JP2010058060A - Method and apparatus of treating siloxane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus of treating siloxanes, which can reduce industrial waste by a selective adsorption-degradative treatment of siloxanes in a gas. <P>SOLUTION: A step of contacting a siloxane-containing gas with an adsorbent having ozonolysis characteristics to adsorb siloxane to the adsorbent, and a step of decomposing siloxane desorbed by contacting ozone with the adsorbent are carried out alternately. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for treating a siloxane contained in a gas, and mainly aims at selectively adsorbing and decomposing siloxane in the gas, and by ozonolysis of siloxane which has been conventionally discarded as industrial waste. The present invention relates to a siloxane treatment method and a siloxane treatment apparatus that can reduce industrial waste.

  In recent years, as a new energy source to replace fossil fuels, the use of biomass energy to make effective use of methane gas contained in digestion gas for power generation has become active, and efforts to recover biomass energy have been promoted. This is in response to the reduction in the use of fossil fuels to reduce carbon dioxide emissions in connection with the Kyoto Protocol. The government has announced the “New Biomass / Nippon Comprehensive Strategy”, which shows the policy of promoting the use of domestic biomass fuel.

  In order to obtain energy from biomass gas, it can be obtained as thermal energy / electric energy by burning biomass in a combustion engine. However, burning biomass gas, such as digestion gas, produces various by-products, particularly silicone-derived siloxane, which requires a process to remove it.

  Siloxane is an organic or inorganic compound mainly composed of silicon and oxygen. When biomass gas containing siloxane is burned in a combustion engine, silicon dioxide produced by combining silicon and oxygen, so-called quartz glass, is produced. If this silicon dioxide adheres to and accumulates in the combustion engine or in the exhaust pipe, the facility may not function sufficiently, and power generation may be stopped or combustion troubles may occur.

  In order to prevent such equipment failure troubles caused by siloxanes and to effectively use digestion gas as biomass energy, it is necessary to arrange an apparatus for removing siloxanes in front of the combustion engine.

  For example, as shown in FIG. 8, in the conventional siloxane processing apparatus 100, the digestion gas, which is a siloxane-containing gas, is supplied from the digestion gas generation source 102 through the line L1 to the line L3 that communicates with the inlet of the siloxane removal apparatus 103. The siloxane contained in the introduced gas is adsorbed by the adsorbent of the adsorbing unit 104, the line communicating with the inlet line L3 of the removing device 103 is switched, and ozone is passed from the ozone generator 106 through the line L2 to the inlet of the siloxane removing device 103. Is supplied to the adsorption unit 104 through a line L3 communicating with the gas, and the adsorbed siloxane is decomposed with ozone. The gas after the siloxane decomposition treatment is discharged from the removing device 103 through the discharge line L4 and burned in the combustion engine provided on the downstream side.

  Various proposals have conventionally been made as methods and means for removing siloxane. For example, in Patent Document 1, a method of adsorbing and removing siloxane with activated carbon is used. In Patent Document 2, a method of performing adsorption of siloxane with water is adsorbed. In Patent Document 3, after adsorbing and removing with an adsorbent, the adsorbent is regenerated by heat. Each method is proposed.

  In these siloxane removal methods, since siloxane is adsorbed by an adsorbent, the adsorbent after use is subjected to secondary treatment or discarded as industrial waste.

  In the method of Patent Document 1, activated carbon adsorbed with siloxane is directly used as industrial waste. Moreover, in the method of patent document 2, it is possible that the water which adsorb | sucked the siloxane is processed as water treatment or industrial waste. Further, in the method of Patent Document 3, the siloxane desorbed from the adsorbent by thermal heating is subjected to adsorption treatment again.

However, these Patent Documents 1 to 3 all aim to regenerate the adsorbent by desorbing siloxane, and are not proposals for substantial decomposition treatment of siloxane.
JP 2004-270624 A JP 2004-189157 A JP 2007-197548 A

  The present invention has been made to solve the above problems, and provides a siloxane treatment method and a siloxane treatment apparatus capable of reducing industrial waste by selectively adsorbing and decomposing siloxane in a gas. With the goal.

  The method for treating siloxane according to the invention of 1) includes a step of bringing a siloxane-containing gas into contact with an adsorbent having ozone decomposition characteristics to adsorb the siloxane on the adsorbent, and a step of adsorbing siloxane adsorbed by bringing ozone into contact with the adsorbent. And the step of disassembling alternately. According to the invention of 1), by alternately performing the siloxane adsorption step and the siloxane decomposition step, it is possible to secure a pause period from adsorption to the next adsorption, and the function of the adsorbent during the pause period. In order to recover, the adsorbent can adsorb siloxane equivalent to or higher than the conventional one while reducing the amount of adsorbent discarded as industrial waste (FIG. 6A). As a result, the processing efficiency of the entire processing system is improved.

  The outline of the adsorption action and the decomposition action of siloxane will be described. First, the siloxane-containing gas is adsorbed by an adsorbent having ozonolysis characteristics. Further, the ozonized gas is supplied to an adsorbent having an ozonolysis characteristic in which a siloxane gas is adsorbed. When the ozonized gas reaches the adsorbent having the ozone decomposing property, the ozone in the ozonized gas is decomposed and dissociated into oxygen molecules and oxygen atoms. Oxygen atoms are unstable and highly reactive with other substances. Siloxane is first adsorbed on the surface of the adsorbent having ozonolysis characteristics. For this reason, siloxane is oxidized by reacting with oxygen atoms, and finally becomes silicon dioxide.

  The decomposition reaction of siloxane is performed on the surface of the adsorbent. That is, since the reaction is a reaction occurring on the surface, it is difficult to treat a large amount of siloxane at a time. For this reason, it becomes possible to improve the removal performance of siloxane by alternately performing the adsorption step and the decomposition step with ozone.

  When the ozonized gas reaches the adsorbent having ozonolysis characteristics, it is dissociated into oxygen molecules and oxygen atoms according to the following formula (1).

O ₃ → Cat. → O ₂ + O (1)
In the formula (1), O ₃ represents ozone, Cat. Is an adsorbent having ozonolysis characteristics, and here, a catalyst is described as an example, O ₂ represents an oxygen molecule, and O represents an oxygen atom. The oxygen atom O generated here reacts with siloxane according to the following formulas (2) and (3) and is finally decomposed into silicon dioxide.

O + siloxane → siloxane _oxide (2)
Siloxane _oxide + O → SiO ₂ + H ₂ O + CO ₂ (3)
In the formulas (2) and (3), the siloxane _oxide is a secondary product of siloxane generated by the oxidation reaction of siloxane. SiO ₂ represents silicon dioxide, H ₂ O represents water molecules, and CO ₂ represents carbon dioxide.

The oxidation reaction of siloxane and siloxane _oxide is considered to be slower than the reaction rate of reaction with oxygen atoms, but reaction with ozone is also considered. The final product is considered to be silicon dioxide, water molecules, and carbon dioxide, but water molecules and carbon dioxide are in a gas state and do not remain. However, since silicon dioxide is a solid, it remains on the surface of the adsorbent having ozonolysis characteristics. Since the gasified siloxane is reduced in molecular weight, and the remaining one is further solidified and remains as silicon dioxide, the volume is considered to be very small. However, since siloxane is adsorbed and remains on the adsorbent surface, the adsorption performance of siloxane gradually declines, and the ozonolysis property also gradually declines, so that adsorption → decomposition → adsorption → decomposition alternately It is necessary to replace the adsorbent while observing the processing effect of the operation.

  The invention of 2) has at least two systems of processing means, and at least one of the processing systems of the two or more systems performs adsorption treatment of siloxane, and in parallel with this, the remaining systems In this processing means, siloxane decomposition treatment with ozone is performed, and thereafter, the one processing means is switched to siloxane decomposition treatment, and at least one of the remaining processing means is changed to siloxane adsorption treatment. By switching, the siloxane-containing gas is substantially continuously adsorbed and decomposed. According to the invention of 2), since the inflowing siloxane-containing gas is alternately adsorbed by a plurality of adsorbing means, it becomes possible to perform continuous processing substantially without a break.

  In the invention of 3), an adsorbing part having an adsorbent having an ozonolysis property for adsorbing siloxane, means for supplying a siloxane-containing gas to the adsorbing part, and ozone in the adsorbing part to decompose the adsorbed siloxane And an operating means for alternately operating the gas supplying means and the ozone generating section. According to the invention of 3), the inflowing siloxane-containing gas can be continuously processed, and the processing efficiency as a whole is improved without interruption of the processing.

  In the invention of 4), the adsorption unit has at least two or more siloxane adsorption units, and the operation unit alternately operates the gas supply unit and the ozone generation unit, thereby Rather than letting the siloxane adsorbing portion perform the same operation at the same time, at least one siloxane adsorbing portion of the two or more siloxane adsorbing portions is allowed to perform the siloxane adsorbing operation, and the other siloxane adsorbing portions Is characterized by performing an ozone treatment operation. According to the invention of 4), the processing efficiency of the entire system is further improved.

  The invention of 5) is characterized in that the siloxane adsorption part has activated carbon. Activated carbon has a high siloxane adsorption effect and at the same time has ozonolysis properties. According to the invention of 5), adsorption and decomposition of siloxane can be performed with high efficiency by using activated carbon in the adsorption part.

  The invention of 6) is a honeycomb structure (Fig. 3) or at least one ozonized substance of manganese, copper, nickel oxide, porous carbon containing nickel, cobalt, manganese, copper, zeolite, clay mineral. A three-dimensional network structure (FIG. 4) is formed. All of the above mineral substances have ozonolysis characteristics. According to the invention of 6), these mineral substances are contained in porous carbon, zeolite, and clay mineral, and are further formed into a honeycomb structure or a three-dimensional network structure, thereby improving the adsorption effect of siloxane. In addition, the improvement of the ozonolysis effect is expected, and the adsorbed siloxane and the oxygen atom after the ozonolysis can be present at close positions, so that the siloxane gas of the above formulas (1) to (3) This processing reaction can be further promoted. For this reason, the processing effect can be improved.

  In the invention 7), the siloxane adsorbing portion carries fine particles of at least one platinum-based noble metal such as platinum, iridium, osmium, palladium, rhodium, and ruthenium. According to the invention of 7), the oxidation reaction between the oxygen atom obtained by decomposing ozone and the siloxane adsorbed on the adsorbent can be further promoted. Therefore, the processing efficiency of siloxane can be further improved.

  According to the present invention, the siloxane-containing gas is adsorbed by an adsorbent having ozonolysis characteristics, whereby only the siloxane gas is removed and supplied to the subsequent process. The siloxane gas is decomposed into silicon dioxide, water, and carbon dioxide by supplying ozone to the adsorbent having ozone decomposing characteristics. As a result, a siloxane treatment method and a siloxane treatment apparatus capable of dramatically extending the life of a siloxane adsorbent such as activated carbon that has been conventionally discarded and greatly reducing the amount of industrial waste are provided.

  The best mode for carrying out the present invention will be described below with reference to the accompanying drawings.

(First embodiment)
A siloxane processing apparatus according to a first embodiment of the present invention will be described with reference to FIG. The siloxane treatment apparatus 1 includes a siloxane-containing gas supply source 2, a siloxane adsorption / decomposition tower 3, a compressor 5, an ozone generator 6, and a control unit 10 as necessary. The siloxane-containing gas supply source 2 contains a siloxane-containing gas (digestion gas) G1 containing siloxane. Siloxane is a general term for various silicon-containing gases, and among them, the component called D4 gas is contained most in the siloxane-containing gas G1. The siloxane-containing gas G1 contains D3 gas and D5 gas in addition to the D4 gas in its components, and is generally mostly composed of D3, D4, and D5 gases.

  The siloxane-containing gas supply source 2 is connected so as to receive a digestion gas serving as a biomass energy source from a biomass generation source (not shown) and introduce it into the bottom of the siloxane adsorption / decomposition tower 3 via lines L1 and L3. Yes. The adsorbent 4 is filled in the siloxane adsorption decomposition tower 3 to a predetermined thickness. The thickness of the layer of the adsorbent 4 is appropriately set according to the process conditions such as the type, shape and size of the adsorbent, the inner diameter of the siloxane adsorption / decomposition tower 3, the flow rate and composition of the siloxane-containing gas G1.

  The ozone generator 6 generates ozonized gas G2 using compressed air supplied from the compressor 5 as a raw material. The ozone generator 6 communicates with the bottom of the siloxane adsorption / decomposition tower 3 via lines L2 and L3, supplies the ozonized gas G2 to the siloxane adsorption / decomposition tower 3, and ozonizes the siloxane adsorbed on the adsorbent 4. It has a role of being decomposed by the gas G2.

  The siloxane-containing gas supply line L1 and the ozonized gas supply line L2 are connected to a common three-way valve 7. That is, two inlets of the three-way valve 7 are connected to lines L1 and L2, respectively, and one outlet of the three-way valve 7 is connected to a line L3 at the bottom of the tower. The power switch of the drive circuit that drives the valve body of the three-way valve 7 is connected to the output side of the control unit 10, and the control unit 10 controls the opening / closing switching operation of the three-way valve 7.

  The control unit 10 controls the entire siloxane processing apparatus 1 in an integrated manner. Based on detection signals sent from a flow sensor, pressure sensor, temperature sensor, concentration sensor, etc. (not shown) The operations of the drive unit of the supply source 2, the compressor 5 and the ozone generator 6 are controlled.

  The siloxane-containing gas G1 flows into the bottom of the siloxane adsorption / decomposition tower 3 via the line L3, is introduced into the adsorbent 4 layer from one end side, and the siloxane contained in the gas G1 is selectively adsorbed by the adsorbent 4. The The desiloxaneized gas G3 after the siloxane is adsorbed is discharged from the top via the line L4 and supplied to a combustion device (not shown) arranged on the rear stage side.

  By switching the flow path of the three-way valve 7, the ozonized gas G <b> 2 flows into the same column end as the inflow side of the siloxane-containing gas G <b> 1 by the adsorbent 4. The ozonized gas G2 is generated by the ozone generator 6. The raw material for generating the ozonized gas G2 is a gas containing oxygen. As an example, the apparatus of this embodiment shown in FIG. 1 shows a case where air is used as the raw material gas. Various types such as a creeping discharge type, a coplanar discharge type, a volume discharge type, and a corona discharge type can be used for the ozone generator 6, and the ozone generation amount and concentration required according to the amount of siloxane treated. In addition, an optimal ozone generation method can be selected according to the situation such as generation efficiency. The ozone generating capacity of the ozone generator 6 is such that the ozone concentration in the ozonized gas G2 is set to a level of 100 to 700 ppm, for example.

  The air is boosted to a specified pressure by the compressor 5. The degree of pressure increase is determined by the pressure required when the piping, adsorbent, and air are ozonized and when the desiloxane gas G3 is used.

  The type of adsorbent can be individually selected from the following group according to the process and equipment. That is, activated carbon can be used as the adsorbent, but at least one ozone decomposing substance of oxides of manganese, copper, nickel, porous carbon containing nickel, cobalt, manganese, and copper, zeolite, and clay minerals. A structure having a honeycomb structure or a three-dimensional network structure may be used.

  FIG. 3 shows an example of an adsorbent having a honeycomb structure. The carrier 45 made of the ozone decomposing substance is formed in a honeycomb structure, and adsorbent particles 46 are supported in each chamber of the honeycomb structure.

  FIG. 4 shows an example of an adsorbent having a three-dimensional network structure. The carrier 47 made of the ozone decomposing substance is formed in a three-dimensional network structure, and adsorbent particles 48 are supported on the three-dimensional network structure. As these adsorbent particles to be supported, fine particles of at least one platinum-based noble metal such as platinum, iridium, osmium, palladium, rhodium, and ruthenium can be used.

  The siloxane-decomposed gas G4 after decomposing the adsorbed siloxane by the ozonized gas G2 is sent from the top through the line L4 to a downstream combustion device (not shown) and combusted.

  Next, the operation of the present embodiment will be described in comparison with the conventional method with reference to FIG.

  At the time t1 shown in FIG. 5A, the flow path of the three-way valve 7 is opened to connect the lines L1 and L3, and the siloxane-containing gas G1 is introduced into the adsorption cracking tower 3 from the gas supply source 2. The siloxane concentration of the siloxane-containing gas G1 is, for example, 300 ppm. The siloxane-containing gas G1 flows from one end side of the adsorbent 4 having an ozonolysis effect, and the siloxane contained therein is selectively adsorbed by the adsorbent 4. The siloxane-containing gas G1 after the siloxane is adsorbed and removed by the adsorbent 4 is sent as a desiloxane gas G3 to a subsequent fuel device via a line L4, and burned in the combustion device to extract biomass energy. .

  As shown in FIG. 5A, when the siloxane is adsorbed to the adsorbent 4 to a certain amount S1, the siloxane adsorbing ability of the adsorbent 4 is almost saturated and the processing efficiency is lowered. Since the time t2 when the adsorption capacity decreases depends on the type of the adsorbent 4 and the siloxane content of the gas G1, it can be grasped in advance by a demonstration test and stored in the database of the control unit 10. Is possible.

  A control signal is sent from the control unit 10 to the three-way valve 7 at a time t2 after a predetermined time has elapsed, the flow path of the three-way valve 7 is switched, the supply of the siloxane-containing gas G1 from the gas supply source 2 is stopped, and an ozone generator The supply of ozonized gas G2 from 6 to the adsorption cracking tower 3 is started. The ozone concentration in the ozonized gas G2 is 100 to 700 ppm. Ozone in the ozonized gas G2 is decomposed on the surface of the adsorbent 4, and the generated oxygen atoms are adsorbed with siloxane to decompose siloxane. The siloxane-decomposed gas G4 after decomposing siloxane is sent to the subsequent combustion apparatus via the line L4.

  A control signal is sent from the control unit 10 to the three-way valve 7 at a time t3 after a predetermined time has elapsed, the flow path of the three-way valve 7 is switched, and the supply of the ozonized gas G2 from the ozone generator 6 to the adsorption cracking tower 3 is stopped. At the same time, the supply of the siloxane-containing gas G1 from the gas supply source 2 is restarted. The siloxane decomposition times t2 to t3 vary depending on the type, amount and size of the adsorbent and the amount of siloxane adsorbed, and this can also be obtained in advance by a demonstration test and stored in a database.

  The entire amount S1 of the adsorbed siloxane is not decomposed by the decomposition reaction, but a part of the amount S1-2 is decomposed and the remaining amount S1-1 is adsorbent 4 as shown in FIG. Remains on the surface of the adsorbent even after the adsorption capacity is restored. For this reason, the adsorption operation of the adsorbent 4 after resumption is added to the residual amount S1-1. The second siloxane adsorption time t3 to t4 may be set to be the same as or longer than the first siloxane adsorption time t1 to t2.

  A control signal is sent from the control unit 10 to the three-way valve 7 at a time t4 after a predetermined time has elapsed, the flow path of the three-way valve 7 is switched, the supply of the siloxane-containing gas G1 from the gas supply source 2 is stopped, and an ozone generator The supply of ozonized gas G2 from 6 to the adsorption cracking tower 3 is resumed. The siloxane adsorption amount S2 at the time t4 when the decomposition process is resumed is obtained by adding a new adsorption amount to the residual amount S1-1.

  In the second decomposition process, the entire amount S2 of the adsorbed siloxane is not decomposed, but a part of the amount S2-2 is decomposed and the remaining amount S2− is decomposed as shown in FIG. 1 remains on the surface of the adsorbent even after the adsorbent 4 has recovered the adsorption capacity. For this reason, the adsorption operation of the adsorbent 4 after the restart is added to the residual amount S2-1. The second siloxane decomposition time t4 to t5 may be set to be the same as or longer than the first siloxane decomposition time t2 to t3.

  A control signal is sent from the control unit 10 to the three-way valve 7 at a time t5 after a predetermined time has elapsed, the flow path of the three-way valve 7 is switched, and the supply of the ozonized gas G2 from the ozone generator 6 to the adsorption cracking tower 3 is stopped. At the same time, the supply of the siloxane-containing gas G1 from the gas supply source 2 is restarted. This further decomposes the siloxane. The third siloxane adsorption time t5 to t6 may be set to be the same as the first adsorption time t1 to t2 or the second adsorption time t3 to t4, or set to a longer time. May be.

  As described above, according to the above-described embodiment according to the present invention, a large amount of the siloxane-containing gas G1 can be efficiently processed by the intermittent operation in which the siloxane adsorption process and the decomposition process are alternately switched.

  On the other hand, in the conventional processing method using the apparatus of FIG. 8, since the siloxane-containing gas G1 is continuously flowed to the adsorbent 104 for a long time, as shown in FIG. The decrease in adsorption performance is remarkable, and the siloxane adsorption amount Sp is finally reduced. That is, when viewed at the same processing time t1 to t6, the siloxane adsorption amount S3 by the method of the present invention using the apparatus of FIG. 1 is considerably larger than the siloxane adsorption amount Sp by the conventional method (S3> Sp). As described above, it is difficult to treat a large amount of siloxane at a time by the conventional method of treating by an adsorbent surface reaction.

  According to the present embodiment, once the siloxane is adsorbed to the adsorbent and then the ozonized gas is supplied, it is possible to give a longer time for the decomposition of the siloxane and ozone. As a result, the siloxane treatment can be performed more efficiently than the siloxane treatment.

(Second Embodiment)
Next, a siloxane processing apparatus and a processing method according to the second embodiment of the present invention will be described with reference to FIGS. In addition, description of the part which this embodiment overlaps with said embodiment is abbreviate | omitted.

  The processing concept of this embodiment is substantially the same as that of the first embodiment, but the siloxane processing apparatus 1A of this embodiment has two siloxane adsorption / decomposition towers 31, 32, 2 and 2 as shown in FIG. Two three-way valves 71, 72 and a pair of two discharge valves (81, 82) (91, 92). When the siloxane-containing gas G1 is sent to one siloxane adsorption / decomposition tower 31, the other When the ozonized gas G2 is sent to the siloxane adsorption / decomposition tower 32 and the ozonized gas G2 is sent to one siloxane adsorption / decomposition tower 31, the other siloxane adsorption / decomposition tower 32 simultaneously receives the siloxane-containing gas G1. I am trying to send it. That is, when attention is paid to one siloxane adsorption / decomposition tower, adsorption and decomposition of siloxane are alternately carried out, and the repeated operation of adsorption treatment → decomposition treatment → adsorption treatment → decomposition treatment is performed substantially continuously. It is supposed to be.

  As described above, the second embodiment is characterized in that the siloxane-containing gas G1 can be continuously processed. The siloxane-containing gas G <b> 1 is caused to flow to either the first adsorption tower 31 or the second adsorption tower 32. In FIG. 2, it flows toward the first adsorption tower 31. At this time, the siloxane-containing gas three-way valve 71 is set so that the siloxane-containing gas G <b> 1 flows only in the first adsorption tower 31, and does not flow in the second adsorption tower 32. At this time, the ozonized gas three-way valve 72 is set so that the ozonized gas G <b> 2 is supplied to the second adsorption tower 32, and the ozonized gas G <b> 2 does not flow to the first adsorption tower 31. That is, when the siloxane-containing gas G1 flows to one side, the ozonized gas flows to the other adsorbent. The desiloxane gas G3 after the siloxane-containing gas G1 is adsorbed by the first adsorption tower 31 is discharged to the subsequent stage by the desiloxane gas valve 81. At this time, the gas valve 82 after siloxane decomposition is closed.

  At the same time, the ozonized gas G2 flows through the second adsorption tower 32 in parallel. At this time, the desiloxane removal valve 91 is closed, the siloxane decomposition gas valve 92 is opened, and the siloxane decomposition gas G4 is discarded. The operations of the three-way valves 71 and 72 for ozonized gas, the valves 81 and 91 for desiloxane gas, and the valves 82 and 92 for decomposed siloxane gas may all be automatically controlled by the control unit 10A. As described above, in the apparatus 1A of the present embodiment, the siloxane-containing gas G1 and the ozonized gas G2 are supplied to the first and second adsorption towers 31 and 32 adsorbents 41 and 42 alternately in time.

  The adsorbents 41 and 42 can be appropriately replaced depending on the processing conditions. The adsorbents 41 and 42 may be activated carbon, manganese / copper / nickel oxide, porous carbon containing nickel / cobalt / manganese / copper, zeolite, or at least one ozone decomposing substance of clay mineral. The honeycomb structure shown in FIG. 3 or the three-dimensional network structure shown in FIG. 4 can also be used.

  Next, a siloxane treatment method according to a second embodiment of the present invention will be described with reference to FIG. In addition, description of the part which this embodiment overlaps with said embodiment is abbreviate | omitted.

  At time t1 shown in FIG. 6, the flow path of the first three-way valve 71 is opened to connect the lines L1 and L11, and the siloxane-containing gas G1 is introduced from the gas supply source 2 into the first adsorptive decomposition tower 31. . The siloxane concentration of the siloxane-containing gas G1 is, for example, 300 ppm. The siloxane-containing gas G1 flows from one end side of the adsorbent 41 having an ozonolysis effect, and the siloxane contained therein is selectively adsorbed by the adsorbent 41. The siloxane adsorption amount S11 adsorbed on the adsorbent 41 during the adsorption time t1 to t2 is an amount that does not saturate the adsorption capacity of the adsorbent 41. The desiloxaneized gas G3 after the siloxane is adsorbed and removed by the adsorbent 41 is sent to the subsequent fuel device via the line L41, and burned in the combustion device to extract biomass energy.

  As shown in FIG. 6, when the siloxane is adsorbed to the adsorbent 41 up to a certain amount S11, the siloxane adsorbing capacity of the adsorbent 41 is almost saturated and the processing efficiency is lowered. Since the time t2 when the adsorption capacity decreases depends on the type of the adsorbent 41, the siloxane content of the gas G1, and the like, it can be grasped beforehand by a verification test and stored in the database of the control unit 10A. Is possible.

  A control signal is sent from the control unit 10A to the first three-way valve 71 at time t2 after a predetermined time has elapsed, the flow path of the three-way valve 71 is switched, and the siloxane-containing gas from the gas supply source 2 to the first adsorptive decomposition tower 31 The supply of G1 is stopped and the supply of the ozonized gas G2 from the ozone generator 6 to the first adsorption / decomposition tower 31 is started, and a control signal is also sent to the second three-way valve 72. The flow path is switched, supply of the ozonized gas G2 from the ozone generator 6 to the second adsorption / decomposition tower 32 is stopped, and supply of the siloxane-containing gas G1 from the gas supply source 2 to the second adsorption / decomposition tower 32 To start. Ozone in the ozonized gas G2 is decomposed on the surface of the adsorbent 41, and the generated oxygen atoms are adsorbed with siloxane to decompose siloxane. The siloxane-decomposed gas G4 after decomposing siloxane is sent to the subsequent combustion apparatus via the line L42.

  In the first adsorptive decomposition tower 31, the total amount S11 of the adsorbed siloxane is not decomposed by the decomposition reaction, but a part of the amount Sb is decomposed as shown in the upper part of FIG. Remains on the surface of the adsorbent even after the adsorbent 41 has recovered the adsorption capacity. For this reason, the adsorption operation of the adsorbent 41 after the restart is added to the residual amount Sa.

  A control signal is sent from the control unit 10A to the first three-way valve 71 at a time t3 after a predetermined time has elapsed, the flow path of the three-way valve 71 is switched, and the ozonized gas from the ozone generator 6 to the first adsorptive decomposition tower 31 The supply of G2 is stopped, and the supply of the siloxane-containing gas G1 from the gas supply source 2 is restarted. At the same time, a control signal is sent to the second three-way valve 72, and the flow path of the three-way valve 72 is changed. Switching, the supply of the siloxane-containing gas G1 from the gas supply source 2 to the second adsorption / decomposition tower 32 is stopped, and the supply of the ozonized gas G2 from the ozone generator 6 to the second adsorption / decomposition tower 32 is started. .

  In the second adsorptive decomposition tower 32, the total amount S21 of the adsorbed siloxane is not decomposed by the decomposition reaction, but a part of the amount Sb is decomposed as shown in the lower part of FIG. Remains on the surface of the adsorbent even after the adsorbent 42 has recovered the adsorption capacity. For this reason, the adsorption operation of the adsorbent 42 after the restart is added to the residual amount Sa. The siloxane adsorption time t2 to t3 of the second adsorptive decomposition tower 32 may be set to be the same as or longer than the siloxane adsorption time t1 to t2 of the first adsorptive decomposition tower 31. May be. Further, the siloxane decomposition times t3 to t4 of the second adsorptive decomposition tower 32 may be set to be the same as or longer than the siloxane decomposition times t2 to t3 of the first adsorptive decomposition tower 31. May be.

  A control signal is sent from the control unit 10A to the first three-way valve 71 at a time t4 after a predetermined time has elapsed, the flow path of the three-way valve 71 is switched, and the siloxane-containing gas from the gas supply source 2 to the first adsorptive decomposition tower 31 The supply of G1 is stopped, and the supply of the ozonized gas G2 from the ozone generator 6 to the first adsorption / decomposition tower 31 is restarted, and a control signal is also sent to the second three-way valve 72. The flow path is switched, supply of the ozonized gas G2 from the ozone generator 6 to the second adsorption / decomposition tower 32 is stopped, and supply of the siloxane-containing gas G1 from the gas supply source 2 to the second adsorption / decomposition tower 32 To resume. The siloxane adsorption amount S12 of the first adsorbent 41 at the time t4 when the decomposition process is resumed is obtained by adding a new adsorption amount to the residual amount Sa.

  In the second decomposition process, the entire amount S12 of the adsorbed siloxane is not decomposed, but a part of the amount Sb is decomposed as shown in the upper part of FIG. Remains on the surface of the adsorbent even after the adsorption capacity is restored. For this reason, the adsorption operation of the adsorbent 41 after the restart is added to the residual amount Sb. The second siloxane decomposition time t4 to t5 may be set to be the same as or longer than the first siloxane decomposition time t2 to t3.

  A control signal is sent from the control unit 10A to the first three-way valve 71 at time t5 after a predetermined time has elapsed, the flow path of the three-way valve 71 is switched, and the ozonized gas G2 is supplied from the ozone generator 6 to the adsorption cracking tower 3 And the supply of the siloxane-containing gas G1 from the gas supply source 2 is restarted, a control signal is also sent to the second three-way valve 72, the flow path of the three-way valve 72 is switched, and the gas supply source 2 The supply of the siloxane-containing gas G1 to the second adsorption / decomposition tower 32 is stopped, and the supply of the ozonized gas G2 from the ozone generator 6 to the second adsorption / decomposition tower 32 is resumed. The siloxane adsorption amount S22 of the second adsorbent 42 at the time t5 when the decomposition process is resumed is obtained by adding a new adsorption amount to the residual amount Sa.

  A control signal is sent from the control unit 10A to the first three-way valve 71 at a time t6 after a predetermined time has elapsed, the flow path of the three-way valve 71 is switched, and the siloxane-containing gas from the gas supply source 2 to the first adsorptive decomposition tower 31 The supply of G1 is stopped, and the supply of the ozonized gas G2 from the ozone generator 6 to the first adsorption / decomposition tower 31 is restarted, and a control signal is also sent to the second three-way valve 72. The flow path is switched, supply of the ozonized gas G2 from the ozone generator 6 to the second adsorption / decomposition tower 32 is stopped, and supply of the siloxane-containing gas G1 from the gas supply source 2 to the second adsorption / decomposition tower 32 To resume. The siloxane adsorption amount S13 of the first adsorbent 41 at the time t6 when the decomposition process is resumed is obtained by adding a new adsorption amount to the residual amount Sa. The third siloxane adsorption time t5 to t6 may be set to be the same as the first adsorption time t1 to t2 or the second adsorption time t3 to t4, or set to a longer time. May be.

  According to this embodiment, by using the two systems of adsorption / decomposition towers 31 and 32, the operation of each adsorption / decomposition tower 31 and 32 is continuously performed by switching the adsorption process and the decomposition process of siloxane alternately. And a large amount of siloxane-containing gas G1 can be treated with high efficiency.

(Third embodiment)
A siloxane treatment method according to a third embodiment of the present invention will be described with reference to FIG. In addition, description of the part which this embodiment overlaps with said embodiment is abbreviate | omitted.

  In the third embodiment, the second embodiment is applied so that the siloxane-containing gas G1 can be continuously processed. The second embodiment or the first embodiment can be appropriately selected and used depending on the amount of the siloxane gas to be processed and the supply form of the siloxane-containing gas G1.

  The processing concept of the present embodiment is substantially the same as that of the second embodiment. Although the illustration of the apparatus is omitted in the present embodiment, it includes three siloxane adsorption / decomposition towers, three three-way valves, and a pair of three discharge valves, and the siloxane-containing gas G1 is provided in the first siloxane adsorption / decomposition tower. Is sent to the second and third siloxane adsorption / decomposition towers simultaneously, and the decomposition process is performed in parallel with the adsorption process in the first tower. I am doing so.

  The rotation of the adsorption process is in the order of the first adsorption / decomposition tower → second adsorption / decomposition tower → third adsorption / decomposition tower → first adsorption / decomposition tower. That is, as shown in FIG. 7, during the time t4 to t5, the siloxane decomposition treatment is performed in the second and third adsorption decomposition towers while the first adsorption decomposition tower is performing the siloxane adsorption treatment, and the next time t5. While the siloxane adsorption treatment is performed in the second adsorption / decomposition tower at t6, the siloxane decomposition treatment is performed in the first and third adsorption / decomposition towers, and the third adsorption / decomposition tower is performed at the next time t6 to t7. During the siloxane adsorption treatment, the first and second adsorption / decomposition towers employ treatment cycles in which the siloxane decomposition treatment is performed. That is, when attention is paid to one siloxane adsorption / decomposition tower, adsorption and decomposition of siloxane are alternately carried out, and the repeated operation of adsorption treatment → decomposition treatment → adsorption treatment → decomposition treatment is performed substantially continuously. It is supposed to be.

  According to the present embodiment, by using the three systems of adsorption / decomposition towers, the operation of each adsorption / decomposition tower can be continuously performed without interruption by the operation of alternately switching the adsorption process and the decomposition process of siloxane. A large amount of siloxane-containing gas can be treated with high efficiency.

  Moreover, according to this embodiment, since the siloxane decomposition treatment time is doubled to the siloxane adsorption time, the amount of residual siloxane remaining on the surface of the adsorbent can be reduced, and the adsorption performance of the adsorbent can be restored efficiently. It can be performed smoothly. As a result, there is an advantage that the life of the adsorbent can be extended.

  The present invention can be used not only for industrial equipment including biomass power generation but also for all processing of siloxane-containing gas.

The block diagram which shows the siloxane processing apparatus which concerns on the 1st Embodiment of this invention. The block diagram which shows the siloxane processing apparatus which concerns on the 2nd Embodiment of this invention. The enlarged schematic diagram which shows the adsorbent of a honeycomb structure. The enlarged schematic diagram which shows the adsorption agent of a three-dimensional network structure. (A) is a timing chart which shows the siloxane processing method of 1st Embodiment, (b) is a timing chart which shows the conventional processing method. The timing chart which shows the siloxane processing method of 2nd Embodiment. The timing chart which shows the siloxane processing method of 3rd Embodiment. The block diagram which shows the conventional apparatus.

Explanation of symbols

1, 1A ... siloxane treatment apparatus, 2 ... siloxane-containing gas supply source,
3, 31, 32 ... siloxane adsorption tower, 4, 41, 42 ... adsorbent,
5 ... Compressor, 6 ... Ozone generator,
7, 71, 72 ... three-way valve,
81, 91 ... valve for desiloxaneization,
82, 92 ... Valve for decomposing siloxane,
10, 10A ... control unit,
L1, L3, L11, L12 ... siloxane-containing gas supply line,
L2, L3, L21, L22 ... ozone supply line,
L4, L41, L42, L411, L412, L412, L422 ... gas discharge line,
G1: siloxane-containing gas,
G2 ... ozonized gas,
G3 ... desiloxane gas,
G4: Gas after decomposition of siloxane.

Claims (7)

A step of bringing a siloxane-containing gas into contact with an adsorbent having an ozone decomposition characteristic to adsorb the siloxane on the adsorbent and a step of bringing the adsorbent into contact with an ozonized gas to decompose the adsorbed siloxane are alternately performed. A process for treating siloxane characterized by the following. It has at least two systems of processing means, and at least one of the two or more systems of processing means performs siloxane adsorption treatment, and in parallel with this, the remaining systems of processing means are ozonated. By performing siloxane decomposition treatment with gas, and then switching the one system processing means to siloxane decomposition treatment, and switching at least one system processing means of the remaining system processing means to siloxane adsorption treatment, The method according to claim 1, wherein the siloxane-containing gas is substantially continuously adsorbed and decomposed. An adsorbing part having an adsorbent having an ozonolysis property for adsorbing siloxane;
Means for supplying a siloxane-containing gas to the adsorption part;
An ozone generator for supplying an ozonized gas to the adsorption unit to decompose the adsorbed siloxane;
Operation means for alternately operating the gas supply means and the ozone generator;
The siloxane processing apparatus characterized by having. The adsorption part has at least two or more siloxane adsorption parts,
The operation means alternately operates the gas supply means and the ozone generation section, so that the siloxane adsorption sections of all systems are not operated at the same time, but the two or more systems of siloxane adsorption are performed. 4. The apparatus according to claim 3, wherein at least one siloxane adsorbing portion of the units is caused to perform a siloxane adsorbing operation, and the other siloxane adsorbing portions are subjected to an ozone treatment operation. The said siloxane adsorption | suction part has activated carbon, The apparatus of any one of Claim 3 or 4 characterized by the above-mentioned. The siloxane adsorbing part is composed of at least one ozone decomposing substance such as manganese / copper / nickel oxide, nickel / cobalt / manganese / copper-containing porous carbon, zeolite, and clay mineral. The apparatus according to claim 3, wherein the apparatus is configured as follows. 5. The apparatus according to claim 3, wherein the siloxane adsorbing portion carries fine particles of at least one platinum-based noble metal of platinum, iridium, osmium, palladium, rhodium, and ruthenium.

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