System and method for producing SAF based on pulses

Abstract

The invention relates to the technical field of aviation fuel preparation, and provides a system and method for producing SAF based on pulses. The system comprises a raw material pretreatment unit, a pulse reaction unit communicated with the raw material pretreatment unit, a product separation and purification unit communicated with the pulse reaction unit, and a pulse regeneration unit and a central control unit which are connected with the pulse reaction unit. The technical problems that in traditional SAF continuous production, catalyst deactivation is fast, product selectivity is low, and energy consumption is high are solved, finally, an SAF product with the C8-C16 long-chain alkane content larger than or equal to 90% is obtained through separation and purification, the SAF yield is remarkably improved compared with a traditional process, the service life of the catalyst is prolonged, and the method has industrial application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of aviation fuel preparation, in particular to a system and method for producing SAF based on pulse. BACKGROUND

[0002] As a clean energy to replace traditional petroleum-based aviation kerosene, SAF has the advantages of low carbon footprint, excellent combustion performance, and good compatibility with existing aviation fuel systems, and is one of the core paths to achieve carbon neutrality in the aviation industry. The mainstream production processes of SAF currently include Fischer-Tropsch synthesis (using synthesis gas as raw material), hydrodeoxygenation (using waste oil and vegetable oil as raw material), and methanol-to-hydrocarbon (using methanol as raw material). However, the existing processes mostly use a continuous constant reaction condition operation mode, which has the following key technical bottlenecks:

[0003] (1) Fast catalyst deactivation: During the synthesis of SAF, carbon deposition or metal site sintering easily occurs on the surface of the catalyst. The traditional continuous process cannot adjust the reaction conditions in real time to inhibit the generation of carbon deposition, resulting in a catalyst life of usually only 800-1000h, and frequent replacement of catalysts greatly increases production costs;

[0004] (2) Poor product selectivity: The core component of SAF is C8-C16 straight-chain alkanes, and in the traditional continuous process, constant control of reaction temperature, pressure or reactant concentration easily leads to a wide product distribution, and the selectivity of C8-C16 alkanes is usually only 65-75%, resulting in high energy consumption in the subsequent separation and purification process;

[0005] (3) High energy consumption and cost: In order to maintain constant reaction conditions, the traditional process needs to continuously input a large amount of energy, and due to the low selectivity of the product, the energy consumption of the separation and purification process accounts for 30-40% of the total energy consumption, resulting in a SAF production cost that is 2-3 times that of traditional aviation kerosene, which limits its large-scale application.

[0006] Therefore, it is a key requirement in the field to develop a production technology that can dynamically match the demand for SAF synthesis, inhibit catalyst deactivation, and has low energy consumption. SUMMARY

[0007] The present application provides a system and method for producing SAF based on pulse, which breaks the constant condition limitation of traditional continuous process through pulse regulation of reaction and catalyst regeneration process, optimizes reaction kinetics and catalyst activity, and realizes efficient and low-consumption production of SAF.

[0008] To achieve the above purpose, the present application proposes the following technical solutions:

[0009] In a first aspect, the present application provides a system for producing SAF based on pulse, comprising:

[0010] The raw material pretreatment unit is used to purify and adjust the composition of the initial raw materials to obtain pretreated raw materials;

[0011] A pulse reaction unit connected to the raw material pretreatment unit is used to convert the pretreated raw material under pulse-controlled reaction conditions to obtain a mixed product containing SAF.

[0012] The product separation and purification unit, which is connected to the pulse reaction unit, is used to separate and purify the mixed product containing SAF to obtain purified SAF.

[0013] A pulse regeneration unit connected to the pulse reaction unit is used to perform pulse regeneration on the deactivated catalyst within the pulse reaction unit.

[0014] The central control unit is electrically connected to the raw material pretreatment unit, the pulse reaction unit, the product separation and purification unit, and the pulse regeneration unit, respectively, and is used to coordinate the operating parameters of each unit.

[0015] Furthermore, the raw material pretreatment unit includes at least one of a desulfurization tower, a decarbonization tower, a deacidification tower, a denitrification tower, a dehydrator, a component blender, and a heavy metal adsorber.

[0016] Furthermore, the pulse reaction unit includes a pulse reactor connected to the raw material pretreatment unit, the pulse reactor is equipped with a multi-parameter pulse control module, and the pulse reactor is provided with a catalyst packing layer for accommodating the catalyst.

[0017] Furthermore, the product separation and purification unit includes a gas-liquid separator connected to the pulse reactor, and the gas-liquid separator is connected in series with a light hydrocarbon removal tower, a heavy hydrocarbon removal tower and a molecular sieve dryer.

[0018] Furthermore, the pulse regeneration unit includes a regeneration gas preparation device and a pulse injection device connected to the regeneration gas preparation device. The pulse injection device is connected to the pulse reactor and is also connected to the catalyst packing layer.

[0019] In a second aspect, the present invention provides a method for generating SAF based on pulses, the method using the system described in any one of the first aspects above, comprising the following steps:

[0020] S1. The initial raw material is fed into the raw material pretreatment unit for pretreatment to obtain pretreated raw material;

[0021] S2. The pretreated raw material is fed into the pulse reaction unit. Under the action of the catalyst, at least one of the reaction temperature, reaction pressure and reactant concentration is pulsedly controlled by the multi-parameter pulse control module to carry out the SAF synthesis reaction and obtain a mixed product containing SAF.

[0022] S3. The SAF-containing mixed product is passed into a product separation and purification unit for separation and purification to obtain the SAF product;

[0023] S4. When the activity of the catalyst drops to a set threshold, the pulse regeneration unit is activated to periodically inject regeneration gas into the pulse reaction unit to regenerate the catalyst in a pulse manner.

[0024] Furthermore, the initial raw materials include at least one of biomass syngas, waste oil derivatives, and coal-based syngas.

[0025] Furthermore, the preprocessing in step S1 specifically includes:

[0026] If the initial feedstock is biomass syngas, H2S is removed to <1ppm through a desulfurization tower, CO2 content is adjusted to <5% through a decarbonization tower, and the H2 / CO molar ratio is adjusted to 2.0-4.0 through a component blender.

[0027] If the initial raw material is waste oil derivative, the free fatty acids are removed to <0.5% by a deacidification tower and the water is removed to <0.1% by a dehydrator.

[0028] If the initial feedstock is coal-based syngas, NH3 is removed to <0.1ppm by a denitrification tower, and heavy metals are removed to <0.01ppm by a heavy metal adsorber.

[0029] Furthermore, the catalyst is at least one of Ni-Co / Al2O3 and Pt-Sn / SiO2.

[0030] Furthermore, the parameters for pulse-type control in step S2 are specifically as follows:

[0031] The baseline reaction temperature is 280-350℃, the pulse cycle is 10-60min, and the temperature fluctuation range is ±5-20℃.

[0032] The baseline reaction pressure is 2-5 MPa, the pulse cycle is 15-45 min, and the pressure fluctuation range is ±0.2-0.8 MPa.

[0033] For reactant concentrations, if the raw material is syngas, the H2 / CO molar ratio is 2.5-3.5, the pulse period is 20-50 min, and the ratio fluctuation range is ±0.3-0.8; if the raw material is oil derivative, the H2 flow rate is 500-800 mL / min, the pulse period is 25-40 min, and the flow rate fluctuation range is ±50-150 mL / min.

[0034] The beneficial effects of this invention are as follows:

[0035] 1. Significantly improved SAF yield and selectivity: By pulse-controlled reaction temperature, pressure and reactant concentration, the kinetic requirements of SAF synthesis are precisely matched, and the selectivity of C8-C16 alkanes is increased to over 90%, with a significantly higher SAF yield compared to traditional continuous processes.

[0036] 2. Significantly extended catalyst life: The pulse regeneration process avoids the catalyst structure damage caused by the high-temperature oxidation of traditional constant regeneration. At the same time, the temperature / concentration pulse inhibits the formation of carbon deposits, thus extending the catalyst life and reducing catalyst replacement costs.

[0037] 3. Reduced energy consumption and costs: Higher raw material recycling rate and pulse control reduce continuous energy consumption under constant conditions. At the same time, improved product selectivity reduces the load on the separation process, further reducing production costs and bringing SAF costs closer to those of traditional aviation kerosene.

[0038] 4. Strong process adaptability: It is compatible with a variety of raw materials such as biomass syngas, waste oil derivatives, and coal-based syngas. By adjusting the pulse parameters, it can be adapted to the reaction characteristics of different raw materials without large-scale equipment modification, and has a wide range of applications. Attached Figure Description

[0039] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of the system flow provided by the present invention;

[0041] Figure 2 This is a schematic diagram of the method flow provided by the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and beneficial effects of the embodiments of the present invention clearer, 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 some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort should be considered to fall within the protection scope of the present invention.

[0043] In the description of this invention, it should be understood that the terms indicating orientation or positional relationship are based only on the orientation or positional relationship shown in the drawings and are used to facilitate the description of this invention and to simplify the explanation, rather than indicating or implying that the device or element must be constructed or operated in a specific orientation, and therefore should not be construed as limiting the invention.

[0044] Please refer to Figure 1 To better understand this invention, this invention provides a system for generating SAF based on pulses, comprising:

[0045] The raw material pretreatment unit is used to purify and adjust the composition of the initial raw materials to obtain pretreated raw materials;

[0046] The pulse reaction unit, connected to the raw material pretreatment unit, is used to convert the pretreated raw materials under pulse-controlled reaction conditions to obtain a mixed product containing SAF.

[0047] The product separation and purification unit, which is connected to the pulse reaction unit, is used to separate and purify the mixed products containing SAF to obtain purified SAF.

[0048] The pulse regeneration unit, connected to the pulse reaction unit, is used to regenerate the deactivated catalyst within the pulse reaction unit in a pulse manner.

[0049] The central control unit is electrically connected to the raw material pretreatment unit, the pulse reaction unit, the product separation and purification unit, and the pulse regeneration unit, and is used to coordinate the operating parameters of each unit.

[0050] It is worth noting that the system of this invention uses a central control unit to precisely control the operating parameters of each unit. The core relies on pulse technology to dynamically optimize reaction conditions and catalyst regeneration process, breaking the limitations of constant conditions in traditional continuous processes. It solves the key bottlenecks in traditional SAF production, such as rapid catalyst deactivation, poor product selectivity, and high energy consumption and cost. It achieves efficient, low-consumption, and large-scale production of SAF. Each unit works together to meet the needs of the entire SAF synthesis process, providing a basic guarantee for subsequent pulse control and regeneration. This can improve the selectivity of C8-C16 alkanes, increase the SAF yield compared to traditional processes, and extend catalyst life.

[0051] Optionally, the central control unit adopts a PLC programmable controller, which is equipped with 16 analog input modules, 8 analog output modules, and supports the Modbus-RTU communication protocol.

[0052] It is equipped with a 16-channel analog input module to receive real-time data from the component detector of the raw material pretreatment unit, the temperature / pressure / concentration sensor of the pulse reaction unit, the liquid level / component sensor of the product separation and purification unit, and the regeneration gas concentration / flow sensor of the pulse regeneration unit.

[0053] It is equipped with an 8-channel analog output module for sending control commands to the actuators of each unit;

[0054] Equipped with a Modbus-RTU communication module, it enables bidirectional data interaction with the multi-parameter pulse control module and the pulse regeneration control module, with a communication baud rate of 9600bps and a data transmission delay of ≤100ms.

[0055] The central control unit coordinates the operating parameters of each unit through a preset hierarchical collaborative control logic, as follows:

[0056] In the data acquisition and preprocessing layer, sensor data from each unit is acquired at a period of 500ms. Abnormal data is removed by filtering algorithm, the acquired analog data is converted into standardized digital data, and it is determined in real time whether the data is within the preset safety threshold.

[0057] In the pulse parameter coordination matching layer, based on the pre-treated raw material components output by the raw material pre-treatment unit, the preset pulse control parameter library is automatically retrieved to match the corresponding temperature / pressure / concentration pulse reference value, cycle and fluctuation amplitude for the pulse reaction unit; at the same time, the parameter linkage relationship between the pulse reaction unit and the pulse regeneration unit is established. When the temperature pulse of the reaction unit enters the heating stage, the regeneration gas injection flow rate of the regeneration unit is automatically reduced by 20% to avoid local overheating.

[0058] In the regeneration and reaction linkage control layer, the catalyst activity index of the pulse reaction unit is monitored in real time. When the index reaches the activity decline threshold, the feed from the raw material pretreatment unit to the pulse reaction unit is first suspended, and then the regeneration program of the pulse regeneration unit is started. After the regeneration is completed, the pretreated raw material composition is finely adjusted through the raw material pretreatment unit, and then the feed to the reaction unit is resumed to ensure a smooth restart of the reaction.

[0059] In the abnormal early warning and emergency handling layer, when any unit parameter is detected to exceed the safety threshold, a three-level emergency response is immediately triggered: Level 1 response is when the parameter is slightly out of control, and the corresponding actuator parameters are automatically adjusted; Level 2 response is when the parameter is moderately out of control, and the non-core operation of the corresponding unit is suspended; Level 3 response is when the parameter is severely out of control, and the feeding and power supply of all units are cut off, and inert gas is introduced to replace the system.

[0060] The core algorithms for pulse coordination in the central control unit include a multi-parameter pulse phase matching algorithm, a catalyst activity prediction algorithm, and an energy consumption optimal adjustment algorithm, which are as follows:

[0061] Multi-parameter pulse phase matching algorithm: used to coordinate the pulse period and phase of temperature, pressure, and reactant concentration, supporting both synchronous and asynchronous modes. In synchronous mode, the pulse start time of the three parameters is consistent and the fluctuation direction is matched. In asynchronous mode, the temperature pulse is used as the reference, the pressure pulse starts 10 minutes later and the concentration pulse starts 5 minutes earlier, realizing the staggered control of parameters. The phase matching error of the algorithm is ≤1 minute.

[0062] Catalyst activity prediction algorithm: Based on the LSTM neural network model, inputting historical reaction time, reactor pressure difference, and product selectivity data, it predicts the trend of catalyst activity decline 2 hours in advance, reserving sufficient regeneration preparation time for the pulse regeneration unit and avoiding temporary shutdown.

[0063] Energy consumption optimization algorithm: With SAF yield ≥80% and C8-C16 alkane selectivity ≥90% as constraints, the operating parameters of each unit are optimized in real time through gradient descent algorithm to reduce the total energy consumption of the system.

[0064] In some examples, the raw material pretreatment unit includes at least one of a desulfurization tower, a decarbonization tower, a deacidification tower, a denitrification tower, a dehydrator, a component blender, and a heavy metal adsorber.

[0065] Optionally, the desulfurization tower is a Φ800x3000mm stainless steel packed tower, using activated alumina as the desulfurizing agent; the denitrification tower is a pressure swing adsorption denitrification device, with modified molecular sieve as the adsorbent; the deacidification tower is a Φ600x2500mm plate tower, equipped with an online free fatty acid detector; the denitrification tower is a low-temperature adsorption denitrification device, with activated carbon fiber as the adsorbent; the dehydrator is a dual-tower switching molecular sieve dryer, equipped with a dew point meter; the component blender is a dynamic mixer, equipped with an online gas chromatograph; and the heavy metal adsorber is a Φ500×2000mm fixed bed adsorber, filled with modified activated carbon adsorbent, equipped with an online heavy metal detector.

[0066] It is worth noting that, for different initial raw materials with different impurity characteristics, special processing equipment is configured to remove harmful impurities and adjust the proportion of raw material components through physicochemical means such as adsorption, separation, and blending. This avoids impurities causing catalyst poisoning and a decrease in reaction efficiency. At the same time, the raw material components are adjusted to the optimal range for SAF synthesis, providing high-purity and highly adaptable pre-treated raw materials for subsequent pulse reactions, significantly reducing the risk of catalyst deactivation and improving the selectivity and stability of subsequent reactions.

[0067] In some examples, the pulse reaction unit includes a pulse reactor connected to the feed pretreatment unit, the pulse reactor being equipped with a multi-parameter pulse control module, and a catalyst packing layer for containing the catalyst being provided inside the pulse reactor.

[0068] Optionally, the pulse reactor is a Φ500×4000mm fixed bed reactor with three layers of catalyst packing, with a layer spacing of 200mm. Each layer is equipped with a temperature sensor and a pressure sensor. The multi-parameter pulse control module includes a temperature sensor (with an electric heating jacket), a pressure pulse regulator (with a pneumatic regulating valve), and a flow pulse controller (with a flow controller).

[0069] It is worth noting that the pulse reactor's built-in catalyst packing layer provides reactive sites, and the multi-parameter pulse control module can dynamically adjust key parameters such as reaction temperature, pressure, and reactant concentration in real time. It optimizes reaction kinetics through baseline values ​​and periodically fluctuating pulse patterns. This solves the problems of wide product distribution and easy carbon deposition under traditional constant reaction conditions, precisely matching the dynamic reaction requirements of SAF synthesis and suppressing side reactions. Reaction conditions can be adapted to the characteristics of raw materials and the reaction process in real time, effectively suppressing catalyst carbon deposition and metal site sintering, significantly improving the selectivity of C8-C16 alkanes, while shortening the reaction induction period and increasing reaction efficiency.

[0070] It should be noted that the collaborative control logic of the aforementioned multi-parameter pulse control module is as follows: In terms of phase relationship, it supports synchronous or asynchronous control of pulse parameters such as temperature, pressure, and reactant concentration. Through preset modes in the central control unit, the pressure pulse depressurization phase can be triggered synchronously during the temperature pulse heating phase to suppress side reactions at high temperatures. In terms of triggering conditions, the module's built-in sensor group collects temperature, pressure, and component data within the reactor in real time. When a parameter deviates from the reference value by ±5%, a pulse correction program is automatically triggered. In terms of feedback mechanism, the central control unit receives module data via the Modbus-RTU communication protocol and generates a control command every 5 minutes. If the parameter fails to meet the standard three times consecutively, the pulse period and fluctuation amplitude are automatically adjusted until the reaction conditions return to the optimal range. In terms of pulse signal generation, the central control unit generates a coordinated electrical signal based on the preset pulse reference value, period, and amplitude, driving temperature control, pressure control, and concentration control respectively, achieving multi-parameter linkage pulse regulation.

[0071] In some examples, the product separation and purification unit includes a gas-liquid separator connected to a pulse reactor, which is connected in series with a light hydrocarbon removal tower, a heavy hydrocarbon removal tower, and a molecular sieve dryer.

[0072] Optionally, the gas-liquid separator is a Φ1000×2000mm horizontal separator with a separation efficiency ≥99.5%, an operating temperature of 40-60℃, a pressure of 1.5-2.0MPa, and is equipped with a liquid level sensor; the light hydrocarbon removal tower is a Φ800×3500mm distillation tower with sieve trays, a top temperature of 60-80℃, a bottom temperature of 180-200℃, an operating pressure of 0.8-1.0MPa, and a reflux ratio of 3:1; the heavy hydrocarbon removal tower is a Φ800×4000mm distillation tower with valve trays, a top temperature of 230-250℃, a bottom temperature of 300-320℃, an operating pressure of 0.6-0.8MPa, and a reflux ratio of 5:1; the molecular sieve dryer is a dual-tower switching dryer with a regeneration temperature of 200-220℃, a regeneration time of 2 hours, a switching cycle of 4 hours, and is equipped with a dew point meter.

[0073] It is worth noting that a stepwise purification process involving gas-liquid separation, light hydrocarbon removal, heavy hydrocarbon removal, and drying is employed. Utilizing the differences in boiling points and states of the components, unreacted feed gas, light hydrocarbons (C1-C7), heavy hydrocarbons (C17+), and moisture are sequentially separated, achieving enrichment of the core SAF components (C8-C16 alkanes). This solves the problem of high separation energy consumption caused by low product selectivity in traditional processes, yielding high-purity SAF products that meet aviation fuel standards. Unreacted feed gas can be recycled, and the separation of light and heavy hydrocarbons is thorough. The final SAF product contains ≥90% C8-C16 alkanes and ≤10ppm moisture, meeting ASTM D7566 standards, with lower separation energy consumption than traditional processes.

[0074] In some examples, the pulse regeneration unit includes a regeneration gas preparation device and a pulse injection device connected to the regeneration gas preparation device, the pulse injection device being connected to a pulse reactor and connected to a catalyst packing layer.

[0075] Optionally, the regenerated gas preparation device is a mixed gas generator with a processing capacity of 50 Nm³. 3 The system can produce a mixture of air and water vapor regeneration gas per hour, with oxygen concentration controlled within the range of 18-20℃ and water vapor temperature within the range of 150-180℃. The pulse injection device uses a pulsed gas distributor, which is directly connected to the catalyst packing layer of the pulsed reactor. The injection pressure is 0.4-0.6MPa, the pulse flow rate is adjustable within the range of 100-300mL / min, and the pulse period is adjustable within the range of 5-15min.

[0076] It is worth noting that the regeneration gas preparation unit generates a mixed gas suitable for catalyst regeneration, and the pulse injection device precisely injects the regeneration gas into the catalyst packing layer through periodic pulses. Under mild conditions, the carbon deposits on the catalyst surface are oxidized and removed, avoiding the catalyst structure damage caused by constant regeneration. This solves the problems of limited activity recovery and easy catalyst loss in traditional catalyst regeneration processes, extending catalyst life and reducing replacement costs. The catalyst carbon removal rate can reach ≥90%, and the activity after regeneration is restored to more than 90% of the initial activity, extending catalyst life, eliminating the need for frequent shutdowns to replace catalysts, and improving production continuity.

[0077] It should be noted that, at the positions corresponding to each catalyst packing layer on the side wall of the pulse reactor, a pressure-resistant gas injection channel penetrating the reactor wall is opened. The end of the channel is connected to an annular gas collecting chamber. Several atomizing nozzles with an aperture of 0.5-1mm are evenly arranged on the side of the gas collecting chamber facing the catalyst packing layer. The nozzles are at a 30° angle to the catalyst bed. The annular gas collecting chamber is connected to the main pipeline of the pulse injection device through a high-temperature and pressure-resistant hose, which can realize the precise and uniform injection of regeneration gas into the interior of the catalyst packing layer. At the same time, the angle design of the nozzles can avoid interfering with the flow path of the main reactive material and prevent overheating caused by local airflow turbulence.

[0078] This invention also provides a method for generating SAF based on pulses, comprising the following steps:

[0079] S1. The initial raw material is fed into the raw material pretreatment unit for pretreatment to obtain pretreated raw material;

[0080] S2. The pretreated raw materials are fed into the pulse reaction unit. Under the action of the catalyst, at least one of the reaction temperature, reaction pressure and reactant concentration is pulsedly controlled by the multi-parameter pulse control module to carry out the SAF synthesis reaction and obtain a mixed product containing SAF.

[0081] S3. Pass the mixed product containing SAF into the product separation and purification unit for separation and purification to obtain the SAF product;

[0082] S4. When the activity of the catalyst drops to the set threshold, the pulse regeneration unit is started, and regeneration gas is periodically injected into the pulse reaction unit to regenerate the catalyst in a pulse manner.

[0083] It should be noted that the separation and purification in step S3 is as follows: The mixed product containing SAF consists of a gas phase of light hydrocarbons and unreacted raw material gas, and a liquid phase of crude SAF and heavy hydrocarbons. It first enters a gas-liquid separator with a residence time of 10 minutes. The liquid phase product is discharged from the bottom, and the gas phase product is recovered by a compressor and recycled to the raw material pretreatment unit. The crude SAF contains C1-C7 light hydrocarbons and heavy hydrocarbons. It enters a light hydrocarbon removal tower. C1-C7 light hydrocarbons are collected from the top of the tower, and the bottom product enters a heavy hydrocarbon removal tower. C8-C16 alkanes are collected from the top of the heavy hydrocarbon removal tower, and C17+ heavy hydrocarbons are discharged from the bottom of the tower. The C8-C16 alkanes content in the top product is ≥90%. The crude SAF product enters a molecular sieve dryer with an outlet moisture content of ≤10ppm, and finally, a SAF product conforming to ASTM D7566 standard is obtained.

[0084] An online gas chromatograph is installed at the bottom outlet of the light hydrocarbon removal tower to monitor the content of components below C7 in the output in real time, ensuring that the removal rate of light hydrocarbons below C7 is ≥99%; a buffer separator is installed between the light hydrocarbon removal tower and the heavy hydrocarbon removal tower, and a demister is installed in the separator to prevent gaseous components from being carried into the heavy hydrocarbon removal tower by the output from the bottom of the tower.

[0085] Regarding operating temperature, the top temperature of the heavy hydrocarbon removal tower is 230-250℃. This temperature range meets the vaporization and separation requirements of C8-C16 alkanes while being lower than the cracking temperature of C16 alkanes, thus avoiding product cracking losses. The bottom temperature is maintained at 300-320℃ to ensure that C17+ heavy hydrocarbons are discharged in liquid form.

[0086] It should also be noted that, in step S4, the pulse regeneration of the catalyst is specifically as follows: For syngas feedstocks, when the CO conversion rate is detected to be below 60% for 30 consecutive minutes, or the reactor pressure difference increases by 0.5 MPa from the initial value, it indicates carbon buildup and blockage, and the activity is judged to have dropped to the threshold. For waste oil derivative feedstocks, the hydrodeoxygenation rate and C8-C16 alkane selectivity are the core indicators. When the hydrodeoxygenation rate is below 75% for 30 consecutive minutes, or the C8-C16 alkane selectivity drops to below 80%, the activity is judged to have dropped to the threshold. At this point, the central control unit automatically starts the pulse regeneration program with the following parameters: the regeneration gas is an air-to-water vapor ratio of 9:1, the oxygen concentration is 19±1%, the water vapor temperature is 160±5℃, the pulse cycle during injection is 10min, the injection flow rate is 200±20mL / min, and the regeneration temperature is 350±10℃. When the CO conversion rate is continuously monitored and rises to above 85%, and the reactor pressure difference returns to the initial value ±0.1MPa, or the hydrodeoxygenation rate is above 80% for 30 consecutive minutes, and the C8-C16 alkane selectivity is above 85%, the regeneration process ends.

[0087] In pulse regeneration operation, it is important to clarify that there are two operating modes: co-regeneration and intermittent regeneration. When the catalyst carbon deposit is ≤5wt%, the co-regeneration mode is selected, and when the catalyst carbon deposit is >5wt%, the intermittent regeneration mode is selected. The amount of catalyst carbon deposit can be indirectly determined by the change in reactor pressure difference.

[0088] In the collaborative regeneration mode, the main reaction feed is not stopped during regeneration. The oxygen concentration in the regeneration gas is controlled at ≤3% through the central control unit. At the same time, the H2 volume ratio in the reactor is monitored in real time and must be maintained within the safe range of ≤4%. A combustible gas monitor is also installed. Once the combustible gas concentration is detected to exceed the standard, the regeneration gas supply is immediately cut off and inert gas is introduced for replacement.

[0089] In the intermittent regeneration mode, when the catalyst is severely carbonized, the connecting valve between the raw material pretreatment unit and the pulse reaction unit is first suspended, and N2 is introduced to replace the combustible gas such as H2 in the reactor for a period of ≥30 minutes, and then the regeneration program is started. After the regeneration is completed, N2 is introduced again to replace the regeneration tail gas, and the main reaction feed is resumed after the gas in the reactor reaches the standard.

[0090] In some examples, the initial feedstock includes at least one of biomass syngas, waste oil derivatives, and coal-based syngas.

[0091] Optionally, biomass syngas is derived from straw and forestry waste gasification; waste oil derivatives are derived from waste catering oil and gutter oil hydrogenation pretreatment.

[0092] In some examples, the preprocessing in step S1 specifically includes:

[0093] If the initial feedstock is biomass syngas, H2S is removed to <1ppm through a desulfurization tower, CO2 content is adjusted to <5% through a decarbonization tower, and the H2 / CO molar ratio is adjusted to 2.0-4.0 through a component blender.

[0094] If the initial raw material is waste oil derivative, the free fatty acids are removed to <0.5% by a deacidification tower and the water is removed to <0.1% by a dehydrator.

[0095] If the initial feedstock is coal-based syngas, NH3 is removed to <0.1ppm by a denitrification tower, and heavy metals are removed to <0.01ppm by a heavy metal adsorber.

[0096] Optionally, if the feedstock is biomass syngas, the desulfurization tower should be set to operate at a pressure of 0.3-0.5 MPa and a space velocity of 1000-1500 h⁻¹. -1 The inlet temperature is 30-40℃; the adsorption pressure of the decarbonization tower is set to 0.6-0.8MPa, the desorption pressure to 0.1-0.2MPa, the adsorption time to 10min, and the desorption time to 5min; the H2 / CO molar ratio is adjusted by supplementing high-purity H2 in the component mixer.

[0097] If the raw material is waste oil derivative, set the deacidification tower operating temperature to 60-80℃, pressure to 0.1-0.2MPa, and liquid hourly space velocity to 0.5-1.0h. -1 A 5% NaOH solution was used as the deacidifying agent; the dehydrator adsorption pressure was set at 0.2-0.4 MPa, the regeneration temperature at 120-150℃, the regeneration time at 2 hours, and the dual-tower switching cycle at 4 hours.

[0098] If the feedstock is coal-based syngas, the denitrification tower should be set to operate at a pressure of 0.4-0.6 MPa and a space velocity of 800-1200 h⁻¹. -1 The inlet temperature is 20-30℃; the heavy metal adsorber is set to operate at a temperature of 40-60℃, a pressure of 0.3-0.5MPa, and a space velocity of 500-800 h⁻¹. -1 .

[0099] In some examples, the catalyst is at least one of Ni-Co / Al2O3 and Pt-Sn / SiO2.

[0100] Optionally, the Ni-Co / Al2O3 catalyst has a Ni loading of 12 wt%, a Co loading of 8 wt%, and an Al2O3 support with a specific surface area ≥ 200 m². 2 / g, particle size 2-3mm, bulk density 1.3g / cm³ 3 The Pt-Sn / SiO2 catalyst has a Pt loading of 0.8 wt% and a Sn loading of 2 wt%, and the SiO2 support has a specific surface area ≥ 300 m². 2 / g, particle size 2-3mm, bulk density 1.1g / cm³3 .

[0101] After the catalyst is loaded, high-purity hydrogen gas at a flow rate of 300 mL / min is introduced, and the temperature is raised from room temperature to 400°C. The temperature is kept constant for 4 hours for activation. After the temperature is naturally cooled to the reaction temperature, the feed is started.

[0102] In some examples, the parameters for pulsed control in step S2 are specifically as follows:

[0103] The baseline reaction temperature is 280-350℃, the pulse cycle is 10-60min, and the temperature fluctuation range is ±5-20℃.

[0104] The baseline reaction pressure is 2-5 MPa, the pulse cycle is 15-45 min, and the pressure fluctuation range is ±0.2-0.8 MPa.

[0105] For reactant concentrations, if the raw material is syngas, the H2 / CO molar ratio is 2.5-3.5, the pulse period is 20-50 min, and the ratio fluctuation range is ±0.3-0.8; if the raw material is oil derivative, the H2 flow rate is 500-800 mL / min, the pulse period is 25-40 min, and the flow rate fluctuation range is ±50-150 mL / min.

[0106] The present invention will be further illustrated below with reference to specific embodiments.

[0107] Example 1

[0108] Please refer to Figure 1 and Figure 2 Based on the design concept of this invention, and in conjunction with the pulse-based SAF generation system provided by this invention, this embodiment 1 provides a pulse-based SAF generation method, including the following steps:

[0109] S1. The initial raw material is crude syngas generated from straw gasification, with the following composition: 28% CO, 62% H2, 8% CO2, 5ppm H2S, and 2% CH4; it is passed into a desulfurization tower to remove H2S to 0.5ppm; it is then passed into a decarbonization tower to adjust the CO2 content to 3%; hydrogen is added through a component adjuster to adjust the H2 / CO molar ratio to 3.0, thus obtaining the pretreated raw material;

[0110] S2. The pretreated raw materials are introduced into the pulse reaction unit, and Ni-Co / Al2O3 catalyst is loaded. The pulse parameters are set as follows: temperature pulse: reference 320℃, cycle 30min, amplitude ±10℃; pressure pulse: reference 3MPa, cycle 25min, amplitude ±0.5MPa; reactant concentration pulse: H2 / CO molar ratio reference 3.0, cycle 35min, amplitude ±0.5; space velocity is set to 1.0 h⁻¹. -1The mixture was introduced into a reactor and reacted continuously for 800 hours to obtain a mixed product containing SAF.

[0111] S3. The SAF-containing mixed product is passed into a gas-liquid separator to separate unreacted syngas. The liquid product is passed into a light hydrocarbon removal tower with a top temperature of 60°C to remove C1-C7 light hydrocarbons. Then it is passed into a heavy hydrocarbon removal tower with a top temperature of 230°C to remove C17+ heavy hydrocarbons. Finally, it is dehydrated to 5 ppm by a molecular sieve dryer to obtain the SAF product.

[0112] S4. When the catalyst has been running for 1200 hours (its activity drops to 68% of its initial activity), start the pulse regeneration unit and periodically inject regeneration gas into the pulse reaction unit. The regeneration gas is a mixture of N2 and 3% O2. Set the regeneration pulse parameters to a cycle of 30 minutes, a single injection duration of 10 minutes, a regeneration temperature of 330℃, and a duration of 6 hours. After regeneration, the catalyst activity will recover to 92% of its initial activity and can be used again.

[0113] The SAF product prepared by the above examples has a C8-C16 alkane content of 92.3%, which meets the ASTM D7566 SAF international standard; the SAF yield is 82.5% (based on C and H elements in the synthesis gas), which is 21.3% higher than the 68% of the traditional continuous process; the catalyst life reaches 1500h, which is 50% longer than the 1000h of the traditional process; and the total energy consumption is reduced by more than 20% compared with the traditional process.

[0114] Example 2

[0115] Please refer to Figure 1 and Figure 2 Based on the design concept of this invention, and in conjunction with the pulse-based SAF generation system provided by this invention, this embodiment 2 provides a pulse-based SAF generation method, including the following steps:

[0116] S1. Select fatty acid methyl esters generated by hydrogenation of catering waste oil, with a free fatty acid content of 1.2% and a moisture content of 0.8%; pass through a deacidification tower to remove free fatty acids to 0.3%; pass through a dehydrator to dehydrate to 0.08%, and obtain pretreated raw materials;

[0117] S2. The pretreated raw materials are introduced into the pulse reaction unit, and Pt-Sn / SiO2 catalyst is loaded. The pulse parameters are set as follows: temperature pulse: reference 300℃, period 25min, amplitude ±8℃; pressure pulse: reference 4MPa, period 20min, amplitude ±0.6MPa; reactant concentration pulse: H2 injection rate reference 600mL / min, period 30min, amplitude ±100mL / min; space velocity is set to 0.8h. -1 The mixture was introduced into a reactor and reacted continuously for 900 hours to obtain a mixed product containing SAF.

[0118] S3. The mixed product containing SAF is passed into a gas-liquid separator to separate unreacted H2. The liquid product is passed into a light hydrocarbon removal tower with a top temperature of 55°C to remove C1-C7 light hydrocarbons. Then it is passed into a heavy hydrocarbon removal tower with a top temperature of 310°C to remove C17+ heavy hydrocarbons. Finally, it is dehydrated to 5 ppm by a molecular sieve dryer to obtain the SAF product.

[0119] S4. When the catalyst has been running for 1200 hours (its activity drops to 68% of its initial activity), start the pulse regeneration unit and periodically inject regeneration gas into the pulse reaction unit. The regeneration gas is a mixture of N2 and 3% O2. Set the regeneration pulse parameters to a cycle of 30 minutes, a single injection duration of 10 minutes, a regeneration temperature of 330℃, and a duration of 6 hours. After regeneration, the catalyst activity will recover to 92% of its initial activity and can be used again.

[0120] The SAF product prepared by the above examples has a C8-C16 alkane content of 91.8%, which meets the ASTM D7566 SAF international standard; the SAF yield is 85.2% (based on FAME), which is 21.7% higher than the 70% of the traditional continuous process; the catalyst lifetime reaches 1400h, which is 55.6% longer than the 900h of the traditional process; and the total energy consumption is reduced by more than 15% compared with the traditional process.

[0121] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been described in detail through specific embodiments, those skilled in the art can make various equivalent substitutions, improvements, or modifications without departing from the spirit and scope of the present invention, and such equivalent substitutions, improvements, or modifications should all be considered to fall within the protection scope of the present invention.

Claims

1. A system for generating SAF based on pulses, characterized in that, include: The raw material pretreatment unit is used to purify and adjust the composition of the initial raw materials to obtain pretreated raw materials; A pulse reaction unit connected to the raw material pretreatment unit is used to convert the pretreated raw material under pulse-controlled reaction conditions to obtain a mixed product containing SAF. The product separation and purification unit, which is connected to the pulse reaction unit, is used to separate and purify the mixed product containing SAF to obtain purified SAF. A pulse regeneration unit connected to the pulse reaction unit is used to perform pulse regeneration on the deactivated catalyst within the pulse reaction unit. The central control unit is electrically connected to the raw material pretreatment unit, the pulse reaction unit, the product separation and purification unit, and the pulse regeneration unit, respectively, and is used to coordinate the operating parameters of each unit.

2. The system according to claim 1, characterized in that, The raw material pretreatment unit includes at least one of the following: desulfurization tower, decarbonization tower, deacidification tower, denitrification tower, dehydrator, component blender, and heavy metal adsorber.

3. The system according to claim 2, characterized in that, The pulse reaction unit includes a pulse reactor connected to the raw material pretreatment unit. The pulse reactor is equipped with a multi-parameter pulse control module and a catalyst packing layer for accommodating the catalyst is provided inside the pulse reactor.

4. The system according to claim 3, characterized in that, The product separation and purification unit includes a gas-liquid separator connected to the pulse reactor, and the gas-liquid separator is connected in series with a light hydrocarbon removal tower, a heavy hydrocarbon removal tower and a molecular sieve dryer.

5. The system according to claim 3, characterized in that, The pulse regeneration unit includes a regeneration gas preparation device and a pulse injection device connected to the regeneration gas preparation device. The pulse injection device is connected to the pulse reactor and is also connected to the catalyst packing layer.

6. A method for generating SAF based on pulses, using the system according to any one of claims 1-5, characterized in that, Includes the following steps: S1. The initial raw material is fed into the raw material pretreatment unit for pretreatment to obtain pretreated raw material; S2. The pretreated raw material is fed into the pulse reaction unit. Under the action of the catalyst, at least one of the reaction temperature, reaction pressure and reactant concentration is pulsedly controlled by the multi-parameter pulse control module to carry out the SAF synthesis reaction and obtain a mixed product containing SAF. S3. The SAF-containing mixed product is passed into a product separation and purification unit for separation and purification to obtain the SAF product; S4. When the activity of the catalyst drops to a set threshold, the pulse regeneration unit is activated to periodically inject regeneration gas into the pulse reaction unit to regenerate the catalyst in a pulse manner.

7. The method according to claim 6, characterized in that, The initial raw materials include at least one of biomass syngas, waste oil derivatives, and coal-based syngas.

8. The method according to claim 7, characterized in that, The preprocessing in step S1 specifically includes: If the initial feedstock is biomass syngas, H2S is removed to <1ppm through a desulfurization tower, CO2 content is adjusted to <5% through a decarbonization tower, and the H2 / CO molar ratio is adjusted to 2.0-4.0 through a component blender. If the initial raw material is waste oil derivative, the free fatty acids are removed to <0.5% by a deacidification tower and the water is removed to <0.1% by a dehydrator. If the initial feedstock is coal-based syngas, NH3 is removed to <0.1ppm by a denitrification tower, and heavy metals are removed to <0.01ppm by a heavy metal adsorber.

9. The method according to claim 6, characterized in that, The catalyst is at least one of Ni-Co / Al2O3 and Pt-Sn / SiO2.

10. The method according to claim 6, characterized in that, The specific parameters for pulse-type regulation in step S2 are as follows: The baseline reaction temperature is 280-350℃, the pulse cycle is 10-60min, and the temperature fluctuation range is ±5-20℃. The baseline reaction pressure is 2-5 MPa, the pulse cycle is 15-45 min, and the pressure fluctuation range is ±0.2-0.8 MPa. For reactant concentrations, if the raw material is syngas, the H2 / CO molar ratio is 2.5-3.5, the pulse period is 20-50 min, and the ratio fluctuation range is ±0.3-0.8; if the raw material is oil derivative, the H2 flow rate is 500-800 mL / min, the pulse period is 25-40 min, and the flow rate fluctuation range is ±50-150 mL / min.

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