Process for preparing a desulfurizer, desulfurizer, and oil vapor desulfurization system using the same

Abstract

The application provides a desulfurizer preparation method, a desulfurizer and an oil vapor desulfurization system using the same, and belongs to the technical field of oil vapor treatment. A chelating agent and a metal salt are mixed into water to contact and react, to obtain a desulfurizer; wherein the chelating agent is one of diethylenetriamine pentaacetic acid and ethylenediamine tetramethylene phosphonic acid; and / or the metal salt is one or more of a metal nitrate and a metal nitrate hydrate, and the metal element in the metal salt includes Fe. Thus, the desulfurizer has good thermal stability and is not easy to decompose under high-temperature conditions, i.e. 50-100 DEG C, and the temperature resistance is greater than or equal to 150 DEG C, so that the active components in the desulfurizer, i.e. diethylenetriamine pentaacetic acid or ethylenediamine tetramethylene phosphonic acid and Fe 3+ stably exist. Thus, the desulfurizer can be used to react with oil vapor obtained by in-situ dry distillation technology underground, Fe 3+ oxidizes hydrogen sulfide in the oil vapor, and the effect of oil vapor desulfurization is achieved, so that the oil vapor does not need to be cooled, the desulfurization time is saved, and the desulfurization efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of oil vapor treatment technology, and more particularly to a method for preparing a desulfurizing agent, the desulfurizing agent, and an oil vapor desulfurization system using the same. Background Technology

[0002] Underground in-situ dry distillation technology is used to obtain high-temperature shale oil vapor, which contains abundant natural gas, alkanes, olefins and a small amount of water. It is of great significance for meeting energy demand and alleviating dependence on traditional petroleum resources.

[0003] In related technologies, high-temperature shale oil steam is typically first cooled and separated to collect the oil, gas, and water phases, and then each phase undergoes desulfurization and purification treatment. Specifically, after the incoming feed is cooled, it passes through a feed gas separator, an air cooler, and a three-phase separator to separate the gas, oil, and water phases. The gas phase passes through a stripping tower, a booster compressor, a gas phase separator, and a gas phase desulfurization unit to obtain purified gas, and sulfur products are obtained for external transportation. The oil phase is desulfurized by adding a desulfurizing agent to obtain light oil.

[0004] However, the above desulfurization methods are time-consuming and have low desulfurization efficiency. Summary of the Invention

[0005] This application provides a method for preparing a desulfurizing agent, the desulfurizing agent, and an oil vapor desulfurization system using the same, in order to address the shortcomings of related technologies.

[0006] In a first aspect, this application provides a method for preparing a desulfurizing agent, comprising:

[0007] A desulfurizing agent is obtained by mixing a chelating agent and a metal salt in water and reacting them.

[0008] The chelating agent is one of diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid; and / or

[0009] Metal salts are one or more of the nitrates of metals and nitrate hydrates of metals, and the metal element in metal salts includes Fe.

[0010] In one possible implementation, the desulfurizing agent preparation method provided in this application has a metal salt, calculated as metal element, a chelating agent to metal salt mass ratio of 8-20:1; and / or a chelating agent to water volume ratio of 0.1-1.5 g:10 mL.

[0011] Secondly, this application provides a desulfurizing agent, which is prepared by any of the desulfurizing agent preparation methods in the first aspect.

[0012] Thirdly, this application provides an oil vapor desulfurization system, including a reaction device, a separation device, and a desulfurizing agent treatment device; the reaction device is filled with the desulfurizing agent described in the second aspect, and the reaction device is used to supply oil vapor and the desulfurizing agent to carry out a chemical reaction, so that the desulfurizing agent removes hydrogen sulfide from the oil vapor to obtain a mixed liquid, wherein the temperature of the chemical reaction is 50 ℃-100 ℃, and the mixed liquid is a purified oil vapor stream and a desulfurizing agent solution containing sulfur and mercaptans; the separation device is connected to the reaction device and is used to separate the gas phase and oil phase in the mixed liquid to obtain an aqueous phase; the desulfurizing agent treatment device has a first inlet and a first outlet, the first inlet is connected to the separation device, and the first outlet is connected to the reaction device, the desulfurizing agent treatment device is used to supply the desulfurizing agent in the aqueous phase for regeneration reaction, so that the desulfurizing agent after regeneration reaction flows into the reaction device through the first outlet, and to separate the sulfides in the aqueous phase.

[0013] In one possible implementation, the oil vapor desulfurization system provided in this application includes a separation device comprising a gas-liquid separator, a flash oil outlet tank, and an oil storage tank; the gas-liquid separator has a second inlet, a second gas outlet, and a second oil outlet, the second inlet being connected to a reaction device, and the second gas outlet being connected to a purified gas pipeline; the flash oil outlet tank has a third inlet, a third gas outlet, a third oil outlet, and a third water outlet, the third inlet being connected to the second oil outlet via a first regulating valve, the third gas outlet being connected to a flare device, and the third water outlet being connected to the first inlet via a second regulating valve; the oil storage tank is connected to the third oil outlet via a filter.

[0014] In one possible implementation, the oil vapor desulfurization system provided in this application includes a first inlet comprising a first sub-inlet and a second sub-inlet, a first outlet comprising a first sub-outlet and two second sub-outlets, and a desulfurizing agent treatment device comprising a regeneration tank, a settling tank, and a filter. Both the first sub-inlet and the first sub-outlet are located on the regeneration tank, and the first sub-inlet is connected to a third outlet via a second regulating valve. Both the second sub-inlet and the two second sub-outlets are located on the settling tank, and the second sub-inlet is connected to the first sub-outlet. One of the two second sub-outlets is connected to a reaction device via a circulating pump. The filter is connected between the other of the two second sub-outlets and the circulating pump.

[0015] In one possible implementation, the oil vapor desulfurization system provided in this application further includes a tail gas treatment device, which includes a heat exchanger, a cooling scrubbing tower, and a deodorization tower; the heat exchanger has a fourth inlet, a fifth outlet, a sixth inlet, and a fourth outlet, and both the regeneration tank and the settling tank are connected to the fourth inlet; the cooling scrubbing tower has a seventh inlet and a sixth outlet, the seventh inlet being connected to the fifth outlet; the sixth outlet being connected to the sixth inlet; and the deodorization tower has an eighth inlet, which is connected to the fourth outlet.

[0016] In one possible implementation, the oil vapor desulfurization system provided in this application further includes a temperature regulation component, which comprises a control element, a detection element, a first cooler, and a cooling pump. The regeneration tank, the cooling pump, and the first cooler are connected in sequence, and the first cooler is connected to the regeneration tank to form a loop. The detection element and the cooling pump are both electrically connected to the control element. The detection element is used to detect whether the temperature of the regeneration tank is greater than a preset value. The control element is configured to control the cooling pump to turn on when the detection element detects that the temperature of the regeneration tank is greater than the preset value, so as to connect the loop, and to control the cooling pump to turn off when the detection element detects that the temperature of the regeneration tank is less than or equal to the preset value, so as to disconnect the loop.

[0017] In one possible implementation, the oil vapor desulfurization system provided in this application includes a cooling scrubbing tower comprising a scrubbing tower body, a spray pump, and a second cooler connected in sequence; a seventh inlet and a sixth outlet are provided on the scrubbing tower body.

[0018] In one possible implementation, the oil vapor desulfurization system provided in this application has a reaction device that is one of a spray tower, a bubble tower, a packed tower, a static mixer, and a Venturi reactor.

[0019] This application provides a method for preparing a desulfurizing agent, the desulfurizing agent itself, and an oil vapor desulfurization system using the same. The method for preparing the desulfurizing agent includes: mixing a chelating agent and a metal salt in water for contact reaction to obtain the desulfurizing agent; wherein the chelating agent is one of diethylenetriaminepentaacetic acid (DICA) and ethylenediaminetetramethylenephosphonic acid (EDTA); and / or the metal salt is one or more of a metal nitrate and a metal nitrate salt hydrate, wherein the metal element in the metal salt includes Fe. Therefore, the desulfurizing agent formed by the metal chelate has good thermal stability and is not easily decomposed under high temperature conditions, i.e., 50 ℃-100 ℃, with a temperature resistance greater than or equal to 150 ℃. This ensures that the active components inside the desulfurizing agent, namely DICA or EDTA and Fe, are effectively neutralized. 3+ It exists stably. Therefore, the desulfurizing agent can react with the oil vapor obtained from underground in-situ dry distillation technology, utilizing Fe... 3+ The hydrogen sulfide in the oxidized oil vapor achieves the effect of desulfurization of the oil vapor, thus eliminating the need to wait for the oil vapor to cool down, saving desulfurization time and improving desulfurization efficiency. Attached Figure Description

[0020] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0021] Figure 1 The change in mass of diethylenetriaminepentaacetic acid sample with temperature in the thermal stability test provided in the embodiments of this application;

[0022] Figure 2The change in the mass of ethylenediaminetetramethylenephosphonic acid sample with temperature in the thermal stability test provided in the embodiments of this application;

[0023] Figure 3 The change in mass of a desulfurizing agent sample containing diethylenetriaminepentaacetic acid as a function of temperature in the thermal stability test provided in the embodiments of this application;

[0024] Figure 4 The change in mass of the desulfurizing agent sample as a function of temperature in the thermal stability test provided in the embodiments of this application;

[0025] Figure 5 A schematic diagram of the structure of the oil vapor desulfurization system provided in the embodiments of this application. Figure 1 ;

[0026] Figure 6 Electrical connection diagram of the control components, detection components, and cooling pump in the oil vapor desulfurization system provided in the embodiments of this application;

[0027] Figure 7 A schematic diagram of the structure of the oil vapor desulfurization system provided in the embodiments of this application. Figure 2 .

[0028] Explanation of reference numerals in the attached figures:

[0029] 100 - Reaction apparatus;

[0030] 200 - Separation device; 210 - Gas-liquid separator; 211 - Second inlet; 212 - Second gas outlet; 213 - Second oil outlet; 220 - Flash oil tank; 221 - Third inlet; 222 - Third gas outlet; 223 - Third oil outlet; 224 - Third water outlet; 230 - Oil storage tank; 240 - Filter; 250 - Flare device; 260 - First regulating valve; 270 - Second regulating valve; 280 - Purified gas pipeline;

[0031] 300 - Desulfurizing agent treatment device; 301 - First inlet; 302 - First outlet; 310 - Regeneration tank; 311 - First sub-inlet; 312 - First sub-outlet; 313 - Fan; 314 - Gas distributor; 320 - Settling tank; 321 - Second sub-inlet; 322 - Second sub-outlet; 330 - Circulation pump; 340 - Filter; 350 - Temperature control component; 351 - Control unit; 352 - Detection unit; 353 - First cooler; 354 ​​- Cooling pump; 360 - Sulfide storage tank;

[0032] 400 - Exhaust gas treatment device; 410 - Heat exchanger; 411 - Fourth inlet; 412 - Fifth outlet; 413 - Sixth inlet; 414 - Fourth outlet; 420 - Cooling scrubbing tower; 421 - Scrubbing tower body; 4211 - Seventh inlet; 4212 - Sixth outlet; 422 - Spray pump; 423 - Second cooler; 430 - Deodorizing tower; 431 - Eighth inlet. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0034] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, an indirect connection through an intermediate medium, or the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0035] In the description of this application, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0036] The terms "first," "second," "third," "fourth," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented, for example, in a sequence other than those illustrated or described herein.

[0037] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion, such that a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0038] Underground in-situ dry distillation technology is used to obtain high-temperature shale oil vapor, which contains abundant natural gas, alkanes, olefins and a small amount of water. It is of great significance for meeting energy demand and alleviating dependence on traditional petroleum resources.

[0039] In related technologies, high-temperature shale oil steam is typically first cooled and separated to collect the oil, gas, and water phases, and then each phase undergoes desulfurization and purification treatment. Specifically, after the incoming feed is cooled, it passes through a feed gas separator, an air cooler, and a three-phase separator to separate the gas, oil, and water phases. The gas phase passes through a stripping tower, a booster compressor, a gas phase separator, and a gas phase desulfurization unit to obtain purified gas, and sulfur products are obtained for external transportation. The oil phase is desulfurized by adding a desulfurizing agent to obtain light oil.

[0040] However, the above desulfurization method requires waiting for the oil vapor to cool down before desulfurization and three-phase separation can be carried out, resulting in a long time consumption and low desulfurization efficiency.

[0041] In view of this, embodiments of this application provide a method for preparing a desulfurizing agent, a desulfurizing agent, and an oil vapor desulfurization system using the same. The method for preparing the desulfurizing agent includes: mixing a chelating agent and a metal salt in water for contact reaction to obtain the desulfurizing agent; wherein the chelating agent is one of diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid; and / or the metal salt is one or more of a metal nitrate and a metal nitrate salt hydrate, and the metal element in the metal salt includes Fe. Therefore, the desulfurizing agent formed by the metal chelate has good thermal stability and is not easily decomposed under high temperature conditions, i.e., 50 ℃-100 ℃, with a temperature resistance greater than or equal to 150 ℃. This ensures that the active components inside the desulfurizing agent, i.e., diethylenetriaminepentaacetic acid or ethylenediaminetetramethylenephosphonic acid and Fe... 3+ It exists stably. Therefore, the desulfurizing agent can react with the oil vapor obtained from underground in-situ dry distillation technology, utilizing Fe... 3+ The hydrogen sulfide in the oxidized oil vapor achieves the effect of desulfurization of the oil vapor, thus eliminating the need to wait for the oil vapor to cool down, saving desulfurization time and improving desulfurization efficiency.

[0042] The present application will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0043] This application provides a method for preparing a desulfurizing agent, comprising:

[0044] A desulfurizing agent is obtained by mixing a chelating agent and a metal salt in water and reacting them.

[0045] The chelating agent is one of diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid; and / or the metal salt is one or more of a metal nitrate or nitrate salt hydrate, and the metal element includes Fe.

[0046] The desulfurizing agent prepared in this application embodiment can be applied to the desulfurization of high-temperature shale oil vapor. Here, high temperature refers to the temperature at which the oil vapor exits the well using underground in-situ dry distillation technology, i.e., 300 ℃. Of course, it can also be used for the desulfurization of liquefied petroleum gas, etc., and this application embodiment does not limit this application.

[0047] The desulfurizing agent has a temperature resistance of ≥150℃, and its operating temperature is 50-100℃ when it reacts with shale oil vapor.

[0048] Specifically, the metal chelate liquid generated by the reaction of chelating agent and metal salt in water is used as a liquid-phase desulfurizing agent. When it reacts with oil vapor, the water in the oil vapor can act as a partial solvent for the desulfurizing agent and mix evenly with it. On the one hand, the two exchange heat to maintain the overall reaction temperature at 50-100 ℃, so that the desulfurizing agent can desulfurize the oil vapor. On the other hand, it ensures that the desulfurizing agent reacts fully with the oil vapor to achieve a more thorough desulfurization.

[0049] In this embodiment, one of diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid is used as a chelating agent. The chelating agent itself has high temperature stability. After the chelating agent and metal salt are reacted to obtain the desulfurizing agent, the desulfurizing agent can be prevented from decomposing during the desulfurization process when it reacts with oil vapor.

[0050] For example, thermogravimetric analysis was performed on diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid, respectively. Figure 1 and Figure 2 As shown in the curve, the mass of diethylenetriaminepentaacetic acid (DTA) changes with temperature. A slight weight loss occurs between 30-100 °C, indicating the presence of a small amount of water in the chelating agent. A 60% weight loss occurs between 250-400 °C, suggesting that DTA begins to decompose at 250 °C.

[0051] In the mass change curve of ethylenediaminetetramethylenephosphonic acid with temperature, a slight weight loss process also occurred between 30-100 °C, indicating the evaporation of a small amount of water in the chelating agent. More significant weight loss occurred between 300-550 °C, indicating that ethylenediaminetetramethylenephosphonic acid decomposed.

[0052] Example 1: 1.5 g of diethylenetriaminepentaacetic acid (DTA) was dissolved in 60 mL of water at 60 °C. 0.615 g of ferric nitrate nonahydrate, 0.035 g of 50 wt% manganese nitrate solution, and 0.051 g of cobalt nitrate hexahydrate were added to the solution. The reaction was carried out at 30 °C and 500 rpm for 12 h with stirring. The resulting product was then evaporated and concentrated to 20 mL in an oil bath at 80 °C to obtain 22.184 g of a DTA metal chelate solution, which was used as a desulfurizing agent.

[0053] Example 2: 1.5 g of ethylenediaminetetramethylenephosphonic acid (EDTA) was dissolved in 60 mL of water at 60 °C. The pH was adjusted to 8 using a 10 wt% NaOH aqueous solution. 0.561 g of ferric nitrate nonahydrate, 0.042 g of 50 wt% manganese nitrate solution, and 0.047 g of cobalt nitrate hexahydrate were added. The reaction was carried out at 30 °C and 500 rpm for 12 h with stirring. The resulting product was then evaporated and concentrated to 20 mL in an 80 °C oil bath to obtain 22.129 g of EDTA metal chelate solution, which was used as a desulfurizing agent.

[0054] Comparative Example 1: The method of Example 1 was followed, except that the pH value was adjusted to 8 using a 10wt% NaOH aqueous solution before adding ferric nitrate nonahydrate, manganese nitrate solution and cobalt nitrate hexahydrate.

[0055] In Examples 1 and 2, the desulfurizing agents were acidic, with a pH less than 7 (e.g., pH 5.5, 6, or 6.5); in Comparative Example 1, the desulfurizing agent was alkaline, with a pH greater than 7 (e.g., pH 8, 8.5, or 9). The desulfurizing agent prepared in Example 1 was used as the first sample, and the desulfurizing agent prepared in Comparative Example 2 was used as the second sample. The mass change curve of the first sample with temperature is shown below. Figure 3 As shown, the mass change curve of the second sample with temperature is as follows: Figure 4 As shown in the table below, the results of thermogravimetric analysis of the two are as follows.

[0056]

[0057] It is understandable that weight loss and thermal stability are inversely proportional; that is, the greater the weight loss within a temperature range, the worse the thermal stability of the desulfurizer within that temperature range. As can be seen from the table, at 100 ℃, the weight loss of the first sample is less than that of the second sample, indicating that the first sample has better thermal stability. Here, 100 ℃ is the operating temperature of the aforementioned catalyst and oil vapor reaction.

[0058] Furthermore, such as Figure 3As shown, the first sample, namely the diethylenetriaminepentaacetic acid metal chelate, exhibited significant weight loss between 30 and 100 °C. This is because the desulfurizer contains a large amount of water, which evaporates during the heating process. The weight loss rate slows down after 100 °C, indicating that the desulfurizer still contains a small amount of water of crystallization. This suggests that the active components within the desulfurizer, such as diethylenetriaminepentaacetic acid and Fe, are still present. 3+ It exists stably and will not be consumed in the actual oil and gas desulfurization process.

[0059] Thus, when the first sample is applied to oil vapor desulfurization, the active components within it, namely diethylenetriaminepentaacetic acid and Fe, can be ensured. 3+ It exists stably. Utilizing Fe 3+ The hydrogen sulfide in the oxidized oil vapor achieves the effect of desulfurization of the oil vapor, thus eliminating the need to wait for the oil vapor to cool down, saving desulfurization time and improving desulfurization efficiency.

[0060] In some embodiments, the mass ratio of the chelating agent to the metal salt, calculated as a metal element, is 8-20:1; and / or the volume ratio of the chelating agent to water is 0.1-1.5 g:10 mL.

[0061] Specifically, metal chelates are the main active ingredient in desulfurizers. If the concentration is too low, desulfurization may be incomplete; if the concentration is too high, it may lead to resource waste and increase treatment costs.

[0062] In this embodiment, the mass ratio of chelating agent to metal salt is set to 8-20:1; and / or the ratio of chelating agent to water is 0.1-1.5 g:10 mL. Within this range, the concentration of the metal chelate formed by the contact reaction of the chelating agent and metal salt in water can ensure sufficient reaction with hydrogen sulfide in shale oil vapor, thereby effectively removing sulfur compounds therein.

[0063] For example, the mass ratio of chelating agent to metal salt can be 10:1, 12:1, 14:1, 16:1, or 18:1; the volume ratio of chelating agent to water solvent can be 0.3 g:10 mL, 0.5 g:10 mL, 0.7 g:10 mL, 0.9 g:10 mL, 1.1 g:10 mL, or 1.3 g:10 mL.

[0064] In practice, the metal elements in the prepared desulfurizing agent may also include Mn and / or Co.

[0065] The content of Mn can be selected within a wide range. For example, in the metal chelate, the mass ratio of Mn to Fe is 10-20:1, based on elemental composition. For example, it can be 12:1, 14:1, 16:1, or 18:1.

[0066] The Co content can be selected within a wide range. For example, in the metal chelate, the mass ratio of Co to Fe, based on elemental composition, is 5-10:1. Examples include 6:1, 7:1, 8:1, and 9:1.

[0067] This application provides a desulfurizing agent, which is prepared using the desulfurizing agent preparation method of any of the foregoing embodiments.

[0068] It is understandable that desulfurizing agents consist of metal chelates and water-based solvents. The metal chelates are typically either diethylenetriaminepentaacetic acid (DITA) or ethylenediaminetetramethylenephosphonic acid (EDTA). Due to the good thermal stability of metal chelates, they are not easily decomposed at high temperatures (50°C-100°C) and have a temperature resistance greater than or equal to 150°C. This ensures that the active components within the desulfurizing agent, namely DITA or EDTA and Fe, are effectively utilized. 3+ It exists stably. Therefore, the desulfurizing agent can be reacted with oil vapor obtained through underground in-situ dry distillation technology, utilizing Fe... 3+ The hydrogen sulfide in the oxidized oil vapor achieves the effect of desulfurization of the oil vapor, thus eliminating the need to wait for the oil vapor to cool down, saving desulfurization time and improving desulfurization efficiency.

[0069] See Figure 5 This application also provides an oil vapor desulfurization system, including a reaction device 100, a separation device 200, and a desulfurizing agent treatment device 300. The reaction device 100 is filled with the desulfurizing agent described in the previous embodiment. The reaction device 100 is used to supply oil vapor and the desulfurizing agent for a chemical reaction, so that the desulfurizing agent removes hydrogen sulfide from the oil vapor to obtain a mixture. The temperature of the chemical reaction is 50℃-100℃. The mixture is a purified oil vapor stream and a desulfurizing agent solution containing sulfur and mercaptan. The separation device 200 is connected to the reaction device 100 and is used to separate the gas phase and oil phase in the mixture to obtain the water phase. The desulfurizing agent treatment device 300 has a first inlet 301 and a first outlet 302. The first inlet 301 is connected to the separation device 200 and the first outlet 302 is connected to the reaction device 100. The desulfurizing agent treatment device 300 is used to supply the desulfurizing agent in the water phase for regeneration reaction, so that the desulfurizing agent after regeneration reaction flows into the reaction device 100 through the first outlet 302, and to separate the sulfides in the water phase.

[0070] Thus, the oil vapor desulfurization system provided in this application embodiment, by setting up a reaction device 100, a separation device 200 and a desulfurizing agent treatment device 300, can desulfurize oil vapor and separate the three phases of oil, gas and water after desulfurization, simplifying the process flow, making the process smooth and compact, and achieving high processing efficiency.

[0071] Specifically, the reaction device 100 is used to provide a reaction environment for oil vapor and desulfurizing agent, ensuring that the two can fully contact and react chemically to remove hydrogen sulfide from the oil vapor.

[0072] The separation unit 200 is used to separate the gas phase from the mixture delivered from the reaction unit 100, namely the purified oil vapor, oil phase, and water phase. It is understood that the water phase includes the desulfurizing agent to be regenerated, as well as dissolved or suspended sulfides.

[0073] The desulfurizing agent treatment device 300 is used for the regeneration of desulfurizing agent, that is, to extract and restore the active components of desulfurizing agent from the separated aqueous phase so that it can be reused.

[0074] For example, the desulfurizing agent comprises a diethylenetriaminepentaacetic acid metal chelate and an aqueous solvent, and the desulfurizing agent is reacted with oil vapor, wherein the hydrogen sulfide content in the oil vapor is 9.43%wt, and the hydrogen sulfide removal rate after the reaction is complete is greater than or equal to 99%.

[0075] The specific type of the reaction device 100 is not limited in the embodiments of this application. For example, the reaction device 100 is one of a spray tower, a bubble tower, a packed tower, a static mixer, and a Venturi reactor.

[0076] Among them, the spray tower increases the gas-liquid contact area and promotes chemical reaction by spraying desulfurizing agent solution into the rising oil vapor flow; the bubble tower increases the contact area between the two by using the bubbles formed when the oil vapor passes through the desulfurizing agent, so as to promote the full reaction between the desulfurizing agent and the hydrogen sulfide in the oil vapor; the packed tower fills the tower with packing of a specific shape to increase the contact area between the oil vapor and the desulfurizing agent phases and enhance the mass transfer efficiency.

[0077] The static mixer, through its internal structural design, enables the oil vapor and desulfurizing agent to be fully mixed without moving parts, achieving a rapid and uniform reaction; the Venturi reactor utilizes the Venturi effect to accelerate the mixing process between the oil vapor and the desulfurizing agent, thereby increasing the reaction rate.

[0078] In some embodiments, the separation device 200 includes a gas-liquid separator 210, a flash oil tank 220, and an oil storage tank 230; the gas-liquid separator 210 has a second inlet 211, a second gas outlet 212, and a second oil outlet 213, the second inlet 211 being connected to the reaction device 100, and the second gas outlet 212 being connected to the purified gas pipeline 280; the flash oil tank 220 has a third inlet 221, a third gas outlet 222, a third oil outlet 223, and a third water outlet 224, the third inlet 221 being connected to the second oil outlet 213 via a first regulating valve 260, the third gas outlet 222 being connected to the flare device 250, and the third water outlet 224 being connected to the first inlet 301 via a second regulating valve 270; the oil storage tank 230 is connected to the third oil outlet 223 via a filter 240.

[0079] Thus, by setting up the gas-liquid separator 210 and the flash oil tank 220, a multi-stage separation mechanism is formed to ensure the effective separation of substances in different phases and improve the system's efficiency in processing oil vapor.

[0080] Specifically, the gas-liquid separator 210 is used to perform preliminary separation of the mixture from the reaction device 100. The second inlet 211 is connected to the reaction device 100 to receive the mixture; the second outlet 212 directs the separated purified oil vapor, i.e., the gas phase, to the purified gas pipeline 280 for collection and use; and the third oil outlet 223 directs the separated liquid phase to the flash evaporation oil tank 220.

[0081] The flash oil outlet tank 220 is used to further process the liquid phase from the gas-liquid separator 210 to separate the oil phase, water phase, and a small amount of incompletely condensed gas. Specifically, the third inlet 221 is connected to the second oil outlet 213 of the gas-liquid separator 210 via the first regulating valve 260 to receive the initially separated liquid phase; the third gas outlet 222 is used to discharge the incompletely condensed gas to the flare device 250 for combustion treatment to ensure safety; the third oil outlet 223 is connected to the oil storage tank 230 via the filter 240 to store the separated oil phase after filtration; and the third water outlet 224 is connected to the first inlet 301 of the desulfurizing agent treatment device 300 via the second regulating valve 270 to send the water phase containing desulfurizing agent into the desulfurizing agent regeneration process.

[0082] Understandably, incompletely condensed gases may contain small amounts of light hydrocarbons or other volatile organic compounds.

[0083] Specifically, the liquid level in the flash oil tank 220 is controlled by setting a first regulating valve 260 and a second regulating valve 270. For example, at a pressure of 0.2-0.5 MPa, the flash oil tank 220 has a filling degree of 50-70%. This helps to ensure that the gas and liquid phases have sufficient residence time and contact area in the flash oil tank 220, thereby ensuring that the oil phase and water phase can be fully separated. In addition, maintaining a suitable liquid level can avoid overflow problems caused by excessive liquid level and dry operation of the equipment caused by excessive liquid level.

[0084] For example, when the filling degree in the flash oil tank 220 is less than 50%, the residence time of the liquid in the tank is shortened, reducing the chance of dissolved gas escaping from the liquid phase. As the flow rate of the liquid in the tank increases, there is not enough time for the oil droplets and water droplets to settle and separate, which can easily lead to the oil-water mixture not being fully separated.

[0085] When the filling degree of the flash oil tank 220 is higher than 70%, the higher filling degree will reduce the space available for the gas phase in the tank, limit the effective accumulation and emission of gas, and cause overflow problems.

[0086] In a specific example, the first inlet 301 includes a first sub-inlet 311 and a second sub-inlet 321, the first outlet 302 includes a first sub-outlet 312 and two second sub-outlets 322, and the desulfurizing agent treatment device 300 includes a regeneration tank 310, a settling tank 320 and a filter 340; the first sub-inlet 311 and the first sub-outlet 312 are both located on the regeneration tank 310, and the first sub-inlet 311 is used to connect to the third outlet 224 through the second regulating valve 270; the second sub-inlet 321 and the two second sub-outlets 322 are both located on the settling tank 320, and the second sub-inlet 321 and the first sub-outlet 312 are connected; one of the two second sub-outlets 322 is used to connect to the reaction device 100 through the circulation pump 330; the filter 340 is connected between the other of the two second sub-outlets 322 and the circulation pump 330.

[0087] In the regeneration tank 310, air is introduced to oxidize the desulfurizing agent in the aqueous phase, thereby restoring the activity of the desulfurizing agent. At the same time, the thiols dissolved in the aqueous phase are oxidized into insoluble sulfides.

[0088] The aqueous phase in the regeneration tank 310 enters the settling tank 320 for static settling, forming three layers: the upper layer is a sulfur ether organic phase, the middle layer is a clear aqueous phase containing desulfurization catalyst, and the lower layer is a sulfur slurry containing a large amount of sulfur particles. The sulfur slurry is extracted from the other of the two secondary outlets 322 of the settling tank 320 and enters the filter 340. The filter residue is sulfur paste, and the filtrate is an aqueous phase containing desulfurizing agent, which can be returned to the reaction device 100 for use by the circulation pump 330. The clear aqueous phase in the middle layer is transported to the reaction device 100 by the circulation pump 330 from one of the two secondary outlets 322 of the settling tank 320 to complete the circulation of the desulfurizing agent. The sulfur ether separated from the upper layer in the settling tank 320 can be stored in the sulfur ether storage tank 360.

[0089] In this way, valuable byproducts such as sulfides and sulfur paste can be recovered through the desulfurizing agent treatment device 300, and the desulfurizing agent can be recycled, which helps to reduce operating costs.

[0090] For example, a gas distributor 314 is provided inside the regeneration tank 310, and the gas distributor 314 is connected to a blower 313; specifically, an air duct is connected to the output end of the blower 313, and one end of the air duct extends into the regeneration tank 310 and connects to the gas distributor 314. In this way, air is introduced into the regeneration tank 310 through the blower 313.

[0091] The specific type of filter 340 is not limited in the embodiments of this application. For example, the filter 340 can be a continuous filter 340, or an intermittent plate and frame filter press or centrifuge.

[0092] Furthermore, a regulating valve can be installed between the circulating pump 330 and the reaction device 100, or a frequency converter can be installed on the circulating pump 330 to regulate the desulfurization dosage entering the reaction device 100.

[0093] See Figure 5 and Figure 6 In some examples, the desulfurizing agent treatment device 300 further includes a temperature regulation assembly 350, which includes a control element 351, a detection element 352, a first cooler 353, and a cooling pump 354. The regeneration tank 310, the cooling pump 354, and the first cooler 353 are connected in sequence, and the first cooler 353 is connected to the regeneration tank 310 to form a loop. The detection element 352 and the cooling pump 354 are both electrically connected to the control element 351. The detection element 352 is used to detect whether the temperature of the regeneration tank 310 is greater than a preset value. The control element 351 is configured to control the cooling pump 354 to turn on to connect the loop when the detection element 352 detects that the temperature of the regeneration tank 310 is greater than the preset value, and to control the cooling pump 354 to turn off to disconnect the loop when the detection element 352 detects that the temperature of the regeneration tank 310 is less than or equal to the preset value.

[0094] Thus, since the oxidation reaction that occurs when oxygen is introduced into the regeneration tank 310 will generate high temperatures, the temperature inside the regeneration tank 310, i.e. the temperature of the regeneration reaction, is controlled to be less than or equal to a preset value by setting the temperature regulating component 350. For example, the preset value can be 100 °C, thereby controlling the amount of water heated and evaporated, while maintaining the regeneration tank 310 at normal pressure.

[0095] In practice, the first cooler 353 can be an air cooler or a shell-and-tube heat exchanger 410. In this way, when the aqueous phase containing the desulfurizing agent circulates in the loop through the cooling pump 354, the aqueous phase contacts the air cooler or the shell-and-tube heat exchanger 410 for heat exchange, so that the heat of the aqueous phase is removed by the air or cooling water.

[0096] Furthermore, the detection element 352 can be a temperature sensor, and the control element 351 can be a programmable logic controller.

[0097] For example, a regulating valve may be provided between the cooling pump 354 and the first cooler 353, or a frequency converter may be installed on the cooling pump 354 to regulate the amount of water phase that needs to be cooled.

[0098] See Figure 7 In some embodiments, the oil vapor desulfurization system further includes a tail gas treatment device 400, which includes a heat exchanger 410, a cooling scrubbing tower 420, and a deodorizing tower 430. The heat exchanger 410 has a fourth inlet 411, a fifth outlet 412, a sixth inlet 413, and a fourth outlet 414. The regeneration tank 310 and the settling tank 320 are both connected to the fourth inlet 411. The cooling scrubbing tower 420 has a seventh inlet 4211 and a sixth outlet 4212. The seventh inlet 4211 is connected to the fifth outlet 412, and the sixth outlet 4212 is connected to the sixth inlet 413. The deodorizing tower 430 has an eighth inlet 431, which is connected to the fourth outlet 414.

[0099] Thus, by setting up the exhaust gas treatment device 400, the environmental performance of the oil vapor desulfurization system is improved, ensuring that the emitted gas does not pollute the environment.

[0100] The heat exchanger 410 is used to receive the regeneration tail gas generated during the regeneration reaction in the regeneration tank 310 and the tail gas generated during the settling process in the settling tank 320 through the fourth inlet 411, and to cool the tail gas by heat exchange. In the cooling scrubbing tower 420, water is used as a scrubbing coolant to remove some malodorous substances such as mercaptans and sulfides from the tail gas. At the same time, because water has a good specific heat capacity, it can significantly reduce the temperature of the regeneration tail gas. The deodorization tower 430 usually adopts technologies such as chemical absorption and activated carbon adsorption, which can effectively remove odorous substances and other volatile organic compounds from the waste gas, ensuring that the emitted gas is odorless.

[0101] For example, in a specific implementation, the deodorization tower 430 is an activated carbon adsorber.

[0102] Specifically, the cooling scrubbing tower 420 includes a scrubbing tower body 421, a spray pump 422, and a second cooler 423 connected in sequence; a seventh inlet 4211 and a sixth outlet 4212 are provided on the scrubbing tower body 421.

[0103] The washing coolant in the washing tower body 421 is water; the washing tower body 421 can be a spray tower, a packed tower or a plate tower.

[0104] In the scrubbing tower body 421, water, as an absorbent, can partially remove malodorous substances such as mercaptans and sulfides from the exhaust gas. At the same time, due to the good specific heat capacity of water, it can significantly reduce the temperature of the regenerated exhaust gas. The regenerated exhaust gas contains a large amount of water vapor, which is cooled and removed by the spray pump 422 into the second cooler 423. The resulting condensate can continue to be discharged to the downstream sewage collection equipment.

[0105] The exhaust gas from the scrubbing tower body 421 first enters the heat exchanger 410 through the exhaust port, namely the sixth outlet 4212, and exchanges heat with the regenerated exhaust gas that subsequently enters the heat exchanger 410. Then it enters the activated carbon adsorber to further adsorb and remove odorous components such as mercaptans and sulfides from the exhaust gas before being discharged, ensuring that the gas emissions meet environmental protection requirements.

[0106] Since the gas discharged from the exhaust port of the scrubbing tower body 421 is water-saturated gas, water condensation will occur when it comes into contact with the cold activated carbon in the activated carbon adsorber, thus affecting the adsorption and purification effect of the activated carbon adsorber. After the exhaust gas of the scrubbing tower body 421 is preheated by the heat exchanger 410, the dew point during the activated carbon adsorption process can be reduced.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A method for preparing a desulfurizing agent, characterized in that, include: A desulfurizing agent is obtained by mixing a chelating agent and a metal salt in water and reacting them. The chelating agent is one of diethylenetriaminepentaacetic acid and ethylenediaminetetramethylenephosphonic acid; and / or The metal salt is one or more of a metal nitrate and a metal nitrate salt compound, and the metal element in the metal salt includes Fe.

2. The method for preparing the desulfurizing agent according to claim 1, characterized in that, The metal salt is calculated based on the metal element, and the mass ratio of the chelating agent to the metal salt is 8-20:1; and / or The ratio of the chelating agent to water is 0.1-1.5 g:10 mL.

3. A desulfurizing agent, characterized in that, The desulfurizing agent is prepared by the method for preparing the desulfurizing agent according to claim 1 or 2.

4. An oil vapor desulfurization system, characterized in that, include: A reaction apparatus (100) is filled with the desulfurizing agent as described in claim 3. The reaction apparatus (100) is used to supply oil vapor and the desulfurizing agent to carry out a chemical reaction, so that the desulfurizing agent removes hydrogen sulfide from the oil vapor to obtain a mixture. The temperature of the chemical reaction is 50 ℃-100 ℃, and the mixture is a purified oil vapor stream and a desulfurizing agent solution containing sulfur and mercaptan. A separation device (200) is connected to the reaction device (100) and is used to separate the gas phase and oil phase in the mixture to obtain an aqueous phase; The desulfurizing agent treatment device (300) has a first inlet (301) and a first outlet (302). The first inlet (301) is connected to the separation device (200), and the first outlet (302) is connected to the reaction device (100). The desulfurizing agent treatment device (300) is used to regenerate the desulfurizing agent in the aqueous phase, so that the desulfurizing agent after regeneration flows into the reaction device (100) through the first outlet (302), and to separate the sulfides in the aqueous phase.

5. The oil vapor desulfurization system according to claim 4, characterized in that, The separation device (200) includes: The gas-liquid separator (210) has a second inlet (211), a second gas outlet (212), and a second oil outlet (213). The second inlet (211) is connected to the reaction device (100), and the second gas outlet (212) is used to connect to the purified gas pipeline (280). The flash oil tank (220) has a third inlet (221), a third gas outlet (222), a third oil outlet (223), and a third water outlet (224). The third inlet (221) is used to connect to the second oil outlet (213) through a first regulating valve (260). The third gas outlet (222) is used to connect to the flare device (250). The third water outlet (224) is used to connect to the first inlet (301) through a second regulating valve (270). An oil storage tank (230) is used to connect to the third oil outlet (223) via a filter (240).

6. The oil vapor desulfurization system according to claim 5, characterized in that, The first inlet (301) includes a first sub-inlet (311) and a second sub-inlet (321), the first outlet (302) includes a first sub-outlet (312) and two second sub-outlets (322), and the desulfurizing agent treatment device (300) includes: The regeneration tank (310) has a first sub-inlet (311) and a first sub-outlet (312) both located on it. The first sub-inlet (311) is used to connect to the third outlet (224) via the second regulating valve (270). A settling tank (320), a second sub-inlet (321) and two second sub-outlets (322) are all provided on the settling tank (320). The second sub-inlet (321) and the first sub-outlet (312) are connected. One of the two second sub-outlets (322) is used to connect to the reaction device (100) via a circulation pump (330). The filter (340) is connected between the other of the two second sub-outlets (322) and the circulation pump (330).

7. The oil vapor desulfurization system according to claim 6, characterized in that, It also includes an exhaust gas treatment device (400), which includes: The heat exchanger (410) has a fourth inlet (411), a fifth outlet (412), a sixth inlet (413) and a fourth outlet (414), and the regeneration tank (310) and the settling tank (320) are both connected to the fourth inlet (411); The cooling scrubbing tower (420) has a seventh inlet (4211) and a sixth outlet (4212), wherein the seventh inlet (4211) is connected to the fifth outlet (412); and the sixth outlet (4212) is connected to the sixth inlet (413). The deodorization tower (430) has an eighth inlet (431) which is connected to the fourth outlet (414).

8. The oil vapor desulfurization system according to claim 6, characterized in that, The desulfurizing agent treatment device (300) also includes a temperature regulation component (350), which includes a control component (351), a detection component (352), a first cooler (353), and a cooling pump (354). The regeneration tank (310), the cooling pump (354) and the first cooler (353) are connected in sequence, and the first cooler (353) is connected to the regeneration tank (310) to form a loop; The detection element (352) and the cooling pump (354) are both electrically connected to the control element (351). The detection element (352) is used to detect whether the temperature of the regeneration tank (310) is greater than a preset value. The control element (351) is configured to control the cooling pump (354) to turn on to connect the circuit when the detection element (352) detects that the temperature of the regeneration tank (310) is greater than the preset value, and to control the cooling pump (354) to turn off to disconnect the circuit when the detection element (352) detects that the temperature of the regeneration tank (310) is less than or equal to the preset value.

9. The oil vapor desulfurization system according to claim 7, characterized in that, The cooling scrubbing tower (420) includes a scrubbing tower body (421), a spray pump (422), and a second cooler (423) connected in sequence. The seventh inlet (4211) and the sixth outlet (4212) are located on the washing tower body (421).

10. The oil vapor desulfurization system according to any one of claims 4 to 9, characterized in that, The reaction apparatus (100) is one of a spray tower, a bubble tower, a packed tower, a static mixer, and a Venturi reactor.

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