JP2013180265A - Sonochemistry reaction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop an apparatus capable of continuously and efficiently processing sonochemistry reaction.SOLUTION: An apparatus preferably performing sonochemistry reaction includes: a vibration body which is arranged in a liquid at least one part of which contains a reaction material and can vibrate at ≥10 kHz frequency and at an amplitude of ≥10 μm, a gas supplying means for supplying gas to the vibration body, and a flow passage for supplying gas from the gas supplying means into the liquid by passing through the inside of the vibration body.

Description

The present invention supplies a gas to a vibrating body through which gas can pass and releases the gas from the vibration surface, thereby simultaneously generating bubbles and applying pressure vibration to the generated bubbles, and accompanying expansion and contraction of the bubbles. The present invention relates to an apparatus that performs a sonochemical reaction using a high-temperature and high-pressure environment inside a bubble.

When a sudden pressure fluctuation occurs in a liquid in a short period of time, the phenomenon in which bubbles are generated and disappeared instantaneously is called cavitation, and when a bubble contracts rapidly, it contracts in a process close to adiabatic compression, Is known to become high temperature and pressure. In particular, cavitation that is generated by applying an abrupt pressure fluctuation of a liquid with ultrasonic waves is called acoustic cavitation. The reaction using high-temperature and high-pressure fields inside and in the vicinity of bubbles generated by acoustic cavitation is called sonochemical reaction or sonochemistry, and it is oxidized, reduced, polymerized, decomposed, synthesized, sterilized, washed, heated, burned, separated, solid Surface modification or the like is possible (Non-Patent Document 1). Furthermore, Non-Patent Document 2 also shows the possibility of nuclear fusion by acoustic cavitation. The present invention shows the optimum conditions and apparatus configuration that contribute to an increase in throughput and continuous reaction for the sonochemical reaction described above.

As a known sonochemical reaction device, the distance between the vibration plate and the reflection plate is adjusted to control the acoustic standing wave according to the wavelength of the ultrasonic wave, and a high vibration pressure field is formed in the liquid. By attaching a vibrator to the side of the cylindrical container and converging the sound wave in the direction of the central axis, a field with a high sound pressure is formed in the liquid near the central axis to cause the sonochemical reaction. There is a device to perform (Patent Document 2). However, in the apparatus shown in Patent Document 1 and Patent Document 2, the improvement in reactivity associated with gas supply and gas supply reaction is not clearly described.

In Patent Document 3, an ultrasonic horn that amplifies the amplitude of the ultrasonic wave is used to apply a strong pressure vibration in the liquid to generate vapor bubbles of the organic solvent. Further, when the vapor bubbles contract, A technique and apparatus for generating various nano-order particles sonochemically using a high-temperature and high-pressure field are described. However, in this device, the bubbles that become the reaction field of the sonochemical reaction are vapor bubbles that are foamed by instantaneous pressure reduction accompanying the periodic vibration of ultrasonic waves, and gas is supplied from the outside using gas supply means. There is no suggestion of improved reactivity due to.

Patent Document 4 describes a technique for promoting a sonochemical reaction by adding bubbles from the side of a sound wave propagation direction of an acoustic field to which ultrasonic waves are applied. However, in the above-described method, the vibrating body and the bubble supply are performed at different locations, and it is not explicitly stated that the generation of the bubble and the generation of the vibration pressure are integrated.

JP 2000-84403 A JP 2000-84404 A JP 2010-8276A JP 2007-275694 A JP 2011-50832 A

Maeda Yasuaki, “Ultrasound technology collection”, NTS Publishing, April 7, 2005, p. 3-148 Science, vol. 295, p. 1868-1873, 2002

In the above-described background art, when a liquid vapor bubble generated by applying pressure vibration to a liquid without using a gas supply means is used in a sonochemical reaction, the pressure is instantaneously reduced to a pressure lower than the liquid vapor pressure by the pressure vibration. Since foaming needs to be promoted, a large pressure fluctuation is required and the amount of foaming is small, so that it is difficult to increase the processing amount.

In the above-described background art, in the case of using for the sonochemical reaction a bubble obtained by precipitating a gas dissolved in advance under reduced pressure accompanying a pressure fluctuation to the liquid without using a gas supply means, a gas that can be dissolved in the liquid in advance. Since the amount of slag is limited and small, continuous processing is difficult, and it is difficult to increase the processing amount.

In the above background art, when bubbles are generated using the gas supply means and introduced into the pressure vibration field to promote the sonochemical reaction, the pressure is reduced before the bubbles are transferred to the region where the pressure vibration is strong. The problem is that sufficient bubbles are not supplied to the region where pressure vibration is strong due to the so-called ultrasonic degassing action that induces trapping and coalescence of bubbles by standing waves.

In the present invention, the generation of bubbles and the generation of pressure vibration in a liquid containing a reactant are performed using the same vibrating body, thereby generating bubbles in the vicinity of a vibration surface where pressure vibration is strong and continuous acoustics. An object of the present invention is to provide a new sonochemical reaction device characterized by enabling a chemical reaction.

In the present invention, at least a part of the vibrating body that is disposed in a liquid containing a reactive substance and capable of vibrating with a frequency of 10 kHz or more and an amplitude of 10 μm or more, a gas supply unit that supplies gas to the vibrating body, and the gas supply By having a flow path for supplying a gas into the liquid from the means through the inside of the vibrator, the sonochemical reaction can be suitably performed.

In another aspect of the present invention, a surfactant is dissolved in a liquid containing the reactant. According to this, the sonochemical reaction can be suitably performed.

As another aspect of the present invention, the flow rate of the gas discharged from the gas discharge port of the vibrating body is more than 0 mL / min and 1000 mL / min or less. According to this, the sonochemical reaction can be suitably performed.

In the sonochemical reaction device of the present invention, the following preferred effects can be obtained.
(1) By supplying bubbles, an increase in the sonochemical reaction field and a continuous sonochemical reaction are possible.
(2) Since the bubble generation unit and the pressure vibration generation unit are integrated, it is possible to transmit powerful pressure fluctuations to the bubbles with little loss and use them as energy for the volume fluctuations of the bubbles, thereby improving the efficiency of the sonochemical reaction.
(3) By adjusting the addition of the surfactant and the flow rate to suitable values, the generation of large bubbles that do not contribute to the sonochemical reaction can be suppressed, and the sound pressure attenuation due to excessive bubble supply can be prevented. Will improve.

It is the figure which showed the optimal structure of this invention. It is a figure which shows the shape of the vibrating body used in Example 1-9. It is a figure which shows the state of the bubble generate | occur | produced from the gas discharge port vicinity on the conditions of Example 1. FIG. It is a figure which shows the relationship between the flow volume of the argon gas supplied to a vibrating body, and the decomposition amount of indigo carmine. It is a figure which shows the state of the bubble generate | occur | produced from the gas discharge opening vicinity on the conditions of Example 7. FIG. It is a figure which shows the time-dependent change of the reaction time in Example 3, Example 7, and Example 8 and indigo carmine degradation amount.

The sonochemical reaction device according to the present invention includes a vibrating body provided with a gas flow path therein, a gas supply means for supplying gas to the internal flow path of the vibrating body, and a reactant in which a gas discharge port of the vibrating body is disposed. It is comprised by the liquid containing. Hereinafter, the best mode for carrying out the present invention will be described with reference to FIG.

In the best mode for carrying out the present invention, the gas discharge port 2 of the vibrating body 4 provided therein with the flow path 3 connecting the gas introduction port 1 and the gas discharge port 2 is a reactant substance held in the tank 5. It arrange | positions in the liquid 6 containing. The gas from the gas supply means 7 is supplied to the gas discharge port 2 via the flow path 3 inside the vibrating body 4, and contains the reactant from the vicinity of the gas discharge port 2 by vibrating the vibration surface 8. Bubbles 9 are generated in the liquid 6. Further, the bubble 9 rapidly expands and contracts due to pressure vibration generated from the vibration surface 8 of the vibrating body 4, so that the inside of the bubble 9 is instantaneously close to adiabatic compression, and the bubble 9 is in the inside of the bubble 9 and in the vicinity of the interface. A high temperature and high pressure reaction field is formed. A sonochemical reaction occurs using the high-temperature and high-pressure field, and a single reactant or a plurality of reactants contained in the liquid 6 containing the reactant is changed to a new substance.

The shape of the vibrating body 4 that integrally generates the bubbles and the pressure vibration includes at least one gas introduction port 1 for introducing the gas from the gas supply means 6 into the inside, and the gas introduction port 1 inside the vibration body 4. There is no particular limitation as long as at least one gas discharge port 2 is provided on the vibration surface 8 that causes a pressure fluctuation. The shape and size of the gas discharge port 2 are not particularly limited, but preferred examples of the shape include a circular shape, a rectangular shape, and a gear shape. The opening area is preferably in the range of 1 mm ² to 1000 mm ² . The arrangement of the vibrating body 4 is not particularly limited as long as the vibrating surface 8 and at least one gas discharge port 2 are arranged in the liquid 5. The vibration generated on the vibration surface 8 is not particularly limited as long as the vibration surface can vibrate with a single amplitude of 10 μm or more at a frequency of 10 kHz or more. This vibrating body 4 is provided with a flow path in a known vibrating body such as an ultrasonic vibrator in which piezoelectric elements that generate displacement due to voltage application are laminated or an ultrasonic horn that is connected to the ultrasonic vibrator and amplifies the amplitude. As a particularly preferable example, a hollow stepped cylindrical structure shown in the microbubble generation method (Patent Document 5) capable of simultaneously generating bubbles of 100 μm or less and applying ultrasonic waves to the liquid And an ultrasonic horn.

The gas supply means 7 is not particularly limited as long as it can supply gas to the gas inlet 1, and examples thereof include a compressor, a diaphragm pump, a suction pump, a gear pump, and a high-pressure cylinder. The flow rate is not limited as long as the gas is continuously supplied to the vibrating surface, that is, if it exceeds 0 mL / min per each gas discharge port, but if there are too many bubbles, the pressure of each bubble Since vibration may weaken, 1000 mL / min per gas outlet is preferable, and 200 mL / min or lower per gas outlet is particularly preferable.

The gas supplied to the gas discharge port 2 is not limited, and examples thereof include air, nitrogen, oxygen, carbon dioxide, ozone, and the like. Preferably, the inside tends to become high temperature and high pressure when the bubbles contract due to pressure fluctuation. Argon, helium, xenon, etc. with high specific heat ratio are illustrated.

The tank 5 for holding the liquid 6 containing the reactant can be appropriately selected from known containers such as a beaker, a flask, and a water tank, and may be a river, a lake, or the sea. The capacity is preferably 10 L or less. In addition, although not essential, temperature control exemplified by a hot plate, a cool stirrer, a heat exchanger, an oil bath, or the like that adjusts the temperature of the liquid 6 containing the reactant for controlling and stabilizing the sonochemical reaction environment. It is desirable to provide the means in the tank 5.

The liquid 6 containing a reactive substance is not particularly limited as long as it can contain a reactive substance that changes due to a sonochemical reaction, and examples thereof include water, oil, an organic solvent, and alcohol. Regarding the containing form of the reactant, either a dissolved solution state or a mixed phase state dispersed in any of bubbles, particles, and droplets may be used. As a particularly preferable example of the liquid 6 containing the reactive substance, an aqueous solution in which a known surfactant that reduces the surface tension of the liquid and suppresses the formation of bubbles and coalescing is dissolved may be mentioned. Examples include polyvinyl alcohol, polyethylene glycol, fatty acid sodium, alkylglycoside, sodium cholate, sodium alkylbenzenesulfonate, sodium lauryl sulfate, Triton-X, Tween, lower alcohol, higher alcohol and the like.

Reactive substances contained in the liquid 6 are oxidized, reduced, polymerized, decomposed, synthesized, sterilized, washed, heated, combusted, separated, solid surface modified by high-temperature and high-pressure fields inside the bubbles generated in the present invention and in the vicinity of the interface. There is no particular limitation as long as the substance undergoes any state change or structural change of quality, indigo carmine, lignin, benzene, chlorobenzene, dichlorobenzene, trichlorobenzene, benzaldehyde, benzyl bromide, benzoic acid, acrylonitrile, phenol, benzyl chloride , Chlorophenol, trichlorethylene, monochloroacetaldehyde, dichloroacetaldehyde, chloral hydrate, chlorofluorocarbon, tetrachloroethylene, polychlorinated biphenyl, perfluorooctanesulfonic acid, perfluorooctanoic acid, dioxins, al Ruphenol, aniline, dimethyl maleate, dibromodiphenylethane, acetophenone, n-butylamine, 1,2-diol, pyrene, methyl iodide, chalcogen, thiophene, ammonium aluminum sulfate, silicon alkoxide, iron chloride, zinc, calcium, platinum, Examples include copper, silver, gold, palladium, nickel, lanthanum, ruthenium, zirconium, titanium oxide, alcohol, paraffin, silica, oxalic acid, protein, microorganism, tar, and radioisotope.

Hereinafter, although this invention is further demonstrated based on Example 1 to Example 9 which applied the decomposition reaction of indigo carmine, this invention is not limited to this. The amount of indigo carmine degradation shown in Examples 1 to 9 is determined by using the fact that the carbon double bond, which is the chromophore of indigo carmine, is cleaved by sonochemical reaction, and the transmittance at a wavelength of 610 nm changes. Calculated using a photometer.

Example 1 shows an example in which indigo carmine is decomposed using an ultrasonic stepped horn having a hollow structure as a vibrator, argon as a gas, and water as a liquid containing a reactant. Into a 150 mL glass beaker, 100 mL of an aqueous solution in which 2.0 mg of indigo carmine is dissolved is put, and an argon gas is supplied from an argon cylinder to an ultrasonic stepped horn whose gas discharge port is arranged at a depth of 12 mm in the liquid. Supply to the horn with sonic step. As shown in Fig. 2, the hollow-structured ultrasonic stepped horn has a combination of cylinders with different diameters. The gas inlet is on the side of the cylindrical part with the large diameter, the gas outlet is on the end face with the small diameter, and the horn is inside the horn. The thing of the shape which comprises the flow path which connects a gas inlet and a gas discharge port was used. In this embodiment, the vibration from the ultrasonic transducer connected to the end face having the large diameter of the ultrasonic stepped horn is amplified by the stepped portion, and the end face having the small diameter, that is, the vibration surface is 19.5 kHz and the half amplitude is 20 μm. It was vibrated, and argon was supplied at a flow rate of 10 mL / min from a circular gas discharge port having a diameter of 3 mm to generate bubbles and apply pressure vibration to the bubbles. In this example, application of ultrasonic waves produced fine bubbles as shown in FIG. 3, and 1.00 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

As Example 2, an example in which the flow rate of argon in Example 1 is changed to 30 mL / min is shown. Equipment used and processing conditions other than the flow rate were the same as in Example 1. In Example 2, 0.95 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

As Example 3, an example in which the flow rate of argon in Example 1 is changed to 50 mL / min is shown. Equipment used and processing conditions other than the flow rate were the same as in Example 1. In Example 3, 0.95 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

As Example 4, an example in which the flow rate of argon in Example 1 is changed to 100 mL / min is shown. Equipment used and processing conditions other than the flow rate were the same as in Example 1. In Example 4, 0.52 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

Example 5 shows an example in which the argon flow rate in Example 1 is changed to 200 mL / min.
Equipment used and processing conditions other than the flow rate were the same as in Example 1. In Example 5, 0.54 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

Example 6 shows an example in which the supply of argon in Example 1 is stopped. The processing conditions except for the gas supply were the same as in Example 1. In Example 6, 0.26 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

FIG. 4 shows the relationship between the indigo carmine decomposition amount and the argon gas flow rate in Examples 1 to 6. First, compared with 0 mL / min of Example 6 in which no gas is supplied, all of Examples 1 to 5 can be decomposed twice or more, and it is effective to supply gas continuously. Sex is shown. In addition, under the conditions of the flow rate of 50 mL / min or less in the first to third embodiments, the decomposition can be performed approximately twice as much as the flow rate of 100 mL / min or more shown in the fourth and fifth embodiments. Thus, the effectiveness of continuously supplying gas and the effect of promoting the sonochemical reaction by suppressing the gas flow rate are shown.

Example 7 shows an example in which 0.2 g of 1-pentanol was added as a surfactant to the indigo carmine aqueous solution in Example 3. The equipment used and the processing conditions were the same as in Example 3. In Example 7, as shown in FIG. 5, more fine bubbles were generated than in FIG. 3, and 1.83 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

Example 8 shows an example in which oxygen is supplied instead of the argon gas in Example 3. The equipment used and the processing conditions were the same as in Example 3. In Example 7, 0.79 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

FIG. 6 shows the relationship between the time and the amount of decomposition of indigo carmine in Example 8 in which the surfactant was added to Example 3 and Example 3, and Example 8 in which the gas in Example 3 was changed from argon to oxygen. FIG. 6 shows that the degradation of indigo carmine is dramatically accelerated by the addition of a surfactant. Moreover, the amount of decomposition | disassembly is seen by using oxygen with a low specific heat ratio, The effectiveness of using gas with a high specific heat ratio is shown.

Example 9 shows an example in which the shape of the gas discharge port in Example 1 is expanded from a circle with a diameter of 3 mm to a circle with a diameter of 5 mm. The equipment used and the processing conditions were the same as in Example 1. In Example 9, 1.07 mg of indigo carmine in the beaker was decomposed in a treatment time of 30 minutes.

The sonochemical reaction obtained by the present invention is not only capable of continuously treating sonochemical reactions that have been mostly batch processing (batch processing) by gas supply, but also in sonochemical regions where pressure fluctuations are strong. By supplying a suitable amount of gas for the reaction, the reaction efficiency is expected to be improved, synthesis of new materials such as ceramic nanoparticles, magnetic nanoparticles, platinum nanoparticles, bioethanol purification, polymer synthesis, PCB and It is expected to be effective for the decomposition of persistent substances such as dioxins, sterilization of harmful microorganisms, and soil purification.

DESCRIPTION OF SYMBOLS 1 Gas introduction port 2 Gas discharge port 3 Flow path 4 Vibrating body 5 Tank 6 Liquid containing reactive substance 7 Gas supply means 8 Vibrating surface 9 Bubble

Claims (5)

A vibration body capable of vibrating with a frequency of 10 kHz or more and an amplitude of 10 μm or more, disposed in a liquid containing at least a part of the reactant, a gas supply means for supplying a gas to the vibration body, and the gas supply means from the gas supply means A reaction apparatus comprising a flow path for supplying a gas into the liquid through the inside of a vibrating body. The reaction apparatus according to claim 1, wherein a surfactant is included in the liquid containing the reactant in which a part of the vibrator according to claim 1 is disposed. The flow rate of the gas discharged from at least one gas discharge port of the vibrator according to claim 1 is more than 0 mL / min and 1000 mL / min or less. Reactor. The reactor according to any one of claims 1 to 3, wherein an opening area of at least one gas discharge port of the vibrator according to claim 1 is in a range of 1 mm ^{2 to} 1000 mm ² . The treatment of the substance by the reactor according to any one of claims 1 to 4 is imparting reactivity in any of oxidation, reduction, polymerization, decomposition, synthesis, sterilization, washing, heating, combustion, separation, and solid surface modification. The reaction apparatus according to claim 1, wherein the reaction apparatus is an improvement.