JP2006122881A - High-pressure reaction apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-pressure reaction apparatus in which hydrogen peroxide of high concentration can stably be supplied continuously to a high pressure zone by surely restraining oxygen gas from being accumulated on the primary side of a pump without producing an air lock owing to the oxygen gas to be produced by pyrolysis. <P>SOLUTION: This high-pressure reaction apparatus is provided with: a hydrogen peroxide storage tank 2 for storing hydrogen peroxide; a hydrogen peroxide supplying pump 7 connected to the hydrogen peroxide storage tank by a hydrogen peroxide supplying pipeline; a reaction vessel 11 connected to the discharge side of the hydrogen peroxide supplying pump via a hydrogen peroxide discharging pipeline; and a pressure reducing valve 14 connected to the downstream side of the reaction vessel. An oxygen gas separating means for separating the oxygen gas to be generated from hydrogen peroxide from hydrogen peroxide is arranged on the hydrogen peroxide supplying pipeline. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to, for example, a high-pressure reactor that oxidizes organic substances under high temperature and high pressure, and more particularly, to a high-pressure reactor that includes means for stably and continuously supplying hydrogen peroxide to a reaction vessel portion that is a high-pressure region.

  Conventionally, as a high-pressure reactor that oxidizes organic matter at high temperature and high pressure, a hydrogen peroxide storage tank that stores hydrogen peroxide, and hydrogen peroxide connected to the hydrogen peroxide storage tank via a hydrogen peroxide supply pipe There is known a high-pressure reactor comprising a supply pump, a reaction vessel connected to the discharge side of the hydrogen peroxide supply pump via a hydrogen peroxide discharge pipe, and a pressure reducing valve connected to the downstream side of the reaction vessel. It has been.

  As such a high-pressure reactor, for example, in a supercritical water atmosphere or a subcritical water atmosphere, an organic substance, water and an oxygen-containing fluid are mixed, and the organic substance is oxidatively decomposed in a supercritical state exceeding the critical point of water. An organic matter oxidation method in supercritical water is known (see Patent Document 1).

  In this organic matter oxidation process, when hydrogen peroxide is used as an oxidant, hydrogen peroxide is in a liquid form and is supplied using a pump. As such a pump, a plunger pump or a syringe pump is generally applied. However, since a syringe pump is not suitable for continuous supply of high flow rate or high concentration hydrogen peroxide, a plunger pump is used. There are many cases.

A method of supplying hydrogen peroxide without using a pump is also known. For example, hydrogen peroxide is injected into an airtight container leaving a gap at the upper end, and hydrogen peroxide is decomposed into water and oxygen gas using a catalyst previously charged in the airtight container. There has been proposed a method in which water and oxygen gas can be supplied by operating a piston provided in the sealed container by the internal pressure of the sealed container that rises as a result of the occurrence of gas (see Patent Document 2).
Japanese Patent Publication No. 1-38532 JP-A-1-22342

  In the above-described prior art, when a plunger pump is applied for continuous supply of hydrogen peroxide, hydrogen gas is gradually decomposed even at room temperature to generate oxygen gas. It may accumulate on the side and cause an air lock, reducing the flow rate or supplying hydrogen peroxide.

  On the other hand, in a method that does not use a pump, the flow rate of oxygen gas is unstable, and it is difficult to continuously and stably supply oxygen gas to a high-pressure region.

  The present invention has been made in view of such circumstances, reliably suppressing the accumulation of oxygen gas on the primary side of the pump, without generating an air lock due to oxygen gas generated by thermal decomposition, An object of the present invention is to provide a high-pressure reactor capable of stably and continuously supplying high-concentration hydrogen peroxide to a high-pressure region and capable of oxidizing organic substances at a constant rate.

  In order to achieve the above object, a high-pressure reactor according to the present invention comprises a hydrogen peroxide storage tank for storing hydrogen peroxide, and a peroxidation connected to the hydrogen peroxide storage tank via a hydrogen peroxide supply pipe. In a high-pressure reactor comprising a hydrogen supply pump, a reaction vessel connected to the discharge side of the hydrogen peroxide supply pump via a hydrogen peroxide discharge pipe, and a pressure reducing valve connected to the downstream side of the reaction vessel The hydrogen peroxide supply pipe is provided with oxygen gas separation means for separating oxygen gas generated from the hydrogen peroxide from the hydrogen peroxide.

  In the present invention, it is preferable that the oxygen gas separation means rubs against an oxygen gas inflow upward pipe or an oxygen gas suction device communicating with the hydrogen peroxide supply pipe.

  In the present invention, it is preferable that the hydrogen peroxide supply pipe is provided with a cooling means for cooling the hydrogen peroxide flowing through the pipe.

  The hydrogen peroxide storage tank is preferably an open tank, a sealed tank, or a sealed tank having a tank pressurizing mechanism.

  According to the present invention, the oxygen gas separating means for separating the oxygen gas generated from hydrogen peroxide from the hydrogen peroxide is provided in the hydrogen peroxide supply pipe, thereby ensuring that the oxygen gas is deposited on the primary side of the pump. Stable and continuous supply of high-concentration hydrogen peroxide to the high-pressure region without causing airlock due to oxygen gas generated by thermal decomposition, and oxidizing organic substances at a constant rate Can do.

  In particular, when a cooling means for cooling hydrogen peroxide is provided in the hydrogen peroxide supply pipe, air lock can be prevented more reliably by suppressing the generation of oxygen gas.

  Further, when the hydrogen peroxide storage tank is a sealed tank having a pressurizing mechanism inside, the hydrogen peroxide storage tank is placed at a high place by pressurizing the hydrogen peroxide storage tank. The need for increasing the pressure is reduced and the tank installation position is lowered, so that the space of the equipment can be saved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment (FIG. 1)
FIG. 1 is a schematic configuration diagram showing a high-pressure reactor according to a first embodiment of the present invention.

  As shown in FIG. 1, the high-pressure reactor 1 according to this embodiment includes, for example, an open hydrogen peroxide storage tank 2 as a tank 2 for storing hydrogen peroxide 15. The hydrogen peroxide storage tank 2 is covered with a cooling water tank 3, and the hydrogen peroxide storage tank 2 is cooled from the outer surface side by the cooling water a accommodated in the cooling water tank 3. Yes.

  A hydrogen peroxide supply pump 7 is connected to the hydrogen peroxide storage tank 2 through a hydrogen peroxide supply pipe 4, a pipe joint 5 and a hydrogen peroxide suction pipe 6. A reaction vessel 11 is connected to the discharge side of the hydrogen peroxide supply pump 7 through a hydrogen peroxide discharge pipe 8, a pipe joint 9, and a reactor supply pipe 10.

  The reaction vessel 11 is provided with an external heater 12 so that the reaction vessel 11 can be heated. A discharge pipe 13 is connected to the rear stage of the reaction vessel 11, and a pressure reducing valve 14 is provided in the discharge pipe 13.

  Under such a configuration, the inside of the reaction vessel 11 can be maintained at a high pressure by the hydrogen peroxide supply pump 7 and the pressure reducing valve 14. In addition, although not shown in figure, it is good also as a structure which connects the line and organic substance feeder which supply organic substance in the reaction container 11, and supplies organic substance continuously.

  In this embodiment, the hydrogen peroxide supply pipe 4 communicates with the hydrogen peroxide supply pipe 4 as oxygen gas separation means for separating the oxygen gas 18 generated from the hydrogen peroxide 15 from the hydrogen peroxide 15. An upward piping 17 for inflowing oxygen gas is provided. The oxygen gas inflow upward pipe 17 is configured to rise obliquely upward, for example, with one hydrogen peroxide suction pipe 6 communicating with the lower end thereof.

  In such a configuration, the hydrogen peroxide 15 stored in the hydrogen peroxide storage tank 2 is sent to the hydrogen peroxide supply pump 7 via the hydrogen peroxide supply pipe 4 and the hydrogen peroxide suction pipe 6 by the water head pressure. Then, the hydrogen peroxide supply pump 7 sends the solution to the reaction vessel 11 through the hydrogen peroxide discharge pipe and the reaction vessel supply pipe. By loading the organic substance into the reaction vessel 11, the organic substance can be oxidized in high-temperature and high-pressure water.

  By the way, since the hydrogen peroxide 15 is cooled by the cooling water a stored in the cooling water tank 3, the generation of oxygen gas in the hydrogen peroxide storage tank 2 is suppressed. However, the hydrogen peroxide supply pipe 4 is heated by the driving heat of the hydrogen peroxide supply pump 7 or the atmospheric temperature, and oxygen gas gradually accumulates. However, the upward pipe 17 for extracting oxygen gas bubbles is connected to the hydrogen peroxide supply pipe 4 with hydrogen peroxide. By providing in the middle of the supply pipe 4, the oxygen gas generated in the hydrogen peroxide supply pipe 4 spontaneously escapes due to the difference in specific gravity.

  In order to facilitate the escape of oxygen gas, it is desirable that the diameter of the hydrogen peroxide supply pipe 4 is at least twice that of the hydrogen peroxide suction pipe 6.

  Moreover, it is preferable that the cooling water supply piping which connects the hydrogen peroxide storage tank 2 and the hydrogen peroxide supply pump 7 by the cooling water tank 3 to 10 ° C. or less.

Table 1 below shows the results of observing the state of the line through which bubbles escape when the temperature of the hydrogen peroxide storage tank 2 and the hydrogen peroxide supply pipe 4 is 20 ° C. and 5 to 10 ° C. . The other conditions were a pressure of 30 MPa, a hydrogen peroxide concentration of 31 wt%, and a hydrogen peroxide flow rate of 15 mL / min.

  As shown in Table 1, when the temperature of the hydrogen peroxide supply pipe 4 is 20 ° C., oxygen gas is frequently generated and sent to the reaction vessel 11 at a lower hydrogen peroxide concentration than the intended concentration. However, when the temperature of the hydrogen peroxide supply pipe 4 is 5 to 10 ° C., the oxygen gas is discharged at a rate of 5 minutes / time, so Can be supplied.

  As described above, according to the present embodiment, by providing the hydrogen peroxide supply pipe 4 with the oxygen gas separation means for separating the oxygen gas generated from the hydrogen peroxide 15 from the hydrogen peroxide 15, the primary of the pump It is possible to reliably and continuously supply high-concentration hydrogen peroxide 15 to the high-pressure region without causing oxygen gas accumulation on the side and reliably generating airlock due to oxygen gas generated by thermal decomposition. The organic matter can be oxidized at a constant rate.

  Further, in the present embodiment, by providing a cooling means for cooling the hydrogen peroxide 15 in the hydrogen peroxide supply pipe 4, the generation of oxygen gas is suppressed, thereby further preventing air lock.

[Second Embodiment] (FIG. 2)
FIG. 2 is a schematic configuration diagram illustrating a high-pressure reactor according to a second embodiment of the present invention.

  As shown in FIG. 2, this embodiment is different from the first embodiment in that oxygen gas separation means provided in the hydrogen peroxide supply pipe 4 is connected to, for example, a connecting pipe 19 branched from the hydrogen peroxide supply pipe 4. The oxygen gas suction device is connected via, for example, an oxygen gas suction plunger type suction device 20 having a syringe-like configuration. Since the other configuration is the same as that of the first embodiment, the same reference numerals as those in FIG.

  In this embodiment configured as described above, oxygen gas can be positively sucked and removed from the hydrogen peroxide supply pipe 4 by the plunger-type suction device 20 which is an oxygen gas suction device.

  Accordingly, in the present embodiment, as in the first embodiment, the plunger-type suction device 20 that is an oxygen gas suction device that separates the oxygen gas generated from the hydrogen peroxide 15 from the hydrogen peroxide 15 in the hydrogen peroxide supply pipe 4. Therefore, it is possible to reliably suppress the accumulation of oxygen gas on the primary side of the pump, and to supply high-concentration hydrogen peroxide 15 to the high-pressure region without generating an air lock due to oxygen gas generated by thermal decomposition. Stable and continuous supply is possible. In particular, in the present embodiment, the above effect can be further improved by positively discharging oxygen gas.

  In the present embodiment, the upward piping 17 of the first embodiment may be provided.

[Third Embodiment] (FIG. 3)
FIG. 3 is a schematic configuration diagram illustrating a high-pressure reactor according to a third embodiment of the present invention.

  In the first and second embodiments described above, when the flow rate of the hydrogen peroxide 15 is increased, the hydrogen peroxide 15 is more sucked by the hydrogen peroxide supply pump 7. The line 3 connecting the hydrogen peroxide supply pump 7 has a negative pressure, and cavitation may occur.

  In this case, in order to prevent cavitation, it is necessary to increase the water head pressure by installing the hydrogen peroxide storage tank 2 at a higher position and increasing the water level of the hydrogen peroxide 15 inside. However, when the water head pressure is increased, the configuration becomes large and a large facility space is required.

  In the present embodiment, the hydrogen peroxide storage tank 2 is a sealed tank, particularly a sealed tank having an in-tank pressurization mechanism, and a pressure similar to the water head pressure is applied to the hydrogen peroxide storage tank 2. Specifically, nitrogen is supplied from the nitrogen gas source 22 to the gas phase side of the hydrogen peroxide storage tank 2 through the gas supply pipe 21 to perform pressurization. Thereby, an action equivalent to increasing the water head pressure can be provided, and generation of oxygen gas from the hydrogen peroxide 15 existing in the hydrogen peroxide supply pipe 4 can be suppressed. Since the other configuration is the same as that of the first embodiment, the same reference numerals as those in FIG.

Table 2 below shows the test results for examining the effect of water head pressure. The test conditions were a pressure of 30 MPa, a hydrogen peroxide concentration of 31 wt%, a hydrogen peroxide flow rate of 15 mL / min, and a temperature of a line connecting the hydrogen peroxide storage tank 2 and the hydrogen peroxide supply pump 7 of 5 to 10 ° C.

  As shown in Table 2, it can be seen that the frequency at which the hydrogen peroxide supply pump 7 sucks oxygen gas is lower when the head pressure is 600 mm than when the head pressure is 200 mm.

  As described above, in order to increase the water head pressure, it is necessary to install the hydrogen peroxide storage tank 21 at a high position. As a result, the hydrogen peroxide supply pipe 4 becomes long and oxygen gas is easily generated. On the other hand, as shown in FIG. 3, the hydrogen peroxide storage tank 2 is closed, and nitrogen gas is sent from the gas supply pipe to the gas phase side of the hydrogen peroxide storage tank 2 to pressurize it, thereby reducing the water head pressure. The same effect as that of increasing the pressure can be provided, whereby the generation of oxygen gas from the hydrogen peroxide 15 existing in the hydrogen peroxide storage tank 2 and the hydrogen peroxide supply pipe 4 can be suppressed.

  According to this embodiment, it is not necessary to place the hydrogen peroxide storage tank 2 at a high position in order to increase the water head pressure, and space can be saved by applying pressure in the hydrogen peroxide storage tank 2.

  In the present embodiment, both or one of the upward piping 17 of the first embodiment and the suction device 20 of the second embodiment may be provided.

1 is a schematic configuration diagram showing a first embodiment of a high-pressure reactor according to the present invention. The schematic block diagram which shows 2nd Embodiment of the high-pressure reactor which concerns on this invention. The schematic block diagram which shows 3rd Embodiment of the high-pressure reactor which concerns on this invention.

Explanation of symbols

2 Hydrogen peroxide storage tank 4 Hydrogen peroxide supply pipe 7 Hydrogen peroxide supply pump 11 Reaction vessel 14 Pressure reducing valve

Claims (4)

A hydrogen peroxide storage tank for storing hydrogen peroxide, a hydrogen peroxide supply pump connected to the hydrogen peroxide storage tank via a hydrogen peroxide supply pipe, and a peroxide on the discharge side of the hydrogen peroxide supply pump In a high-pressure reactor equipped with a reaction vessel connected through a hydrogen discharge pipe and a pressure reducing valve connected to the downstream side of the reaction vessel, oxygen generated from the hydrogen peroxide is supplied to the hydrogen peroxide supply pipe. An oxygen gas separation means for separating gas from the hydrogen peroxide is provided. The high-pressure reactor according to claim 1, wherein the oxygen gas separation means is an upward pipe for oxygen gas inflow communicating with the hydrogen peroxide supply pipe or an oxygen gas suction device. The high-pressure reactor according to claim 1, wherein the hydrogen peroxide supply pipe is provided with a cooling means for cooling hydrogen peroxide flowing through the pipe. The high-pressure reactor according to claim 1, wherein the hydrogen peroxide storage tank is an open tank, a closed tank, or a closed tank having an in-tank pressurization mechanism.

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