Organic matter removal apparatus and organic matter removal method

Abstract

To provide a removal device and a removal method for removing an organic matter including a water-soluble substance from groundwater.SOLUTION: There is provided an organic matter removal device 100 that removes an organic matter from groundwater, the device including: an activated carbon packed tower 2 filled with an adsorbent 2a that adsorbs an organic matter in groundwater; and a regeneration device that desorbs the organic matter adsorbed on the adsorbent 2a with liquefied gas. A method for removing an organic matter from groundwater includes: a step in which the groundwater is made to pass through the activated carbon packed tower 2 filled with the adsorbent 2a that adsorbs the organic matter, and a regeneration step in which the organic matter adsorbed on the adsorbent 2a is desorbed with liquefied gas.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an organic matter removal device and an organic matter removal method.

Background Art

[0002] Patent Document 1 includes an adsorption step of adsorbing iodine ions in oil field brine onto an anion exchange resin, and an elution step of eluting iodine ions from the resin to obtain iodine. The pretreatment step removes solid oil components, adjusts the pH, and adds an oxidizing agent. The adsorption step introduces brine while fluidizing the resin and adsorbs polyiodine ions onto the resin. The elution step elutes polyiodine ions from the resin to obtain iodine, and a method for producing iodine from brine is described.

[0003] Patent Document 2 describes an apparatus for removing and regenerating an adsorbate from a used adsorbent used in water treatment. By holding a gaseous substance under saturated vapor pressure at normal temperature and pressure, a liquefied substance in a liquid state is used. The adsorbate is desorbed and eluted into the liquefied substance by bringing the adsorbent into contact with the liquefied substance in a treatment tank. The liquefied substance in contact with the adsorbent is vaporized in an evaporator to separate the adsorbate. The vaporized substance is compressed by a compressor, and the compressed substance is liquefied by a condenser.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] One example of groundwater is brine. Brine is water that is sometimes generated during oil extraction or natural gas production, and it is known to contain a large amount of oil as well as iodine. Of this, brine containing a high concentration of iodine is used as a raw material for iodine production.

[0006] Because brine containing oil and iodine has traditionally been buried underground without being utilized as a resource, there are few industrially established technologies for producing iodine from oil-containing brine.

[0007] Here, as a technique for removing oil from groundwater, the technique described in Patent Document 1 above is known. Patent Document 1 discloses a configuration for removing oil by static separation.

[0008] However, while Patent Document 1 discloses a configuration for producing iodine with high efficiency by separating water from solid and liquid oils based on density differences, it does not describe or suggest the separation of organic substances such as water-soluble oils, revealing that there is room for improvement.

[0009] Herein lies the technology described in Patent Document 2. While Patent Document 2 uses an adsorbent to remove organic matter, it does not disclose a configuration for handling groundwater such as iodine-containing brine.

[0010] In response to this, the present inventors conducted diligent research and found that by removing organic matter from groundwater containing organic matter, it becomes possible to effectively utilize the groundwater, reduce waste, or mitigate the environmental burden during waste disposal. Furthermore, by applying this to, for example, iodine-containing brine, it becomes possible to obtain iodine water that does not contain organic matter that contributes to iodine production, or has a low concentration of organic matter, thereby improving the efficiency of iodine production.

[0011] Therefore, the present invention is based on the above findings and aims to provide a removal device and method for removing organic matter, including water-soluble substances, from groundwater. [Means for solving the problem]

[0012] The present invention includes several means for solving the above problems, but one example is: Contains iodine An organic matter removal device for removing organic matter from groundwater, comprising an adsorbent-filled tower filled with an adsorbent that adsorbs the organic matter in the groundwater, A mixer is provided in front of the adsorbent-packed tower and mixes the groundwater and the reducing agent, The system includes a regeneration device that desorbs the organic matter adsorbed on the adsorbent using a liquefied gas. [Effects of the Invention]

[0013] According to the present invention, organic matter, including water-soluble substances, can be removed from groundwater. Other problems, configurations, and effects will be clarified by the following description of embodiments. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram showing the configuration of an organic matter removal device according to the first embodiment. [Figure 2] This is a schematic diagram showing the configuration of an organic matter removal device according to the second embodiment. [Modes for carrying out the invention]

[0015] Embodiments of the organic matter removal apparatus and organic matter removal method of the present invention will be described below with reference to the drawings. In the drawings used herein, the same or corresponding components are denoted by the same or similar reference numerals, and repeated descriptions of these components may be omitted.

[0016] In the following embodiments, the case where the groundwater contains iodine, also known as brine, will be described as an example. However, the groundwater targeted by the organic matter removal device and organic matter removal method of the present invention is not limited to brine, and is not particularly limited.

[0017] <First Embodiment> A first embodiment of the organic matter removal apparatus and the organic matter removal method of the present invention will be described with reference to FIG. 1.

[0018] First, the overall configuration of the organic matter removal apparatus will be described with reference to FIG. 1. FIG. 1 is a schematic diagram showing the configuration of the organic matter removal apparatus of the present embodiment.

[0019] The organic matter removal apparatus 100 shown in FIG. 1 is an apparatus for removing organic matter from iodine-containing brine discharged during oil extraction or natural gas production, and includes a pump 1, an activated carbon packed tower 2, an evaporator 8, a condenser 9, valves 11, 12, 13, 14, 15, pipes 20, 21, 22, 23, 24, 25, etc.

[0020] The pump 1 is provided on the pipe 23 connecting the condenser 9 and the activated carbon packed tower 2, and sends the liquefied gas liquefied by the condenser 9 to the activated carbon packed tower 2 in order to desorb the organic matter adsorbed by the adsorbent 2a.

[0021] The activated carbon packed tower 2 is filled with activated carbon as an adsorbent 2a for adsorbing organic matter in iodine-containing groundwater. After adsorbing the organic matter in iodine-containing groundwater, the iodine-containing groundwater from which the organic matter has been removed is sent to iodine production equipment (omitted for illustration purposes) via the pipe 21.

[0022] In this embodiment, there is no particular limitation on the specific form of the iodine production equipment, and various configurations can be adopted.

[0023] The evaporator 8 supplies energy for the latent heat of vaporization for the liquefied gas used during the regeneration of the adsorbent 2a filled in the activated carbon packed tower 2, vaporizes only the liquefied gas with the lowest boiling point, and leaves impurities and water remaining. The vaporized liquefied gas is sent to the condenser 9 via the pipe 25.

[0024] The condenser 9 is a device that cools and liquefies the vaporized liquefied gas.

[0025] Piping 20 connects the brine supply unit (not shown) to the activated carbon packed column 2. Piping 21 connects the activated carbon packed column 2 to the iodine production equipment. Piping 22 connects the activated carbon packed column 2 to the recovery tank (not shown). Piping 23 connects the condenser 9 to the activated carbon packed column 2. Piping 24 connects the activated carbon packed column 2 to the evaporator 8. Piping 25 connects the evaporator 8 to the condenser 9.

[0026] Similar to iodine production equipment, there are no particular limitations on the details of the brine supply section and recovery tank, and various configurations can be adopted.

[0027] Next, the organic matter removal method according to this embodiment will be described with reference to Figure 1.

[0028] First, we will explain the process of passing groundwater through an activated carbon-filled tower 2, which is filled with an adsorbent 2a that adsorbs organic matter.

[0029] In this process, which is a mode for adsorbing organic matter from groundwater, valve 11 located on the piping 23 connecting the condenser 9 and the activated carbon packed tower 2, valve 12 located on the piping 24 connecting the activated carbon packed tower 2 and the evaporator 8, and valve 15 located on the piping 22 connecting the activated carbon packed tower 2 and the recovery tank are closed. At the same time, valve 13 located on the piping 20 connecting the brine supply unit and the activated carbon packed tower 2, and valve 14 located on the piping 21 connecting the activated carbon packed tower 2 and the iodine production equipment are operated in an open state.

[0030] When iodine-containing groundwater is brought into contact with activated carbon, which is used as an adsorbent 2a packed in the activated carbon-packed tower 2, organic matter such as oil is adsorbed onto the activated carbon, and groundwater containing iodine but free of organic matter is obtained from the outlet of the activated carbon-packed tower 2.

[0031] When groundwater used for iodine production contains organic matter, the production efficiency decreases, and under certain conditions, it may become unsuitable as raw water for production. In contrast, by using groundwater from which organic matter has been removed by the organic matter removal device 100 of this embodiment as raw water for the iodine production facility, the amount of raw water available for production can be increased compared to conventional methods, thereby improving the efficiency of iodine production.

[0032] Here, if the system is simply operated by passing iodine-containing groundwater through the activated carbon-packed tower 2, the adsorbent 2a will reach its adsorption saturation for organic matter, making it difficult or impossible to remove organic matter from the iodine-containing groundwater being passed through, and it is anticipated that organic matter will leak into the iodine production facility.

[0033] Therefore, the inventors conceived of a method to improve iodine productivity by temporarily stopping the flow of groundwater before organic matter leaks out and switching to the activated carbon regeneration mode, thereby stably removing organic matter.

[0034] During the transition, water is removed from the activated carbon packed column 2, but water and organic matter remain attached to the activated carbon. Therefore, a regeneration process is performed to desorb the organic matter adsorbed on the adsorbent 2a using liquefied gas, at a time when a predetermined amount of water has been passed through.

[0035] During the regeneration process of the adsorbent 2a, valve 11 located on pipe 23 and valve 12 located on pipe 24 are opened. Conversely, valve 13 located on pipe 20, valve 14 located on pipe 21, and valve 15 located on pipe 22 are kept closed during operation.

[0036] The liquefied gas used to regenerate the adsorbent 2a can be dimethyl ether, which is a gas at room temperature and pressure, but is not limited to this. Dimethyl ether is maintained at its saturated vapor pressure within the flow path of the regeneration mode, and some of it exists in a liquefied state. Temperature and pressure are also indicated in the diagram. The pressure is assumed to be constant, but this is an ideal state; pressure drops occur due to various pipes and equipment, and the closed loop is restored by pump 1.

[0037] First, liquefied dimethyl ether is withdrawn from the bottom of the condenser 9 and pumped by pump 1 through valve 11 to the activated carbon packed column 2. In the activated carbon packed column 2, the activated carbon is immersed in the supplied liquefied dimethyl ether. At this time, organic matter adsorbed on the activated carbon is desorbed due to its high affinity for liquefied dimethyl ether and dissolves into the liquefied dimethyl ether along with water.

[0038] Next, the liquefied dimethyl ether containing water and organic matter is sent to the evaporator 8 through valve 12.

[0039] In the evaporator 8, the latent heat energy required for the liquefied dimethyl ether to vaporize is supplied, causing the liquefied dimethyl ether, which has the lowest boiling point, to vaporize, while the organic matter and water remain.

[0040] The vaporized dimethyl ether is sent to the condenser 9, where the latent heat energy is removed, causing the dimethyl ether to liquefy. The liquefied dimethyl ether obtained here is then sent again to the activated carbon packed column 2, where it is used again to desorb organic matter from the activated carbon.

[0041] By repeating the above dimethyl ether phase change cycle multiple times as needed, most of the organic matter attached to the adsorbent 2a is removed.

[0042] Once the removal and installation are complete, valve 12 is closed, and the liquefied dimethyl ether is extracted from the activated carbon packed column 2 by reversing the rotation of pump 1 or by a separately prepared extraction pump (not shown). Then, valve 11 is closed, and valve 15 is opened to release the activated carbon packed column 2 into the atmosphere or reduce the pressure with a vacuum pump. This causes the liquefied dimethyl ether attached to the adsorbent 2a to vaporize, restoring the adsorption capacity of the activated carbon in the activated carbon packed column 2, and making it nearly new regenerated activated carbon.

[0043] Furthermore, if operation continues, organic matter and water will accumulate at the bottom of the evaporator 8. As the amount of accumulation increases, it will affect the evaporation of liquefied dimethyl ether, so it is desirable to install a drain valve (not shown) at the bottom of the evaporator 8 as needed to discharge the contents from there.

[0044] Furthermore, in this embodiment, the organic matter to be removed from the groundwater can be either water-soluble or water-insoluble. In either form, it can be separated from the groundwater by adsorption onto activated carbon and desorbed with liquefied dimethyl ether.

[0045] In this embodiment, pump 1 is used for circulating dimethyl ether, but this function can be replaced by a compressor. However, since a compressor is a machine that circulates gas, when used in this embodiment, it should be installed downstream of evaporator 8 and upstream of condenser 9.

[0046] Furthermore, while activated carbon is given as an example of the adsorbent 2a for removing organic matter in this invention, it is possible to use modified activated carbon or other types of adsorbents other than activated carbon, rather than pure activated carbon.

[0047] Next, the effects of this embodiment will be described.

[0048] The organic matter removal apparatus 100 of the first embodiment of the present invention described above is an apparatus for removing organic matter from groundwater containing iodine, and comprises an activated carbon packed tower 2 filled with an adsorbent 2a that adsorbs organic matter in the groundwater, and a regeneration apparatus that desorbs the organic matter adsorbed on the adsorbent 2a with liquefied gas. As a result, organic matter can be removed from groundwater containing iodine with high efficiency, making it possible to use groundwater that was previously unsuitable for iodine production as a raw material, or to reduce manufacturing costs even with conventional production equipment by removing organic matter such as oil.

[0049] Therefore, such organic matter removal devices make it possible to effectively utilize groundwater containing organic matter, thereby reducing the amount of waste itself and mitigating the environmental burden during disposal.

[0050] <Second Embodiment> A second embodiment of the present invention, consisting of an organic matter removal apparatus and an organic matter removal method, will be described with reference to Figure 2. Figure 2 is a schematic diagram showing the configuration of the organic matter removal apparatus of this embodiment.

[0051] The organic matter removal device 100A of this embodiment, shown in Figure 2, differs from the organic matter removal device 100 shown in Figure 1 in that it further includes a reducing agent mixer 18 in front of the activated carbon packed tower 2, which mixes a reducing agent that reduces iodine from a solid to an ion with groundwater.

[0052] The reducing agent mixer 18 is located upstream of a valve 13, which is installed on a pipe 20 connecting the brine supply section (omitted for illustrative purposes) and the activated carbon packed tower 2.

[0053] Iodine contained in groundwater exists in two chemical forms: a solid that is poorly soluble in water and an ionic form that is dissolved in water.

[0054] If solid iodine containing undissolved iodine is present, passing the water through the activated carbon-packed tower 2 will result in the iodine being adsorbed onto the activated carbon. In this case, there is a concern that the iodine concentration in the groundwater discharged from the activated carbon-packed tower 2 will decrease. Therefore, it is desirable to eliminate this solid iodine before it passes through the activated carbon-packed tower 2 to reduce the amount adsorbed onto the adsorbent 2a, thereby suppressing the decrease in iodine content and improving the value of the water as raw water for iodine production.

[0055] For this purpose, in this embodiment, the groundwater and reducing agent are mixed in the reducing agent mixer 18 before the groundwater is applied to the activated carbon.

[0056] In this case, the reducing agent ionizes solid iodine in the groundwater and dissolves it in the groundwater. Since the ionized and dissolved iodine ions are not easily adsorbed by activated carbon, most of the iodine that flows into the activated carbon packed column 2 is directly guided to the iodine production facility.

[0057] From a cost perspective, the reducing agent used in the reducing agent mixer 18 is preferably one or a combination of sulfur compounds, sulfites, or bisulfites. More specifically, using one or a combination of sulfur dioxide, sodium sulfite, ammonium sulfite, sodium bisulfite, or potassium bisulfite can achieve ionization of iodine in groundwater.

[0058] The other configurations and operations are substantially the same as those of the organic matter removal device 100 and organic matter removal method of the first embodiment described above, and details are omitted.

[0059] In the second embodiment of the present invention, the organic matter removal device 100A and organic matter removal method also provide substantially the same effects as the organic matter removal device 100 and organic matter removal method of the first embodiment described above.

[0060] Furthermore, by providing a reducing agent mixer 18 located upstream of the activated carbon packed tower 2, which mixes groundwater with a reducing agent, it is possible to handle cases where the groundwater contains solids that should not be removed. For example, in the case of brine, it is possible to improve the productivity of iodine extraction when solid iodine is present.

[0061] <Other> It should be noted that the present invention is not limited to the embodiments described above, and various modifications are included. The embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. [Explanation of symbols]

[0062] 1…Pump 2… Activated carbon packed tower (adsorbent packed tower) 2a…Adsorbent 8... Evaporator 9... Condenser 11, 12, 13, 14, 15… valve 18…Reducing agent mixer 20, 21, 22, 23, 24, 25… Piping 100,100A…Organic matter removal equipment

Claims

1. An organic matter removal device for removing organic matter from groundwater containing iodine, An adsorbent-filled tower is filled with an adsorbent that adsorbs the organic matter in the groundwater, A mixer is provided in front of the adsorbent-packed tower and mixes the groundwater and the reducing agent, The regeneration device comprises a device for desorbing the organic matter adsorbed on the adsorbent using a liquefied gas. Organic matter removal equipment.

2. In the organic matter removal apparatus according to claim 1, The aforementioned groundwater is brine discharged during natural gas production. Organic matter removal equipment.

3. In the organic matter removal apparatus according to claim 1, The groundwater is the iodine-containing brine. Organic matter removal equipment.

4. In the organic matter removal apparatus according to claim 1, The adsorbent is activated carbon. Organic matter removal equipment.

5. In the organic matter removal apparatus according to claim 1, The reducing agent is one or a combination of sulfur compounds, sulfites, and bisulfites. Organic matter removal equipment.

6. In the organic matter removal apparatus according to claim 5, The reducing agent is one or a combination of sulfur dioxide, sodium sulfite, ammonium sulfite, sodium bisulfite, and potassium bisulfite. Organic matter removal equipment.

7. In the organic matter removal apparatus according to claim 1, The liquefied gas is dimethyl ether. Organic matter removal equipment.

8. A method for removing organic matter from groundwater containing iodine, The process of mixing the groundwater and the reducing agent, A step of passing the groundwater through an adsorbent-filled tower, which is filled with an adsorbent that adsorbs the aforementioned organic matter, The process includes a regeneration step of desorbing the organic matter adsorbed on the adsorbent using a liquefied gas. Organic matter removal method.

Images