KR20100014773A - Hydrogen-oxygen mixer-sparger - Google Patents

Abstract

An apparatus is disclosed for the generation of hydrogen peroxide. The apparatus provides for the production of a large scale volume of hydrogen peroxide by the generation of a liquid bearing bubble cloud. The bubbles are generated with a tiny volume before flowing over the reactor bed to generate the hydrogen peroxide.

Description

Hydrogen-oxygen mixer-sparger {HYDROGEN-OXYGEN MIXER-SPARGER}

The present invention relates to the production of hydrogen peroxide, and more particularly to the large-scale production of hydrogen peroxide.

The most widely used industrial scale production of hydrogen peroxide is the indirect reaction of hydrogen and oxygen employing alkylanthraquinone as an agent. In the first catalytic hydrogenation step, alkyllantraquinone dissolved in a working solution comprising organic solvents (eg, diisobutylcarbinol and methyl naphthalene) is converted to alkylanthrahydroquinone. In a separate automatic oxidation step, this reduced compound is oxidized to regenerate alkyllantraquinone to yield hydrogen peroxide. Subsequent separation by aqueous extraction, refining and concentration operations is employed to provide a commercial grade product.

Overall, the indirect route to H ₂ O ₂ formation, where the carrier medium is reduced and then oxidized, adds complexity and requires high plant and operating costs. One notable drawback is the significant solubility of alkyllantraquinones in the aqueous extraction media used to separate the hydrogen peroxide product. This promotes loss of working fluid and leads to contamination of the hydrogen peroxide product by organic species that react with hydrogen peroxide when the hydrogen peroxide is concentrated to a level suitable for transport. The second problem concerns the solubility of the aqueous extraction solution in the alkyllantraquinone working solution. In case the wet working solution is separated from the aqueous state for recycling to the indirect oxidation step, the "pocket" of the aqueous state remaining in the organic solution provides a zone for the hydrogen peroxide product and concentrates to a dangerous range. The third problem concerns the use and recovery of organic compounds when a small amount of hydrogen peroxide is required in the aqueous stream without organic contaminants.

A much simpler and more economical route than the alkyllanteraquinone route is the direct synthesis of hydrogen peroxide from the gaseous hydrogen and oxygen feed streams. Although this process is disclosed in US Pat. No. 4,832,938 B1 and other cited documents, commercialization attempts lead to industrial disasters resulting from the explosion hazard inherent to this process. That is, the explosive concentration of hydrogen in the oxygen-hydrogen gaseous mixture at normal temperature and pressure is 4.7 to 93.9 volume percent.

Dilution of the gaseous mixture with an inert gas such as nitrogen is known to hardly change the lower concentrations of the two gases, considering the absence of an inert gas. Within the normal range of pressure fluctuations (0.1-20 MPa) and temperature fluctuations (0-100 ° C.), the explosion range is known to hardly change. Moreover, even if these reactants are combined at a rate outside the combustible envelope in homogeneous conditions, the attainment of homogeneity from pure components necessarily involves at least a temporary passage through the combustible envelope. For this reason, the explosion risk associated with the direct contact of hydrogen and oxygen is not easily mitigated.

Several efforts have also been made to include reactions in the liquid phase in the region of direct contact of hydrogen with oxygen. For example, US Pat. No. 5,925,588 B1 discloses the use of a catalyst with a hydrophobic / hydrophilic support modified to provide optimal performance in aqueous liquid phases. U. S. Patent No. 6,042, 804 B1 also discloses dispersing microbubbles of hydrogen and oxygen into a rapidly flowing acidic aqueous liquid medium containing a catalyst. Unfortunately, however, hydrogen and oxygen reactants can only be slightly dissolved in the aqueous reaction solvents disclosed in these documents.

Another document, US Pat. No. 4,336,240 B1 and US Pat. No. 4,347,231 B1, discloses a two-phase reaction system with a homogeneous catalyst dissolved in an organic phase. As mentioned in the former of these two documents, homogeneous catalyst systems generally have the disadvantage of hindering commercial use. Disadvantages include insufficient catalyst stability under reaction conditions, limited catalyst solubility in the reaction medium, and low reaction rates for the production of hydrogen peroxide. In addition, the gaseous H ₂ / O ₂ containing environment above the two-phase liquid reaction system maintains an equilibrium concentration of these reactants dissolved in the liquid phase. Thus, this gaseous atmosphere on the reaction liquid must be outside the combustible envelope, thus greatly limiting the range of potential reactant molar ratios in the liquid phase.

There are two types of reactors for producing hydrogen peroxide from water. The first reactor is a slurry reactor in which gas bubbles and catalyst are dispersed in the flowing liquid phase. This slurry reactor has the advantage of mixing to provide good heat and mass transfer, but this method requires large amounts of expensive catalysts in addition to the catalyst recovery and recycle methods. The second reactor is a trickle bed reactor in which gas and liquid flow over a packed bed of catalyst. The main disadvantage of the trickle bed reactor is that the gas is in a continuous phase, requiring a small channel size, and hence a small particle size, to prevent hydrogen and oxygen from entering the critical period.

It is useful to have an apparatus and process for producing large amounts of hydrogen peroxide based on the need for no extra chemicals for environmental safety methods and no waste product stream generation.

One way to overcome the shortcomings of current hydrogen peroxide production processes is to generate a large amount of hydrogen and oxygen mixture in the dispersion of small bubbles in the liquid. The present invention provides an apparatus for generating a mixture of hydrogen and oxygen as small gas bubbles. According to the present invention, a first plate has a plurality of small channels formed in the first plate for carrying the main channel and the first gas, and a second plate has a plurality of small channels formed in the second plate for carrying the main channel and the second gas. It has a pair of plates with small channels. The plates, when stacked, provide a mixture of the first gas stream and the second gas stream in the small channel of the second plate, and the gas mixture exits as small bubbles into the liquid stream.

In another embodiment, the apparatus includes a cold plate that also provides a liquid stream for containing gas bubbles exiting the small channel. The cold plate is laminated with the first and second gas distribution plates in a manner that the first plate, the second plate, and the cold plate repeat.

In yet another embodiment, the apparatus includes a gas bubble containing hydrogen and oxygen and a reactor for generating hydrogen peroxide from the liquid. The configuration is such that liquid containing gas bubble clouds flows over the reactor, and the gas bubble clouds do not aggregate into larger gas bubbles to provide safe operation of the reactor.

Other objects, advantages and applications of the present invention will become apparent to those skilled in the art from the following detailed description and drawings. Further objects, examples and details of the invention can be obtained from the following detailed description of the invention.

1 is a configuration of a first plate for a mixer.

2 is a configuration of a second plate for a mixer.

3 is a schematic diagram of the first and second plates, showing the flow through the plates of the mixer.

4 is a configuration of a cooling plate for a mixer.

5 is a diagram of an assembled sparger in which gas and liquid flow in the sparger.

6A and 6B show a configuration of a first plate for a mixer having an annular shape, in which FIG. 6A is a plan view and FIG. 6B is a sectional view.

7A and 7B show a configuration of a second plate for a mixer having an annular shape, in which FIG. 7A is a plan view and FIG. 7B is a plan view.

8 is a schematic of the first and second plates, showing flow through the plate for the mixer.

9A and 9B are configurations of a cooling plate for a mixer having an annular shape, in which Fig. 9A is a plan view and Fig. 9B is a sectional view.

FIG. 10 is a configuration of a radial reactor using the sparger configuration of FIG. 5.

11 is a schematic diagram of stages of a sparger and a reactor for generating hydrogen peroxide.

12 is a schematic of the stages of a hydrogen peroxide reactor using countercurrent flow.

13 is a schematic diagram of a hybrid configuration for a hydrogen peroxide reactor.

The present invention includes an apparatus for massively mixing hydrogen and oxygen in water to react to generate hydrogen peroxide (H ₂ O ₂ ). A problem in increasing the production of hydrogen peroxide is the generation of amounts that result in the mixing of large volumes of hydrogen and oxygen. This is a potentially dangerous situation. Thus, it is desired to generate large amounts of mixed hydrogen and oxygen, but to produce a small bubble dispersed phase in water for reactions that result in rapid dissolution in water and hydrogen peroxide. New configurations of mixers suitable for large scale applications are presented.

In one embodiment, the apparatus comprises a plate array, each plate having a channel formed in the plate, the plates being joined to each other. Means for forming the channel include, but are not limited to, etching, pressing, stamping and milling, and are well known in the art. Means for joining the plates together are well known in the art and include but are not limited to diffusion bonding, brazing and welding. The plate array is preferably a pair of plates, where the plates are stacked in an alternating order. As shown in FIG. 1, the first plate 10 of the pair of plates has a first surface, an opposing surface, a first edge, a second edge, a third edge, and a fourth edge. The first plate 10 includes a main channel 12 having an inlet 14 and a plurality of outlets 16 on one surface of the first plate 10. The main channel is etched, pressed, stamped or milled into the plate without penetrating the first plate 10. The first plate 10 further comprises a plurality of small channels 18 on the same face of the plate 10 as the main channel 12, each small channel having a corresponding outlet 16 from the main channel 12. Has an inlet in fluid communication with the. The small channels 18 each have an outlet 20 extending through the first plate 10 on opposite sides to create an array of slits on opposite sides of the plate. In a particular embodiment, the small channel 18 does not extend to the edge of the plate 10, but in other embodiments, the small channel may extend to the edge of the first plate 10.

The embodiment further includes a second plate 30 of the pair of plates having a first surface, an opposing surface, a first edge, a second edge, a third edge and a fourth edge as shown in FIG. 2. The second plate 30 has a main channel 32 having an inlet 34 and a plurality of outlets 36 on one side of the second plate 30. The main channel is etched, pressed, stamped or milled into the plate without penetrating the second plate 30. The second plate 30 further comprises a plurality of small channels 38 on the same side of the plate 30 as the main channel 32, each small channel 38 having a corresponding outlet from the main channel 32. 36) has an inlet in fluid communication. The small channels 38 each have an outlet 40 which opens to one edge of the second plate 30. Like the main channel 32, the small channel 38 does not extend through the second plate 30 to the opposite side.

The two plates 10, 30 each have the same number of small channels 18, 38, each channel 18 having a corresponding channel 38. When the plates 10, 30 are stacked, the corresponding small channels 18, 38 cause the outlet 20 of the small channel 18 of the first plate to be in fluid communication with the corresponding channel 38 of the second plate. Aligned. The small channel 18 of the first plate has an outlet 20 which terminates into the small channel 38 of the second plate. The section of the second plate small channel 38 downstream of the outlet 20 of the first plate small channel 18 provides a zone for the gases from the two channels 18, 38 to mix. The length of this section in the second small channel 38 is selected to achieve good mixing of the gases before the gas mixture exits the second plate small outlet 40.

In the case where a plurality of pairs of plates 10, 30 are stacked and fixed together, the resulting embodiment has a six-sided rectangular prism shape to form a sparger. On one side there is an inlet of the main plate 12 for the first plate, on the second side opposite the first side there is an inlet of the main channel 32 for the second plate, and on the third side the small channel of the second plate. There is an array of small openings that are outlets 40 at 38. This enters the main channels 12, 32 and provides good mixing of the gases exiting from the small channel outlet 40 as a mixture. As the liquid flows over the small channel outlet 40, a gas bubble cloud is entrained in the liquid to provide improved mass transfer that dissolves the gas mixture in the liquid.

A schematic diagram showing the mixing of two gases according to the present invention is shown in FIG. 3. The first gas is introduced into the first plate main channel 12 as indicated by arrow 15. The first gas is then dispensed and introduced into the secondary channel 18 as indicated by arrow 17. The first gas exits the first plate secondary channel 18 and enters the second plate secondary channel as indicated by arrow 19. The second gas is introduced into the second plate main channel 32 as indicated by arrow 25. The second gas is then distributed and flows into the secondary channel 38 as indicated by arrow 27. The second gas mixes with the first gas and enters the second plate secondary channel 38 as indicated by arrow 19. The mixture of the first gas and the second gas exits the second plate secondary channel 38, as indicated by arrow 29.

In this embodiment, the size of the main channels 12, 32 is approximately 50 mm wide and approximately 0.5 mm deep, providing a cross-sectional area of 25 mm ² . The small channels 18, 38 are approximately 0.2 mm wide and approximately 0.2 mm deep, providing a cross-sectional area of 0.04 mm ² . Good distribution of gas from the main channel to the small channel is achieved by maintaining the ratio of the sum of the cross-sectional area of the main channel to the cross-sectional area of the small channels is at least three. In this embodiment, the size of the current channel allows more than 200 small channels on each main channel. The use of small channel dimensions for small channels has been shown to provide lamellae mixing of gases to be a safe and effective way of mixing hydrogen and oxygen without combustion.

The specific configuration of the small channels 18, 38 for this embodiment has an effective diameter of 200 micrometers (0.2 mm), and the channel shape and configuration of the small channels 18, 38 are the gases to be mixed by the sparger only. Forced on the basis of their composition. In the immediate case of mixing hydrogen and oxygen, the small channels 18, 38 have an effective diameter of 50 micrometers (0.05 mm) to 300 micrometers (0.3 mm), preferably 200 micrometers (0.2 mm) or less. .

While the configuration of the present invention is for use in mixing hydrogen and oxygen for the production of hydrogen peroxide, the present invention is not limited to these gases, but rather any lamellar mixing of gases may be carried out by the present invention.

In another embodiment, the present invention includes a cold plate 50 as shown in FIG. The cold plate 50 also serves as a conduit for providing a liquid component that is accompanied by gas bubbles exiting the outlet 40. The cooling plate 50 is in an alternating order, that is, the first plate 10, the second plate 30, the cooling plate 50, the first plate 10, the second plate 30, the cooling plate 50. It is configured to overlap with the first plate 10 and the second plate 30, etc.).

The cooling plate 50 is constituted by a series of parallel channels 52. Channels 52 are etched, stamped, pressed, milled or otherwise formed in the plate. Channel 52 has an inlet 54 and an outlet 56. When the plates are stacked, the outlet 56 of the cold plate 50 is on the same stack side as the second plate small channel outlet 40. A diagram of the assembled sparger 62 is shown in FIG. 5 showing the gas inlets 58 and 60 and the gas outlet 40, wherein the liquid flowing upward through the cold plate channel 52 is dispersed gas bubble. Generate the flow with Gas inlets 58, 60 direct individual gases to corresponding main channel inlets 14, 34 of plates 10, 30. The cold plate 50 permits a third component, in particular a liquid. Liquids that may be used in the present invention include water, methanol, alcohols and mixtures thereof. Preferred liquid is water. The cooling plate 50 may be configured with a small channel (not shown) for transporting the third gaseous component to a suitable manifold in fluid communication with the cooling channel inlet 54. A plurality of spargers 62 may be used in parallel or in series to increase the production of gas bubbles.

In the third embodiment, the lamination is described as above but without the cold plate 50. This embodiment includes a manifold (not shown) for transporting liquid across the exit 40 of the sparger. This manifold preferably directs the fluid to flow across the outlet side of the sparger in the shorter dimension direction. The manifold can be split to create separate channels, separating the flow and further preventing coalescence of bubbles carried in the liquid phase.

In an annular embodiment, the device comprises an array of plates, each plate having an annular shape. As in the first embodiment, the array is a pair of plates stacked in alternating order. 6A and 6B are a plan view and a cross-sectional view of the first annular plate 70. As shown in FIGS. 6A and 6B, the first plate 70 of the plate pair has a top surface, a bottom surface, an inner edge, and an outer edge. The first plate 70 has a main channel 72 having one or more inlets 74 disposed on the outer edge of the plate 70 and a plurality of outlets 76 on the top surface of the plate 70. The first plate 70 also has a plurality of small channels 78 on the same side of the first plate 70 as the main channel 72, with each small channel 78 having a corresponding outlet from the main channel 72. An inlet in fluid communication with 76. The small channels 78 each have an outlet 80 extending through the plate 70 to the bottom of the plate, creating an array of slits at the bottom of the plate 70. In this embodiment, the small channel 78 does not extend to the inner edge of the plate 70.

The annular embodiment further comprises a second plate 90 of a pair of plates having a top surface, a bottom surface, an inner edge and an outer edge as shown in FIGS. 7A and 7B. 7A and 7B show a plan view and a cross-sectional view of the second annular plate 90. The second plate 90 has a main channel 92 having an inlet 94 and a plurality of outlets 96 on one side of the second plate 90. The second plate 90 further has a plurality of small channels 98 on the same side of the plate 90 as the main channel 92, with each small channel 98 having a corresponding outlet from the main channel 92. 96) and has an inlet in fluid communication. The small channels 98 each have an outlet 100 that opens at the inner edge of the second plate 90. As in the main channel 92, the small channel 98 does not extend to the opposite side through the second plate 90. The section of the small channel 98 of the second plate 90 provides a zone for the gases from the channels 78, 98 to mix before exiting the outlet 100.

As in the first embodiment, the plates are etched, stamped, milled, pressed or otherwise produced by methods known in the art.

In this embodiment, the stack of plates produces a pipe-like structure, where the liquid phase flows down the central region of the structure. The mixed gases exiting the outlet 100 are dispersed in the liquid phase and carried down the length of the structure. Pairs of plates 70 and 90 are stacked and secured together, and the resulting embodiment is a toroidal structure, forming a sparger with an outer surface and an inner surface. On the outer side there is an inlet for the main channels 72, 92 of the plates and on the inner side there is an array of small openings which are the outlet 100 for the small channel 98 of the second plate. The liquid flows down the channel formed by the inner surface of the stack of plates. As the liquid flows over the small channel outlet 100, a gas bubble cloud entrains in the liquid to provide improved mass transfer to dissolve the gas mixture in the liquid.

A schematic showing the mixing of two gases by the present invention is shown in FIG. 8. The first gas is introduced into the first plate main channel 72 as indicated by arrow 73. The first gas is then introduced into the first plate secondary channel 78 as indicated by arrow 75. The first gas exits the bottom of the first plate through the outlet 80 as shown in FIG. 6B and enters into the second plate secondary channel 98 as indicated by arrow 77. The second gas is introduced into the second plate main channel 92 as indicated by arrow 93. The second gas is then introduced into the secondary channel 98 as indicated by arrow 95. The second gas is mixed with the first gas flowing from the first plate 70 in the second plate secondary channel 98. The mixture of the first gas and the second gas exits the second plate secondary channel 98 as indicated by arrow 97.

In another embodiment, the present invention further includes an annular cooling plate 110 that also provides a liquid conduit to carry the gas mixture exiting the outlet 100 as bubbles, as shown in FIGS. 9A and 9B. . 9A and 9B show a plan view and a cross-sectional view of the cooling plate 110. The cooling plate 110 has a main channel 112 for liquid. Main channel 112 includes at least one inlet 114 and a plurality of outlets 116. The cooling plate 110 further includes a plurality of small distribution channels 118, each small channel 118 having an inlet corresponding to the main channel outlet 116 and an outlet 119. The cold plate 110 has an inner edge and an outer edge, and the outlet 119 is disposed around the inner edge to distribute the liquid exiting the small channel 118.

This embodiment produces a pipe-like structure (not shown) with inner conduits when plates 70, 90, 110 are stacked in an alternating order, and along this structure alternating rows of openings for gas mixtures and liquids. It is provided.

In another embodiment, the apparatus further comprises a reactor bed. The apparatus includes a conduit for conveying a liquid feed across the gas sparger, the liquid in fluid communication with the outlet of the sparger. The liquid after passing through the sparger outlet is the liquid supporting the gas bubble cloud. The reactor bed (not shown) has an inlet and an outlet in fluid communication with a liquid containing a gas bubble cloud.

In one embodiment of the sparger-reactor combination of the present invention, a plurality of spargers 62 as shown in FIG. 5 are disposed around the donut-shaped reactor core 120 as shown in FIG. Create reactor unit 128. The array of channel outlets 40 of the sparger 62 is small enough to serve as an effective screen to hold the catalyst in place in this embodiment. In the case of sparger 62 with large channel outlet 40, an optional screen (not shown) is used. Sparger-reactor unit 128 includes an inner screen 122 over the inner surface of reactor core 120. Screen 122 separates reactor core 120 from collection space 124, which is a space defined by inner screen 122 and inner wall 126 within the reactor. Screen 122 also provides a means to hold the particles of the reactor in place. The inner wall 126 is provided by a tube inside the reactor, the size of which is to minimize the pressure drop while collecting the liquid containing hydrogen peroxide. Optionally, the tube is omitted, and the inner space 124 is a space formed by the inner screen 122. This reactor structure provides several advantages. Radial reactors overcome the pressure drop limitations associated with trickle bed reactors with small particle sizes. The small particle size of the trickle bed reactor is essential to avoid large gas spaces for the hydrogen-oxygen mixture. The radial reactor configuration allows for easier replacement of reactor bed 120. The configuration of the sparger 62 quickly distributes the liquid containing the small gas bubbles to the reactor bed 120 without the gas clumping into larger gas bubbles. Sparger-reactor unit 128 is easily manufactured and assembled as a module for convenient expansion to cover a wide range of flow rates.

The reactor bed is equipped with a catalyst for the formation of hydrogen peroxide from hydrogen and oxygen. The catalyst comprises one or more catalytic metal components disposed on a support, the catalytic metal components comprising platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), osmium (Os) and It is selected from the group consisting of gold (Au). The catalyst component preferably comprises a mixture of two metals. In one embodiment, the catalyst comprises at least one metal selected from the above metals on a support. The support material is any inert material on which the catalyst can be deposited and includes, but is not limited to, silica, alumina, titania, zirconia, carbon, silicon carbide, silica-alumina, diatomaceous earth, clays, and molecular sieves. The support is preferably a porous material to provide a larger surface area for the reaction to proceed.

Spargers with reactors can optionally be manufactured as a single body, in which a plurality of units are used to generate hydrogen peroxide.

In one embodiment of the hydrogen peroxide reactor, the apparatus includes two sparger-reactor stages as shown in FIG. The sparger reactor unit 128 includes a liquid supply 130, a hydrogen supply 58 and an oxygen supply 60. Hydrogen and oxygen are directed to the sparger in unit 128 and dispersed into a liquid and flow over the reactor bed in unit 128. Sparger-reactor unit 128 has a product outlet 132 that receives a liquid stream carrying residual bubbles of gas. The product stream enters the gas-liquid separation unit 134 where any residual gas is collected and separated from the liquid. The liquid stream containing some hydrogen peroxide is further fed to the subsequent sparger-reactor unit 128. Any residual gas can be exhausted or directed to other parts of the plant and used for combustion or other purposes. Optionally, the gas-liquid separation unit 134 includes a gas inlet in fluid communication with the gas collection zone. This allows the addition of gas to dilute the hydrogen-oxygen mixture to be exhausted. The diluent gas may be an inert gas such as nitrogen. The advantage of using a stage is to produce a high concentration of hydrogen peroxide in the liquid without requiring a high ratio of gas to liquid in any reactor. This promotes the generation of gas as bubble clouds in the liquid while limiting the agglomeration of gas bubbles, thereby preventing the formation of large gas volumes. The flow of oxygen to hydrogen towards each reactor stage has a volume ratio of 1, or stoichiometric ratio.

In a variant of the hydrogen peroxide reactor, the apparatus includes at least two sparger-reactor stages in a countercurrent flow reactor configuration as shown in FIG. 12. In the countercurrent flow configuration, the last reactor unit 128a has a liquid feed stream 136 from the previous reactor unit / gas-liquid separator and hydrogen 58 and oxygen 60 are sparger at a high oxygen to hydrogen volume ratio. Supplied. The product stream is separated in gas-liquid separator 134 and the oxygen rich gas is directed to the sparger for the previous reactor 128b. The former reactor 128b again receives the liquid feed stream from the initial reactor 128c and receives hydrogen 58 and oxygen from the oxygen rich gas stream 138 in the subsequent reactor 128a. This process is repeated again with the first reactor 128. The countercurrent flow configuration allows for a high oxygen to hydrogen volume ratio in the gas phase at the last reactor stage. Operating at a higher oxygen concentration in the last stage improves the selectivity of hydrogen peroxide. By this process, the oxygen to hydrogen volume ratio in the gas increases as the process proceeds from one reactor to subsequent reactors. The oxygen to hydrogen volume ratio in the last reactor is preferably 2 to 10, and the oxygen to hydrogen volume ratio in the first reactor is preferably 1. This provides an overall high oxygen conversion while maintaining the advantages of low gas to liquid flow volume ratios in each reactor stage and high oxygen concentrations in subsequent stages.

In another embodiment of the reactor (not shown), the reactor has a simplified version of the countercurrent configuration. This is called a pseudo-counter current reactor configuration. The flow scheme is shown in FIG. 11 and as described above, but the oxygen to hydrogen flow volume ratio varies from 1 to 20, with the volume ratio increasing from 1 in the first reactor to 1-20 in the last stage. As for the final volume ratio, 2-4 are preferable.

In another variation, the reactor has a flow scheme as shown in FIG. 13. The flow is similar to that described above for FIG. 11 except for the addition of a recycle stream for the liquid phase. A portion of the liquid product stream from the last reactor 128a is recycled through the pump 140 to the inlet of the last reactor stage 128a. The use of the recycle stream should only be used for situations where the oxygen to hydrogen volume ratio is greater than 2 in the last reactor 128a. As a modification to this embodiment, the recycle stream may be directed to the inlet of the reactor upstream of the last reactor 128a, but this reactor should be one of the reactors close to the last reactor 128a.

One embodiment (not shown) also enables movement of the catalyst through the reactor stage. The selectivity of the catalyst for hydrogen peroxide production has been found to increase when the catalyst is deactivated. Since it is desirable to have higher selectivity in the last reactor, a reactor configuration is advantageous in which the catalyst is moved from reactor unit 128 to the subsequent reactor unit 128, where fresh catalyst is transferred to the first reactor unit 128. Is added. One way to configure this reactor is to stack reactor unit 128 so that first reactor unit 128 is on top and subsequent stages are stacked below. At this time, the catalyst is added to the upper unit, the catalyst in the reactor unit moves downward to the continuing unit, and the catalyst is extracted from the last reactor unit and separated.

This embodiment allows the use of a low ratio of gas to liquid volume flow rate, which allows for the formation of stable bubble clouds in the liquid phase for the production of high concentrations of hydrogen peroxide. In addition, using reactor units in series allows greater control over operating conditions and improves selectivity for hydrogen peroxide production.

Although the present invention has been described using what are presently considered to be the preferred embodiments, the invention is not limited to the disclosed embodiments but is intended to cover various modifications and equivalent apparatus falling within the scope of the appended claims.

Claims (10)

A mixing device for mixing two gases, One or more first plates 10 and one or more second plates 30, The first plate defines a first gas main channel 14 having an inlet 14 and a plurality of outlets 16 and a plurality of first gas secondary channels 18, each of which corresponds to a first gas secondary channel. An inlet in fluid communication with a first gas main channel outlet, and a first gas secondary channel outlet 20, The second plate defines a second gas main channel 32 having an inlet 34 and a plurality of outlets 36 and a plurality of second gas secondary channels 38, each second gas secondary channel corresponding thereto. An inlet in fluid communication with a second gas main outlet channel, and a second gas secondary channel outlet 40, Each first gas secondary channel outlet 20 is in fluid communication with a second gas secondary channel outlet 40, and the first plate 10 and the second plate 20 are stacked in alternating order and held together to provide a first A gas sparger (62) having a gas inlet, a second gas inlet, and a mixed gas outlet. The method of claim 1, wherein the plurality of inlets in fluid communication with the secondary channel outlet 40, at least one inlet through which the third component is introduced, and discharge of the mixture of the first gas, the second gas and the third component Further comprising a manifold having one or more outlets, the manifold having plates defining a plurality of channels, each channel having one or more of the first gas secondary channel outlets 40 and a second gas secondary channel. And is in fluid communication with at least one of the outlets (40) and having at least one inlet for the third component and at least one outlet for the discharge of the mixture of the first gas, the second gas and the third component. A cooling plate (50) is further provided, wherein the cooling plate (50) has a plurality of channels (52) each having an inlet (54) and an outlet (56), and cooling The channel outlet (56) is in fluid communication with the second gas secondary channel outlet (40). 4. The outlet of any of the preceding claims, wherein the outlet of the first gas secondary channel 18 terminates in the second gas secondary channel 38 and is downstream of the outlet of the first gas secondary channel 18. Mixing device, characterized in that the section of the second gas secondary channel (38) comprises a mixing section having an effective diameter of less than 300 micrometers. 5. A liquid feed conduit according to any one of claims 1 to 4, having a liquid feed inlet in fluid communication with the gas sparger 62, an outlet for liquid carrying a gas bubble cloud, Reactor bed having an inlet in fluid communication with the liquid feed conduit outlet and an outlet forming a reactor-sparger unit Mixing apparatus further comprising. 6. The reactor of claim 5 wherein said reactor bed comprises a catalyst, said catalyst comprising at least one catalytic metal component disposed on a support, said catalytic metal component being platinum (Pt), palladium (Pd), ruthenium (Ru). , Rhodium (Rh), iridium (Ir), osmium (Os), gold (Au) and mixtures of ids, the support is silica, alumina, titania, zirconia, carbon, silicon carbide, silica-alumina And a material selected from the group consisting of diatomaceous earth, clay, molecular sieve and mixtures thereof. 7. The reactor of claim 1, further comprising a reactor bed, wherein the reactor bed comprises: Annular reactor bed 120 having an inner surface and an outer surface and having a substantially cylindrical shape, Catalyst retention screen 122, Product Conduit (124) And the sparger 62 is disposed on either the inner surface or the outer surface, the catalyst retention screen 122 is disposed on the other of the surfaces, and the product conduit is bounded by the catalyst retention screen. A mixing device in fluid communication with the surface. 8. The reactor of claim 7, wherein the reactor bed comprises a catalyst on a support, the catalyst comprising platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), osmium (Os) , At least one metal selected from the group consisting of gold (Au) and mixtures, the support comprising silica, alumina, titania, zirconia, carbon, silicon carbide, silica-alumina, diatomaceous earth, clay, molecular sieve and mixtures thereof Mixing apparatus comprising a material selected from the group consisting of. 5. The mixing apparatus according to claim 1, wherein the first plate and the second plate define channels having a rectangular planar shape. 6. 5. The mixing apparatus according to claim 1, wherein the first plate and the second plate define a channel having a radial shape. 6.

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