discharged from a waste treatment furnace for incineration or gasification / melting of waste. Activate and regenerate.

  In such an activated carbon regenerator, according to the present invention, the above-mentioned problems are solved by the following first invention or second invention.

<First invention>
Discharge from a solar heat collector that collects solar heat, an activated carbon activation device that heats the deteriorated activated carbon by the solar heat collected by the solar heat collector and activates it in an activated reaction gas atmosphere, and a waste treatment furnace Activated at least one of the water vapor generated in the waste heat boiler by the treated exhaust gas that has been detoxified and the exhaust gas discharged from the waste treatment furnace, and this is heated by solar heat from the solar heat collector and activated A gas heater to be supplied to the activated carbon activation device as a reaction gas, and an activation reaction generated gas feedback means for returning the generated gas generated by the activation reaction from the activated carbon activation device to the waste treatment furnace. A featured activated carbon regenerator.

  According to the first invention having such a configuration, the deteriorated activated carbon after being subjected to adsorption removal of harmful substances in the exhaust gas is sent to the activated carbon activation device. On the other hand, the gas heater receives at least one of the exhaust gas discharged from the waste treatment furnace and the steam from the boiler as the gas and steam necessary for activation, and reaches the temperature necessary for activation. Heat with solar heat received by a solar heat collector. The heated gas is sent to the activated carbon activation device, and combined with solar heat input from the solar heat collector to the activated carbon activation device, heats the deteriorated activated carbon to activate and regenerate it. Obtain activated carbon. The generated gas generated by the activation of the activated carbon is returned to the waste treatment furnace by the activation reaction generating gas feedback means and used for incineration or gasification / melting of the waste here.

<Second invention>
A solar heat collector that collects solar heat, a solar heat receiver that heats the heat medium by receiving solar heat from the solar heat collector, and an activated reaction by heating the deteriorated activated carbon with the heat medium heated by the solar heat receiver At least one of activated carbon activation device activated in a gas atmosphere, treated exhaust gas discharged from a waste treatment furnace and detoxified, and steam generated in a waste heat boiler by exhaust gas discharged from the waste treatment furnace Gas heater that is heated by a heat medium heated by a solar heat receiving device and supplied to the activated carbon activation device as an activated reaction gas, and generated gas generated by the activation reaction from the activated carbon activation device An activated carbon regenerating apparatus comprising an activated reaction generating gas feedback means for returning the gas to the waste treatment furnace.

  In the second invention having such a configuration, the solar heat receiving device is provided, the solar heat receiving device heats the heat medium with solar heat from the solar heat collecting device, and the heat medium is sent to the gas heater and the activated carbon activation device. The gas is heated with a gas heater and the activated carbon is heated with an activated carbon activation device.

In the present invention, since the activated carbon and the activated reaction gas are heated using solar heat in this way, activated carbon regeneration can be performed without using power energy, and there is an effect of reducing carbon dioxide emissions and activation. Since the treated exhaust gas from the waste treatment furnace and the water vapor generated in the waste heat boiler are used as the chemical reaction gas, it is not necessary to provide a special device for generating water vapor. Furthermore, the activated reaction gas can be returned to the waste treatment furnace, where CO and H ₂ can be burned and used as waste heat energy, and the desorbed harmful substances are decomposed and made harmless in the waste treatment furnace. Therefore, an apparatus for processing the activation reaction generating gas becomes unnecessary.

It is a schematic block diagram of the apparatus of one Embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. 1 of the accompanying drawings.

  The apparatus of this embodiment is roughly divided into a waste treatment apparatus I and an activated carbon regeneration apparatus II.

  The waste treatment apparatus I includes, as a preceding stage, a waste treatment furnace 11 into which waste is input and incinerated or gasified / melted, and receives waste gas from the waste treatment furnace 11 to recover heat from the waste heat and steam. A waste heat boiler 12 that generates heat, a temperature reduction tower 13 that receives the exhaust gas recovered from the waste heat boiler 12 to reduce the temperature of the exhaust gas, and an exhaust gas that has been reduced in temperature by the temperature reduction tower 13 A dust collector 14 that removes dust, an activated carbon adsorber 15 that receives exhaust gas removed from the dust collector 14 and adsorbs and removes harmful substances such as dioxins, and a chimney that releases exhaust gas detoxified by removing harmful substances 16 are sequentially connected.

  The activated carbon regeneration apparatus II receives the activated carbon that has deteriorated by adsorbing harmful substances by the activated carbon adsorption apparatus 15 from the activated carbon adsorption apparatus 15 and activates the activated carbon activation apparatus 21 and the activated carbon activation apparatus 21. It has a gas heater 22 for supplying high-temperature gas necessary for activation, a solar heat collector 23 and a solar heat receiver 24. The solar heat collector 23 is a device that collects solar heat and supplies this heat to the gas heater 22 and the activated carbon activation device 21, and supplies the heat directly to the gas heater 22 and the activated carbon activation device 21. Alternatively, the solar heat receiving device 24 may heat the heat medium and supply heat with this heat medium.

  The gas heater 22 receives at least one of a part of the steam generated in the waste heat boiler 12 and a part of the treated exhaust gas from the activated carbon adsorption device 15, and at least one of the steam and the exhaust gas is received by the solar heat. Heat with.

  The gas heater 22 is connected to the activated carbon activation device 21 connected to the activated carbon adsorption device 15 so as to receive the deteriorated activated carbon. The activated carbon activation device 21 is connected to the waste treatment furnace 11 via the blower 25 and the generated gas return path 26 so as to return the generated gas to the waste treatment furnace 11.

  The solar heat collecting device 23 is connected to the gas heater 22 and the activated carbon activating device 21 directly (broken line in FIG. 1) or indirectly through the solar heat receiving device 24 (solid line in FIG. 1).

  Hereinafter, each apparatus which comprises said activated carbon reproduction | regeneration apparatus II is explained in full detail.

<Activated carbon activation device>
This is an apparatus for activating the deteriorated activated carbon in a high temperature activation reaction gas atmosphere by heating the deteriorated activated carbon with a heat medium.

  The activated carbon activation device 21 receives deteriorated activated carbon whose adsorption performance has been lowered by adsorption adsorption removal of harmful substances in the activated carbon adsorption device 15 from the activated carbon adsorption device 15, and has processed treated exhaust gas or water vapor as an activation reaction gas. Under the atmosphere, the deteriorated activated carbon is heated to a high temperature of 800 to 1000 ° C., and harmful substances adsorbed on the activated carbon are volatilized, decomposed and desorbed, and fine pores are generated in the activated carbon to activate and restore the adsorption performance. Thus, the activated activated carbon whose activated and recovered adsorption performance is returned to the activated carbon adsorption device 15 and can be reused. The activated activated carbon may be taken out from the activated carbon activation device 21 and temporarily stored in another place (solid arrow in FIG. 1) or may be immediately returned to the activated carbon adsorption device 15 (broken line in the drawing). Arrow).

The activation reaction of activated carbon is performed as follows.
When water vapor is used as the activation reaction gas, the reaction of C + H ₂ O → CO + H ₂ occurs on the activated carbon surface, and micropores are generated in the activated carbon and activated, and high adsorption performance for harmful substances is obtained.
When exhaust gas is used as the activation reaction gas Since the exhaust gas contains water vapor, CO ₂ , and O ₂ , a reaction of C + CO ₂ → 2CO occurs on the activated carbon surface along with the reaction of the water vapor, and fine pores are generated in the activated carbon To be activated. Further, the exhaust gas contains a small amount of O ₂ , and a part of CO and H ₂ generated in the above reaction is partially oxidized to cause an oxidation exothermic reaction, and the above steam reaction and CO ₂ reaction. Is an endothermic reaction, and has an effect of preventing the temperature in the activated carbon activation device from decreasing. Since activated carbon burns when the oxygen concentration is high, the oxygen concentration is preferably less than 10 vol%.

Further, by using water vapor as the activation reaction gas, there is an effect that the organic halogen compound adsorbed on the activated carbon is decomposed into CO, H ₂ and HCl by reaction with water vapor. The generated HCl is returned to the waste treatment furnace where it is decomposed and rendered harmless.

  The temperature control in the activated carbon activation device is such that a temperature measuring sensor is provided in the activated carbon activation device, a valve for adjusting the flow rate of the activated reaction gas is provided, and the temperature in the activated carbon activation device is within a predetermined range. Can be controlled.

  The activated carbon activation device 21 is preferably a mechanism that heats activated carbon while flowing or stirring in a furnace type such as a fluidized bed furnace or a rotary kiln furnace.

  The activated carbon activation device 21 distributes a heat medium in a heat receiving portion provided in the solar heat receiving device 24 of FIG. 1, provides a heat exchanger in the activated carbon layer, and distributes the heat medium through the heat exchanger. The activated carbon may be heated indirectly by heat exchange with solar heat from the solar heat receiving device 24, or may be directly heated by solar heat from the solar heat collecting device 23.

  Furthermore, the activated carbon activation device 21 also heats the activated carbon by blowing an activation reaction gas heated to a high temperature into the activated carbon layer.

<Gas heater>
The gas heater 22 is a waste heat boiler that recovers waste heat from a part of the treated exhaust gas from which the dust, acid gas, and dioxins are removed and from the exhaust gas discharged from the waste treatment furnace 11. 12 is heated directly by solar heat from the solar heat collector 23 or indirectly by heat exchange with a heat medium heated by the solar heat receiver 24. It is an apparatus which supplies to the activated carbon activation apparatus 21 as activation reaction gas.

  The gas heater 22 activates at least one of a part of the steam generated in the waste heat boiler 12 and a part of the exhaust gas after removing harmful substances discharged from the activated carbon adsorption device 15 as a reaction gas. And a heat exchanger that heats the activated reaction gas using solar heat. The heat exchanger is connected so as to heat the activation reaction gas directly by solar heat or indirectly by the heat exchange and send it to the activated carbon activation device 21. Thus, the heat exchanger is configured to receive heat for heating the gas directly or indirectly from solar heat.

  The gas heater 22 is provided with a heat storage material therein, receives the solar heat collected by the solar heat collector 23, heats the heat storage material, contacts the heated heat storage material with the gas, and heats the gas. May be heated.

<Solar heat collector and solar heat receiver>
The solar heat collector 23 is configured to collect solar heat. For example, the solar heat collector 23 includes a plurality of reflecting mirrors and a converging reflecting mirror having a parabolic section in order to converge reflected sunlight. The sunlight reflected by the reflecting mirror is condensed by the converging reflecting mirror, and the solar heat is efficiently utilized by irradiating the converged sunlight on the heat receiving portion of the solar heat receiving device 24. The solar heat receiving device 24 has a heat receiving portion through which the heat medium is circulated, and heats the heat medium by solar heat from the solar heat collecting device 23. The heated heat medium is sent to the heat exchanger of the activated carbon activation device 21 to heat the activated carbon. The heated heat medium is sent to the heat exchanger of the gas heater 22 to heat the activated reaction gas. The surface of the solar heat receiving device 24 is covered with transparent glass, transparent quartz, or the like, and heat loss due to staying heat transfer can be suppressed by evacuating the space between the transparent glass and the heat receiving portion. In addition, the surface of the heat receiving part is coated with black paint or has an uneven mirror surface structure, so that the radiation heat transfer loss can be suppressed, and the amount of heat received from the solar heat collecting device 23 is maximized. And minimizing heat loss.

  Thus, the solar heat receiving device 24 is connected to the activated carbon activating device 21 in a form suitable for using the solar heat received from the solar heat collecting device 23 in the activated carbon activating device 21. The activated carbon may be heated by the solar heat receiving device 24 through the heat medium as described above, or may be directly heated by the solar heat collecting device 23 without using the heat medium. When the solar heat received by the solar heat collector 23 is directly applied to the activated carbon in the activated carbon activation device 21, the surface of the heat receiving part of the activated carbon activation device 21 is covered with transparent glass, transparent quartz, etc. It is preferable to be able to transmit.

  Further, the solar heat receiving device 24 is connected to the gas heater 22 in a form suitable for using the solar heat received from the solar heat collecting device 23 in the gas heater 22. The activation reaction gas may be heated by the solar heat receiving device 24 through the heat medium as described above, or may be directly heated by the solar heat collecting device 23 without using the heat medium. When directly irradiating the activated reaction gas activated carbon in the gas heater 22 with the solar heat received by the solar heat collector 23, the surface of the heat receiving portion of the gas heater 22 is covered with transparent glass, transparent quartz, etc. It is preferable that solar heat can be transmitted.

<Activation reaction generating gas feedback means>
The activation reaction generated gas feedback means is a device for returning the generated gas in the activated carbon activation device 21 to the waste treatment furnace 11, and a blower 25 for returning the generated gas to the waste treatment furnace 11 and the generated gas return path 26. And have.

The gas generated by the activated carbon activation reaction in the activated carbon activation device 21 includes CO, H ₂ , and harmful substances adsorbed and desorbed on the activated carbon.

CO and H ₂ become part of a heat source that is burned in the waste treatment furnace 11 and recovers waste heat, and the desorbed harmful substances are decomposed and rendered harmless in the waste treatment furnace 11.

  The present invention activates and regenerates deteriorated activated carbon that has been used in activated carbon adsorption equipment that adsorbs and removes harmful substances in exhaust gas discharged from a waste treatment furnace that incinerates or gasifies and melts waste and has reduced adsorption performance. This is related to activated carbon regenerators that are used in activated carbon adsorbers that adsorb and remove harmful substances from exhaust gas discharged from melting furnaces such as scrap melting electric furnaces and metal smelting furnaces, but the deterioration of the adsorption performance It can also be applied to the purpose of activating and regenerating activated carbon.

DESCRIPTION OF SYMBOLS 11 Waste processing furnace 12 Waste heat boiler 15 Activated carbon adsorption apparatus 21 Activated carbon activation apparatus 22 Gas heater 23 Solar thermal collector 24 Solar thermal receiver 26 Activation reaction generation gas return path
II Activated carbon regenerator

Claims (2)

Activated carbon regenerator that activates and regenerates deteriorated activated carbon that has been used in activated carbon adsorbers that absorb and remove harmful substances in exhaust gas discharged from waste treatment furnaces that incinerate or gasify and melt waste. In
A solar heat collector for collecting solar heat;
An activated carbon activation device that heats a deteriorated activated carbon by solar heat collected by a solar heat collector and activates the activated activated gas in an activated reaction gas atmosphere;
It receives at least one of the treated exhaust gas discharged from the waste treatment furnace and detoxified and the water vapor generated in the waste heat boiler by the exhaust gas discharged from the waste treatment furnace, and receives it from the solar heat collector. A gas heater that is heated by and supplied to the activated carbon activation device as an activated reaction gas;
An activated carbon regenerating apparatus comprising: an activated reaction generating gas feedback means for returning a generated gas generated by an activation reaction from an activated carbon activation apparatus to a waste treatment furnace. Activated carbon regenerator that activates and regenerates deteriorated activated carbon that has been used in activated carbon adsorbers that absorb and remove harmful substances in exhaust gas discharged from waste treatment furnaces that incinerate or gasify and melt waste. In
A solar heat collector for collecting solar heat;
A solar heat receiving device that heats the heat medium by receiving solar heat from the solar heat collecting device;
An activated carbon activation device that heats a deteriorated activated carbon with a heat medium heated by a solar heat receiving device and activates the activated activated gas in an activated reaction gas atmosphere;
At least one of the treated exhaust gas discharged from the waste treatment furnace and detoxified and the water vapor generated in the waste heat boiler by the exhaust gas discharged from the waste treatment furnace was received and heated by a solar heat receiving device. A gas heater that is heated by a heat medium and supplied to the activated carbon activation device as an activated reaction gas;
An activated carbon regenerating apparatus comprising: an activated reaction generating gas feedback means for returning a generated gas generated by an activation reaction from an activated carbon activation apparatus to a waste treatment furnace.

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