Turbine oil regeneration method

Abstract

To provide a reproducing method that can reproduce a used turbine oil.SOLUTION: A reproducing method for a used turbine oil comprises: a contacting step of contacting the used turbine oil with an adsorbent; and an addition step of adding additives to the used turbine oil after the contacting step, wherein the contacting step includes passing the used turbine oil through a column filled with at least a part of the adsorbent.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for regenerating turbine oil used as lubricating oil in steam turbines and gas turbines.

Background Art

[0002] Patent Document 1 describes a method for regenerating used insulating oil. Specifically, an adsorbent having one or more of plaster, diatomaceous earth, bentonite, and marine silt is brought into contact with the used insulating oil to adsorb the deteriorated components in the insulating oil onto the adsorbent, and then the adsorbent is removed from the insulating oil and an antioxidant is added to the insulating oil, whereby regenerated insulating oil is obtained.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] According to the method of Patent Document 1, it is possible to regenerate insulating oil, but it is not known whether it is possible to regenerate turbine oil used as lubricating oil in steam turbines and gas turbines.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a regeneration method capable of regenerating used turbine oil.

Means for Solving the Problems

[0006] To achieve the above objective, the turbine oil regeneration method according to the present disclosure is a method for regenerating used turbine oil, comprising a contact step of bringing the used turbine oil into contact with an adsorbent, and an addition step of adding an additive to the used turbine oil after the contact step, wherein the contact step includes passing the used turbine oil through a column packed with at least a portion of the adsorbent. fruit , The contact step includes bringing a portion of the adsorbent into contact with the used turbine oil while stirring, before the used turbine oil is passed through the column, wherein the mass of the adsorbent used when bringing the adsorbent into contact with the used turbine oil while stirring is 1.5% to 2% of the mass of the used turbine oil, and the mass of the adsorbent packed into the column is 7% to 13% of the mass of the used turbine oil. . [Effects of the Invention]

[0007] According to the turbine oil regeneration method of this disclosure, by passing used turbine oil through a column packed with an adsorbent, degraded components contained in the used turbine oil are adsorbed by the adsorbent, thereby removing the degraded components from the used turbine oil. Along with the adsorption of degraded components to the adsorbent, additives contained in the used turbine oil are also adsorbed by the adsorbent and thus removed. However, by adding additives to the used turbine oil from which the degraded components have been removed, the used turbine oil can be regenerated. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the configuration of an apparatus for implementing the turbine oil regeneration method according to Embodiment 1 of this disclosure. [Figure 2] This is a schematic diagram of the configuration of an apparatus for implementing the turbine oil regeneration method according to Embodiment 2 of this disclosure. [Figure 3] This is a schematic diagram of the configuration of an apparatus for implementing the turbine oil regeneration method according to Embodiment 3 of this disclosure. [Figure 4] This is a schematic diagram of the configuration of an apparatus for implementing the turbine oil regeneration method according to Embodiment 4 of this disclosure. [Modes for carrying out the invention]

[0009] A method for regenerating turbine oil according to embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below represent one aspect of this disclosure and are not limiting, and can be modified at will within the scope of the technical idea of ​​this disclosure.

[0010] The turbine oil regenerated by the turbine oil regeneration method disclosed herein is used turbine oil that has been used as a lubricant in steam turbines and gas turbines. Used turbine oil deteriorates and comes to contain degradation components such as organic acids such as carboxylic acids, causing it to change color to a brownish-red. Used turbine oil is regenerated by removing the degradation components, and the regenerated turbine oil becomes transparent. This regeneration method can be performed in batches during regular inspections of steam turbines and gas turbines, or it can be used to continuously extract and regenerate used turbine oil while the steam turbine or gas turbine is in operation.

[0011] (Embodiment 1) <Apparatus for implementing the turbine oil regeneration method according to Embodiment 1> As shown in Figure 1, the apparatus 1 for carrying out the turbine oil regeneration method according to Embodiment 1 of the present disclosure comprises a tank 3 that communicates with a turbine oil tank 2 provided in a steam turbine or gas turbine and stores the turbine oil supplied from the turbine oil tank 2 as used turbine oil, a column 5 filled with an adsorbent 4, a line 6 connecting the tank 3 and the column 5, a pump 7 provided in the line 6, a line 8 connecting the column 5 and the turbine oil tank 2, and an additive device 9 for adding an additive to the line 8.

[0012] Although not a mandatory configuration, line 8 may be equipped with a sensor 10 upstream of the point where the additive is supplied from the additive device 9 to detect the regeneration state of the turbine oil, or a mixing device 11 downstream of the point where the additive is supplied from the additive device 9 to mix the turbine oil and the additive. The turbine oil tank 2 may also be equipped with a sensor 12 to detect the deterioration state of the stored turbine oil. Sensors 10 and 12 may be, for example, a sensor for detecting the dielectric constant of the turbine oil or a sensor for detecting the color of the turbine oil. Based on the dielectric constant, color, etc., of the turbine oil, the deterioration state or regeneration state of the turbine oil can be detected. Therefore, the detected values ​​detected by sensors 10 and 12, such as the dielectric constant and color of the turbine oil, serve as indicators of the deterioration state or regeneration state of the turbine oil. The mixing device 11 may be, for example, a guide vane rotatably installed in line 8.

[0013] As adsorbents, silica gel, zeolite, activated alumina, activated clay, kaolin, etc., can be used. Silica gel may be spherical silica gel or silica gel modified with amino groups. The mass of the adsorbent 4 contained in column 5 is preferably 8.5% to 15% of the mass of used turbine oil processed in apparatus 1. If there is too little adsorbent 4, degraded components cannot be sufficiently removed from the used turbine oil, that is, the regeneration effect on the used turbine oil cannot be sufficiently obtained. Conversely, if there is too much adsorbent 4, turbine oil loss occurs due to the adsorption and absorption of turbine oil by the adsorbent 4. Therefore, it is preferable to use the appropriate amount of adsorbent 4 as described above. Additives added by the additive device 9 include, for example, antioxidants, rust inhibitors, defoamers, friction inhibitors, extreme pressure agents, metal deactivators, anti-emulsifiers, etc.

[0014] <Method for regenerating turbine oil according to Embodiment 1> Next, the operation of the device 1, that is, the turbine oil regeneration method according to Embodiment 1 of this disclosure, will be described. During regular maintenance of a steam turbine or gas turbine, all or part of the turbine oil in the turbine oil tank 2 is transferred to tank 3 and stored in tank 3 as used turbine oil. During operation of a steam turbine or gas turbine, part of the turbine oil in the turbine oil tank 2 is transferred to tank 3 and stored in tank 3 as used turbine oil. Whether or not it is necessary to regenerate the turbine oil in the turbine oil tank 2 can be determined based on the detection value of the sensor 12, if the sensor 12 is provided in the turbine oil tank 2.

[0015] When pump 7 is started, turbine oil in tank 3 flows into column 5 via line 6. As the turbine oil passes through column 5, it comes into contact with the adsorbent 4 packed in column 5 (contact step). At this time, degraded components contained in the turbine oil are adsorbed by the adsorbent 4, thereby removing the degraded components from the turbine oil. Along with the degraded components, additives contained in the turbine oil are also adsorbed by the adsorbent 4. While the turbine oil that has flowed out of column 5 is circulating through line 8, additives are added to the turbine oil from the additive device 9 (addition step). This allows the amount of additives that was reduced by adsorption to the adsorbent 4 to be added back into the turbine oil. If a mixing device 11 is provided in line 8, the mixing device 11 promotes the mixing of the additives and the turbine oil. In this way, the used turbine oil is regenerated and returned to the turbine oil tank 2 as reusable turbine oil.

[0016] If a sensor 10 is provided, the sensor 10 detects an indicator of the deterioration state of the turbine oil leaking from column 5. For example, if the detected indicator does not reach a preset threshold, it can be determined that the turbine oil regeneration is insufficient, and therefore it can be determined that there is a shortage of adsorbent 4 or that the adsorbent 4 has deteriorated. In this case, the turbine oil regeneration operation is temporarily suspended, and additional adsorbent 4 is added, or the adsorbent 4 is regenerated or replaced.

[0017] Furthermore, the contact between the turbine oil and the adsorbent 4 in column 5 (contact step) is preferably carried out at a temperature of 25°C to 100°C. To ensure such a temperature range, a heater may be provided in tank 3 to heat the used turbine oil, or line 6, pump 7 and column 5 may be insulated to prevent the turbine oil from being cooled while flowing from tank 3 to column 5.

[0018] Thus, according to the method for regenerating turbine oil according to Embodiment 1 of the present disclosure, by passing the used turbine oil through column 5 filled with adsorbent 4, the degradation components contained in the used turbine oil are adsorbed by adsorbent 4, so that the degradation components can be removed from the used turbine oil. Along with the adsorption of the degradation components onto adsorbent 4, the additives originally contained in the used turbine oil are also adsorbed by adsorbent 4 and thus removed. However, since additives are added to the used turbine oil from which the degradation components have been removed, the used turbine oil can be regenerated.

[0019] (Embodiment 2) Next, a method for regenerating turbine oil according to Embodiment 2 will be described. The method for regenerating turbine oil according to Embodiment 2 enables the addition of adsorbent 4 to column 5, the regeneration or replacement of adsorbent 4 while continuing the regeneration operation of the turbine oil, compared to Embodiment 1. In Embodiment 2, the same components as those in Embodiment 1 are denoted by the same reference numerals, and detailed descriptions thereof are omitted.

[0020] <Apparatus for implementing the method for regenerating turbine oil according to Embodiment 2> As shown in FIG. 2, in apparatus 1 for implementing the method for regenerating turbine oil according to Embodiment II of the present disclosure, column 5 includes two columns 5a and 5b arranged in parallel on line 8, and each of columns 5a and 5b is filled with adsorbent 4a and 4b, respectively. The mass of adsorbent 4a and 4b accommodated in each column is preferably 8.5% to 15% with respect to the mass of the used turbine oil processed by apparatus 1, similar to Embodiment 1.

[0021] A three-way valve can be provided at the branching point 6a of line 6 upstream of columns 5a and 5b, or an on-off valve can be provided between the branching point 6a and each of columns 5a and 5b, so that turbine oil flows to either column 5a or 5b by operating the three-way valve or the on-off valve. Figure 2 shows a configuration in which column 5 has two columns 5a and 5b, but column 5 may have three or more columns, and turbine oil may flow to any one of the three or more columns. The other configurations are the same as in Embodiment 1.

[0022] <Method for regenerating turbine oil according to Embodiment 2> Next, a turbine oil regeneration method according to Embodiment 2 of this disclosure will be described. When the pump 7 is started in the same manner as in Embodiment 1, the turbine oil in the tank 3 flows into one of the columns of column 5, for example, column 5a, via the line 6. As the turbine oil passes through column 5a, degraded components and additives contained in the turbine oil are adsorbed onto the adsorbent 4a. As the amount of degraded components and additives adsorbed onto the adsorbent 4a increases and the adsorbent 4a approaches the breakthrough state, the deterioration of the turbine oil regeneration state can be determined based on the values ​​detected by the sensor 10. If it is determined that the adsorbent 4a has reached the breakthrough point based on the values ​​detected by the sensor 10, the turbine oil supply destination is switched to column 5b. While turbine oil is being supplied to column 5b, the adsorbent 4a in column 5a is replaced with a new adsorbent or a regenerated adsorbent. Next, if it is determined that the adsorbent 4b in column 5b has reached the breakthrough point, the turbine oil supply destination is switched back to column 5a, and the adsorbent 4b in column 5b is replaced. By repeating this operation, the adsorbents 4a and 4b can be replaced and regenerated without stopping the operation of device 1.

[0023] Even if the amount of adsorbents 4a and 4b is insufficient, the amount of adsorbent can be increased without stopping the operation of the apparatus 1 by switching the turbine oil supply to either column 5a or 5b and adding the adsorbent to the other column.

[0024] (Embodiment 3) Next, a turbine oil regeneration method according to Embodiment 3 will be described. The turbine oil regeneration method according to Embodiment 3 is modified from Embodiment 1 or 2 by performing the contact step in two stages. Hereinafter, Embodiment 3 will be described as an embodiment that has been modified from Embodiment 1, but Embodiment 3 may also be configured as an embodiment that has been modified from Embodiment 2. In Embodiment 3, components that are the same as those in Embodiment 1 are given the same reference numerals, and their detailed descriptions will be omitted.

[0025] <Apparatus for implementing the turbine oil regeneration method according to Embodiment 3> As shown in Figure 3, in the apparatus 1 for carrying out the turbine oil regeneration method according to Embodiment 3 of the present disclosure, a stirring tank 21 and a solid-liquid separator 22 are provided between the turbine oil tank 2 and the tank 3. The stirring tank 21 is equipped with a stirrer 24 to bring the turbine oil supplied from the turbine oil tank 2 and the adsorbent 23 into contact while stirring. The solid-liquid separator 22 is a device that separates the mixture of turbine oil and adsorbent 23 supplied from the stirring tank 21 into turbine oil and adsorbent 23. For example, it may be a filtration device, or it may be a tank that allows the mixture to stand to settle the adsorbent 23 and supplies only the turbine oil to the tank 3.

[0026] The total mass of adsorbents 4 and 23 is preferably 8.5% to 15% of the mass of used turbine oil processed by the apparatus 1, the mass of adsorbent 23 is preferably 1.5% to 2% of the mass of used turbine oil processed by the apparatus 1, and the mass of adsorbent 4 is preferably 7% to 13% of the mass of used turbine oil processed by the apparatus 1. The other configurations are the same as in Embodiment 1.

[0027] <Method for regenerating turbine oil according to Embodiment 3> Next, a method for regenerating turbine oil according to Embodiment 3 of this disclosure will be described. During regular inspection or operation of a steam turbine or gas turbine, all or part of the turbine oil in the turbine oil tank 2 is transferred to a stirring tank 21. Adsorbent 23 in the above-mentioned range of mass is put into the stirring tank 21, and the turbine oil and the adsorbent 23 are brought into contact while being stirred by a stirrer 24 (contact step). It is preferable that the contact between the turbine oil and the adsorbent 23 be carried out at a temperature of 25°C to 100°C, similar to the contact between the turbine oil and the adsorbent 4 in the column 5.

[0028] After the turbine oil and adsorbent 23 have been in contact for a sufficient amount of time, the mixture of turbine oil and adsorbent 23 in the stirring tank 21 is transferred to the solid-liquid separator 22 to separate the turbine oil and adsorbent 23. The separated turbine oil is then transferred to the tank 3. The subsequent operations are the same as in Embodiment 1. Therefore, in Embodiment 3, the contact step is performed in two stages: contact between the turbine oil and adsorbent 23 in the stirring tank 21, and contact between the turbine oil and adsorbent 4 in the column 5.

[0029] In Embodiment 3, the agitation tank 21 is not limited to a device installed in the apparatus 1. If the location where the steam turbine or gas turbine is installed is far from the location where the apparatus 1 is installed, it is conceivable that the turbine oil in the turbine oil tank 2 will be transferred to a tank truck and transported to the apparatus 1. In such a case, if an agitator is installed in the storage tank of the tank truck and an adsorbent 23 is put into the storage tank, the turbine oil and the adsorbent 23 can come into contact in the tank truck while the used turbine oil is being transported to the apparatus 1 by the tank truck. In this case, the tank truck corresponds to the agitation tank 21.

[0030] (Embodiment 4) Next, a turbine oil regeneration method according to Embodiment 4 will be described. The turbine oil regeneration method according to Embodiment 4 is a modification of Embodiment 3 in which the turbine oil and silica gel are brought into contact while being agitated. In Embodiment 4, components that are the same as those in Embodiment 3 are given the same reference numerals, and their detailed descriptions are omitted.

[0031] <Apparatus for implementing the turbine oil regeneration method according to Embodiment 4> As shown in Figure 4, in the apparatus 1 for implementing the turbine oil regeneration method according to Embodiment 4 of the present disclosure, a continuous flow device 36 is provided between the turbine oil tank 2 and the tank 3. The continuous flow device 36 comprises a tank 30 communicating with the turbine oil tank 2 and the tank 3 respectively, a column 31 filled with an adsorbent 32, a line 33 connecting the tank 30 and the column 31, a pump 34 provided on the line 33, and a line 35 connecting the column 31 and the tank 30. As will be described later, turbine oil in the tank 30 flows into the column 31 via line 33, and turbine oil that flows out of the column 31 returns to the tank 30 via line 35, so that the turbine oil circulates between the tank 30 and the column 31. For this reason, lines 33 and 35 constitute a circulation path for the turbine oil to circulate between the tank 30 and the column 31.

[0032] The total mass of adsorbents 4 and 32 is preferably 8.5% to 15% of the mass of used turbine oil processed by the apparatus 1, the mass of adsorbent 32 is preferably 1.5% to 2% of the mass of used turbine oil processed by the apparatus 1, and the mass of adsorbent 4 is preferably 7% to 13% of the mass of used turbine oil processed by the apparatus 1. The other configurations are the same as in Embodiment 3.

[0033] <Method for regenerating turbine oil according to Embodiment 4> Next, a turbine oil regeneration method according to Embodiment 4 of the present disclosure will be described. During regular maintenance or operation of a steam turbine or gas turbine, all or part of the turbine oil in the turbine oil tank 2 is transferred to tank 30. When the pump 34 is started, the turbine oil in tank 30 flows into column 31 via line 33. As the turbine oil passes through column 31, it comes into contact with the adsorbent 32 packed in column 31 (contact step). At this time, degraded components contained in the turbine oil are adsorbed by the adsorbent 32, thereby removing the degraded components from the turbine oil. Additives contained in the turbine oil are also adsorbed by the adsorbent 32 along with the degraded components. The turbine oil that flows out of column 31 is returned to tank 30 via line 35.

[0034] By continuing this operation, the turbine oil in tank 30 repeatedly comes into contact with the adsorbent 32 packed in column 31 and is mixed with the turbine oil in tank 30. As a result, the turbine oil in tank 30 repeatedly comes into contact with the adsorbent 32 packed in column 31, so it can be considered that the turbine oil and the adsorbent 32 are in contact while being agitated. It is preferable that the contact between the turbine oil and the adsorbent 32 be carried out at a temperature of 25°C to 100°C, similar to the contact between the turbine oil and the adsorbent 4. However, the contact between the turbine oil and the adsorbent 4 differs from the contact between the turbine oil and the adsorbent 32 in that the turbine oil passes through the adsorbent 4 in column 5 in a single pass; that is, the turbine oil does not repeatedly come into contact with the adsorbent 4, so it cannot be considered that the turbine oil and the adsorbent 4 are in contact while being agitated.

[0035] After the turbine oil and adsorbent 32 have been in contact for a sufficient amount of time, the turbine oil in tank 30 is transferred to tank 3. The subsequent operation is the same as in Embodiment 1. Therefore, in Embodiment 4, as in Embodiment 3, the contact step is performed in two stages: contact between the turbine oil and adsorbent 32 in column 31, and contact between the turbine oil and adsorbent 4 in column 5. [Examples]

[0036] <Preparation of used turbine oil> Turbine oil to be regenerated in the examples and comparative examples described later (corresponding to the used turbine oil of this disclosure), i.e., degraded oil, was prepared by the following procedure. Degraded oil was prepared based on the Dry-TOST test conditions specified in ASTM D 7873. Specifically, oxygen was blown into 400 mL of turbine oil (FBK Turbine 32, ENEOS Corporation) at a flow rate of 1 L / min under conditions of 136 °C in the presence of a catalyst containing iron and copper (outer diameter 1.6 mm, length 3 m). The RPVOT value of the turbine oil was measured periodically from the start of oxygen blowing into the turbine oil using the method specified in ASTM D 2272, and oxygen was continued to blow into the turbine oil until the measured RPVOT value fell to 25% of the RPVOT value of the turbine oil before the start of oxygen blowing. Turbine oil from which oxygen blowing was stopped was designated as degraded oil.

[0037] <Example 1> A 5C filter was placed in a column with an inner diameter of 20 mm and a length of 10 mm, which could be heated by a mantle heater. 15 g of silica gel (Silopute® 71R, Fuji Silicia Chemical Co., Ltd.) was placed on top of the 5C filter. 100 g of degraded oil was poured into the column and vacuum filtration was performed at a suction pressure of 0.08 to 0.095 MPa. Vacuum filtration was performed under conditions where the column temperature was set to 25°C and 100°C. The degraded oil used for vacuum filtration was also heated for 1 hour in a hot air dryer set to the same temperature as the column before being added to the column. It took 3 to 4 hours for the entire amount of degraded oil to flow out of the column. The mass of the recycled oil obtained by this vacuum filtration of degraded oil was measured, and after adding additives (0.72 mass% antioxidant and 0.03 mass% rust inhibitor), the RPVOT value was measured.

[0038] We confirmed that the RPVOT values ​​of the recycled oil obtained by vacuum filtration under conditions of 25°C and 100°C were approximately the same as those of the turbine oil used as the raw material for the degraded oil. When the transparency of the recycled oil and the turbine oil used as the raw material for the degraded oil were visually compared, no difference was observed, indicating that they were almost equivalent in transparency. Furthermore, the recovery rate, which is the ratio of the mass of recycled oil to the mass of 100g of degraded oil used in vacuum filtration, was 80% under the 25°C condition and 81.4% under the 100°C condition.

[0039] <Comparative Example 1> 100 g of degraded oil and 15 g of silica gel were placed in a 200 mL beaker, and the mixture of degraded oil and silica gel was stirred at 100°C using a hot stirrer. After 1 hour, stirring was stopped, and the mixture was filtered through a 5C filter to collect the filtrate. Visual comparison of the clarity of the filtrate with the clarity of the turbine oil, the raw material for the degraded oil, confirmed that the former had not recovered to the same level as the latter.

[0040] <Comparison of Example 1 and Comparative Example 1> In Example 1, the degraded oil was successfully regenerated, whereas in Comparative Example 1, the regeneration of the degraded oil was insufficient. Specifically, when the degraded oil is passed through silica gel packed in a column in a single pass, it is possible to regenerate the degraded oil, whereas when the mixture of degraded oil and silica gel is stirred, the regeneration of the degraded oil is insufficient. From this, it can be said that the turbine oil regeneration method according to Embodiment 1 of this disclosure can regenerate used turbine oil.

[0041] <Example 2> 100 g of degraded oil and silica gel (mass as described below) were placed in a 200 mL beaker, and the mixture of degraded oil and silica gel was stirred using a hot stirrer. After 1 hour, stirring was stopped, and the mixture was filtered through a 5C filter to collect the filtrate. Next, this filtrate was poured into a column packed with silica gel used in Example 1 (mass of silica gel as described below), and vacuum filtration was performed at a suction pressure of 0.08 to 0.095 MPa. The mass of the recycled oil obtained by vacuum filtration was measured, and the recovery rate was calculated. The above experiment was performed under various conditions, with the mass of silica gel placed in the beaker, the mass of silica gel packed in the column, and the temperature varied as shown in Table 1 below.

[0042] [Table 1]

[0043] The recovery rate was calculated from the mass of recycled oil measured in each of Experiments 1-11, and the presence or absence of a regeneration effect was determined by visually observing the transparency of the recycled oil. The recovery rates and regeneration effects (◎ for high regeneration effect, ○ for regeneration effect, × for no regeneration effect) for Experiments 1-11 are summarized in Table 2 below.

[0044] [Table 2]

[0045] From experiments 1-3, 6-9, and 11, it can be said that used turbine oil can be regenerated even by performing the contact step in two stages. Furthermore, based on the degree of regeneration effect and recovery rate, the conditions in experiments 1, 2, 6-9, and 11 can be judged to be preferable. From this, it can be said that the mass of silica gel used when contacting silica gel with degraded oil while stirring is preferably 1.5% to 2% of the mass of degraded oil, and the mass of silica gel packed in the column is preferably 7% to 13% of the mass of degraded oil.

[0046] The contents described in each of the above embodiments can be understood, for example, as follows:

[0047] [1] A method for regenerating turbine oil according to one embodiment is: A method for recycling used turbine oil, A contact step of bringing the used turbine oil into contact with the adsorbent (4, 23, 32), An additive step is to add an additive to the used turbine oil after the contact step. Includes, The contact step includes passing the used turbine oil through a column (5) filled with at least a portion (4) of the adsorbent.

[0048] According to the turbine oil regeneration method of this disclosure, by passing used turbine oil through a column packed with an adsorbent, degraded components contained in the used turbine oil are adsorbed by the adsorbent, thereby removing the degraded components from the used turbine oil. Along with the adsorption of degraded components to the adsorbent, additives contained in the used turbine oil are also adsorbed by the adsorbent and thus removed. However, by adding additives to the used turbine oil from which the degraded components have been removed, the used turbine oil can be regenerated.

[0049] [2] A turbine oil regeneration method according to another embodiment is the turbine oil regeneration method of [1], The adsorbent (4,23,32) is silica gel. The mass of the silica gel used in the contact step is 8.5% to 15% of the mass of the used turbine oil.

[0050] If the amount of adsorbent is too small, it may not be possible to completely remove degraded components from used turbine oil. Conversely, if the amount of adsorbent is too large, turbine oil loss will occur due to the adsorption and absorption of turbine oil by the adsorbent. In contrast, this configuration allows for the regeneration of used turbine oil while suppressing turbine oil loss.

[0051] [3] A further embodiment of the turbine oil regeneration method is the turbine oil regeneration method of [1] or [2], The aforementioned contact step is performed at a temperature of 25°C to 100°C.

[0052] With this configuration, used turbine oil can be recycled.

[0053] [4] A further embodiment of the turbine oil regeneration method is any of the turbine oil regeneration methods described in [1] to [3], The contact step includes bringing a portion of the adsorbent (23, 32) into contact with the used turbine oil while stirring, before the used turbine oil is passed through the column (5).

[0054] With this configuration, used turbine oil can be recycled.

[0055] [5] A further embodiment of the turbine oil regeneration method is the turbine oil regeneration method of [4], When the adsorbents (23, 32) are brought into contact with the used turbine oil while stirring, the mass of the adsorbents (23, 32) is 1.5% to 2% of the mass of the used turbine oil, and the mass of the adsorbent (4) packed into the column (5) is 7% to 13% of the mass of the used turbine oil.

[0056] With this configuration, turbine oil can be regenerated while suppressing losses.

[0057] [6] A further embodiment of the turbine oil regeneration method is the turbine oil regeneration method of [4] or [5], The process of bringing the adsorbent (23, 32) into contact with the used turbine oil while stirring is carried out in a stirring tank (21) containing the adsorbent (23, 32) and the used turbine oil.

[0058] With this configuration, used turbine oil can be recycled.

[0059] [7] A further embodiment of the turbine oil regeneration method is the turbine oil regeneration method of [4] or [5], The process of bringing the adsorbent (32) into contact with the used turbine oil while stirring is carried out in a continuous flow device (36). The continuous flow device (36) is A tank (30) for storing the used turbine oil, A column (31) packed with the adsorbent (32), A circulation path (33, 35) for the used turbine oil to circulate between the tank (30) and the column (31), A pump (34) provided in the aforementioned circulation path (33) and Equipped with, The used turbine oil in the tank (30) continuously passes through the column (31).

[0060] With this configuration, used turbine oil can be recycled. [Explanation of symbols]

[0061] 4 Adsorbent 5 columns 23 Adsorbent 30 tanks 31 columns 32 Adsorbents 33 lines (circulation routes) 35 lines (circulation routes) 36 Continuous flow device

Claims

1. A method for recycling used turbine oil, A contact step of bringing the used turbine oil and the adsorbent into contact, An additive step is to add an additive to the used turbine oil after the contact step. Includes, The contact step includes passing the used turbine oil through a column filled with at least a portion of the adsorbent, The contact step includes bringing a portion of the adsorbent into contact with the used turbine oil while stirring, before the used turbine oil is passed through the column. A method for regenerating turbine oil, wherein the mass of the adsorbent used when bringing the adsorbent into contact with the used turbine oil while stirring is 1.5% to 2% of the mass of the used turbine oil, and the mass of the adsorbent packed into the column is 7% to 13% of the mass of the used turbine oil.

2. The adsorbent is silica gel. The turbine oil regeneration method according to claim 1, wherein the mass of the silica gel used in the contact step is 8.5% to 15% of the mass of the used turbine oil.

3. The method for regenerating turbine oil according to claim 1 or 2, wherein the contact step is performed at a temperature of 25°C to 100°C.

4. The process of bringing the adsorbent and the used turbine oil into contact while stirring is carried out using a continuous flow device. The aforementioned continuous flow apparatus, A tank for storing the used turbine oil, A column packed with the adsorbent, A circulation path for the used turbine oil to circulate between the tank and the column, A pump provided in the aforementioned circulation path and Equipped with, The turbine oil regeneration method according to claim 1 or 2, wherein the used turbine oil in the tank continuously passes through the column.

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