A multi-feed flexible hydroprocessing apparatus and method

Abstract

This invention discloses a flexible multi-feedstock hydrotreating device and method, belonging to the field of petrochemical technology. It includes: a feed system configured to switchably transport naphtha, aviation kerosene, or diesel feedstock; a reaction system, whose hydrotreating reactor sequentially contains a protective agent bed, a hydrorefining catalyst bed, and a hydrotreating post-treatment catalyst bed; a hydrogen system, including a fresh hydrogen supply and a circulating hydrogen subsystem, which directly connects to the pipeline hydrogen network and shuts down the fresh hydrogen compressor under specific operating conditions via a hydrogen bypass pipeline, and the circulating hydrogen compressor is equipped with a speed regulation mechanism; and a fractionation system, including a fractionation tower and an adaptive pump group composed of pumps with different flow rates. This invention achieves smooth switching and efficient operation of a single unit across multiple feedstocks, from naphtha and aviation kerosene to diesel, by flexibly adjusting the hydrogen flow direction, compressor speed, and pump group load according to the characteristics of different feedstocks, thereby improving the adaptability and yield stability of the unit under different production modes.

Description

Technical Field

[0001] This invention belongs to the field of petrochemical technology, specifically relating to a flexible hydrogenation device and method for multiple raw materials. Background Technology

[0002] In the refining and chemical industry, hydrogenation technology is a key process for producing clean fuels and high-quality feedstocks. Depending on the target product, existing industrial plants are typically designed for single or dual-product production, exhibiting significant limitations and shortcomings. 1. The device has limited functionality and poor flexibility. Current Status at Home and Abroad: Most industrial hydrogenation units are currently designed for specific feedstocks or products. For example, naphtha hydrogenation refining units are specifically designed to produce reforming feedstocks or ethylene cracking feedstocks; kerosene hydrogenation units mainly produce aviation kerosene; and diesel hydrogenation units are used to produce diesel fuel meeting China V and China VI standards. A few units can achieve mixed hydrogenation of diesel and wax oil, or switching between kerosene and diesel products. However, no unit can process naphtha, kerosene, and diesel as three feedstocks.

[0003] The core problem is the lack of an integrated system capable of simultaneously and efficiently processing three significantly different feedstocks—straight-run naphtha, aviation kerosene fractions, and diesel fractions—and producing corresponding qualified products on demand. When market supply and demand, refinery feedstock supply, or the refinery's overall processing flow change, single-function units cannot flexibly adjust, resulting in low asset utilization and high investment return risk.

[0004] 2. Design bottlenecks restrict compatibility with multiple raw materials The production of ultra-low sulfur diesel (such as the China VI standard) presents a contradiction in terms of reaction severity: high hydrogen partial pressure and temperature are required to ensure deep desulfurization and denitrification; while naphtha hydrorefining, to prevent over-saturation of olefins and loss of aromatics, is usually carried out under relatively mild hydrogen partial pressure. Existing reaction systems are designed for fixed operating conditions, making it difficult to achieve safe and efficient switching between the two extreme conditions.

[0005] Adaptability issues of fractionation systems: The yield of light naphtha at the top of the fractionation tower fluctuates greatly when processing different feedstocks. Traditional designs use fixed-capacity top reflux pumps and product pumps, which can easily lead to low-flow operation or even cavitation when processing feedstocks with low light naphtha yields (such as diesel), while the capacity may be insufficient when processing naphtha.

[0006] Hydrogen system rigidity: Most units have a continuous new hydrogen compressor running, and the means of regulating the circulating hydrogen flow are limited (usually only through the compressor circulation valve), making it difficult to quickly and economically adapt to the huge differences in the hydrogen-to-oil ratio and hydrogen partial pressure requirements of different feedstocks in the reaction system.

[0007] 3. The catalyst system is not optimized. Existing dual-product or multi-product units typically use the same simple loading method for single-product catalysts or perform simple gradation. They fail to tailor and grade the catalysts to meet the different needs of the three feedstocks in terms of reaction activity, diffusion requirements, and resistance to impurities. This results in poor performance or shortened operating cycles under certain feedstock conditions. Summary of the Invention

[0008] This invention addresses the aforementioned problems in the existing technology by proposing a flexible hydrotreating device and method for processing three feedstocks—straight-run naphtha, aviation kerosene, and diesel—in a flexible, efficient, and safe manner.

[0009] This invention can be achieved through the following technical solutions: A flexible hydrogenation processing device for multiple feedstocks includes: The feeding system is configured to switch between conveying naphtha, aviation kerosene, or diesel feedstock; The reaction system includes a hydrogenation reactor, wherein the hydrogenation reactor is provided with, in sequence along the material flow direction, a protective agent bed for removing impurities from raw materials, a hydrogenation refining catalyst bed with desulfurization and denitrification functions, and a hydrogenation post-treatment catalyst bed with aromatic saturation or hydrogenation ring-opening functions. The hydrogen system includes a new hydrogen supply subsystem and a circulating hydrogen subsystem for supplying hydrogen to the reaction system. The hydrogen bypass line is configured to directly connect to the external hydrogen network and shut down the new hydrogen compressor when the unit processes naphtha or aviation kerosene. The circulating hydrogen subsystem includes a circulating hydrogen compressor equipped with a speed regulation mechanism for adjusting the hydrogen-to-oil ratio of the system for different feedstock conditions. A fractionation system, connected downstream of the reaction system, includes a fractionation column and an adaptive pump set installed on the fractionation column. The adaptive pump set consists of multiple pumps with different flow rates connected in parallel to match the yield fluctuations under different raw material conditions.

[0010] As a further improvement of the present invention, the feeding system includes a raw material tank and a feed pump. The raw material in the raw material tank is output to the reaction system through the reaction feed pump, and a backwash filter is provided on the inlet pipeline of the raw material tank.

[0011] As a further improvement of the present invention, the reaction system further includes a heating furnace, the raw material tank is connected to the inlet of the heating furnace via the feed pump, the new hydrogen supply subsystem and the circulating hydrogen subsystem are connected to the inlet of the heating furnace, and the outlet of the heating furnace is connected to the hydrogenation reactor.

[0012] As a further improvement of the present invention, a separation system is also included, disposed between the reaction system and the fractionation system, the separation system comprising: A high-pressure separator, the gas phase outlet of which is connected to the circulating hydrogen subsystem; A low-pressure separator has its inlet connected to the liquid phase outlet of the high-pressure separator, and its liquid volume outlet is connected to the fractionation system.

[0013] As a further improvement of the present invention, a circulating hydrogen desulfurization subsystem is also included, the circulating hydrogen desulfurization subsystem comprising: The circulating hydrogen desulfurization tower has its gas inlet connected to the gas phase outlet of the high-pressure separator, and its outlet connected to the circulating hydrogen compressor. The inlet pipeline and outlet pipeline of the circulating hydrogen desulfurization tower are respectively equipped with an inlet separator and an outlet separator.

[0014] As a further improvement of the present invention, the fractionation system further includes: The stripping tower has its inlet connected to the outlet of the low-pressure separator, and its outlet is connected to the inlet of the fractionation tower.

[0015] As a further improvement of the present invention, the adaptive pump set specifically includes: The fractionation tower top reflux pump set includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel, and the fractionation tower top reflux pump set is installed on the reflux pipeline at the top of the fractionation tower; The light naphtha product external delivery pump set includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel, and the light naphtha product external delivery pump set is installed on the product external delivery pipeline of the fractionation tower.

[0016] As a further improvement of the present invention, the circulating hydrogen compressor is equipped with a drive turbine or variable frequency motor, and its outlet pipeline and inlet pipeline are connected by an anti-surge return line with flow regulation function.

[0017] As a further improvement of the present invention, it also includes a control system, which is connected via signal lines to the new hydrogen compressor, the shut-off valve on the hydrogen bypass pipeline, the circulating hydrogen subsystem, and the adaptive pump group, respectively.

[0018] This invention also provides a flexible hydrogenation method for multiple feedstocks, applied to the aforementioned flexible hydrogenation apparatus for multiple feedstocks, comprising the following steps: S1. Operating mode setting: Select naphtha mode, aviation kerosene mode or diesel mode according to the raw materials and target products. S2. Hydrogen supply system switching: When in diesel mode, start the new hydrogen compressor to boost the hydrogen supply and at the same time increase the speed of the circulating hydrogen compressor through the control system to increase the circulating hydrogen flow rate; When in naphtha mode or aviation kerosene mode, the new hydrogen compressor is shut down, and hydrogen is supplied through the hydrogen bypass line using the pipeline pressure. At the same time, the speed of the circulating hydrogen compressor is reduced through the control system, and fine-tuning is performed using the anti-surge valve on the anti-surge return line. S3. Reaction condition adjustment: The control system adjusts the inlet temperature and temperature rise of each bed of the hydrogenation reactor to control the reaction temperature under different modes within the preset temperature range in order to match the reaction severity required by the target raw material. S4. Flow load matching: The control system calculates the required pumping flow rate based on the real-time flow rate at the top of the distillation tower, and automatically selects and starts the appropriate flow rate pump combination from the adaptive pump group.

[0019] Compared with the prior art, the present invention has the following beneficial effects: 1. Breakthrough flexible production capacity: For the first time, a single hydrogenation unit has achieved flexible processing of three feedstocks: straight-run naphtha, aviation kerosene, and diesel. The unit's annual operating flexibility can reach 30%-130%, enabling timely adjustments to the product structure based on changes in the supply and demand of the refined oil market, thereby maximizing asset utilization.

[0020] 2. Significant Energy Saving and Consumption Reduction: Based on the logic of on-demand start-stop of the new hydrogen compressor and fine-tuning of the speed of the circulating hydrogen compressor, the ineffective power consumption of starting a high-power compressor under low-pressure conditions is eliminated. Through this wide-range control of the compressor load, it is expected that the overall energy saving can reach 15%-25% compared with the traditional rigid design of similar-scale units when processing naphtha and aviation kerosene.

[0021] 3. High investment and operational economy: This solution realizes the functions of three single-function devices through a flexible system during the design phase, which greatly saves land occupation, infrastructure investment and investment in repetitive rotating equipment, and significantly reduces the fixed cost of unit products and the labor cost of later maintenance.

[0022] 4. Safe and stable operation: All equipment in the unit is designed according to the highest pressure level standard and is equipped with an advanced process index prediction and control system, which ensures the system thermal balance and pressure stability during multiple raw material switching and large fluctuations in operating load, fundamentally avoiding the risks of over-temperature, over-pressure and pump cavitation that are prone to occur in traditional production conversion operations.

[0023] 5. Excellent product quality: Through the optimization and adaptation of special catalyst gradation and multi-condition process parameters, the straight-run refined naphtha produced meets the requirements of continuous reforming feedstock, aviation kerosene meets the No. 3 jet fuel standard, and diesel products can stably meet the China VI and above emission standards, realizing "one machine with multiple functions and one machine with multiple advantages".

[0024] 6. High technical replicability: This design concept and adaptive adjustment logic are not only applicable to the integrated design of new plants, but also provide a clear and easy-to-implement technical path for the capacity expansion and operation flexibility improvement of existing single-function hydrogenation plants, and have extremely high industrial application potential. Attached Figure Description

[0026] Figure 1 This is a process flow diagram of the multi-raw material flexible hydrogenation treatment device of the present invention; Figure 2 This is a flowchart of the circulating hydrogen desulfurization system of the present invention; Figure 3 This is a flowchart of the novel hydrogen compressor system of the present invention.

[0027] In the diagram, 100 is the raw material tank; 110 is the backwash filter; and 120 is the reaction feed pump. 200. Hydrogenation reactor; 210. Heating furnace; 220. High-pressure separator; 230. Low-pressure separator; 240. Circulating hydrogen desulfurization tower; 241. Inlet separator; 242. Outlet separator; 243. Circulating hydrogen compressor; 250. Fresh hydrogen compressor; 251. Fresh hydrogen inlet separator; 300. Stripping tower; 310. Stripping tower cooling equipment; 320. Stripping tower separator; 330. Stripping tower reflux pump; 400. Fractionating tower; 410. Fractionating tower top reflux pump set; 420. Light naphtha product external delivery pump set; 430. Fractionating tower cooling equipment; 440. Fractionating tower separator; 450. Fractionating tower reboiler; 460. Heat exchanger; 470. Filtration and coalescence unit. Detailed Implementation

[0029] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings to further illustrate the technical methods of the present invention. However, the present invention is not limited to these embodiments.

[0030] like Figures 1-3 As shown, the present invention provides a flexible hydrogenation processing device for multiple feedstocks, comprising: The feeding system is configured to switch between conveying naphtha, aviation kerosene, or diesel feedstock; The reaction system includes a hydrogenation reactor 200, inside which, along the material flow direction, are arranged a protective agent bed for removing impurities from raw materials, a hydrogenation refining catalyst bed with desulfurization and denitrification functions, and a hydrogenation post-treatment catalyst bed with aromatic saturation or hydrogenation ring-opening functions. The hydrogen system includes a new hydrogen supply subsystem for supplying hydrogen to the reaction system and a circulating hydrogen subsystem. The hydrogen bypass line is configured to directly connect to the external hydrogen network and shut down the new hydrogen compressor 250 when the unit processes naphtha or aviation kerosene. The circulating hydrogen subsystem includes a circulating hydrogen compressor 243 equipped with a speed regulating mechanism for adjusting the hydrogen-to-oil ratio of the system for different feedstock conditions. The fractionation system, connected downstream of the reaction system, includes a fractionation tower 400 and an adaptive pump set installed on the fractionation tower 400. The adaptive pump set consists of multiple pumps with different flow rates connected in parallel to match the yield fluctuations under different raw material conditions.

[0031] It should be noted that existing hydrogenation units typically have the limitation of being "dedicated to a single purpose," meaning that the pressure rating, catalyst gradation, hydrogen load, and pump displacement of the unit are all rigidly designed based on the physical properties of a single feedstock (such as diesel only). This results in a single unit being unable to meet the processing needs of light naphtha and heavy diesel, which have vastly different properties.

[0032] To address the aforementioned issues, this application achieves compatible guidance for multiple raw materials at the feeding end through a switchable process flow. The specific principle is explained below: When the system switches from heavy feedstock to light feedstock, the hydrogenation reactor 200 in the reaction system utilizes its preset gradient catalyst bed to intercept impurities, perform precise deep hydrogenation and regulate the potential content of aromatic hydrocarbons in the product from top to bottom, so that feedstocks of different fractions can obtain the best reaction kinetic environment. In the hydrogen supply stage, the system achieves "high and low pressure decoupling" through bypass logic: when processing diesel fuel with high pressure demand, the new hydrogen compressor 250 is run; while when switching to naphtha or jet fuel with low pressure demand, hydrogen is supplied directly through the bypass pipeline using the pipeline pressure and the compressor is shut down. At the same time, the speed regulation function of the circulating hydrogen compressor 243 is used to dynamically match the hydrogen-to-oil ratio to the target operating condition. In the fractionation stage, the control system monitors the current operating rate and, through the combined action of adaptive pump sets, starts a high-flow-rate pump set in naphtha mode and automatically switches to a low-flow-rate pump set in diesel mode (when the top yield is extremely low).

[0033] Overall, the device provided in this application has at least the following advantages compared to the prior art: 1. Breakthrough flexible production capacity: For the first time, a single hydrogenation unit has achieved flexible processing of three feedstocks: straight-run naphtha, aviation kerosene, and diesel. The unit's annual operating flexibility can reach 30%-130%, enabling timely adjustments to the product structure based on changes in the supply and demand of the refined oil market, thereby maximizing asset utilization.

[0034] 2. Significant Energy Saving and Consumption Reduction: Based on the logic of on-demand start / stop of the new hydrogen compressor 250 and fine speed adjustment of the circulating hydrogen compressor 243, the ineffective power consumption of starting high-power compressors under low-pressure conditions is eliminated. Through this wide-range control of compressor load, it is expected that when processing naphtha and aviation kerosene, the overall energy saving can reach 15%-25% compared with traditional rigid-designed units of the same scale.

[0035] 3. High investment and operational economy: This solution realizes the functions of three single-function devices through a flexible system during the design phase, which greatly saves land occupation, infrastructure investment and investment in repetitive rotating equipment, and significantly reduces the fixed cost of unit products and the labor cost of later maintenance.

[0036] 4. Safe and stable operation: All equipment in the unit is designed according to the highest pressure level standard and is equipped with an advanced process index prediction and control system, which ensures the system thermal balance and pressure stability during multiple raw material switching and large fluctuations in operating load, fundamentally avoiding the risks of over-temperature, over-pressure and pump cavitation that are prone to occur in traditional production conversion operations.

[0037] 5. Excellent product quality: Through the optimization and adaptation of special catalyst gradation and multi-condition process parameters, the straight-run refined naphtha produced meets the requirements of continuous reforming feedstock, aviation kerosene meets the No. 3 jet fuel standard, and diesel products can stably meet the China VI and above emission standards, realizing "one machine with multiple functions and one machine with multiple advantages".

[0038] 6. High technical replicability: This design concept and adaptive adjustment logic are not only applicable to the integrated design of new plants, but also provide a clear and easy-to-implement technical path for the capacity expansion and operation flexibility improvement of existing single-function hydrogenation plants, and have extremely high industrial application potential.

[0039] Preferably, the feeding system includes a raw material tank 100 and a feed pump. The raw material in the raw material tank 100 is output to the reaction system through the reaction feed pump 120. A backwash filter 110 is installed on the inlet pipeline of the raw material tank 100. The raw material oil enters the raw material tank 100 after passing through the backwash filter 110 to intercept mechanical impurities. The feed pump operates at a variable frequency according to the flow rate set by the control system.

[0040] The backwash design ensures that impurities are effectively prevented from entering the system when switching to diesel feedstocks with complex compositions, and the filter's self-cleaning function ensures a continuous feed supply.

[0041] Preferably, the reaction system also includes a heater 210. The raw material tank 100 is connected to the inlet of the heater 210 via a feed pump. The new hydrogen supply subsystem and the circulating hydrogen subsystem are connected to the inlet of the heater 210. The heater 210 is used to heat the mixed material to the reaction temperature (e.g., 270℃-355℃) and then send the material to the hydrogenation reactor 200.

[0042] The reaction temperature setting is selected according to the feeding mode of different raw materials, and the reaction temperature of the heating furnace 210 is automatically adjusted to ensure that raw materials of different viscosities and distillation ranges can reach the optimal reaction activation temperature before entering the reactor.

[0043] Preferably, it further includes a separation system disposed between the reaction system and the fractionation system, the separation system comprising: The high-pressure separator has its gas phase outlet connected to the circulating hydrogen subsystem. The inlet of the low-pressure separator is connected to the liquid phase outlet of the high-pressure separator, and the liquid flow outlet of the low-pressure separator is connected to the fractionation system.

[0044] Specifically, the reaction products are condensed and then enter a high-pressure separator for gas-liquid separation. Hydrogen is recovered through a circulating hydrogen system, while the liquid phase enters a low-pressure separator for further flash evaporation. The liquid phase after removing light components enters the downstream fractionation system. This staged separation design ensures the recycling rate of hydrogen and reduces the separation pressure of the fractionation system, thereby improving stability.

[0045] Preferably, it also includes a circulating hydrogen desulfurization subsystem, which comprises: The circulating hydrogen desulfurization tower 240 has its gas inlet connected to the gas phase outlet of the high-pressure separator, and its outlet connected to the circulating hydrogen compressor 243. The inlet pipeline and outlet pipeline of the circulating hydrogen desulfurization tower 240 are respectively equipped with an inlet separator 241 and an outlet separator 242.

[0046] Specifically, the circulating hydrogen gas stream discharged from the high-pressure separator inevitably carries a certain amount of liquid hydrocarbon droplets or condensates. The gas stream first enters the inlet separator 241 to remove the liquid phase. Subsequently, the dry gas after removing the liquid phase flows out from the top of the inlet separator 241 and enters the circulating hydrogen desulfurization tower 240. The circulating hydrogen desulfurization tower 240 is injected with lean amine liquid. The hydrogen sulfide component in the gas is absorbed by the solvent in the circulating hydrogen desulfurization tower 240. The purified gas after desulfurization is discharged from the top of the tower and enters the outlet separator 242 for further removal of the liquid phase to prevent the ammonia-containing solvent from entering the subsequent circulating hydrogen compressor 243. Finally, the circulating hydrogen compressor 243 outputs circulating hydrogen to the heater 210 for reuse.

[0047] This design, by setting up double liquid separation barriers before and after the desulfurization tower, completely solves the cylinder slugging and valve liquid slugging faults that are prone to occur in the circulating hydrogen compressor 243, and greatly improves the operational reliability of the equipment.

[0048] The circulating hydrogen compressor 243 is equipped with a drive turbine or variable frequency motor, and its outlet pipeline and inlet pipeline are connected by an anti-surge return line with flow regulation function. By adjusting the combination mode of the speed of the circulating hydrogen compressor 243 (main control) and the anti-surge return line (auxiliary control), the circulating hydrogen flow rate can be quickly and smoothly adjusted over a wide range to accurately match the requirements of different raw materials for hydrogen-oil ratio and system pressure drop.

[0049] Preferably, the fractionation system further includes: Stripping tower 300 has its inlet connected to the outlet of the low-pressure separator, and its outlet connected to the inlet of fractionation tower 400. Specifically: The liquid-phase hydrogenated oil containing dissolved hydrogen, hydrogen sulfide and light hydrocarbon components discharged from the low-pressure separator enters the stripping tower 300 under the action of pressure difference. The control system adjusts the opening of the regulating valve in real time according to the liquid level signal of the low-pressure separator to ensure a stable feed load. After the material enters the tower, it flows down the tray layer by layer and comes into countercurrent contact with the superheated steam rising from the bottom of the tower at a pressure of . During the stripping process, the principle of partial pressure is utilized to strip away the extremely light components (such as C1-C4) and harmful gases (such as H2S) remaining in the liquid phase. When the unit is operating under naphtha conditions, the stripping tower 300 is mainly responsible for removing light components and stabilizing the saturated vapor pressure. When operating in diesel mode, stripping tower 300 adjusts the bottom steam volume (e.g., the stripping ratio is controlled at around 1% to 3%) to fully strip the light-end components from the diesel fraction, ensuring that the flash point of the subsequent fractionation products meets the standard. The stripped bottom oil is then sent to fractionation tower 400 for precise positioning and cutting under the drive of the bottom pump.

[0050] The presence of stripping tower 300 provides a buffer for the system, absorbing the load impact caused by raw material fluctuations in the reaction system, ensuring the stability of fractionation tower 400 operation, and is a core auxiliary facility for achieving the unit's "30%-130% operational flexibility".

[0051] Furthermore, the top of the stripping tower 300 is equipped with a reflux system consisting of a stripping tower cooling device 310, a stripping tower separator 320, and a stripping tower reflux pump 330. Specifically, the inlet of the stripping tower cooling device 310 is connected to the top gas pipeline of the stripping tower 300, and the high-temperature top oil and gas are condensed and cooled through heat exchange. The cooled material enters the stripping tower separator 320 to achieve gravity sedimentation separation of non-condensable gases (including H2S desulfurized hydrogen sulfide gas), liquid light oil (crude naphtha), and acidic water. The suction end of the stripping tower reflux pump 330 is connected to the bottom oil phase collection tank of the separator, and the discharge end is connected to the top of the stripping tower 300 through a reflux control valve.

[0052] Preferably, the adaptive pump set specifically includes: The fractionation tower top reflux pump group 410 includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel. The fractionation tower top reflux pump group is installed on the reflux pipeline at the top of the fractionation tower 400. The light naphtha product external delivery pump set 420 includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel. The light naphtha product external delivery pump set 420 is installed on the product external delivery pipeline of the fractionation tower 400.

[0053] Because this unit needs to handle three feedstocks with vastly different physical properties—naphtha, jet fuel, and diesel—the yield at the top of the 400-liter fractionation tower fluctuates over a wide range (for example, the yield at the top of the tower can reach over 85% when processing naphtha, while the yield of light oil at the top of the tower is often less than 5% when processing diesel). Its core operating logic is as follows: Heavy load conditions (such as full-volume naphtha processing): When the online flow monitor of the fractionation system detects a high yield signal, the control system prioritizes starting the high-flow-rate pump to meet the power requirements for reflux ratio adjustment and large-scale product delivery. At this time, the low-flow-rate pump is in hot standby mode.

[0054] Light load conditions (such as processing diesel or jet fuel): When the system switches to diesel feedstock, the output at the top of the tower decreases sharply. At this time, the control system triggers a logic switch, shutting down the high-flow pump and automatically starting the low-flow pump. By precisely matching the low flow demand with a small displacement, it ensures that the mechanical operating point always falls in the middle range of the pump efficiency curve.

[0055] By setting up large and small flow rate pump sets in parallel on the top reflux and product delivery pipelines, and combining the dynamic switching logic of frequency conversion regulation and output linkage, this invention solves the mechanical safety hazards such as pump body backflow heat, severe bearing vibration and cavitation damage induced by the traditional single large flow rate pump under light load conditions such as processing diesel fuel, which is caused by long-term operation deviating from the rated operating point. This significantly extends the mean time between failures (MTBF) of the moving equipment.

[0056] Meanwhile, this "on-demand matching" pump operation mode ensures that the motor is always operating within its high-efficiency range, eliminating the power waste caused by "overpowered motors operating in small loads" and significantly optimizing the unit's energy consumption indicators. Furthermore, the linear adjustment capability of the small-flow pump under light loads allows the fractionation tower 400 to maintain stable reflux ratio control even at low production levels, thus ensuring the separation accuracy and distillation range qualification rate of light naphtha and aviation kerosene products across the entire operating range.

[0057] In addition, the top of the fractionation tower 400 is equipped with a fractionation tower cooling device 430 and a fractionation tower separator 440. The fractionation tower cooling device 430, the fractionation tower separator 440 and the fractionation tower top reflux pump group 410 together form the reflux system at the top of the fractionation tower.

[0058] The thermodynamic regulation function of the reflux system not only stabilizes the pressure at the top of the column, but also provides the necessary liquid-to-gas ratio environment for the entire column, ensuring the continuity and stability of the large-scale fractionation process. With the flow matching logic of the adaptive pump group, the reflux pump group can maintain the necessary circulation volume with the lowest power consumption during low load switching, which not only prevents the pump from over-vibration operation in the low flow range, but also minimizes the cooling water or power consumption of the condensation system.

[0059] Furthermore, the bottom of the fractionation column 400 is equipped with a reflux line for the reboiler 450-440. The liquid material at the bottom of the fractionation column 400 is drawn out through the reboiler reflux line, while most of the heavy components enter the reboiler 450-440 for heating. The reboiler uses the heated fuel gas to provide heat, vaporizing part of the liquid phase into a gaseous stream and returning it to the bottom of the column, providing an upward vapor flow for the entire column's fractionation. Another portion of the stable bottom product enters the output pipeline and first passes through heat exchanger 460. In heat exchanger 460, the high-temperature bottom product exchanges heat with the feed oil or demineralized water, recovering heat energy, reducing its own temperature, and replacing part of the heat tracing load.

[0060] After cooling, the product enters the filtration and coalescence device 470, which provides a dual guarantee of "mechanical interception + physical separation". This not only ensures that the product meets high standards for color and moisture content, but also greatly extends the service life of the filters in the subsequent storage tanks and distribution system.

[0061] Preferably, it also includes a control system (APC), which is connected via signal lines to the new hydrogen compressor 250, the shut-off valve on the hydrogen bypass line, the circulating hydrogen subsystem, and the adaptive pump set.

[0062] The APC control system can automatically calculate and issue set values ​​for key parameters such as reaction temperature, hydrogen partial pressure, and circulating hydrogen flow rate according to the raw material switching command. It coordinates and controls the start and stop of the new hydrogen compressor 250, the speed of the circulating hydrogen compressor 243, the start and stop of each pump group, and the operation of the fractionation tower 400, so as to achieve a smooth and rapid switching of the entire unit's operating conditions.

[0063] By introducing an Advanced Control System (APC) as the "intelligent central hub" of the entire plant, this invention achieves closed-loop coordination throughout the entire process, from hydrogen supply and reaction balance to fractionation output, breaking down the operational silos between subsystems. Its benefits include: First, it eliminates the lag and parameter fluctuations of manual adjustment during large-scale operating condition switching (such as switching from diesel operating condition to naphtha operating condition), shortens the smooth transition time of operating condition by more than 50%, and greatly reduces the defective products and unqualified components generated during the switching period. Secondly, APC can accurately calculate and issue the optimal control strategy based on the real-time composition of the raw materials, ensuring that the new hydrogen and circulating hydrogen systems operate under the optimal hydrogen partial pressure, effectively avoiding excessive loss of hydrogen resources or insufficient reactivity. Finally, its "predictive adjustment" function can adjust the compressor speed and pump start-stop status in advance when the load fluctuates, so that the moving equipment always operates in a safe and efficient mechanical range. This not only reduces the energy consumption of the unit, but also endows the entire hydrogenation unit with a very high level of intelligence and excellent high-flexibility processing capabilities at the system level.

[0064] This invention also provides a flexible hydrogenation method for multiple feedstocks, applied to the aforementioned flexible hydrogenation apparatus for multiple feedstocks, comprising the following steps: S1. Operating mode setting: Select naphtha mode, aviation kerosene mode or diesel mode according to the raw materials and target products. S2, Hydrogen Supply Regulation: When in diesel mode, start the new hydrogen compressor 250 to boost the hydrogen supply. When in naphtha mode or aviation kerosene mode, shut down the new hydrogen compressor 250 and supply hydrogen using the pipeline pressure through the hydrogen bypass line. S3. Optimization of reaction conditions: By adjusting the fuel quantity of the upstream heater 210 of the hydrogenation reactor 200, the reaction temperature under different modes is controlled within the preset temperature range; By adjusting the speed of the circulating hydrogen compressor 243 or the opening of the anti-surge return line, the hydrogen-to-oil ratio in naphtha mode or aviation kerosene mode is controlled within the first preset range, and the hydrogen-to-oil ratio in diesel mode is controlled within the second preset range. S4. Flow load matching: Obtain the liquid level signal at the top of the fractionation tower 400, calculate the required pumping flow rate based on the light component yield in the current mode, and automatically select and activate the appropriate flow rate pump combination from the adaptive pump group.

[0065] This method demonstrates significant technical advantages by achieving a leapfrog improvement in the operation of the entire device from "static fixed-point" to "dynamic adaptive": In terms of energy efficiency optimization, its core operating logic can intelligently select "compressor boosting" or "direct hydrogen supply from pipeline pressure difference" based on the hydrogen consumption characteristics of the raw materials, thus completely eliminating the high-energy-consuming new hydrogen compressor 250 operating cost when processing light raw materials. In terms of operational stability, by deeply connecting the "heat management (heater 210)" and "mass transfer (circulating hydrogen)" of the reaction system with the "dynamic response (pump assembly)" of the fractionation system, a smooth transition of process parameters is ensured during mode switching.

[0066] Especially in the fractionation process, the liquid level signal is used to drive the pump group to switch between different sizes in real time. This eliminates the risk of mechanical damage to moving equipment under low load conditions from a process logic perspective, ensuring a precise match between the operation of the fractionation tower 400 and the material yield.

[0067] Ultimately, this method not only enables the device to handle a very wide range of raw materials with flexible processing capabilities, but also maximizes catalyst operating efficiency and optimizes monomer energy efficiency throughout its entire life cycle while ensuring the distillation range and deep desulfurization and denitrification effects of the refined products.

[0068] The technical means disclosed in this invention are not limited to those described above, but also include technical solutions composed of any combination of the above technical features. The above are specific embodiments of this invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

[0069] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0070] Furthermore, in this invention, the use of terms such as "first," "second," and "a" is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. The terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two elements or the interaction between two elements, unless otherwise explicitly specified. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0071] The technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0072] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A flexible hydrogenation processing device for multiple raw materials, characterized in that, include: The feeding system is configured to switch between conveying naphtha, aviation kerosene, or diesel feedstock; The reaction system includes a hydrogenation reactor, wherein the hydrogenation reactor is provided with, in sequence along the material flow direction, a protective agent bed for removing impurities from raw materials, a hydrogenation refining catalyst bed with desulfurization and denitrification functions, and a hydrogenation post-treatment catalyst bed with aromatic saturation or hydrogenation ring-opening functions. The hydrogen system includes a new hydrogen supply subsystem and a circulating hydrogen subsystem for supplying hydrogen to the reaction system. The hydrogen bypass line is configured to directly connect to the external hydrogen network and shut down the new hydrogen compressor when the unit processes naphtha or aviation kerosene. The circulating hydrogen subsystem includes a circulating hydrogen compressor equipped with a speed regulation mechanism for adjusting the hydrogen-to-oil ratio of the system for different feedstock conditions. A fractionation system, connected downstream of the reaction system, includes a fractionation column and an adaptive pump set installed on the fractionation column. The adaptive pump set consists of multiple pumps with different flow rates connected in parallel to match the yield fluctuations under different raw material conditions.

2. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, The feeding system includes a raw material tank and a feed pump. The raw material in the raw material tank is output to the reaction system through the reaction feed pump. A backwash filter is installed on the inlet pipeline of the raw material tank.

3. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, The reaction system also includes a heating furnace. The raw material tank is connected to the inlet of the heating furnace via the feed pump. The new hydrogen supply subsystem and the circulating hydrogen subsystem are connected to the inlet of the heating furnace. The outlet of the heating furnace is connected to the hydrogenation reactor.

4. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, It also includes a separation system disposed between the reaction system and the fractionation system, the separation system comprising: A high-pressure separator, the gas phase outlet of which is connected to the circulating hydrogen subsystem; A low-pressure separator has its inlet connected to the liquid phase outlet of the high-pressure separator, and its liquid volume outlet is connected to the fractionation system.

5. The multi-raw material flexible hydrogenation processing device according to claim 4, characterized in that, It also includes a circulating hydrogen desulfurization subsystem, which comprises: The circulating hydrogen desulfurization tower has its gas inlet connected to the gas phase outlet of the high-pressure separator, and its outlet connected to the circulating hydrogen compressor. The inlet pipeline and outlet pipeline of the circulating hydrogen desulfurization tower are respectively equipped with an inlet separator and an outlet separator.

6. The multi-raw material flexible hydrogenation processing device according to claim 4, characterized in that, The fractionation system also includes: The stripping tower has its inlet connected to the outlet of the low-pressure separator, and its outlet is connected to the inlet of the fractionation tower.

7. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, The adaptive pump set specifically includes: The fractionation tower top reflux pump set includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel, and the fractionation tower top reflux pump set is installed on the reflux pipeline at the top of the fractionation tower; The light naphtha product external delivery pump set includes at least one high-flow-rate pump and at least one low-flow-rate pump connected in parallel, and the light naphtha product external delivery pump set is installed on the product external delivery pipeline of the fractionation tower.

8. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, The circulating hydrogen compressor is equipped with a drive turbine or variable frequency motor, and its outlet pipeline and inlet pipeline are connected by an anti-surge return line with flow regulation function.

9. The multi-raw material flexible hydrogenation processing device according to claim 1, characterized in that, It also includes a control system, which is connected via signal lines to the new hydrogen compressor, the shut-off valve on the hydrogen bypass pipeline, the circulating hydrogen subsystem, and the adaptive pump set.

10. A multi-feed flexible hydrogenation treatment method, applied to the multi-feed flexible hydrogenation treatment apparatus as described in any one of claims 1-9, characterized in that, Includes the following steps: S1. Operating mode setting: Select naphtha mode, aviation kerosene mode or diesel mode according to the raw materials and target products. S2. Hydrogen supply system switching: When in diesel mode, start the new hydrogen compressor to boost the hydrogen supply and at the same time increase the speed of the circulating hydrogen compressor through the control system to increase the circulating hydrogen flow rate; When in naphtha mode or aviation kerosene mode, the new hydrogen compressor is shut down, and hydrogen is supplied through the hydrogen bypass line using the pipeline pressure. At the same time, the speed of the circulating hydrogen compressor is reduced through the control system, and fine-tuning is performed using the anti-surge valve on the anti-surge return line. S3. Reaction condition adjustment: The control system adjusts the inlet temperature and temperature rise of each bed of the hydrogenation reactor to control the reaction temperature under different modes within the preset temperature range in order to match the reaction severity required by the target raw material. S4. Flow load matching: The control system calculates the required pumping flow rate based on the real-time flow rate at the top of the distillation tower, and automatically selects and starts the appropriate flow rate pump combination from the adaptive pump group.

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