A deep desulfurization device and process based on controllable flat membrane and intelligent collaborative control

Abstract

The application discloses a deep desulfurization device and process based on adjustable flat membrane and intelligent collaborative control, the deep desulfurization device comprises a desulfurization tower and an intelligent control system, a variable configuration flat plate absorption membrane device is arranged in the desulfurization tower body, the variable configuration flat plate absorption membrane device is formed by a plurality of groups of hydrophilic corrosion-resistant flat plates arranged in parallel, a plurality of blades with adjustable angles are uniformly distributed on one side or both sides of the flat plate, the device can be driven and controlled by a motor under the control of an intelligent control driver, and the motor is controlled to be synchronously driven and accurately rotated with the blades, so that the device can actively adjust the geometric shape of a gas passage and fluid mechanics conditions according to real-time working conditions; meanwhile, the flow of the absorbent entering the desulfurization tower is dynamically adjusted by means of the design of an absorbent circulating loop in the tower, so that the rapid response to working condition fluctuations and the online optimization of the desulfurization process are realized.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of energy saving and emission reduction and flue gas deep desulfurization, and in particular relates to a deep desulfurization device and process based on adjustable flat membrane and intelligent collaborative control. BACKGROUND

[0002] In the fields of petroleum refining and coal chemical industry, the wet amine absorption process is the mainstream technology for removing hydrogen sulfide (H2S), and the core equipment is the absorption tower. This kind of process allows the sulfur-containing gas to contact with the amine solution through the fillers, trays and other components in the tower to achieve purification. However, the internal components of the traditional absorption tower are fixed in form, and when facing the frequently changing conditions in chemical production (such as gas flow, H2S concentration fluctuation), its limitations are very obvious.

[0003] This fixed tower structure is difficult to actively adapt to the dynamically changing process conditions. When the actual working condition deviates from the design point, it is easy to cause channeling, flooding and other problems, resulting in insufficient gas-liquid contact and significant decrease in mass transfer efficiency. In order to ensure that the outlet H2S concentration meets the standard, the existing control strategy is usually to passively and excessively increase the amine liquid circulation amount. Although this "large liquid-gas ratio" operation mode is reliable, it causes excessive circulation of the absorbent and significantly increases the steam consumption of the subsequent regeneration link, resulting in high overall energy consumption of the system.

[0004] Although there are some improvement schemes in the prior art, such as CN116764412A discloses a desulfurization device by setting reciprocating nozzles to expand the spraying coverage, and CN111760433A proposes a system by connecting multiple desulfurization devices in series to achieve efficient purification, but these methods fail to fundamentally solve the problem of low efficiency of single absorption tower under varying conditions, or increase equipment investment and land area. At the same time, some attempts to introduce intelligent algorithms also focus on optimizing liquid flow, without touching the fundamental bottleneck of the physical structure of the absorption tower.

[0005] Therefore, there is an urgent need in the industry for a new desulfurization device and process that can actively adjust its physical form according to real-time conditions to maintain efficient gas-liquid contact at all times, and at the same time, meet the requirements of deep desulfurization while reducing system operating energy consumption. SUMMARY

[0006] The present application aims to solve the technical problems existing in the prior art wet desulfurization technology, i.e., the physical form of the mass transfer components in the desulfurization tower is fixed, which is difficult to adapt to the dynamic changes of gas flow, component concentration and other conditions, resulting in a decrease in mass transfer efficiency of the device, excessive circulation of the absorbent and high operating energy consumption when deviating from the design condition.

[0007] To achieve the above object, the first aspect of the present application provides a deep desulfurization device based on adjustable flat membrane and intelligent collaborative control, comprising a desulfurization tower and an intelligent control system, wherein:

[0008] The inside of the desulfurization tower is sequentially provided from top to bottom with an absorbent distribution device, a flat absorbent membrane device with variable configuration, a desulfurization tower filler layer, and a liquid storage tank at the bottom. The top and bottom ends of the desulfurization tower are respectively provided with a purified gas outlet and an absorbent rich liquid outlet. The upper and lower parts of the side wall are respectively provided with an absorbent inlet and a sulfur-containing gas inlet. The absorbent inlet is communicated with the absorbent distribution device. The desulfurization tower is provided with an absorbent circulation loop in the tower, which comprises a filter at the bottom of the liquid storage tank. The external connecting pipeline of the filter is connected to the absorbent inlet, and a circulating pump is arranged on the pipeline.

[0009] The flat absorbent membrane device is composed of a plurality of flat plates made of hydrophilic corrosion-resistant materials arranged in parallel. The flat plate is hollow, and one side or both sides are uniformly provided with a plurality of blades with adjustable angles. The plurality of blades are arranged in parallel along the horizontal wall surface on one side or both sides of the flat plate, and the inside of the flat plate is provided with a blade adjusting device connected with the blades for adjusting the included angle θ between the blades and the gas flow direction.

[0010] The intelligent control system has a central control unit. The intelligent control system comprises two multifunctional gas sensors respectively arranged at the sulfur-containing gas inlet and the purified gas outlet, an intelligent control driver arranged outside the flat absorbent membrane device, and a flow control unit arranged on the absorbent inlet pipeline. The two multifunctional gas sensors are signal acquisition units for acquiring the inlet gas flow (Q in ), the inlet H2S concentration (C in ), and the outlet H2S concentration (C out ). The intelligent control driver and the flow control unit are execution mechanisms for adjusting the included angle θ between the blades and the gas flow direction and the flow F of the circulating absorbent entering the desulfurization tower from the absorbent circulation loop in the tower, respectively.

[0011] According to the preferred embodiment of the present application, the intelligent control system further comprises a liquid level sensor arranged at the liquid storage tank for continuously monitoring the liquid level signal in the liquid storage tank to enable the intelligent control system to control the liquid level in the liquid storage tank to remain within a set range.

[0012] According to the present application, the deep desulfurization device further comprises a regeneration device and an absorbent supplementing device, wherein:

[0013] The inlet of the regeneration device is connected to the absorbent rich liquid outlet of the desulfurization tower through a pipeline via a rich liquid pump. The outlet of the regeneration device is connected to the inlet of the absorbent supplementing device through a pipeline via a lean liquid pump.

[0014] The outlet of the absorbent supplement device is connected with the absorbent inlet of the desulfurization tower through a pipeline via a circulating pump, and a liquid supplement port is further arranged on the absorbent supplement device for supplementing the amine liquid absorbent.

[0015] Preferably, the surface of the blade is provided with a pattern for promoting uniform formation of the liquid film, which includes but is not limited to a zigzag pattern, a water droplet pattern, a horizontal groove, a vertical groove, a hemispherical pattern, and other surface structures capable of increasing the wetting area and promoting uniform distribution of the liquid film.

[0016] According to a preferred embodiment of the present application, the blade adjusting device comprises a worm screw vertically arranged inside the flat plate and provided with a thread on the surface, a plurality of worm gear sets engaged with the thread of the worm screw, and a rack engaged with the worm gear sets, the top end of the worm screw is driven by a motor, and the side of the blade facing the flat plate is provided with an upper connecting rod and a lower connecting rod, wherein the lower connecting rod is fixedly connected with the outer side end of the rack of the blade adjusting device.

[0017] In a second aspect of the present application, a deep desulfurization process based on adjustable flat plate membrane and intelligent collaborative control is provided, which adopts the deep desulfurization device as described above, and comprises the following steps:

[0018] S1: passing the sulfur-containing gas into the desulfurization tower of the deep desulfurization device;

[0019] S2: real-time monitoring of at least one operating condition parameter of the inlet gas flow rate Q in , the inlet H2S concentration C in and the outlet H2S concentration C out of the desulfurization tower;

[0020] S3: according to the operating condition parameter, the intelligent control system synchronously and dynamically collaboratively controls the angle θ between the blade of the flat plate absorption membrane device and the gas flow direction, and the absorbent flow rate F of the absorbent circulating loop entering the desulfurization tower, so as to realize rapid response to the operating condition fluctuation and online optimization of the desulfurization process.

[0021] Further, in step S3, when a significant fluctuation of the inlet operating condition is monitored, a feedforward control is performed, which preferentially and quickly adjusts the angle θ to instantaneously suppress the change of the outlet H2S concentration, and then gradually adjusts the absorbent flow rate F to adapt to the new operating condition; at the same time, a feedback control is continuously performed, which corrects the angle θ and the absorbent flow rate F according to the change of the outlet H2S concentration C out .

[0022] According to a preferred embodiment of the present application, the intelligent control system is configured to monitor at least one of the operating condition parameters in real time, and based on the operating condition parameters, execute a compound control logic of feedforward control-feedback control to cooperatively output at least two control instructions:

[0023] The first control instruction is used to dynamically adjust the rotation angle θ of the vane of the flat-plate absorption membrane device to change the gas flow channel configuration; the second control instruction is used to dynamically adjust the absorption agent flow F entering the desulfurization tower from the absorption agent circulation loop in the tower; by synchronously adjusting the two variables of the angle θ and the flow F, online control of the desulfurization process is realized.

[0024] Further, the feedforward control of the intelligent control system is based on the variation of the inlet gas flow Q in and / or the inlet H2S concentration C in to make a predictive adjustment, and the feedback control is based on the comparison between the outlet H2S concentration C out and the preset target value to make a corrective adjustment.

[0025] According to another preferred embodiment, the intelligent control system is further configured to, when the monitored outlet H2S concentration C out is stable and lower than the preset target value, execute an energy-saving optimization mode by reducing the absorption agent flow F for circulation and / or adjusting the angle θ, which, through an embedded heuristic optimization algorithm model, finds and sets the combination of operating parameters (F, θ) with the lowest energy consumption under the premise of ensuring the outlet to meet the standard.

[0026] According to another preferred embodiment, the intelligent control system is further configured to, by monitoring the signal of the liquid level sensor arranged in the liquid storage tank inside the desulfurization tower and controlling the outlet flow of the rich-liquid pump, stabilize the liquid level of the storage tank within a preset range.

[0027] According to the present application, the absorption agent is an aqueous organic amine solution, preferably N-methyldiethanolamine (MDEA), or a mixture of MDEA and one or more of monoethanolamine (MEA), diethanolamine (DEA), and piperazine (PZ).

[0028] The present application has the following beneficial effects:

[0029] 1. The deep desulfurization device of the present application, a variable configuration flat plate absorption membrane device is arranged in the desulfurization tower body, which is formed by a plurality of groups of hydrophilic corrosion-resistant flat plates arranged in parallel, and a plurality of blades with adjustable angles are uniformly distributed on one side or both sides of the flat plate, which can be driven and controlled by the motor under the control of the intelligent control driver, and simultaneously driven and synchronously and accurately rotated, so that the device can actively adjust the geometric shape of the gas passage and the fluid mechanics condition according to the real-time working condition; at the same time, the absorption agent flow entering the desulfurization tower is dynamically adjusted by means of the design of the absorption agent circulation loop in the tower, so as to realize the rapid response to the working condition fluctuation and the online optimization of the desulfurization process.

[0030] 2. The present application improves the adaptability of the device to the change of working condition, and by adopting the mass transfer component with adjustable configuration and combining with intelligent control, the absorption tower is changed from a rigid equipment to a flexible system which can actively adapt to the process change, and the best balance point of mass transfer efficiency and system pressure drop is found online.

[0031] 3. The present application significantly reduces the operating energy consumption of the system, and the intelligent control system cooperatively optimizes the flat plate absorption membrane configuration and the absorption agent flow, avoiding the excessive circulation of the absorption agent. Under the premise of achieving the same desulfurization index, the absorption agent circulation amount can be reduced by more than 20%, and the energy consumption of the regeneration unit can be correspondingly reduced by 15-25%.

[0032] 4. The present application realizes high desulfurization efficiency and purification depth, adopts the series connection type design combining the filler and the variable configuration flat plate membrane, greatly improves the mass transfer efficiency. Even under severe working conditions, the outlet H2S concentration can be stably controlled below 10 ppm, meeting the strict environmental protection and process requirements.

[0033] 5. The present application increases the gas treatment capacity and reduces the system pressure drop, the flat plate absorption membrane adopted is a low-resistance high-efficiency mass transfer element, compared with the traditional packed tower or plate tower, the system operating pressure drop is lower, the power consumption is effectively reduced, and it is suitable for large-scale gas treatment demand. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of the deep desulfurization device based on adjustable flat plate membrane and intelligent cooperative control.

[0035] Figure 2 It is a schematic diagram of the variable configuration flat plate absorption membrane device.

[0036] Figure 3 It is Figure 2 It is a schematic diagram of a single flat plate.

[0037] Figure 4 It is a sectional view of the flat plate provided with a blade adjusting device.

[0038] Figure 5 It is Figure 4 It is a schematic diagram of the blade and the flat plate wall forming an angle θ.

[0039] Figure 6 This is a schematic diagram of a deep desulfurization process based on adjustable flat sheet membranes and intelligent synergistic control.

[0040] Drawing number explanation:

[0041] 10-Rich solution pump; 20-Lean solution pump; 30-Circulation pump; 100-Desulfurization tower; 101-Absorbent distribution device; 102-Flat plate absorbent membrane device; 103-Desulfurization tower packing layer; 104-Storage tank; 105-Purified gas outlet; 106-Absorbent rich solution outlet; 107-Absorbent inlet; 108-Sulfur-containing gas inlet; 111-Intelligent control driver; 112-Multifunctional gas sensor; 113-Filter; 114-Level sensor; 115-Flow control unit; 120-Flat plate; 121-Blade; 122-Upper connecting rod; 123-Lower connecting rod; 130-Blade adjustment device; 131-Worm; 132-Thread; 133-Worm gear assembly; 134-Rack; 200-Regeneration device; 300-Absorbent replenishment device; 301-Replenishment port. Detailed Implementation

[0042] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0043] Example 1: Deep desulfurization device and process based on adjustable flat sheet membrane and intelligent collaborative control.

[0044] 1.1 Deep desulfurization device based on adjustable flat sheet membrane and intelligent collaborative control.

[0045] like Figure 1 As shown, the deep desulfurization device based on adjustable flat sheet membrane and intelligent collaborative control in this embodiment includes a desulfurization tower 100, a regeneration device 200, and an absorbent replenishment device 300, wherein:

[0046] The desulfurization tower 100 is provided with an absorbent distribution device 101, a variable-configuration flat plate absorbent membrane device 102, a desulfurization tower packing layer 103, and a bottom liquid storage tank 104 from top to bottom. The top and bottom of the desulfurization tower 100 are respectively provided with a purified gas outlet 105 and an absorbent rich liquid outlet 106. The upper and lower parts of the side wall are respectively provided with an absorbent inlet 107 and a sulfur-containing gas inlet 108. The absorbent inlet 107 is connected to the absorbent distribution device 101, and the sulfur-containing gas inlet 108 is located below the desulfurization tower packing layer 103.

[0047] The inlet of the regeneration device 200 is connected to the absorbent rich liquid outlet 106 of the desulfurization tower 100 via a pipeline through the rich liquid pump 10, and the outlet of the regeneration device 200 is connected to the inlet of the absorbent replenishment device 300 via a pipeline through the lean liquid pump 20.

[0048] The outlet of the absorbent replenishment device 300 is connected to the absorbent inlet 107 of the desulfurization tower 100 via a pipeline through a circulation pump 30, and the absorbent replenishment device 300 is also provided with a liquid replenishment port 301 for replenishing amine absorbent.

[0049] The main operating process of the above-mentioned device is as follows:

[0050] Sulfur-containing gas enters the bottom of desulfurization tower 100 through sulfur-containing gas inlet 108; inside desulfurization tower 100, the gas passes through desulfurization tower packing layer 103 and flat plate absorption membrane device 102 from bottom to top. The lean absorbent solution enters desulfurization tower 100 through absorbent inlet 107 and is sprayed downward through absorbent distribution device 101, contacting the sulfur-containing gas from bottom to top in a countercurrent manner. The H2S in the gas is efficiently absorbed and discharged from desulfurized purified gas outlet 105 at the top of the tower.

[0051] The absorbent that has absorbed H2S is transformed into a rich solution, which is collected in the storage tank 104 inside the desulfurization tower at the bottom of the tower and led out from the rich solution outlet 106. The rich solution is pressurized by the rich solution pump 10 and enters the regeneration device 200 for regeneration. The regenerated lean solution is collected at the bottom of the regeneration device 200 and extracted by the lean solution pump 20. After exchanging heat with the rich solution and cooling, it enters the absorbent replenishment device 300. After filtration, purification and replenishment, it is sent back to the absorbent inlet 107 of the desulfurization tower 100 through the circulation pump 30. It is then evenly sprayed by the absorbent distribution device 101 inside the tower and recycled for the absorption process.

[0052] The desulfurization tower 100 in this embodiment is also provided with an internal absorbent circulation loop. The internal absorbent circulation loop includes a filter 113 located at the bottom of the storage tank 104. The external pipeline of the filter 113 is connected to the absorbent inlet 107, and a circulation pump 30 is provided on the pipeline.

[0053] Furthermore, the desulfurization tower packing layer 103 preferably uses stainless steel IMTP (inwardly rolled triangular barbed ring) high-efficiency random packing, which is used to perform main and deep absorption of H2S in the incoming sulfur-containing gas, and complete most of the desulfurization task.

[0054] like Figure 2 As shown, the flat plate absorption membrane device 102 consists of several groups of parallel flat plates 120 made of hydrophilic and corrosion-resistant materials (such as 316L stainless steel), preferably configured as a cylindrical shape adapted to the interior of the desulfurization tower 100, for final enhanced purification and fine control. Combined with...Figure 3 As shown, the plate 120 is hollow, and several adjustable blades 121 are evenly distributed on one or both sides of it. The blades 121 are arranged horizontally parallel on one or both sides of the plate 120, and a blade adjustment device 130 is provided inside the plate 120. The blade adjustment device 130 is connected to the blades 121 and is used to adjust the angle θ between the blades 121 and the wall of the plate 120 (i.e., the direction of gas flow between the blades 121 and the wall). Preferably, the surface of the blades 121 is provided with textures to promote the uniform formation of the liquid film. The textures include, but are not limited to, serrated textures, teardrop textures, horizontal grooves, vertical grooves, hemispherical textures, and other surface structures that can increase the wetting area and promote the uniform distribution of the liquid film.

[0055] Furthermore, such as Figure 4 As shown, the blade adjustment device 130 includes a worm 131 vertically disposed inside the plate 120 and having threads 132 on its surface, a plurality of worm gear sets 133 meshing with the threads 132 of the worm 131, and a rack 134 meshing with the worm gear sets 133. The top end of the worm 131 is driven by a motor (not shown in the figure), preferably a servo motor or a stepper motor. The blade 121 has an upper connecting rod 122 and a lower connecting rod 123 on the side facing the plate 120, wherein the lower connecting rod 123 is connected and fixed to the outer end of the rack 134 of the blade adjustment device 130. Thus, when the motor drives the worm 131 to rotate, its threads 132 drive the worm gear sets 133 to rotate, thereby causing the rack 134 to move left and right, which in turn causes the lower connecting rod 123 to move outward or retract from the wall of the plate 120, ultimately achieving angle adjustment of the blade 121. Figure 5 The diagram shows a rack 134 pushing the connecting rod 123 outward, thereby causing the blade 121 to form an angle θ with the initial gas flow direction.

[0056] It should be understood that the blade adjusting device 130 of the present invention is not limited to... Figures 4-5 The specific structural form shown, as well as other known structural forms in the prior art that can drive the blade 121 to rotate at a certain angle θ, are all applicable in this invention, which is obvious to those skilled in the art.

[0057] Furthermore, the deep desulfurization device based on adjustable flat sheet membrane and intelligent collaborative control in this embodiment also includes an intelligent control system with a central control unit. This intelligent control system can be physically implemented by an industrial computer, PLC, or DCS system loaded with control algorithm software. It is used to monitor at least one operating condition parameter in real time, and based on the operating condition parameter, execute a composite control logic of feedforward control and feedback control, ultimately generating and outputting control commands.

[0058] like Figure 1As shown, the intelligent control system includes two multi-functional gas sensors 112 respectively installed at the sulfur-containing gas inlet 108 and the purified gas outlet 105, an intelligent control driver 111 installed outside the flat plate absorption membrane device 102, and a flow control unit 115 installed on the absorbent inlet pipeline. Preferably, the intelligent control system also includes a liquid level sensor 114 installed at the liquid storage tank 104. The multi-functional gas sensors 112, intelligent control driver 111, flow control unit 115, and liquid level sensor 114 can all be connected to the central control unit of the intelligent control system via wired or wireless connections; these connection methods are conventional.

[0059] The two multi-functional gas sensors 112 are signal acquisition units. The multi-functional gas sensor 112 located at the sulfur-containing gas inlet 108 is used to monitor the inlet gas flow rate (Q). in ) and the H2S concentration in the inlet gas (C in The data is fed back to the central control unit of the intelligent control system. A multi-functional gas sensor 112, located at the purified gas outlet 105, is used to monitor the H2S concentration (C) in the outlet gas. out This feedback is then sent to the central control unit of the intelligent control system.

[0060] The central control unit of the intelligent control system receives operating condition parameters (Q) from two multi-functional gas sensors 112. in C in C out Afterwards, the system makes a decision based on the built-in feedforward control-feedback control composite control logic, generating and coordinating the output of at least two control commands: the first control command is used to dynamically adjust the rotation angle θ of the blades 121 of the flat plate absorber membrane device 102 to change the gas flow channel configuration; the second control command is used to dynamically adjust the absorbent flow rate F entering the desulfurization tower 100 from the absorbent circulation loop inside the tower; by synchronously controlling the two variables, angle θ and flow rate F, online control of the desulfurization process is achieved.

[0061] The intelligent control driver 111 and flow control unit 115 are actuators that receive and execute commands from the central control unit of the intelligent control system. The intelligent control driver 111 is electrically connected to the blade adjustment device 130 of the flat plate absorbent membrane device 102, and drives a motor according to the first control command to dynamically adjust the rotation angle θ of the blades 121. The flow control unit 115 adjusts the flow rate F of the circulating absorbent entering the desulfurization tower 100 from the absorbent circulation loop according to the second control command. Specifically, when the multi-functional gas sensor 112 detects the outlet H2S concentration (C... outWhen the flow rate exceeds the set value, the flow control unit 115 will precisely adjust the flow rate so that the absorbent from the storage tank 104 is filtered by the filter 113 and then drawn out by the circulation pump 30 into the absorbent inlet 107. The absorbent flow rate F controlled by the intelligent control system in this embodiment specifically refers to the circulating flow rate within the tower controlled by the flow control unit 115.

[0062] The liquid level sensor 114 is used to continuously monitor the liquid level signal in the storage tank 104 and feed it back to the central control unit of the intelligent control system. When the liquid level value exceeds the preset range, the central control unit of the intelligent control system issues a third command: instructs the frequency converter or outlet regulating valve of the rich liquid pump 10 to adjust its outlet flow rate so that the liquid level in the storage tank 104 is kept within the preset range.

[0063] Combination Figure 6 As shown, the specific control method of the intelligent control system is as follows:

[0064] First, the two multi-functional gas sensors 112 respectively collect operating condition parameters (Q). in C in C out The operating parameters are sent to the central control unit of the intelligent control system. Upon receiving these parameters, the central control unit first determines whether there are significant fluctuations in the operating conditions at the gas inlet. If significant fluctuations occur, it executes "feedforward" predictive regulation. Based on the fluctuation amplitude and model calculations, it sets a predictive parameter set (F, θ), prioritizing and rapidly adjusting the angle θ to instantaneously suppress changes in the outlet H2S concentration. Subsequently, it gradually adjusts the absorbent flow rate F to adapt to the new operating conditions, while continuously executing feedback control based on the outlet H2S concentration (C). out The angle (θ) and absorbent flow rate (F) are corrected according to the changes in the parameters; if no significant fluctuations occur, a "feedback" correction adjustment is performed, and the correction parameter set (F, θ) is calculated and set according to the degree of exceedance.

[0065] Preferably, the intelligent control system is further configured to: when the outlet H2S concentration (C) is detected... out When the value is stable and below the preset target value, energy-saving optimization control is performed by reducing the absorbent flow rate (F) used for circulation and / or adjusting the angle (θ). It uses a built-in heuristic optimization algorithm model, such as the known particle swarm optimization algorithm or genetic algorithm, to find and set the combination of operating parameters (F, θ) with the lowest energy consumption while ensuring that the outlet meets the standard.

[0066] 1.2 Deep desulfurization process.

[0067] Based on the deep desulfurization device based on adjustable flat sheet membrane and intelligent collaborative control described in 1.1 above, combined with Figure 6As shown, the deep desulfurization process in this embodiment includes the following steps:

[0068] S1: Pass sulfur-containing gas into the desulfurization tower;

[0069] S2: Real-time monitoring of at least one operating condition parameter;

[0070] S3: Based on the operating condition parameters, the intelligent control system synchronously and dynamically coordinates and adjusts the angle θ between the blades and the gas flow direction, as well as the absorbent flow rate F entering the desulfurization tower from the absorbent circulation loop inside the tower, in order to achieve rapid response to operating condition fluctuations and online optimization of the desulfurization process.

[0071] The operating condition parameters mentioned in step S2 are selected from the inlet gas flow rate (Q). in ), inlet H2S concentration (C in ), and the outlet H2S concentration (C out One or more of the following.

[0072] Furthermore, step S3 includes: when a significant fluctuation in the inlet operating conditions is detected, feedforward control is executed to pre-adjust the angle θ between the blades and the gas flow direction and the absorbent flow rate F to cope with the load impact; simultaneously, feedback control is continuously executed based on the outlet H2S concentration (C out The change in H2S concentration at the outlet is used to correct the angle θ between the blade and the gas flow direction and the absorbent flow rate F, ensuring that the outlet H2S concentration remains stable and meets the standard.

[0073] When the system is running stably, the energy-saving optimization mode is activated to ensure the outlet H2S concentration (C) is maintained. out Under the premise of meeting the standards, the system searches for and sets the combination of operating parameters (F, θ) with the lowest energy consumption. The search process can be implemented through a built-in optimization algorithm model, which can adopt one or more mature optimization algorithms known in the field, such as heuristic algorithms (e.g., particle swarm optimization algorithm, genetic algorithm, etc.), model-based predictive control algorithms, or machine learning-based reinforcement learning algorithms, to achieve rapid calculation of global or local optimal solutions for multiple variables.

[0074] In this embodiment, the absorbent is an aqueous solution of an organic amine, preferably N-methyldiethanolamine (MDEA), or a mixture of MDEA with one or more of monoethanolamine (MEA), diethanolamine (DEA), and piperazine (PZ).

[0075] Application Example 1

[0076] This application example demonstrates the use of the process and apparatus described in Example 1 above to process dry gas generated by a petroleum refining unit.

[0077] 1. For the process flow, please refer to...Figure 6 .

[0078] The specific parameters of the refinery dry gas (containing sulfur) to be processed are: gas flow rate 8000 Nm³ / h, H2S content 1.5 vol% (15000 ppm), CO2 content 5 vol%, operating pressure 1 MPa, and operating temperature 35℃.

[0079] The sulfur-containing gas enters the bottom of the desulfurization tower 100 through the sulfur-containing gas inlet 108. Inside the desulfurization tower 100, the gas passes sequentially from bottom to top through the desulfurization tower packing layer 103 and the variable configuration flat plate absorbent membrane device 102, where it undergoes enhanced mass transfer contact with the lean absorbent solution sprayed counter-currently from top to bottom, resulting in efficient absorption of H2S in the gas. The H2S concentration in the purified gas drops to below 10 ppm and is discharged from the desulfurized purified gas outlet 105 at the top of the tower.

[0080] The absorbent that has absorbed H2S is converted into a rich solution, which is collected in the storage tank 104 inside the desulfurization tower at the bottom of the tower and led out from the rich solution outlet 106. After being pressurized by the rich solution pump 10, the rich solution enters the regeneration unit 200 for regeneration after heat exchange. The regenerated lean solution is collected at the bottom of the regeneration unit, extracted by the lean solution pump 20, cooled by heat exchange with the rich solution, and then enters the absorbent replenishment unit 300. After filtration, purification, and replenishment, it is sent back to the absorbent inlet 107 of the desulfurization tower 100, where it is evenly sprayed by the absorbent distribution device 101 inside the tower and recycled for the absorption process.

[0081] At the same time, such as Figure 1 As shown, the desulfurization tower in this embodiment is equipped with one internal absorbent circulation loop. The absorbent located in the storage tank 104 inside the desulfurization tower is drawn out by the absorbent circulation pump 30 after passing through the absorbent filter 113, and then enters the absorbent inlet 107 after the flow rate is precisely adjusted by the flow control unit 115. The absorbent flow rate F controlled by the intelligent control system in this embodiment specifically refers to the internal circulation flow rate controlled by the flow control unit 115.

[0082] 2. Core components and parameters.

[0083] For the internal structure of the desulfurization tower, please refer to [link / reference]. Figures 1-5 The desulfurization tower adopts an integrated design, the core of which lies in the enhanced mass transfer components arranged in stages from bottom to top inside, specifically composed of the following parts:

[0084] Desulfurization tower packing layer 103: In this embodiment, the packing layer preferably uses stainless steel IMTP (inwardly rolled triangular barbed ring) high-efficiency random packing, which is used to absorb H2S in the gas in a bulk and deep manner, and complete most of the desulfurization task.

[0085] Variable configuration flat plate absorber membrane device 102: This device is located above the packing layer 103 of the desulfurization tower and consists of several sets of parallel flat plates 120 made of 316L stainless steel with vertical grooves engraved on their surfaces, with a total mass transfer area of ​​150 m². 2 This device is used for final enhanced purification and fine control. The core control function of this device is realized by its internal mechanical structure. Several blades 121 of the flat plate absorption membrane are installed on one or both sides of the flat plate 120, and are linked with the blade adjustment device 130 so that the blade adjustment device 130 can drive the blades 121 to form a certain angle θ with the gas flow direction.

[0086] like Figure 4 and Figure 5 As shown, the blade adjustment device 130 is powered by a servo motor or stepper motor driven by an intelligent control module. The motor drives the worm gear 131 to rotate. The thread 132 of the worm gear 131 meshes with a worm wheel assembly 133 fixed to the end of the lower connecting rod 123 of each blade 121. This worm wheel assembly 133 meshes with a rack 134, the outer end of which is fixed to the lower connecting rod 123 of the blade 121. Thus, when the worm gear 131 rotates, all the worm wheel assemblies 133 rotate synchronously, driving the rack 134 to move, thereby driving all the blades 121 to open and close at the same rotation angle θ. Here, the included angle θ is the angle between the blade 121 of the flat sheet absorber membrane and the initial gas flow direction (usually perpendicular), such as... Figure 5 As shown.

[0087] Different application forms can be adopted depending on different operating conditions. For example, under normal operating conditions, the blade 121 is in a state with a smaller unfolding angle (e.g., 15°); while when the operating conditions fluctuate, the intelligent control module can instruct the blade 121 to unfold to a larger angle (e.g., 24°) to enhance mass transfer efficiency.

[0088] The absorbent used in this embodiment is a complex amine aqueous solution with the following composition: 35 wt% MDEA + 10 wt% PZ + 55 wt% water.

[0089] The control target of the intelligent control system is set to H2S concentration ≤ 10 ppm at the desulfurization tower outlet. During stable operation, the multi-functional gas sensor 112 detected an outlet H2S concentration of 6.5 ppm. At this point, the intelligent control module maintains the lean liquid flow rate F at 24 m³ / h. 3 / h, and simultaneously, the blade angle of the flat sheet absorption membrane device 102 is set to 15°. When fluctuations in the upstream device cause the inlet dry gas H2S concentration to suddenly rise to 1.8 vol%, the intelligent control system responds immediately, with the feedforward control module providing a rapid response and executing a two-stage collaborative control strategy:

[0090] I) Rapid Response Phase: The intelligent control system immediately makes a prediction and adjusts the blade angle of the variable configuration flat plate absorption membrane device 102 from 15° to 24° within 10 seconds. By increasing gas phase turbulence and contact time, it instantly improves mass transfer efficiency and suppresses the rapid rise of outlet H2S concentration.

[0091] II) Steady-state optimization stage: The intelligent control system instructs the flow control unit 115 to gradually increase the flow rate F of the absorbent circulating in the tower provided by the absorbent circulation pump 30; after the outlet H2S concentration stabilizes, the energy-saving optimization mode is activated, and the intelligent control system recalculates the optimal combination of blade angle θ and flow rate F, ultimately stabilizing the blade angle θ at 24° and the absorbent circulating flow rate F in the tower at 25 m³ / s. 3 / h. Throughout the execution of the above main control strategy, as a basic guarantee function, the intelligent control system continuously monitors the liquid level of the internal storage tank 104 of the desulfurization tower through the liquid level sensor 114, and automatically adjusts the outlet flow rate of the rich liquid pump 10, so as to always accurately control the liquid level fluctuation within the set range of ±5%.

[0092] 3. Performance vs. Energy Consumption Comparison.

[0093] Desulfurization efficiency analysis: After the process of this embodiment, the H2S concentration in the final discharged purified dry gas is stable between 6 and 8 ppm, and the desulfurization efficiency is as high as 99.95%.

[0094] Energy consumption comparison analysis: Under the operating conditions of this embodiment, the steam consumption of the regeneration unit 200 is measured to be 0.95 GJ / ton H2S. In contrast, when using a traditional, non-intelligently controlled two-stage MDEA absorber packed tower process to treat the same gas under the same operating conditions, to ensure compliance even under the most unfavorable conditions (e.g., H2S concentration at the desulfurization tower outlet <50 ppm), the operating liquid-to-gas ratio typically needs to be maintained at a high level of 4.5 L / Nm³. 3 According to calculations, its regeneration energy consumption is approximately 1.25 GJ / ton H2S.

[0095] In summary, through intelligent and precise control, this invention achieves efficient, stable, and economical ultra-deep desulfurization of sulfur-containing dry gas in the petroleum refining industry. Through intelligent and precise control, it achieves energy savings of over 24%, resulting in significant economic benefits.

[0096] Application Example 2

[0097] This application example uses the process and apparatus described in Example 1 above to process the pre-treated mixed fuel gas from a large-scale integrated refining and chemical project. The gas has the characteristics of high gas volume and medium to low H2S concentration, and adopts an adaptive optimization control strategy under varying operating conditions.

[0098] 1. For the process flow, please refer to...Figure 6 .

[0099] The specific parameters of the refinery dry gas to be processed are: gas flow rate 12000 Nm³. 3 The operating temperature is 40℃, with an H2S content of 0.8 vol% (8000ppm), a CO2 content of 10 vol%, an operating pressure of 0.8 MPa, and an operating temperature of 40℃.

[0100] The primary objective of the process is to ensure that the H2S concentration at the outlet of the desulfurization tower is consistently ≤5 ppm, in order to meet the stringent feed requirements of the downstream catalytic reforming unit. The secondary objective is to minimize the energy consumption of the unit while ensuring that the primary objective is achieved.

[0101] 2. Core components and parameters.

[0102] The process system used in this embodiment is exactly the same as that in Embodiment 1, and its structure is as follows: Figures 1-5 As shown. The core component configuration remains unchanged.

[0103] Considering the high CO2 content under this operating condition, in order to improve the selectivity for H2S, the absorbent is a composite amine aqueous solution with a total mass fraction of 40%, specifically: 35 wt% MDEA + 5 wt% MEA + 60 wt% water.

[0104] In this embodiment, the intelligent control system is set to an energy-saving priority mode. It uses a built-in particle swarm optimization algorithm to periodically find and execute the optimal economic operating point. Its control logic is as follows:

[0105] I) Baseline liquid-to-gas ratio setting: Based on process model calculations, the theoretical minimum liquid-to-gas ratio required to maintain an outlet H2S concentration ≤ 5 ppm is 1.8 L / Nm³. 3 The system uses this as the benchmark for energy saving.

[0106] II) Energy-Saving Optimization Execution: When the outlet H2S concentration is monitored to be stable within the extremely low range of 0–3 ppm, the intelligent control system determines that there is a margin in the absorbent and automatically triggers the energy-saving optimization mode. This mode will attempt to reduce the absorbent flow rate F and simultaneously fine-tune and reduce the blade angle θ of the flat sheet membrane to maintain efficient mass transfer at a lower liquid volume until a new point of minimum energy consumption is found.

[0107] III) Feedforward Prediction and Correction: The system receives control signals from upstream devices. When fluctuations in upstream operating conditions are predicted (such as an increase in H2S concentration), feedforward control is initiated in advance to increase the blade angle of the flat sheet membrane in advance, smoothly responding to load shocks and avoiding instantaneous exceedances of the outlet H2S concentration.

[0108] 3. Performance vs. Energy Consumption Comparison.

[0109] Desulfurization efficiency analysis: The unit operated continuously for 720 hours, during which the inlet operating conditions fluctuated within ±5%. After treatment using this process, the outlet H2S concentration remained stable below 5 ppm for 99.8% of the time points, fully meeting the requirements of downstream units.

[0110] Energy consumption comparison analysis: Through the energy-saving priority mode, the average liquid-to-gas ratio is controlled at 2.1 L / Nm3, and the regeneration steam consumption is 0.88 GJ / ton H2S. In contrast, if a traditional design without intelligent control is adopted, to cope with the same operating condition fluctuations and ensure an outlet concentration of 5 ppm, at least 3 L / Nm3 of regeneration steam is required. 3 A conservative approach was taken with a constant liquid-to-gas ratio. Simulation calculations showed that its regeneration steam consumption was as high as 1.20 GJ / ton H2S.

[0111] This embodiment further demonstrates that, under the low-to-medium concentration and high-volume operating conditions represented by this embodiment, the present invention exhibits more significant energy-saving advantages, achieving energy savings of up to 26.7% compared to traditional processes, bringing significant environmental and economic benefits to enterprises.

[0112] The above description is merely a preferred embodiment of the present invention, and it should be noted that the scope of protection of the present invention should not be limited thereto. Those skilled in the art can make various modifications, equivalent substitutions, or improvements within the scope of the technical ideas and principles disclosed in the present invention, and all such modifications should fall within the scope of protection of the present invention.

Claims

1. A deep desulfurization device based on adjustable flat-sheet membrane and intelligent collaborative control, characterized in that, Includes a desulfurization tower (100) and an intelligent control system, wherein: The desulfurization tower (100) is provided with an absorbent distribution device (101), a variable-configuration flat plate absorbent membrane device (102), a desulfurization tower packing layer (103), and a bottom storage tank (104) in sequence from top to bottom. The top and bottom of the desulfurization tower (100) are respectively provided with a purified gas outlet (105) and an absorbent rich liquid outlet (106). The upper and lower parts of the side wall are respectively provided with an absorbent inlet (107) and a sulfur-containing gas inlet (108). The absorbent inlet (107) is connected to the absorbent distribution device (101). The desulfurization tower (100) is provided with an internal absorbent circulation loop. The internal absorbent circulation loop includes a filter (113) located at the bottom of the storage tank (104). The external pipeline of the filter (113) is connected to the absorbent inlet (107), and a circulation pump (30) is provided on the pipeline. The flat plate absorption membrane device (102) is composed of several sets of flat plates (120) made of hydrophilic and corrosion-resistant materials arranged in parallel. The flat plate (120) is hollow and has several blades (121) with adjustable angles evenly distributed on one or both sides. The blades (121) are arranged in parallel horizontally on one or both sides of the flat plate (120). The flat plate (120) is provided with a blade adjustment device (130) inside. The blade adjustment device (130) is connected to the blades (121) and is used to adjust the angle (θ) between the blades (121) and the gas flow direction. The intelligent control system has a central control unit, which includes two multi-functional gas sensors (112) respectively installed at the sulfur-containing gas inlet (108) and the purified gas outlet (105), an intelligent control driver (111) installed outside the flat plate absorber membrane device (102), and a flow control unit (115) installed on the absorbent inlet pipeline; wherein, the two multi-functional gas sensors (112) are signal acquisition units used to acquire the inlet gas flow rate (Q) in ), inlet H2S concentration (C in ), and the outlet H2S concentration (C out The intelligent control driver (111) and flow control unit (115) are actuators, respectively used to adjust the angle (θ) between the blade (121) and the gas flow direction and the flow rate (F) of the circulating absorbent entering the desulfurization tower (100) from the absorbent circulation loop in the tower.

2. The deep desulfurization device according to claim 1, characterized in that, The intelligent control system also includes a liquid level sensor (114) installed in the liquid storage tank (104) to continuously monitor the liquid level signal in the liquid storage tank (104) so ​​that the intelligent control system can control the liquid level in the liquid storage tank (104) to be kept within a set range.

3. The deep desulfurization device according to claim 1, characterized in that, The surface of the blade (121) is provided with textures to promote the uniform formation of the liquid film.

4. The deep desulfurization device according to claim 1, characterized in that, The blade adjusting device (130) includes a worm (131) vertically disposed inside the plate (120) and having threads (132) on its surface, a plurality of worm gear sets (133) meshing with the threads (132) of the worm (131), and a rack (134) meshing with the worm gear sets (133). The top end of the worm (131) is driven by a motor. The blade (121) has an upper connecting rod (122) and a lower connecting rod (123) on the side facing the plate (120). The lower connecting rod (123) is connected and fixed to the outer end of the rack (134) of the blade adjusting device (130).

5. A deep desulfurization process based on adjustable flat sheet membrane and intelligent collaborative control, employing the deep desulfurization device according to any one of claims 1 to 4, characterized in that... Includes the following steps: S1: Pass sulfur-containing gas into the desulfurization tower of the deep desulfurization unit; S2: Real-time monitoring of the inlet gas flow rate (Q) of the desulfurization tower in ), inlet H2S concentration (C in ) and the concentration of H2S at the outlet (C out At least one operating condition parameter in ); S3: Based on the operating condition parameters, the intelligent control system synchronously and dynamically coordinates the angle (θ) between the blades (121) of the flat plate absorber membrane device (102) and the gas flow direction, as well as the absorbent flow rate (F) entering the desulfurization tower from the absorbent circulation loop inside the tower, so as to achieve rapid response to operating condition fluctuations and online optimization of the desulfurization process.

6. The deep desulfurization process according to claim 5, characterized in that, In step S3, when a significant fluctuation in the inlet operating conditions is detected, feedforward control is executed. This feedforward control prioritizes and rapidly adjusts the angle (θ) to instantaneously suppress changes in the outlet H2S concentration, and then gradually adjusts the absorbent flow rate (F) to adapt to the new operating conditions. Simultaneously, feedback control is continuously executed based on the outlet H2S concentration (C). out The change in the angle (θ) and absorbent flow rate (F) is used to correct the angle (θ) and absorbent flow rate (F).

7. The deep desulfurization process according to claim 5, characterized in that, The intelligent control system is configured to: monitor at least one of the aforementioned operating condition parameters in real time, and based on the operating condition parameters, execute a composite control logic of feedforward control and feedback control, and collaboratively output at least two control commands: The first control command is used to dynamically adjust the rotation angle (θ) of the blades (121) of the flat plate absorber membrane device (102) to change the gas flow channel configuration; the second control command is used to dynamically adjust the absorbent flow rate (F) entering the desulfurization tower (100) from the absorbent circulation loop in the tower; by synchronously controlling the two variables of angle (θ) and flow rate (F), online control of the desulfurization process is realized.

8. The deep desulfurization process according to claim 7, characterized in that, The feedforward control of the intelligent control system is based on the inlet gas flow rate (Q). in ) and / or inlet H2S concentration (C in The feedback control makes predictive adjustments based on changes in the outlet H2S concentration (C). out The value is compared with the preset target value to make corrective adjustments.

9. The deep desulfurization process according to claim 5, characterized in that, The intelligent control system is also configured to: when the outlet H2S concentration (C) is detected... out When the value is stable and below the preset target value, the energy-saving optimization mode is executed by reducing the flow rate (F) of the absorbent used for circulation and / or adjusting the angle (θ). Through the built-in heuristic optimization algorithm model, the combination of operating parameters (F, θ) with the lowest energy consumption is found and set under the premise of ensuring that the outlet meets the standard.

10. The deep desulfurization process according to claim 5, characterized in that, The intelligent control system is also configured to: monitor the signal of the liquid level sensor (114) in the liquid storage tank (104) inside the desulfurization tower and control the outlet flow rate of the rich liquid pump (10) to stabilize the liquid level of the liquid storage tank (104) within a preset range.

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