A wet process gas production process

Abstract

The application discloses a kind of wet process gas preparation processes, comprising the following steps: step one, saturated steam preparation;Step two, dry process gas selection and transportation;Step three, gas mixing;Step four, temperature rise prevents condensation;Step five, parameter monitoring and adjustment;The application is controlled by saturated steam flow to control the moisture content of wet process gas, high accuracy, flexible adjustment, and wide adjustable range;The composition of dry process gas, operating pressure, flow can be adjusted at any time;Saturated steam tank volume is moderate;The temperature of wet process gas can be flexibly adjusted according to the need;Saturated steam tank sets high-low interlock control electric heater, can set electric heater start-stop cycle according to the need, without continuous heating;Saturated steam tank is set low-low liquid level automatic liquid supplement interlock control, without continuous feeding, the amount of feeding is stable and is not affected by saturated steam production change.

Description

Technical Field

[0001] This invention relates to the field of wet process gas preparation technology in petrochemical, environmental protection and other production processes, specifically a wet process gas preparation process. Background Technology

[0002] In petrochemical, environmental protection, and other production processes, it is often necessary to precisely prepare wet process gases with specific technical requirements, such as reactor feed and catalyst preparation. This is especially true during the development of new processes, such as pilot or pilot-scale tests, where high precision is required for wet process gas parameters like moisture content, temperature, and pressure, allowing for flexible adjustment to find optimal process conditions. Therefore, there are high demands on the flexible preparation of wet process gases. Furthermore, in laboratory environments, the saturated steam required for wet gas preparation must be prepared in-house, further increasing the difficulty of wet process gas preparation.

[0003] Traditional process 1, reference Figure 2 Dry process gas enters a storage tank containing water or other liquids from the bottom, rises to saturation, and exits from the top. Precise temperature control of the storage tank is crucial to maintain the saturated moisture content of the process gas. The storage tank is equipped with an external jacket, and energy can be provided by resistance wires, heating media, or cooling media, depending on the required temperature. A demister is installed inside the storage tank to prevent liquid entrainment. Demineralized water or other liquids must be continuously added to the storage tank to ensure stable internal temperature.

[0004] The problems with this process are: (1) If the controlled temperature range is wide, such as 10℃-80℃, both refrigerant and heat medium in the jacket need to be provided, and the switching is frequent; (2) If the process requires high precision in the moisture content of the gas, the correlation curve between the temperature of the storage tank and the saturated moisture content of the process gas needs to be obtained experimentally, and relevant calculation software or data cannot be provided; (3) When the composition and operating pressure of the dry process gas change, the temperature of the storage tank and the saturated moisture content curve of the process gas need to be re-measured; (4) In order to ensure that the wet process gas reaches saturation, the storage tank needs to be set with a large volume and a reasonable gas velocity needs to be controlled; (5) This method can only prepare saturated wet process gas, and the moisture content cannot be arbitrarily controlled.

[0005] Traditional process 2, reference Figure 3 Dry process gas enters from a suitable space at the bottom of the spray tower. Circulating water or other liquids are drawn from the bottom of the tower by a circulating pump and sent to the top. Tiny droplets or mist are evenly sprayed into the tower through nozzles, contacting the rising gas and undergoing heat and mass transfer. Finally, the humid gas is discharged from the top. A demister is installed inside the tower to prevent mist entrainment. The bottom of the tower is the circulating liquid collection section, which is drawn out by a circulating pump for recirculation.

[0006] The main problem with this process is that the system cannot accurately control the moisture content in the outlet gas. If the temperature of the bottom chamber is controlled, the heat dissipation of the pump and pipeline, the energy loss of the nozzle, and the heat and mass transfer of the gas-liquid contact will all affect the moisture content of the gas. Therefore, this system is usually used for gas purification. Summary of the Invention

[0007] The purpose of this invention is to provide a wet process gas preparation process to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a wet process gas preparation process, comprising the following steps: Step 1: Saturated Steam Preparation: Demineralized water or other liquids meeting process requirements are transported to a saturated steam generator. The saturated steam generator has a built-in electric heater, which provides heat to evaporate the liquid inside the tank to form saturated steam. The saturated steam generator is equipped with a remote liquid level display device and high / low liquid level alarm functions, and is also equipped with an automatic low-low liquid level replenishment interlock control device. The saturated steam generator is also equipped with a pressure display device, and is equipped with a high / low pressure interlock control device linked to the electric heater. Step 2, Dry process gas selection and transportation: Select dry process gas that meets the process requirements, and ensure that the pressure and temperature of the dry process gas meet the subsequent mixing requirements. Transport the dry process gas to the corresponding inlet of the static mixer through the transportation pipeline. Step 3, Gas-gas mixing: The saturated steam generated in Step 1 is discharged from the top of the saturated steam generator and transported to the other inlet of the static mixer; both the dry process gas inlet and the saturated steam inlet of the static mixer are equipped with flow metering devices, and the discharge amount of saturated steam is adjusted by the flow ratio control device. The dry process gas and saturated steam are mixed in the static mixer to form preliminary wet process gas. Step 4, Heating and Anti-condensation: The initial wet process gas is delivered to an electric heater for heating treatment. The electric heater is linked to the temperature detection device at the outlet of the static mixer. Step 5: Parameter monitoring and adjustment: Monitor the liquid level and pressure of the saturated steam generator, the flow rate and temperature at the inlet and outlet of the static mixer, and the temperature and moisture content of the wet process gas at the outlet of the electric heater in real time, and adjust the relevant operating parameters through the interlock control device.

[0009] Furthermore, the working mode of the low-low liquid level automatic replenishment interlock control device in step one is as follows: when the liquid level in the saturated steam generator tank is lower than the set low-low liquid level threshold, the replenishment device is automatically started to replenish demineralized water or other liquids into the tank, and the replenishment stops when the liquid level rises back to the set normal liquid level range.

[0010] Furthermore, the high and low pressure interlock control device in step one operates as follows: when the pressure inside the saturated steam generator tank is higher than the set high pressure threshold, the power supply to the electric heater is automatically cut off; when the pressure inside the tank is lower than the set low pressure threshold, the electric heater is automatically started to maintain the pressure inside the tank within the set range.

[0011] Furthermore, in step three, the flow ratio control device calculates the flow ratio of dry process gas and saturated steam based on the preset target value of moisture content in wet process gas, and achieves precise regulation of saturated steam flow by adjusting the flow control valve on the saturated steam discharge pipeline.

[0012] Furthermore, in step four, the electric heater automatically adjusts its load based on the difference between the actual temperature of the wet process gas at the outlet of the static mixer and the set temperature, so that the temperature of the heated wet process gas is maintained within the set range to avoid condensation.

[0013] Furthermore, during the parameter monitoring and adjustment process in step five, when a parameter is detected to deviate from the set range, the interlock control device issues an alarm signal and automatically initiates corresponding adjustment measures to ensure stable process operation.

[0014] Furthermore, the electric heater includes an electric heater built into the saturated steam generator and an electric heater for heating the wet process gas.

[0015] Furthermore, the moisture content of the wet process gas is adjustable from 0.1% to 5%, the temperature is adjustable from 90°C to 120°C, and the pressure is adjustable from 1 MPa to 2 MPa.

[0016] Compared with the prior art, the beneficial effects of the present invention are: The moisture content of wet process gas is controlled by saturated steam flow rate, which is highly accurate, flexible, and has a wide adjustable range; the composition, operating pressure, and flow rate of dry process gas can be adjusted at any time; the saturated steam generator has a moderate volume; the temperature of wet process gas can be flexibly adjusted as needed; the saturated steam generator is equipped with a high-low pressure interlock control electric heater, and the start-stop cycle of the electric heater can be set as needed, eliminating the need for continuous heating; the saturated steam generator is equipped with a low-low liquid level automatic liquid replenishment interlock control, eliminating the need for continuous feeding, and the feed rate is stable and unaffected by changes in saturated steam output. Attached Figure Description

[0017] Figure 1 This is a process flow diagram of the present invention; Figure 2 This is a flowchart of traditional process 1; Figure 3 This is a flowchart of traditional process 2. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] Please see Figure 1 This invention provides a wet process gas preparation process, comprising the following steps: Step 1: Saturated Steam Preparation: Demineralized water or other liquids meeting process requirements are transported to the saturated steam generator D-111. The saturated steam generator has a built-in electric heater, which provides the heat required to generate saturated steam, causing the liquid in the tank to evaporate and form saturated steam. The saturated steam generator is equipped with a remote liquid level display device and high / low liquid level alarm functions. It also has an automatic low-low liquid level replenishment interlock control device to maintain a stable liquid level in the tank. The saturated steam generator is also equipped with a pressure display device and a high / low pressure interlock control device linked with the electric heater to maintain a stable pressure in the tank.

[0020] Step 2, Dry Process Gas Selection and Delivery: Based on the component requirements of the target wet process gas, select the corresponding dry process gas to ensure that the purity, pressure, and temperature of the dry process gas meet the requirements of the subsequent mixing process. The selected dry process gas is delivered to the corresponding inlet of the static mixer M-111 through a dedicated delivery pipeline. A flow regulating valve is installed on the delivery pipeline to initially control the delivery flow rate of the dry process gas.

[0021] Step 3, Gas-gas Mixing: The saturated steam generated in Step 1 is discharged from the outlet at the top of the saturated steam generator and transported to the other inlet of the static mixer M-111 through a steam delivery pipeline. Both the dry process gas inlet and the saturated steam inlet of the static mixer are equipped with flow metering devices to collect the dry process gas flow rate and saturated steam flow rate data in real time and transmit the data to the control system. The control system adjusts the flow control valve on the saturated steam discharge pipeline through the flow ratio control device according to the preset target value of the moisture content of the wet process gas, thereby adjusting the discharge amount of saturated steam, so that the dry process gas and saturated steam can fully contact and mix evenly in the static mixer according to the preset ratio, initially forming wet process gas.

[0022] Step 4, Heating and Anti-condensation: The wet process gas initially formed in Step 3 is transported from the outlet of the static mixer to the electric heater E-111. The electric heater E-111 heats the wet process gas to prevent condensation from forming due to a sudden temperature drop after the high-temperature saturated steam mixes with the low-temperature dry process gas. A temperature detection device is installed at the outlet of the static mixer to collect the temperature data of the initial wet process gas in real time and transmit it to the control system. The control system automatically adjusts the load of the electric heater E-111 based on the temperature difference between the temperature data and the preset target temperature, so that the temperature of the heated wet process gas is maintained within the set range.

[0023] Step 5: Parameter Monitoring and Adjustment: Throughout the entire process operation, the control system monitors key parameters in real time, including the liquid level and pressure of the saturated steam generator, the dry process gas flow rate, saturated steam flow rate, and initial wet process gas temperature at the inlet and outlet of the static mixer, and the wet process gas temperature and moisture content at the outlet of electric heater E-111. When a parameter deviates from the set range, the control system promptly initiates corresponding adjustment measures through interlocking control devices, such as adjusting the replenishment amount of the replenishment device, controlling the start and stop status of the electric heater, adjusting the saturated steam discharge rate, or adjusting the load of electric heater E-111, to ensure that all parameters meet the process design requirements and guarantee stable process operation. If a parameter deviates beyond the allowable range, the control system simultaneously issues an alarm signal to remind operators to check and handle the issue promptly.

[0024] Example 1: Preparation of 1 MPa of humid air at 90°C with a water content of 1%-5% Step 1: Saturated Steam Preparation: Demineralized water is selected as the steam generating medium. The demineralized water is supplied to the saturated steam generator D-111 through the demineralized water inlet, with the initial liquid level controlled at 50%-60% of the tank volume. The built-in electric heater of the saturated steam generator is activated, and the tank pressure is set to a control range of 1.0-1.2 MPa. The high and low pressure interlock control device is linked with the electric heater. When the tank pressure rises to 1.2 MPa, the control system automatically cuts off the power to the electric heater, stopping heating. When the tank pressure drops to 1.0 MPa, the control system automatically restarts the electric heater, resuming heating to ensure the tank pressure remains stable within the set range. Simultaneously, the low-low liquid level threshold is set to 30% of the tank volume. When the remote liquid level display device detects that the tank level is below 30%, the low-low liquid level automatic replenishment interlock control device is activated, replenishing the tank with demineralized water until the liquid level rises back to 50%, at which point replenishment stops, maintaining a stable tank level. Through the above control, saturated steam generator D-111 continuously generates saturated steam with stable pressure.

[0025] Step 2: Selection and Transportation of Dry Process Gas: 99.5% pure dry air is selected as the feed gas, with initial parameters of 1.1 MPa, 25°C, and a flow rate of 100 Nm³. 3 / h; The dry air is delivered to the corresponding inlet of the static mixer M-111 through the dry process gas inlet, and the flow regulating valve on the delivery pipeline is adjusted to stabilize the dry process gas flow rate at 100 NM. 3 / h or so.

[0026] Step 3, Gas-to-Gas Mixing: Saturated steam discharged from the top outlet of saturated steam generator D-111 is transported to the other inlet of static mixer M-111 via a steam conveying pipeline. Flow metering devices at the dry process gas inlet and saturated steam inlet of static mixer M-111 collect dry air flow and saturated steam flow data in real time, respectively, and transmit them to the control system. Based on the preset target value of humid air moisture content, the control system calculates the flow ratio of dry air to saturated steam through a flow ratio control device. For example, when the target moisture content is 3%, the flow control valve on the saturated steam discharge pipeline is adjusted to ensure that the saturated steam flow and dry air flow meet the corresponding ratio. Dry air and saturated steam fully contact and mix evenly in static mixer M-111 through the action of internal mixing elements, initially forming humid air.

[0027] Step 4, Heating and Anti-condensation: The initially formed humid air is discharged from the outlet of the static mixer M-111. The temperature detection device at the outlet detects its temperature, which is approximately the equilibrium temperature of the mixture of saturated steam and dry air, below 90°C, and transmits the temperature data to the control system. The control system starts the electric heater E-111, sets the target temperature to 90°C, and automatically adjusts the load of the electric heater E-111 according to the difference between the actual temperature and the target temperature, so that the temperature of the humid air rises to 90°C, effectively preventing condensation.

[0028] Step 5, Parameter Monitoring and Adjustment: The control system monitors key parameters in real time: the liquid level and pressure of the saturated steam generator D-111, the dry air flow rate and saturated steam flow rate, and the temperature and moisture content of the humid air at the outlet of the electric heater E-111. When the moisture content deviates from the target value, the control system adjusts the saturated steam flow rate in a timely manner through the flow ratio control device. When the temperature deviates from the set range, the load of the electric heater E-111 is adjusted. When the liquid level or pressure is abnormal, the interlock control device automatically adjusts the replenishment amount or the start / stop status of the electric heater. If the parameters deviate beyond the allowable range, the alarm device issues an alarm signal to remind the operator to check and handle the issue, ensuring that all parameters of the humid air meet the process requirements. Finally, humid air with a concentration of 1 MPa, 90°C, and 3% water content is obtained. If the moisture content needs to be adjusted, it is only necessary to change the flow ratio of saturated steam to dry air through the control system. The adjustable range of moisture content is 1%-5%.

[0029] Example 2: Preparation of 2 MPa wet process gas at 120°C with a water content of 0.1%-2% Step 1: Saturated Steam Preparation: Demineralized water is selected as the steam generating medium and transported to the saturated steam generating tank D-111 through demineralized water inlet 1. The initial liquid level is controlled at 55%-65% of the tank volume. The built-in resistance electric heater is started, and the tank pressure control range is set to 2.0-2.2 MPa. The high and low pressure interlock control device is linked with the electric heater. When the tank pressure is higher than 2.2 MPa, the power supply to the electric heater is automatically cut off. When the tank pressure is lower than 2.0 MPa, the electric heater is automatically started to maintain the tank pressure stable at 2.0-2.2 MPa. The low liquid level threshold is set to 35% of the tank volume. When the liquid level display device detects that the tank liquid level is lower than 35%, the automatic liquid replenishment device is started to replenish the tank with demineralized water until the liquid level rises back to above 55%, at which point the liquid replenishment stops. The saturated steam pressure generated in the tank is maintained at 2.0-2.2 MPa, and the temperature is the saturation temperature at the corresponding pressure.

[0030] Step 2: Selection and Transportation of Dry Process Gas: A mixed process gas is selected as the dry process gas, with a composition of 35% ethylene, 40% ethane, and 25% dry air, wherein the dry air is mainly composed of oxygen and nitrogen. The initial parameters of this dry process gas are 2.1 MPa, 25°C, and a flow rate of 300 Nm³. 3 / h; The dry process gas is delivered to the corresponding inlet of the static mixer M-111 through the dry process gas inlet, and the flow regulating valve is adjusted to stabilize the dry process gas flow rate at 300 NM. 3 / h5NM 3 / h.

[0031] Step 3, Gas-gas Mixing: The saturated steam discharged from the top outlet of the saturated steam generator D-111 is transported to another inlet of the static mixer M-111. The flow metering device at the inlet collects the saturated steam flow data and transmits it to the control system. According to the preset target value of the moisture content of the wet process gas, for example, setting the target moisture content to 0.5%, the control system calculates the flow ratio of the dry process gas and the saturated steam through the flow ratio control device, and adjusts the flow control valve on the saturated steam discharge pipeline to ensure that the saturated steam flow meets the ratio requirement. The dry process gas and the saturated steam are fully mixed in the static mixer M-111 to form the initial wet process gas.

[0032] Step 4, Heating and Anti-condensation: The initially formed wet process gas enters the electric heater E-111. The temperature detection device at the outlet of the static mixer M-111 detects its initial temperature and transmits it to the control system. The control system sets the target temperature to 120℃ and adjusts the load of the electric heater E-111 according to the difference between the actual temperature and the target temperature to raise the temperature of the wet process gas to 120℃ and prevent condensation from forming.

[0033] Step 5, Parameter Monitoring and Adjustment: The control system monitors key parameters in real time: the liquid level and pressure of the saturated steam generator D-111, the dry process gas flow rate and saturated steam flow rate, and the temperature and moisture content of the wet process gas at the outlet of the electric heater E-111. When a parameter deviates from the set range, the control system promptly initiates adjustment measures through the interlock control device to ensure stable process operation. If the parameter deviates significantly, the alarm device issues an alarm signal. Finally, a wet process gas of 2 MPa, 120℃, and 0.5% water content is obtained, with the moisture content flexibly controlled within the range of 0.1%-2% by adjusting the flow rate ratio.

[0034] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A wet process gas preparation process, characterized in that: Includes the following steps: Step 1: Saturated Steam Preparation: Demineralized water or other liquids meeting process requirements are transported to a saturated steam generator. The saturated steam generator has a built-in electric heater, which provides heat to evaporate the liquid inside the tank to form saturated steam. The saturated steam generator is equipped with a remote liquid level display device and high / low liquid level alarm functions, and is also equipped with an automatic low-low liquid level replenishment interlock control device. The saturated steam generator is also equipped with a pressure display device, and is equipped with a high / low pressure interlock control device linked to the electric heater. Step 2, Dry process gas selection and transportation: Select dry process gas that meets the process requirements, and ensure that the pressure and temperature of the dry process gas meet the subsequent mixing requirements. Transport the dry process gas to the corresponding inlet of the static mixer through the transportation pipeline. Step 3, Gas-gas mixing: The saturated steam generated in Step 1 is discharged from the top of the saturated steam generator and transported to the other inlet of the static mixer; both the dry process gas inlet and the saturated steam inlet of the static mixer are equipped with flow metering devices, and the discharge amount of saturated steam is adjusted by the flow ratio control device. The dry process gas and saturated steam are mixed in the static mixer to form preliminary wet process gas. Step 4, Heating and Anti-condensation: The initial wet process gas is delivered to an electric heater for heating treatment. The electric heater is linked to the temperature detection device at the outlet of the static mixer. Step 5: Parameter monitoring and adjustment: Monitor the liquid level and pressure of the saturated steam generator, the flow rate and temperature at the inlet and outlet of the static mixer, and the temperature and moisture content of the wet process gas at the outlet of the electric heater in real time, and adjust the relevant operating parameters through the interlock control device.

2. The wet process gas preparation process according to claim 1, characterized in that: The operation mode of the automatic low-low liquid level replenishment interlock control device in step one is as follows: when the liquid level in the saturated steam generator tank is lower than the set low-low liquid level threshold, the replenishment device is automatically started to replenish demineralized water or other liquids into the tank, and the replenishment stops when the liquid level rises back to the set normal liquid level range.

3. The wet process gas preparation process according to claim 1, characterized in that: The high and low pressure interlock control device in step one operates as follows: when the pressure inside the saturated steam generator tank is higher than the set high pressure threshold, the power supply to the electric heater is automatically cut off; when the pressure inside the tank is lower than the set low pressure threshold, the electric heater is automatically started to maintain the pressure inside the tank within the set range.

4. The wet process gas preparation process according to claim 1, characterized in that: In step three, the flow ratio control device calculates the flow ratio of dry process gas to saturated steam based on the preset target value of moisture content in wet process gas, and achieves precise regulation of saturated steam flow by adjusting the flow control valve on the saturated steam discharge pipeline.

5. The wet process gas preparation process according to claim 1, characterized in that: In step four, the electric heater automatically adjusts its load based on the difference between the actual temperature of the wet process gas at the outlet of the static mixer and the set temperature, so that the temperature of the heated wet process gas is maintained within the set range to avoid condensation.

6. The wet process gas preparation process according to claim 1, characterized in that: During the parameter monitoring and adjustment process in step five, when a parameter is detected to deviate from the set range, the interlock control device issues an alarm signal and automatically initiates corresponding adjustment measures to ensure stable process operation.

7. The wet process gas preparation process according to claim 1, characterized in that: The electric heater includes an electric heater built into the saturated steam generator and an electric heater for heating the wet process gas.

8. The wet process gas preparation process according to claim 1, characterized in that: The moisture content of the wet process gas is adjustable from 0.1% to 5%, the temperature is adjustable from 90℃ to 120℃, and the pressure is adjustable from 1MPag to 2MPag.

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