Anesthetic gas adsorbent, anesthetic gas adsorbing filter, inhalation anesthesia system, and anesthetic gas removal method

Abstract

This anesthetic gas adsorbent comprises activated carbon. The "volume of pores having pore radii of 0.6 nm or less" of the activated carbon calculated via an MP method is 0.41 mL / g or greater. The ratio of the "volume of pores having pore radii of 0.4 nm or less" of the activated carbon calculated via the MP method to the "volume of pores having pore radii of 0.5 nm or less" of the activated carbon calculated via the MP method is 50% or greater.

Description

Anesthetic gas adsorbent, anesthetic gas adsorption filter, inhalation anesthesia system, and method for removing anesthetic gases.

[0001] The present invention relates to an anesthetic gas adsorbent, an anesthetic gas adsorption filter, an inhalation anesthesia system, and a method for removing anesthetic gases.

[0002] Conventionally, a method is known in which excess anesthetic gas containing volatile anesthetics is brought into contact with an adsorbent to adsorb and remove the volatile anesthetics from the excess anesthetic gas (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2002-172171

[0004] In adsorbents such as those described in Patent Document 1, there is a need for further improvement in their ability to adsorb volatile anesthetics.

[0005] The present invention provides an anesthetic gas adsorbent, an anesthetic gas adsorption filter, an inhalation anesthesia system, and a method for removing anesthetic gases, which can improve the performance of adsorbing anesthetic gases in exhaust gases.

[0006] The present invention [1] includes an anesthetic gas adsorbent having activated carbon, wherein the "pore volume of pores with a pore radius of 0.6 nm or less" of the activated carbon, calculated by the MP method, is 0.41 mL / g or more, and the ratio of the "pore volume of pores with a pore radius of 0.4 nm or less" of the activated carbon, calculated by the MP method, to the "pore volume of pores with a pore radius of 0.5 nm or less" of the activated carbon, calculated by the MP method, is 50% or more.

[0007] The present invention [2] includes the anesthetic gas adsorbent described in [1] above, wherein the packing density of the activated carbon after subtracting the ignition residue is greater than 0.38 g / mL and less than 0.50 g / mL.

[0008] The present invention [3] includes the anesthetic gas adsorbent according to [1] or [2] above, wherein the activated carbon has a "pore volume of pores with a pore radius of 0.6 nm or less" calculated by the MP method, which is 1.70 mL / g or less.

[0009] The present invention [4] relates to a specific surface area of ​​the activated carbon which is 950 m². ２ / g or more, 2000m ２The anesthetic gas adsorbent is one of the above [1] to [3], wherein the amount is less than or equal to / g, and the butane adsorption performance of the activated carbon is 24.4% or more and 40.0% or less.

[0010] The present invention [5] is an anesthetic gas adsorption filter comprising any one of the anesthetic gas adsorbents described in [1] to [4] above.

[0011] The present invention [6] includes an anesthetic gas adsorption filter as described in [5] above, comprising: a container having an inlet located at one end of the container in a first direction through which exhaust gas containing anesthetic gas flows in; an outlet located at the other end of the container in a first direction through which the exhaust gas from which the anesthetic gas has been removed flows out; an anesthetic gas adsorbent located between the inlet and the outlet in a first direction; and a spacer located between the inlet and the anesthetic gas adsorbent in a first direction.

[0012] The present invention [7] includes the anesthetic gas adsorption filter of [6], wherein the spacer is a projection that protrudes from the inner surface of one side of the container toward the anesthetic gas adsorbent in the first direction.

[0013] The present invention [8] includes an inhalation anesthesia system comprising a vaporizer that vaporizes a volatile anesthetic to generate an anesthetic gas and supplies the generated anesthetic gas to the inhaled air from a ventilator, and an anesthetic gas adsorption filter connected to the exhaust line of the ventilator and having one of the anesthetic gas adsorbents described in [1] to [4] above.

[0014] The present invention [9] includes the inhalation anesthesia system of [8] further comprising the ventilator.

[0015] The present invention

[10] includes a method for removing anesthetic gas, which involves passing exhaust containing anesthetic gas through one of the anesthetic gas adsorbents [1] to [4] above to remove the anesthetic gas from the exhaust.

[0016] The present invention provides an anesthetic gas adsorbent comprising activated carbon having a "pore volume of pores with a pore radius of 0.6 nm or less" of 0.41 mL / g or more, and a ratio of "pore volume of pores with a pore radius of 0.4 nm or less" to "pore volume of pores with a pore radius of 0.5 nm or less" of 50% or more.

[0017] Therefore, it is possible to improve the performance of adsorbing anesthetic gases in the exhaust.

[0018] The anesthetic gas adsorption filter, inhalation anesthesia system, and method for removing anesthetic gas of the present invention use the anesthetic gas adsorbent described above.

[0019] Therefore, anesthetic gases in the exhaust can be efficiently removed.

[0020] Figure 1 is an explanatory diagram illustrating the activation step in the method for producing an anesthetic gas adsorbent. Figure 2 is a cross-sectional view showing one embodiment of the anesthetic gas adsorption filter of the present invention. Figure 3 is a configuration diagram illustrating the configuration of one embodiment of the inhalation anesthesia system of the present invention. Figure 4 is a cross-sectional view of the anesthetic gas adsorption filter of modification (2). Figure 5 is a cross-sectional view of the anesthetic gas adsorption filter of modification (3). Figure 6A is a perspective view of the lid shown in Figure 5. Figure 6B is a plan view of the lid shown in Figure 6A viewed from the inside. Figure 7A is a cross-sectional view showing the anesthetic gas adsorption filter of modification (4). Figure 7B is a view of the lid shown in Figure 7A viewed from the other side in the first direction. Figure 8 is an explanatory diagram illustrating the lid of modification (5). Figure 9 is an explanatory diagram illustrating the lid of modification (6). Figure 10 is an explanatory diagram illustrating the lid of modification (7).

[0021] 1. An anesthetic gas adsorbent: An anesthetic gas adsorbent as one embodiment of the present invention will be described.

[0022] The anesthetic gas adsorbent is used in the anesthetic gas adsorption filter 10 (see Figure 2) of the inhalation anesthesia system 100. The anesthetic gas adsorption filter 10 and the inhalation anesthesia system 100 will be described later. The anesthetic gas adsorbent has activated carbon. The anesthetic gas adsorbent may consist only of activated carbon. Activated carbon is capable of adsorbing anesthetic gases. Examples of activated carbon include wood-based activated carbon, coconut-based activated carbon, and coal-based activated carbon. Preferably, coconut-based activated carbon and coal-based activated carbon are used, and more preferably, coconut-based activated carbon is used.

[0023] (1) Details of activated carbon The pore volume of activated carbon calculated by the MP method is, for example, 0.43 mL / g to 0.70 mL / g, preferably 0.48 mL / g to 0.66 mL / g.

[0024] The "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is 0.41 mL / g or more, preferably 0.43 mL / g or more, more preferably 0.44 mL / g or more. When the "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is not less than the above lower limit, the performance of adsorbing anesthetic gas in exhaust gas (adsorption performance) can be improved.

[0025] It should be noted that twice the "pore radius" of activated carbon calculated by the MP method is the same as the "pore diameter" of activated carbon calculated by the MP method. Therefore, for example, the "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is the same as the "pore volume with pore diameter of 1.2 nm or less" of activated carbon calculated by the MP method. Therefore, in the present specification, the "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method can be replaced with the "pore volume with pore diameter of 1.2 nm or less" of activated carbon calculated by the MP method; the "pore volume with pore radius of 0.5 nm or less" of activated carbon calculated by the MP method can be replaced with the "pore volume with pore diameter of 1.0 nm or less" of activated carbon calculated by the MP method; and the "pore volume with pore radius of 0.4 nm or less" of activated carbon calculated by the MP method can be replaced with the "pore volume with pore diameter of 0.8 nm or less" of activated carbon calculated by the MP method.

[0026] The upper limit of the "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is not limited. The "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is, for example, 1.70 mL / g or less, preferably 1.20 mL / g or less, more preferably 0.70 mL / g or less. When the "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is not more than the above upper limit, excessive bulkiness of the anesthetic gas adsorbent can be suppressed. Thereby, the increase in size of the anesthetic gas adsorption filter can be suppressed.

[0027] The range of "pore volume with pore radius of 0.6 nm or less" of activated carbon calculated by the MP method is, for example, 0.41 mL / g to 1.70 mL / g, preferably 0.43 mL / g to 1.20 mL / g, more preferably 0.44 mL / g to 0.70 mL / g.

[0028] The "pore volume with pore radius of 0.6 nm or less" is measured by the method described in the Examples described later.

[0029] For the "pore volume V with pore radius of 0.5 nm or less" of activated carbon calculated by the MP method ０．５ , the ratio (V ０．４ / V ０．４ / V ０．５ ) of the "pore volume V with pore radius of 0.4 nm or less" of activated carbon calculated by the MP method is 50% or more. Specifically, the ratio (V ０．４ / V ０．５ ) is a percentage of the "pore volume V with pore radius of 0.4 nm or less" relative to the "pore volume V with pore radius of 0.5 nm or less" ０．５ , and is calculated by the following formula. ０．４

[0030] Formula: ratio (V ０．４ / V ０．５ ) = (pore volume V with pore radius of 0.4 nm or less ０．４ / pore volume V with pore radius of 0.5 nm or less ０．５ ) × 100. The "pore volume V with pore radius of 0.5 nm or less" ０．５ and the "pore volume V with pore radius of 0.4 nm or less" ０．４ are measured by the method described in the Examples described later.

[0031] When the ratio (V ０．４ / V ０．５ ) is equal to or higher than the above lower limit, the performance of adsorbing anesthetic gas in exhaust gas (adsorption performance) can be further improved.

[0032] The ratio (V ０．４ / V ０．５ ) is, for example, 99% or less, preferably 91% or less, more preferably 89% or less, still more preferably 87% or less. The ratio (V ０．４ / V ０．５ ​If the above upper limit is below this value, the proportion of pores with a pore radius of 0.4 nm or more and 0.5 nm or less can be ensured, and a pathway for the movement of anesthetic gas molecules into pores with a pore radius of 0.4 nm or less can be ensured. As a result, the decrease in adsorption performance can be suppressed.

[0033] Ratio (V ０．４ / V ０．５ For example, the percentage is 50% to 99%, preferably 50% to 91%, more preferably 50% to 89%, and more preferably 50% to 87%.

[0034] The packing density of activated carbon is, for example, 0.40 g / mL to 0.50 g / mL.

[0035] The packing density of the activated carbon is measured by the method described in the examples below.

[0036] Activated carbon contains a carbon component and an ignition residue. Activated carbon does not need to contain any components other than the carbon component and the ignition residue. In other words, activated carbon may consist only of a carbon component and an ignition residue.

[0037] The carbon component of activated carbon can adsorb anesthetic gases. The packing density of the carbon component is calculated by subtracting the ignition residue from the packing density of the activated carbon. Specifically, the packing density of the carbon component is calculated using the following formula.

[0038] Formula: Packing density of carbon component = Packing density of activated carbon × [1 - (Ignition residue / 100)] The packing density of activated carbon (packing density of carbon component) after subtracting the ignition residue is greater than 0.38 g / mL and less than 0.50 g / mL. Preferably, the packing density of carbon component is 0.39 g / mL or more. If the packing density of carbon component exceeds the above lower limit, the volume of carbon component relative to the volume of activated carbon can be secured. If the packing density of carbon component is less than the above upper limit, the pore volume of activated carbon can be secured. Therefore, if the packing density of carbon component is within the above range, the adsorption performance can be improved.

[0039] The ignition residue of the activated carbon does not contribute to the adsorption of anesthetic gases. The ignition residue of the activated carbon is, for example, 1.0% to 15.0% by mass, preferably 1.0% to 5.0% by mass.

[0040] The ignition residue of the activated carbon is measured by the method described in the examples below.

[0041] Furthermore, the specific surface area of ​​activated carbon is, for example, 950 m². ２ / g or more, preferably 1050m ２ The value is 1 / g or more. Sufficient adsorption performance can be ensured if the specific surface area of ​​the activated carbon is above the lower limit. There is no upper limit to the specific surface area of ​​the activated carbon. The specific surface area of ​​the activated carbon is 2000 m². ２ It may be less than / g, and 1700m ２ It may be less than / g.

[0042] The specific surface area range of activated carbon is 950 m². ２ / g to 2000m ２ / g, or 1050m ２ / g ~ 1700m ２ / g is also acceptable.

[0043] The specific surface area is measured by the method described in the examples below.

[0044] Furthermore, the butane adsorption performance of the activated carbon is, for example, 24.4% or more, preferably 25.0% or more. If the butane adsorption performance of the activated carbon is above the lower limit, sufficient adsorption performance can be ensured. There is no upper limit to the butane adsorption performance of the activated carbon. The butane adsorption performance of the activated carbon may be 40.0% or less, or 35.0% or less.

[0045] The butane adsorption performance of the activated carbon may be in the range of 24.4% to 40.0%, or 25.0% to 35.0%.

[0046] (2) Details of anesthetic gases The anesthetic gas adsorbent is preferably used for adsorbing the anesthetic gas represented by the following general formula (1).

[0047] General formula (1):

[0048]

[0049] (X is a hydrogen atom, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a perfluoromethyl group. n is 0 or an integer from 1 to 3.) Examples of anesthetic gases represented by the above general formula (1) include isoflurane, desflurane, and sevoflurane.

[0050] For more details, in the general formula (1) above, when X is a chlorine atom and n is 2, the anesthetic gas is isoflurane (molecular weight: 184.5, boiling point: 48.5°C, vapor pressure at 20°C: 31.7 kPa).

[0051] In the above general formula (1), when X is a perfluoromethyl group and n is 1, the anesthetic gas is sevoflurane (molecular weight: 200.6, boiling point: 58.5°C, vapor pressure at 20°C: 20.9 kPa).

[0052] In the above general formula (1), when X is a fluorine atom and n is 2, the anesthetic gas is desflurane (molecular weight: 168.4, boiling point: 23.5°C, vapor pressure at 20°C: 88.5 kPa).

[0053] 2. Method for Manufacturing Activated Carbon Next, we will explain the method for manufacturing the anesthetic gas adsorbent.

[0054] In the manufacture of anesthetic gas adsorbents, activated carbon is produced first. Examples of methods for producing activated carbon include thermal decomposition, activation, coating, and vapor deposition. Preferably, the method for producing activated carbon is the activation method.

[0055] The activation method includes an activation step. The activation method may also include a carbonization step and a removal step.

[0056] (1) Carbonization process: In the carbonization process, the raw material for activated carbon is carbonized. However, if the raw material for activated carbon is coal, the method for producing activated carbon does not need to include a carbonization process.

[0057] Examples of raw materials for activated carbon include plant-based raw materials, fossil-based raw materials, synthetic resins, synthetic rubber, synthetic wood, and synthetic pulp. Examples of plant-based raw materials include wood, wood flour, fruit shells, seeds, by-products of pulp production, bagasse, and molasses. Examples of fruit shells include coconut shells. Examples of seeds include palm kernels, plum seeds, and peach seeds. Examples of fossil-based raw materials include coal, anthracite, petroleum distillation residue components, petroleum pitch, coke, and coal tar. Examples of synthetic resins include phenolic resin, vinyl chloride resin, vinyl acetate resin, melamine resin, urea resin, resorcinol resin, celluloid, epoxy resin, polyurethane resin, polyester resin, acrylic resin, and polyamide resin. Examples of synthetic rubbers include polybutylene, polybutadiene, and polychloroprene. Raw materials can be used individually or in combination of two or more.

[0058] Preferred raw materials for activated carbon include plant-based materials and fossil-based materials, and more preferably, coconut shells and coal.

[0059] The heating conditions in the carbonization process are not limited. In the carbonization process, for example, heating is performed in an oxygen-free environment at, for example, 300°C to 900°C, preferably 400°C to 800°C.

[0060] The heating time in the carbonization process is not limited. For example, the heating time is 15 minutes to 20 hours, preferably 30 minutes to 10 hours.

[0061] The carbonization process may be carried out under reduced pressure or under a nitrogen atmosphere. The carbonization process may be carried out, for example, using a rotary kiln.

[0062] In addition, during the carbonization process, the raw materials may be crushed or molded before being carbonized.

[0063] When the raw material is crushed, the particle size (50% particle size of the cumulative distribution by volume, D50) of the raw material is, for example, 1 μm to 150 μm.

[0064] Furthermore, in the carbonization process, the carbonized raw material (carbonized raw material) may be pulverized. When the carbonized raw material is pulverized, the particle size of the carbonized raw material (50% particle size of the cumulative distribution by volume, D50) is, for example, 1 μm to 150 μm.

[0065] Furthermore, in the carbonization process, after crushing the raw material (or carbonization raw material), additives may be added to the crushed raw material (or carbonization raw material) as needed and kneaded, and the resulting kneaded product may be molded. This allows for the easy production of the activated carbon described above.

[0066] Examples of additives include water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, and petroleum pitch. Additives may be used individually or in combination of two or more.

[0067] The additive is blended in an amount of, for example, 1.0 to 100.0 parts by mass, preferably 1.0 to 50.0 parts by mass, per 100 parts by mass of the raw material (or carbonized raw material).

[0068] When the kneaded material is molded into a cylindrical shape, the diameter of the molded product is preferably 0.1 mm to 4.0 mm or less. The aspect ratio (height / diameter) of the molded product is, for example, 1 to 10.

[0069] (2) Removal process The removal process is performed after the carbonization process and before the activation process. In the removal process, the substance causing the ignition residue (for example, soil and sand) is removed from the carbonization raw material.

[0070] Methods for removing the causative substance from the carbonization raw material include, for example, wet or dry separation of soil and sediment, and heavy liquid separation using a high-density liquid.

[0071] (3) Activation process As shown in Figure 1, in the activation process, the carbonized raw material C from which the causative substance has been removed is activated using the activation system 1.

[0072] The activation system 1 comprises an activation furnace 2, a supply device 3, a conveying device 4, and an activation gas supply device 5. The activation system 1 is a continuous type. Specifically, the activation system 1 continuously supplies carbonization raw material C to the activation furnace 2 while continuously removing activated carbon A activated in the activation furnace 2 from the activation furnace 2.

[0073] (3-1) Activation Furnace The activation furnace 2 extends in the flow direction of the carbonization raw material C. The activation furnace 2 has a cylindrical shape. The activation furnace 2 has an inlet 2A and an outlet 2B. The inlet 2A is located at the upstream end of the activation furnace 2 in the flow direction. The outlet 2B is located at the downstream end of the activation furnace 2 in the flow direction.

[0074] The method for raising the temperature inside the activation furnace 2 is not limited. Examples of methods for raising the temperature inside the activation furnace 2 include heating the activation furnace 2 from the outside with an electric heater, burning fuel inside the activation furnace 2, and burning flammable gases such as hydrogen and carbon monoxide generated in the activation reaction. Preferably, a method for raising the temperature inside the activation furnace 2 is to burn fuel inside the activation furnace 2. More preferably, a method for raising the temperature inside the activation furnace 2 is to burn fuel on the inlet 2A side of the activation furnace 2. By burning fuel on the inlet 2A side of the activation furnace 2, the temperature of the carbonization raw material supplied from inlet 2A and the activation gas supplied by the activation gas supply device 5 can be rapidly increased, and the carbonization raw material supplied from inlet 2A can be rapidly activated.

[0075] The temperature at the inlet 2A side of the activation furnace 2 is, for example, 750°C or higher, preferably 850°C or higher, and more preferably 870°C or higher. When the temperature at the inlet 2A side of the activation furnace 2 is below the above lower limit, the carbonization raw material can be sufficiently activated in the activation furnace 2. As a result, the packing density of the carbon component in the resulting activated carbon can be adjusted to the above range.

[0076] The temperature inside the activation furnace 2 is, for example, 1200°C or less, preferably 1100°C or less, and more preferably 1000°C or less. If the temperature inside the activation furnace 2 is below the above upper limit, it is possible to suppress the high density of the resulting activated carbon, and the packing density of the carbon component of the resulting activated carbon can be adjusted to the above range.

[0077] If the activated carbon described above can be obtained, the time of the activation process is not limited. The time of the activation process is, for example, 1 hour to 120 hours, preferably 4 hours to 72 hours.

[0078] Furthermore, the adsorption performance of the obtained activated carbon (for example, butane adsorption performance) may be measured, and the temperature on the inlet side 2A of the activation furnace 2 may be adjusted to obtain the desired adsorption performance.

[0079] Examples of the activation furnace 2 include a rotary kiln and a conveyor kiln. Preferably, the activation furnace 2 is a rotary kiln.

[0080] (3-2) Supply device The supply device 3 supplies the carbonization raw material C to the inlet 2A of the activation furnace 2. Examples of the supply device 3 include a belt conveyor and a screw feeder.

[0081] (3-3) Conveying device The conveying device 4 conveys the activated carbon A discharged from the outlet 2B of the activation furnace 2. The conveying device 4 may be batch type or continuous type. The activated carbon A is at a high temperature immediately after being discharged from the outlet 2B. Therefore, in order to prevent the activated carbon A from burning, the oxygen concentration inside the conveying device 4 is preferably reduced. Methods for reducing the oxygen concentration inside the conveying device 4 include, for example, introducing an inert gas such as nitrogen into the conveying device 4, or introducing exhaust gas from the rotary kiln into the conveying device 4. The conveying device 4 preferably includes a cooling device for cooling the activated carbon A. The cooling device may be air-cooled or water-cooled.

[0082] (3-4) Activation gas supply device The activation gas supply device 5 introduces the activation gas from the inlet 2A side of the activation furnace 2. In other words, the activation gas supply device 5 introduces the activation gas from the upstream end of the activation furnace 2 in the flow direction.

[0083] Therefore, the concentration of the activating gas inside the activating furnace 2 is highest at the inlet 2A side of the activating furnace 2 and decreases as it approaches the outlet 2B of the activating furnace 2. Consequently, the reaction rate between the carbonization raw material C and the activating gas is fastest at the inlet 2A side of the activating furnace 2 and decreases as it approaches the outlet 2B of the activating furnace 2.

[0084] Therefore, the carbonization raw material C supplied into the activation furnace 2 reacts with the high-concentration activation gas, forming pores with small pore radii on the surface of the carbonization raw material C. Subsequently, as the carbonization raw material C moves through the activation furnace 2 towards the outlet 2B, the concentration of the activation gas decreases, and the reaction rate between the carbonization raw material C and the activation gas decreases. Therefore, it is possible to suppress the expansion of the pores on the surface of the carbonization raw material C by further activation reactions. As a result, the reduction in pores with a pore radius of 0.6 nm or less, and the proportion (V) are reduced. ０．４ / V ０．５ This can suppress the decline of ( ).

[0085] Examples of activating gases include water vapor and carbon dioxide. Water vapor is preferred as the activating gas. When water vapor is used as the activating gas, it is possible to increase the "pore volume with a pore radius of 0.6 nm or less". As a result, activated carbon A with excellent adsorption performance for anesthetic gases can be obtained. In addition, an inert gas such as nitrogen or air may be used in combination with the above-mentioned activating gas.

[0086] If the activated carbon described above can be obtained, the concentration of the activating gas is not limited. The concentration of the activating gas on the inlet 2A side is, for example, 10% to 100% by volume, preferably 20% to 80% by volume.

[0087] The activation process may be carried out under reduced pressure or under a nitrogen atmosphere.

[0088] Furthermore, the obtained activated carbon may be crushed, pulverized, and classified. The obtained activated carbon may also be washed with water, an organic solvent, an acidic aqueous solution, or an alkaline aqueous solution. Additionally, the obtained activated carbon may be subjected to further heat treatment.

[0089] 3. Anesthetic Gas Adsorption Filter The above-described anesthetic gas adsorbent is suitable for the anesthetic gas adsorption filter 10. The anesthetic gas adsorption filter 10 is used for exhaust treatment of the inhalation anesthesia system 100. As shown in Figure 2, the anesthetic gas adsorption filter 10 comprises a container 11 and an anesthetic gas adsorbent 12.

[0090] The container 11 contains the anesthetic gas adsorbent 12 described above. The container 11 extends in a first direction. The shape and material of the container 11 are not limited. The container 11 may, for example, have a cylindrical shape. The container 11 may, for example, be made of rigid plastic. The container 11 has an inlet 11A and an outlet 11B. The inlet 11A is located at one end of the container 11 in the first direction. The shape of the inlet 11A is not limited. The inlet 11A may, for example, have a circular shape. The dimensions of the inlet 11A are smaller than the inner dimensions of the container 11. More specifically, the diameter R1 of the inlet 11A is smaller than the inner diameter R2 of the container 11. The outlet 11B is located at the other end of the container 11 in the first direction. The arrangement, number, and shape of the outlets 11B are not limited. There may be one outlet 11B or multiple outlets 11B. Exhaust gas G1 containing anesthetic gas flows into the inlet 11A. Exhaust gas G1 that enters the container 11 from the inlet 11A passes through the anesthetic gas adsorbent 12. At this time, the anesthetic gas in exhaust gas G1 is adsorbed by the activated carbon of the anesthetic gas adsorbent 12 and removed from exhaust gas G1. In other words, the anesthetic gas adsorption filter 10 removes the anesthetic gas from exhaust gas G1 by passing the exhaust gas G1 containing anesthetic gas through the anesthetic gas adsorbent 12. Exhaust gas G2 from which the anesthetic gas has been removed flows out from the outlet 11B.

[0091] The container 11 may have a container body 111 having an opening 111A and a lid 112 that closes the opening 111A. The container body 111 extends in a first direction. The container body 111 has a cylindrical shape. The opening 111A is located at one end of the container body 111 in the first direction. The diameter of the opening 111A is the same as the inner diameter R2 of the container 11. In the assembly of the anesthetic gas adsorption filter 10, the anesthetic gas adsorbent 12 is placed inside the container body 111 through the opening 111A. The container body 111 may have an outlet 11B. The lid 112 may have an inlet 11A. The lid 112 may be removable from the container body 111.

[0092] The anesthetic gas adsorbent 12 is placed inside the container 11. The anesthetic gas adsorbent 12 is filled inside the container 11. The anesthetic gas adsorbent 12 is placed inside the container 11 between the inlet 11A and the outlet 11B. The anesthetic gas adsorbent 12 is placed in the first direction between the inlet 11A and the outlet 11B.

[0093] 4. Inhalation Anesthesia System As shown in Figure 3, the inhalation anesthesia system 100 comprises a vaporizer 102 and the anesthetic gas adsorption filter 10 described above. The inhalation anesthesia system 100 may further include a ventilator 101.

[0094] The vaporizer 102 is connected to the inspiratory line 103 and the expiratory line 104 of the ventilator 101. The vaporizer 102 vaporizes a volatile anesthetic supplied from an anesthetic supply line (not shown) to generate anesthetic gas. The vaporizer 102 supplies the generated anesthetic gas to the inhaled air from the ventilator 101. The inhaled air containing the anesthetic gas is supplied to the patient through the flexible tube 106.

[0095] The anesthetic gas adsorption filter 10 is connected to the exhaust line 105 of the ventilator 101. The exhaust G1 from the ventilator 101 (see Figure 2) contains anesthetic gas contained in the patient's exhaled breath. As described above, the anesthetic gas adsorption filter 10 removes anesthetic gas from the exhaust G1.

[0096] 5. Effects (1) According to the above-mentioned anesthetic gas adsorbent, the "pore volume of pores with a pore radius of 0.6 nm or less" is 0.41 mL / g or more, and the ratio of "pore volume of pores with a pore radius of 0.4 nm or less" to "pore volume of pores with a pore radius of 0.5 nm or less" (V ０．４ / V ０．５ It contains activated carbon, with 50% or more of the following:

[0097] Therefore, it is possible to improve the performance of adsorbing anesthetic gases in the exhaust.

[0098] (2) According to the above-described method for producing the anesthetic gas adsorbent, as shown in Figure 1, in the activation step, activated carbon A is produced in a continuous manner (a method in which carbonization raw material C is continuously supplied to the activation furnace 2, and activated carbon A activated in the activation furnace 2 is continuously removed from the activation furnace 2). The concentration of the activation gas in the activation furnace 2 is highest at the inlet 2A side of the activation furnace 2 and decreases as it approaches the outlet 2B of the activation furnace 2.

[0099] Therefore, near the inlet 2A, the carbonization raw material C supplied into the activation furnace 2 reacts with a high concentration of activation gas, forming pores with a small pore radius on the surface of the carbonization raw material C.

[0100] Subsequently, as the carbonization raw material C moves through the activation furnace 2 towards the outlet 2B, the concentration of the activation gas decreases.

[0101] Therefore, it is possible to suppress the expansion of the pores on the surface of the carbonized raw material C by further activation reactions.

[0102] As a result, there was a decrease in the number of pores with a pore radius of 0.6 nm or less, and a decrease in the proportion (V ０．４ / V ０．５ This can suppress the decrease in ( ) and enable the efficient production of the anesthetic gas adsorbent described above.

[0103] (3) As shown in Figure 2, the anesthetic gas adsorption filter 10 is equipped with the anesthetic gas adsorbent 12 described above.

[0104] Therefore, anesthetic gases in exhaust gas G1 can be efficiently removed.

[0105] (4) As shown in Figure 3, the inhalation anesthesia system 100 is equipped with the anesthetic gas adsorption filter 10 described above. Therefore, anesthetic gas in the exhaust gas G1 can be efficiently removed.

[0106] 6. Modified Examples Modified examples will be described below. In the modified examples, the same reference numerals are used for components similar to those in the embodiments described above, and their descriptions are omitted.

[0107] (1) The anesthetic gas adsorbent may further include a bag containing activated carbon. The bag is made of, for example, a breathable nonwoven fabric.

[0108] (2) As shown in Figure 4, the anesthetic gas adsorption filter 10 may further include buffer members 13A and 13B and a dust filter 14. In this case, the anesthetic gas adsorbent 12 is filled between buffer member 13A and buffer member 13B in the first direction. In the assembly of the anesthetic gas adsorption filter 10, the dust filter 14, buffer member 13B, anesthetic gas adsorbent 12, and buffer member 13A are arranged in order inside the container body 111 through the opening 111A.

[0109] The buffer member 13A is positioned between the inlet 11A and the anesthetic gas adsorbent 12 in the direction in which the container 11 extends (first direction). The buffer member 13A is positioned between the lid 112 and the anesthetic gas adsorbent 12 in the direction in which the container 11 extends (first direction). The buffer member 13A is made of, for example, a breathable nonwoven fabric or a breathable urethane foam. The buffer member 13A is in contact with the anesthetic gas adsorbent 12. The buffer member 13A prevents the anesthetic gas adsorbent 12 from moving within the container 11. The buffer member 13A also prevents the anesthetic gas adsorbent 12 from becoming unevenly distributed within the container 11. Furthermore, the buffer member 13A prevents the anesthetic gas adsorbent 12 from spilling out of the inlet 11A.

[0110] The thickness of the cushioning member 13A is, for example, 5 mm to 30 mm, preferably 10 mm to 25 mm.

[0111] The buffer member 13B is positioned between the outlet 11B and the anesthetic gas adsorbent 12 in the direction in which the container 11 extends (first direction). The buffer member 13B is made of, for example, a breathable nonwoven fabric or a breathable urethane foam. The buffer member 13B is in contact with the anesthetic gas adsorbent 12. Together with the buffer member 13A, the buffer member 13B prevents the anesthetic gas adsorbent 12 from moving within the container 11. Also, together with the buffer member 13A, the buffer member 13B prevents the anesthetic gas adsorbent 12 from becoming unevenly distributed within the container 11. Furthermore, the buffer member 13A prevents the anesthetic gas adsorbent 12 from spilling out of the outlet 11B.

[0112] The thickness of the cushioning member 13B is, for example, 5 mm to 30 mm, preferably 10 mm to 25 mm.

[0113] The dust filter 14 is positioned between the outlet 11B and the buffer member 13B. The dust filter 14 is made of, for example, a breathable nonwoven fabric. The dust filter 14 collects fine activated carbon particles that have passed through the buffer member 13B. The mesh count of the dust filter 14 is higher than the mesh count of the buffer members 13A and 13B.

[0114] The thickness of the dust filter 14 is thinner than the thickness of the buffer member 13B. The thickness of the dust filter 14 is, for example, 0.1 mm to 1.0 mm, preferably 0.2 mm to 0.5 mm.

[0115] (3) As shown in Figure 5, the anesthetic gas adsorption filter 10 may further include spacers 15. The anesthetic gas adsorption filter 10 may include multiple spacers 15.

[0116] The spacer 15 is positioned between the lid 112 and the buffer member 13A in the direction in which the container 11 extends (first direction). The spacer 15 is positioned between the inlet 11A and the anesthetic gas adsorbent 12 in the first direction. The spacer 15 is in contact with the buffer member 13A. The spacer 15 separates the buffer member 13A from the inlet 11A, thereby securing space between the inlet 11A and the buffer member 13A. In this way, the spacer 15 secures space between the inlet 11A and the anesthetic gas adsorbent 12.

[0117] As shown in Figure 6A, the spacer 15 protrudes from the inner surface S1 of the lid 112 toward the buffer member 13A in a first direction. In other words, the spacer 15 protrudes from the inner surface S1 of the lid 112 toward the anesthetic gas adsorbent 12 in a first direction. To put it another way, the spacer 15 protrudes from the inner surface S1 of one side of the container 11 toward the anesthetic gas adsorbent 12 in a first direction. The spacer 15 is a projection. As shown in Figure 6B, the spacer 15 is arranged around the inlet 11A. Multiple spacers 15 are arranged in the circumferential direction of the inlet 11A. Each of the multiple spacers 15 is spaced apart from one another in the circumferential direction of the inlet 11A. The spacer 15 extends radially around the inlet 11A. The shape and number of spacers 15 are not limited.

[0118] According to this modified example, a portion of the exhaust gas G1 that enters the container 11 from the inlet 11A can be directed radially through the space between the inlet 11A and the buffer member 13A.

[0119] Therefore, the exhaust gas G1 that enters the container 11 from the inlet 11A can act on the entire anesthetic gas adsorbent 12 inside the container 11.

[0120] As a result, anesthetic gases in exhaust gas G1 can be efficiently removed.

[0121] Furthermore, according to this modification, the spacer 15 protrudes from the inner surface S1 of the lid 112 in the first direction.

[0122] Therefore, the spacer 15 can be handled together with the lid 112.

[0123] As a result, the lid 112 can be attached to the container body 111 and the spacer 15 can be placed inside the container 11 in a single operation.

[0124] Alternatively, the spacer 15 can be discarded together with the lid 112.

[0125] (4) As shown in Figure 7A, the anesthetic gas adsorption filter 10 may further include a second spacer 21.

[0126] The second spacer 21 is positioned between the inner surface S2 of the container 11 and the spacer 15 in a second direction perpendicular to the first direction (specifically, the radial direction of the inlet 11A). The second spacer 21, together with the multiple spacers 15, secures space between the inlet 11A and the anesthetic gas adsorbent 12. More specifically, the second spacer 21 is positioned between the lid 112 and the buffer member 13A in the first direction. The second spacer 21 is positioned between the inlet 11A and the anesthetic gas adsorbent 12 in the first direction. The second spacer 21 protrudes from the inner surface S1 of the lid 112 toward the buffer member 13A in the first direction. The second spacer 21 contacts the peripheral edge E of the buffer member 13A. The second spacer 21 presses against the peripheral edge E of the buffer member 13A. As a result, the second spacer 21 can secure space between the inlet 11A and the buffer member 13A in the radial direction of the container 11, closer to the inner surface S2 of the container 11 than the multiple spacers 15.

[0127] As shown in Figure 7B, the second spacer 21 has a ring shape. The second spacer 21 extends along the inner surface S2 of the container 11 in the second direction (see Figure 7A). This prevents exhaust gas G1 that has entered the container 11 from leaking out through the gap between the container body 111 and the lid 112.

[0128] (5) As shown in Figure 8, each of the multiple spacers 15 may extend in the circumferential direction of the inlet 11A.

[0129] (6) As shown in Figure 9, each of the multiple spacers 15 may be cylindrical in shape.

[0130] (7) As shown in Figure 10, the multiple spacers 15 may be continuous with the second spacer 21. The second spacer 21 may also have multiple slits 21A. The multiple slits 21A are arranged at intervals from each other in the circumferential direction of the inlet 11A.

[0131] (8) In the modified examples (1) to (7), the same effects and advantages as those of the embodiments described above can be obtained.

[0132] The present invention will be further described with reference to the following examples, but the present invention is not limited thereto. Specific numerical values ​​such as blending ratios (content), physical properties, and parameters used in the following description may be replaced with the corresponding upper limits (numerical values ​​defined as "less than or equal to" or "less than") or lower limits (numerical values ​​defined as "greater than or equal to" or "greater than or equal to" or "greater than or equal to") of the blending ratios (content), physical properties, and parameters described in the "Modes for Carrying Out the Invention" above. Note that "parts" and "%" refer to mass unless otherwise specified.

[0133] 1. Production of activated carbon (1) Example 1 As a carbonization raw material, carbonized coconut shells from Sri Lanka were prepared.

[0134] Next, a sediment separator was used to remove sediment (the substance causing the ignition residue) from the carbonization raw material (removal process).

[0135] Next, the carbonization raw material from which the soil had been removed was activated using a rotary kiln as the activation furnace. Specifically, the carbonization raw material from which the soil had been removed was continuously supplied to the rotary kiln, while the activated carbon was continuously removed from the rotary kiln.

[0136] By burning heavy oil at the inlet side of the rotary kiln, the inlet temperature of the rotary kiln was adjusted to 900°C to 1000°C.

[0137] Furthermore, steam was introduced as an activating gas through an inlet pipe inserted into the inlet side of the rotary kiln, so that the concentration of the activating gas at the inlet side was between 20% and 70% by volume. The length of the inlet pipe inserted into the rotary kiln was 2.5% of the total length of the rotary kiln.

[0138] Next, the obtained activated carbon was cooled and then crushed to obtain activated carbon for use as an anesthetic gas adsorbent.

[0139] (2) Example 2 Activated carbon was obtained in the same manner as in Example 1, except that the supply amount of carbonization raw material was changed to 1.1 times that of Example 1.

[0140] (3) Example 3 Activated carbon was obtained in the same manner as in Example 1, except that the amount of carbonization raw material supplied was changed to 1.2 times that of Example 1.

[0141] (4) Example 4 Activated carbon was obtained in the same manner as in Example 1, except that the amount of carbonization raw material supplied was changed to 1.3 times that of Example 1.

[0142] (5) Example 5 Activated carbon was obtained in the same manner as in Example 1, except that deashed Chinese coal pellets were used as the carbonization raw material.

[0143] (6) Example 6 Used coconut shell pellet activated carbon (4 x 6 mesh) was prepared as the carbonization raw material.

[0144] The carbonization raw material was washed with water, and soil and sand were removed in the same manner as in Example 1.

[0145] Next, activated carbon was obtained in the same manner as in Example 1, except that the fuel was changed to methane.

[0146] (7) Comparative Example 1 Activated carbon was obtained in the same manner as in Example 1, except that the supply amount of carbonization raw material was changed to 1.5 times that of Example 1.

[0147] (8) Comparative Example 2 Activated carbon was obtained in the same manner as in Example 1, except that deashed Colombian coal pellets were used as the carbonization raw material.

[0148] (9) Comparative Example 3 Activated carbon was obtained in the same manner as in Comparative Example 2, except that the supply amount of carbonization raw material was changed to 1.1 times that of Comparative Example 2.

[0149] (9) Comparative Example 4 Activated carbon was obtained in the same manner as in Comparative Example 2, except that the supply amount of carbonization raw material was changed to 1.2 times that of Comparative Example 2.

[0150] 2. Measurement of physical properties of activated carbon (1) Pore volume and specific surface area The activated carbon obtained in each example and comparative example was heated at 150°C for 2 hours under vacuum conditions.

[0151] Next, using an automated specific surface area / pore size distribution analyzer (Shimadzu Micromeritique, TRISTAR3000 model), the amount of nitrogen adsorption was measured under conditions of -196°C, and a nitrogen adsorption isotherm was created.

[0152] The obtained nitrogen adsorption isotherms were analyzed by the Micropore method to determine the pore volume of pores with a radius of 0.6 nm or less (more specifically, the integrated pore volume of pores with a radius of 0.2 nm to 0.6 nm), the pore volume of pores with a radius of 0.4 nm or less (more specifically, the integrated pore volume of pores with a radius of 0.2 nm to 0.4 nm), the pore volume of pores with a radius of 0.5 nm or less (more specifically, the integrated pore volume of pores with a radius of 0.2 nm to 0.5 nm), and the percentage (V ０．４ / V ０．５ The result was calculated. The results are shown in Table 1.

[0153] Furthermore, using nitrogen adsorption isotherms, the specific surface area per gram of activated carbon was calculated from the straight line in the relative pressure range of 0.01 to 0.10 using the BET multipoint method. The results are shown in Table 1.

[0154] (2) Packing density of carbon components The packing density of the activated carbon obtained in each example and comparative example was measured by the method specified in JIS K1474:2014.

[0155] For details, the activated carbon obtained in each example and comparative example was dried at 115±5°C for 3 hours using a constant-temperature drying oven (DVS402, manufactured by Yamato Scientific Co., Ltd.).

[0156] Next, the activated carbon removed from the constant-temperature dryer was allowed to cool to room temperature in a desiccator using silica gel as a desiccant.

[0157] Next, the cooled activated carbon was introduced into the storage funnel of the packing density measuring container (TD-V5, manufactured by Toyo Electromagnetic Machinery Co., Ltd.), and the attached vibrator was used to fill a 100 mL graduated cylinder to the 100 mL mark.

[0158] The mass of activated carbon inside the graduated cylinder was measured, and the packing density of the activated carbon was calculated.

[0159] Furthermore, the ignition residue of the activated carbon obtained in each example and comparative example was measured by the method specified in JIS K1474:2014.

[0160] For details, the activated carbon obtained in each example and comparative example was dried at 115±5°C for 3 hours using a constant-temperature drying oven (DVS402, manufactured by Yamato Scientific Co., Ltd.).

[0161] Next, the activated carbon removed from the constant-temperature dryer was allowed to cool to room temperature in a desiccator using silica gel as a desiccant.

[0162] After measuring the mass of the cooled activated carbon, it was heated strongly in air at 850 ± 50°C for 1 hour using an electric furnace (Yamato Scientific Co., Ltd. FO811 (model)).

[0163] Next, the obtained ash was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, its mass (mass of ash content) was measured, and the ignition residue was calculated.

[0164] Next, the packing density of the carbon component was calculated using the formula described in the embodiment above. The results are shown in Table 1.

[0165] (3) Butane adsorption performance The butane adsorption performance of the activated carbon obtained in each example and comparative example was measured by the method specified in ASTM D5742.

[0166] For more details, first, the glass tube specified in ASTM D5742 was dried and its weight (A) was measured.

[0167] Next, the packing density of the activated carbon, which had been dried in advance according to the method specified in ASTM D2867, was measured according to the method specified in ASTM D2854.

[0168] Next, activated carbon with a mass corresponding to a volume of 16.70 ± 0.05 mL calculated from the measured packing density was weighed and packed into a glass tube, and the total weight (B) was measured.

[0169] Next, the glass tube was immersed in a water bath at 25 ± 0.2°C, and butane was passed through the activated carbon inside the glass tube at a flow rate of 250 ± 5 mL / min for 900 seconds.

[0170] Next, the glass tube was removed from the water bath, wiped clean, and its total weight (C) was measured.

[0171] The butane adsorption performance was calculated using the following formula. The results are shown in Table 1.

[0172] Formula: Butane adsorption performance = [(C - B) / (B - A)] × 100 3. Performance evaluation of activated carbon The activated carbon obtained in each example and comparative example was dried for 3 hours at 115 ± 5°C using a constant temperature drying oven (DVS402, manufactured by Yamato Scientific Co., Ltd.).

[0173] Next, the activated carbon removed from the constant-temperature dryer was allowed to cool to room temperature in a desiccator using silica gel as a desiccant.

[0174] From the cooled activated carbon, a mass of activated carbon equivalent to 300 mL in volume, calculated from the "packing density of activated carbon" described above, was weighed and packed into the test column.

[0175] The test column has a structure in which an acrylic resin cylinder with an inner diameter of 50 mm is placed between a first lid having an inlet and a second lid having an outlet. Inside the cylinder, a buffer material made of nonwoven fabric, activated carbon, a buffer material made of nonwoven fabric, and a dust filter made of nonwoven fabric are stacked in that order from the first lid to the second lid. The height of the activated carbon layer inside the cylinder (dimension in the direction in which the cylinder extends) was set to approximately 150 mm.

[0176] Next, air containing 0.33% by mass of isoflurane at 20±3°C was introduced into the activated carbon-filled test column from the inlet at a flow rate of 4.5 L / min.

[0177] Subsequently, the cumulative mass of isoflurane that flowed into the test column until the isoflurane concentration in the air flowing out from the outlet exceeded 0.15% by mass was divided by the mass of the packed activated carbon to determine the isoflurane removal performance.

[0178]

[0179] The above invention is provided as an illustrative embodiment of the present invention, but this is merely illustrative and should not be interpreted restrictively. Modifications of the present invention that are obvious to those skilled in the art are included in the claims below.

[0180] The anesthetic gas adsorbent, anesthetic gas adsorption filter, and method for removing anesthetic gases of the present invention can be used for the removal of anesthetic gases. The inhalation anesthesia system of the present invention can be used for inhalation anesthesia.

[0181] 10 Anesthetic gas adsorption filter 11 Container 11A Inlet 11B Outlet 12 Anesthetic gas adsorbent 15 Spacer G1 Exhaust containing anesthetic gas G2 Exhaust from which anesthetic gas has been removed 100 Inhalation anesthesia system 101 Ventilator 102 Vaporizer 105 Exhaust line

Claims

1. An anesthetic gas adsorbent comprising activated carbon, wherein the "pore volume of pores with a pore radius of 0.6 nm or less" of the activated carbon, calculated by the MP method, is 0.41 mL / g or more, and the ratio of the "pore volume of pores with a pore radius of 0.4 nm or less" of the activated carbon, calculated by the MP method, to the "pore volume of pores with a pore radius of 0.5 nm or less" of the activated carbon, calculated by the MP method, is 50% or more.

2. The anesthetic gas adsorbent according to claim 1, wherein the packing density of the activated carbon after subtracting the ignition residue is greater than 0.38 g / mL and less than 0.50 g / mL.

3. The anesthetic gas adsorbent according to claim 1, wherein the "pore volume of pores with a pore radius of 0.6 nm or less" of the activated carbon, calculated by the MP method, is 1.70 mL / g or less.

4. The specific surface area of ​​the activated carbon is 950 m². ２ / g or more, 2000m ２ The anesthetic gas adsorbent according to claim 1, wherein the amount is less than or equal to / g, and the butane adsorption performance of the activated carbon is 24.4% or more and 40.0% or less.

5. An anesthetic gas adsorption filter comprising the anesthetic gas adsorbent described in claim 1.

6. The anesthetic gas adsorption filter according to claim 5, comprising: a container having an inlet located at one end of the container in a first direction for exhaust gas containing anesthetic gas to flow in; an outlet located at the other end of the container in a first direction for exhaust gas from which the anesthetic gas has been removed to flow out; an anesthetic gas adsorbent located between the inlet and the outlet in a first direction; and a spacer located between the inlet and the anesthetic gas adsorbent in a first direction.

7. The anesthetic gas adsorption filter according to claim 6, wherein the spacer is a projection that protrudes from the inner surface of one side of the container toward the anesthetic gas adsorbent in the first direction.

8. An inhalation anesthesia system comprising: a vaporizer that vaporizes a volatile anesthetic to generate an anesthetic gas and supplies the generated anesthetic gas to the inhaled air from a ventilator; and an anesthetic gas adsorption filter connected to the exhaust line of the ventilator and having the anesthetic gas adsorbent described in claim 1.

9. The inhalation anesthesia system according to claim 8, further comprising the ventilator.

10. A method for removing anesthetic gas, comprising passing exhaust containing anesthetic gas through the anesthetic gas adsorbent described in claim 1 to remove the anesthetic gas from the exhaust.

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