Method and system for acetylene and hydrogen production from natural gas based on turbo-decomposition

Abstract

The present application belongs to the technical field of acetylene preparation, and discloses a method and system for efficiently preparing acetylene and hydrogen from natural gas based on turbine cracking. The method comprises the following steps: obtaining 95%-100% purified methane gas through raw material pretreatment, preheating to 523-823 K, and then feeding into a turbine cracking reaction unit to be heated to 1800-2200 K within 1-10 ms and cracked for 1-10 ms; the cracked gas is quenched to below 800 K within 0.5-3 ms and the waste heat is recovered; finally, carbon black, high-purity acetylene and hydrogen are obtained through gas-solid and gas separation. The system comprises raw material pretreatment, preheating, turbine cracking reaction, quenching and waste heat recovery, gas-solid separation, gas separation units, and a matching monitoring and collaborative control module, and realizes multi-parameter collaborative control and online carbon cleaning. The present application does not introduce oxygen, the conversion rate of natural gas is 92%-95%, the acetylene yield is 83%-87.5%, the energy consumption is low, the products are easy to separate, it is green and environmentally friendly, and it is suitable for industrial continuous production.

Description

Technical Field

[0001] This invention belongs to the field of acetylene preparation technology, specifically relating to a method and system for producing acetylene and hydrogen from natural gas based on turbine cracking. Background Technology

[0002] Acetylene is a crucial raw material in the organic chemical industry, widely used in metal processing, welding, cutting, and chemical production. Its broad applications and abundant downstream products have spurred significant industry attention to its production methods. Currently, the mainstream industrial acetylene production process is still the calcium carbide method. However, this method suffers from high energy consumption, high water consumption, and severe pollution from solid waste (calcium carbide slag), contradicting the requirements of green and low-carbon development. To seek a cleaner approach, the partial oxidation of natural gas has emerged. This method utilizes the incomplete combustion of methane to provide high temperatures, causing another portion of the methane to crack and produce acetylene, while simultaneously generating syngas as a byproduct. Compared to the calcium carbide method, its process is simpler and less polluting. However, this method also has inherent drawbacks: nearly two-thirds of the natural gas is burned for heating, resulting in low feedstock utilization; the introduction of oxygen into the reaction system leads to complex compositions of the cracked gas, resulting in high costs for subsequent separation and purification; and bottlenecks include a low acetylene yield (approximately 30%–33%) and the tendency for carbon black byproducts to clog equipment.

[0003] In pursuit of higher atom economy and acetylene yield, the industry has turned its attention to the direct methane cracking route to acetylene, which requires no oxygen. Thermodynamic analysis shows that acetylene is the thermodynamically dominant product under ultra-high temperature conditions exceeding 1500℃. Various technological explorations have emerged regarding how to efficiently generate and control this ultra-high temperature field: the electric arc method uses an electric arc to generate high-temperature cracking methane at 3000-4000℃, yielding high-purity acetylene, but with extremely high energy consumption; the plasma method uses high-temperature plasma heating, achieving high acetylene yields, but also faces challenges such as high energy consumption and a distance from large-scale industrialization. These methods all attempt to create extreme reaction conditions through external energy input, but generally suffer from common problems such as low energy utilization efficiency, complex equipment, and difficulty in controlling the uniformity and stability of the high-temperature field. Even traditional tubular furnace heating methods used for basic research, due to inherent defects such as high thermal inertia, slow heating, and poor temperature control accuracy, cannot meet the stringent requirements of efficiency and controllability for industrialization.

[0004] Turbomachinery, as a highly efficient energy conversion device, has long played a crucial role in aerospace, energy, and power industries. It uses rotating impellers to convert mechanical energy into the kinetic and thermal energy of fluids, thereby achieving controlled acceleration of high-temperature, high-speed fluids and efficient energy injection. In recent years, researchers have actively explored the application of turbomachinery reactors in chemical processes. For example, utilizing supersonic flow to generate shock waves in the diffusion section allows for instantaneous temperature increases in the fluid. This characteristic provides favorable conditions for rapid reactions in chemical processes, theoretically opening up new technological pathways for high-temperature chemical processes.

[0005] However, transforming turbine-heated pyrolysis technology from a theoretically feasible system into a continuous and stable industrial acetylene production system requires overcoming two key challenges. First, there is the challenge of constructing the basic process system architecture. Currently, no complete and reliable acetylene production system centered on a turbine pyrolysis reactor has been developed in the existing technological framework. This system needs to efficiently integrate core units such as raw material pretreatment, millisecond-level ultra-high temperature pyrolysis, instantaneous product quenching, and efficient separation and purification to construct a complete industrial path that can replace traditional high-pollution processes. Seamless connection and coordinated operation between these units are fundamental to ensuring stable and efficient system output. Second, there are the challenges of controlling extreme processes under specific system architectures. Turbine pyrolysis systems face unique control challenges not encountered in traditional chemical processes: Under supersonic flow conditions, the pyrolysis reaction proceeds rapidly on a millisecond scale, requiring real-time and precise monitoring and control to ensure it is precisely "frozen" at the acetylene generation stage. Any delay will lead to excessive acetylene pyrolysis into carbon deposits, severely reducing yield and clogging reactor pipes. Simultaneously, key parameters within the system, such as flow field, temperature, and pressure, are highly coupled and mutually perturbed; changes in a single parameter can trigger chain reactions. Traditional single-parameter adjustment strategies are insufficient; multi-variable coordinated control is necessary to suppress system oscillations and maintain global stability. Furthermore, carbon deposits, as a difficult-to-avoid byproduct, accumulate gradually with the continued reaction, affecting unit performance and lifespan. Therefore, an effective early warning and online proactive carbon deposit removal mechanism is essential to ensure long-term, continuous, and stable operation. Finally, reactor materials suitable for these extreme high-temperature (>1500℃) conditions and efficient cooling systems are fundamental obstacles that must be overcome in the engineering process.

[0006] In summary, existing technologies not only lack a complete turbine cracking process system specifically designed for natural gas-to-acetylene production, but also lack targeted solutions to effectively address the unique challenges of extreme process control inherent in this system. Therefore, the industry urgently needs a comprehensive technological solution that not only provides a new process route but also fundamentally solves core challenges such as instantaneous precise control, coordinated stability, and predictive maintenance, offering a practical path for the green and low-carbon upgrading of acetylene production. Summary of the Invention

[0007] This invention aims to overcome the shortcomings of existing technologies and provide a method and system for the efficient production of acetylene and hydrogen from natural gas based on turbine cracking. The technical problems to be solved by this invention are: first, to provide a novel basic process system for acetylene production based on turbine cracking, replacing the traditional high-energy-consumption and high-pollution process; second, to solve the unique challenges of instantaneous precise control, system synergistic stability, and carbon deposition prevention in the ultra-high temperature, millisecond-level reaction process of this method, so as to achieve highly selective synthesis of acetylene and long-term stable operation of the equipment.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first aspect of this invention is to provide a method for producing acetylene and hydrogen from natural gas based on turbine cracking, comprising the following steps:

[0010] S1. Pretreatment step: Pretreatment of raw natural gas to obtain high-concentration purified methane gas with a methane concentration of 95%~100%;

[0011] S2. Preheating step: Preheat the purified methane gas to 523-823 K;

[0012] S3. Turbine heating and cracking step: The preheated purified methane gas is introduced into the turbine cracking reaction unit. The energy input of the turbine machinery is adjusted by controlling the rotor speed of the turbine cracking reaction unit, so that the purified methane gas is heated to 1800~2200K within 1~10ms, and a cracking reaction is carried out at this temperature for 1~10ms to generate cracked gas containing acetylene, hydrogen and carbon black.

[0013] S4. Quenching and waste heat recovery step: The pyrolysis gas is quenched and rapidly cooled to below 800 K within 0.5~3ms to terminate the acetylene decomposition reaction, and waste heat is recovered, finally cooled to 300~400 K.

[0014] S5. Separation Steps: The gas mixture after quenching and waste heat recovery is subjected to gas-solid separation and gas separation in sequence to obtain solid carbon black, acetylene product and hydrogen product respectively.

[0015] According to an embodiment of the present invention, the pretreatment in step S1 specifically includes: desulfurizing, dehydrating and removing heavy hydrocarbons from the raw natural gas, and stabilizing the pressure to 0.5~1.5 atm.

[0016] According to an embodiment of the present invention, in step S4, the cooling rate of the quenching treatment is 1000~1500K / ms, and the quenching medium used is selected from at least one of water, nitrogen, circulating oil or cold methane gas. The heat recovered in the quenching and waste heat recovery steps is used for preheating the purified methane gas in step S2.

[0017] According to an embodiment of the present invention, in step S5, the carbon black content in the gas after gas-solid separation is ≤10 mg / Nm³. 3 .

[0018] According to an embodiment of the present invention, in step S5, the gas separation includes absorption, desorption and pressure swing adsorption operations, sequentially separating acetylene, hydrogen and methane-rich gas.

[0019] According to an embodiment of the present invention, in step S5, the absorption solvent used in the absorption operation is selected from one or more of N-methylpyrrolidone, dimethylformamide (DMF), acetone, and methanol.

[0020] According to an embodiment of the present invention, in step S5, the operating pressure of the absorption operation is 0.4~0.6MPa and the temperature is 260~290K; the operating pressure of the desorption operation is 0.1~0.2MPa and the temperature is 320~350K.

[0021] According to an embodiment of the present invention, in step S5, the adsorbent used in the pressure swing adsorption operation is an activated carbon-molecular sieve composite adsorbent.

[0022] According to an embodiment of the present invention, in step S5, the pressure swing adsorption operation includes two stages: the first stage is the adsorption stage, with an operating pressure of 0.4~0.6 MPa and a temperature of 300~350 K; the second stage is the desorption stage, with an operating pressure of 0.03~0.08 MPa and a temperature of 300~350 K.

[0023] A second aspect of the present invention is to provide a system for implementing the above method, comprising the following components connected sequentially along a process flow path:

[0024] The feedstock pretreatment unit is used to pretreat the feedstock natural gas to obtain high-concentration purified methane gas;

[0025] A preheating unit, connected to the raw material pretreatment unit, is used to preheat the purified methane gas.

[0026] The turbine cracking reaction unit is equipped with a purified methane gas inlet and a cracked gas outlet. The purified methane gas inlet is connected to the preheating unit to receive the preheated purified methane gas and use the mechanical energy of the turbine to heat the purified methane gas and cause a cracking reaction to generate cracked gas. The cracked gas outlet is used to discharge the cracked gas. The turbine cracking reaction unit includes a turbine heater and a turbine reactor connected in sequence in the fluid flow direction. The turbine heater and turbine reactor are composed of one or more sets of turbine devices.

[0027] The quenching and waste heat recovery unit has its inlet connected to the pyrolysis gas outlet of the turbine pyrolysis reaction unit, and is used to quench the pyrolysis gas and recover waste heat.

[0028] A gas-solid separation unit, connected to the quenching and waste heat recovery unit, is used to separate solid carbon black from the pyrolysis gas after quenching and waste heat recovery.

[0029] A gas separation unit, connected to the gas-solid separation unit, is used to separate acetylene and hydrogen products.

[0030] According to an embodiment of the present invention, the raw material pretreatment unit includes a raw natural gas buffer and pressure stabilization device, a deep desulfurization device, a CO2 removal device, a heavy hydrocarbon separation device, and a fine dehydration device, used to remove impurities (such as sulfur, water, heavy hydrocarbons, CO2, etc.) from the raw natural gas to obtain high-concentration purified methane gas with a methane concentration of 95%~100%, and stabilize the pressure to 0.5~1.5 atm; the various devices of the raw material pretreatment unit achieve coordinated operation through interstage pressure regulation and energy recovery.

[0031] According to an embodiment of the present invention, the preheating unit is selected from one or more of the following: shell and tube heat exchangers, porous medium-filled heat exchangers, finned tube heat exchangers, spiral plate heat exchangers, coaxial heat exchangers, and heat pipe heat exchangers.

[0032] According to an embodiment of the present invention, the turbine device includes

[0033] A housing, wherein a working fluid inlet and a working fluid outlet for a turbine device are provided on the housing, and a flow channel connecting the working fluid inlet and the working fluid outlet of the turbine device is formed inside the housing;

[0034] The rotor shaft is rotatably supported within the housing and configured to be connected to the drive unit;

[0035] The rotor hub is fixedly sleeved on the rotor shaft;

[0036] At least three stages of blades are arranged sequentially in the flow channel within the housing along the axial direction of the rotor shaft, wherein each stage of blades sequentially includes, in the direction of fluid flow: a flow guiding device fixed to the housing, a rotor blade mounted on the rotor hub, and a diffuser blade fixed to the housing.

[0037] Between two adjacent blade groups, an interstage diffusion channel is formed between the outlet of the upper stage diffuser blade and the inlet of the lower stage guide device; the flow cross-sectional area of ​​the interstage diffusion channel varies along the fluid flow direction (the flow cross-sectional area expands along the fluid flow direction), and an interstage flow field adjustment mechanism is provided inside it to enhance the turbulent mixing and pressure recovery of the fluid (the pressure is restored to be consistent with the working fluid inlet pressure of the turbine device), thereby providing the next stage blade group with uniform pressure and uniform flow field inlet conditions;

[0038] The rotor shaft, the rotor hub, and the rotor blades of each stage together constitute the rotor of the turbine device.

[0039] According to an embodiment of the present invention, the system further includes a monitoring and collaborative control module, the monitoring and collaborative control module comprising:

[0040] The signal acquisition unit includes a high-temperature resistant sensor array arranged in the turbine cracking reaction unit, used to monitor the temperature, pressure, flow rate and composition parameters of the reaction fluid in the system in real time.

[0041] The signal processing and controller is communicatively connected to the signal acquisition unit.

[0042] An actuator drive unit is connected to the signal processing and controller;

[0043] The signal processing and controller is configured as follows:

[0044] a) Based on the temperature and composition data of the reaction fluid in the turbine pyrolysis reaction unit, the output power of the drive device is adjusted by the actuator drive unit to control the rotor speed;

[0045] b) Based on the pressure data of the reaction fluid in the turbine pyrolysis reaction unit, the interstage flow field adjustment mechanism is adjusted by the actuator drive unit to stabilize the interstage flow field;

[0046] c) Using the reaction fluid flow rate data as a reference parameter for mass and energy balance calculation, the control settings of the rotor speed and the interstage flow field adjustment mechanism are optimized in a coordinated manner; the coordinated optimization includes: using the reaction fluid flow rate data as a feedforward signal, and simultaneously fine-tuning the interstage flow field adjustment mechanism when adjusting the rotor speed, so as to suppress the disturbance of the interstage flow field caused by the flow rate change.

[0047] According to an embodiment of the present invention, the high-temperature resistant sensor array includes

[0048] The temperature sensing unit includes temperature sensors installed at the rotor blade outlet, the interstage diffusion channel outlet, and the working fluid outlet of the turbine unit, for real-time monitoring of the temperature distribution of the reaction fluid.

[0049] The pressure sensing unit includes a first pressure sensor located at the working fluid inlet of the turbine unit, the working fluid outlet of the turbine unit, and the outlet of the interstage diffusion channel, for real-time monitoring of the static pressure and total pressure distribution of the reaction fluid.

[0050] The flow sensing unit includes flow meters installed at the working fluid inlet and outlet of the turbine unit, for real-time monitoring of the flow distribution of the reaction fluid;

[0051] The component analysis unit includes an online component analyzer located at the working fluid outlet of the turbine unit for real-time analysis of the composition of the reaction fluid.

[0052] According to an embodiment of the present invention, the signal acquisition unit further includes a vibration sensor for monitoring the rotor vibration state of the turbine device;

[0053] The turbine assembly also includes a carbon removal mechanism;

[0054] The signal processing and controller is communicatively connected to the vibration sensor and is further configured to:

[0055] Based on the vibration data collected by the vibration sensor and the pressure difference data at the working fluid inlet and outlet of the turbine unit, a joint analysis is performed to identify the risk of carbon buildup in the turbine cracking reaction unit.

[0056] When a risk of carbon buildup is detected, the actuator drive unit drives the carbon removal mechanism to perform an online carbon removal operation.

[0057] According to an embodiment of the present invention, the carbon removal mechanism includes a plurality of microholes pre-set at the leading edge of the flow guiding device, an inert gas pipeline communicating with the microholes, and a control valve disposed on the inert gas pipeline; the online carbon removal operation includes controlling the control valve to inject an inert gas (N2, Ar) jet into the microholes in a pulse manner.

[0058] According to an embodiment of the present invention, the signal processing and controller is further configured to: when it is determined, based on the cumulative running time or real-time data trend, that the carbon buildup has exceeded the online cleaning capacity, automatically generate an early warning message and output a standardized offline carbon cleaning operation guidance program to guide maintenance personnel to stop the machine for thorough cleaning.

[0059] According to an embodiment of the present invention, the flow guiding device is a Laval nozzle or a flow guide vane, wherein the Laval nozzle is a blade-type nozzle, a perforated nozzle, or a rectangular nozzle.

[0060] According to an embodiment of the present invention, the turbine heater includes 9 to 11 stages of blades, and when the rotor speed of the turbine heater is 8000 to 24000 rpm, it can heat the purified methane gas from 523K to 1800K within 1 to 10 ms; the turbine reactor includes 5 to 9 stages of blades, and when the rotor speed of the turbine reactor is 8000 to 24000 rpm, it can maintain the temperature of the pyrolysis zone in the turbine reactor at 1800K to 2200K.

[0061] According to an embodiment of the present invention, the shell adopts a double-shell structure, consisting of, from the outside to the inside: an outer layer structure made of heat-resistant steel, an inner layer structure made of ceramic matrix composite material or high-temperature resistant ceramic lining, and a multilayer thermal barrier coating covering the working surface of the inner layer structure; the high-temperature resistant ceramic lining is alumina-based ceramic or silicon carbide-based ceramic, etc., the ceramic matrix composite material is SiC / SiC composite material or Al2O3 / Al2O3 composite material, and the thermal barrier coating is yttrium-stabilized zirconia (YSZ) coating or YSZ / Al2O3 composite coating.

[0062] According to an embodiment of the present invention, the flow guiding device, rotor blades and diffuser blades are all made of high-temperature alloy or ceramic matrix composite material and are all coated with an anti-carbon deposition coating; the ceramic matrix composite material is SiC / SiC composite material or Al2O3 / Al2O3 composite material, and the anti-carbon deposition coating is Pt-Al coating, YSZ / Al2O3 composite coating or Al2O3-SiO2 composite coating.

[0063] According to an embodiment of the present invention, the surfaces of the flow guiding device, rotor blades and diffuser blades are provided with discrete cooling holes and / or are sintered porous structures for introducing cooling medium to form gas film cooling or porous divergent cooling.

[0064] According to an embodiment of the present invention, the interstage flow field adjustment mechanism is an active disturbance device or an eddy current generator.

[0065] According to an embodiment of the present invention, the quenching and waste heat recovery unit includes a quenching device and a waste heat recovery device. The waste heat recovery device is configured to recover the waste heat of the quenched cracked gas and exchange heat with the preheating unit. The waste heat recovery device and the preheating unit are independent heat exchange devices or integrated with the preheating unit into a combined heat exchanger.

[0066] According to an embodiment of the present invention, the quenching device comprises 4 to 6 pairs of quenching medium injection holes uniformly arranged circumferentially along the pyrolysis gas outlet, which radially inject quenching medium into the pyrolysis gas flow channel. The quenching medium is selected from at least one of water, nitrogen, circulating oil, or cold methane gas.

[0067] According to an embodiment of the present invention, the waste heat recovery device is a porous media-filled heat exchanger, and the signal acquisition unit further includes a second pressure sensor for real-time monitoring of the pressure difference between the inlet and outlet of the porous media-filled heat exchanger; the porous media-filled heat exchanger is equipped with a backflushing cleaning device that is communicatively connected to the second pressure sensor; the signal processing and controller is configured to: when the pressure difference between the inlet and outlet of the porous media-filled heat exchanger exceeds a preset safety threshold, control the backflushing cleaning device to pulse-feed inert gas (nitrogen, argon, etc.) into the porous media-filled heat exchanger for backflushing cleaning.

[0068] According to an embodiment of the present invention, the gas-solid separation unit includes one or more devices such as a cyclone separator, a bag filter, an electrostatic precipitator, and a scrubbing tower.

[0069] According to an embodiment of the present invention, the gas separation unit includes an absorption tower, a desorption tower, and a pressure swing adsorption device.

[0070] According to embodiments of the present invention, the absorption solvent used in the absorption tower includes, but is not limited to, one or more of N-methylpyrrolidone, dimethylformamide (DMF), acetone, and methanol.

[0071] According to an embodiment of the present invention, the adsorbent used in the pressure swing adsorption device is an activated carbon-molecular sieve composite adsorbent.

[0072] Compared with the prior art, the present invention has at least the following beneficial effects:

[0073] 1. The method and system for high-efficiency natural gas to produce acetylene and hydrogen based on turbine cracking provided in this application adopts the core process of "turbine heating cracking + rapid quenching". The raw material natural gas is pretreated to obtain 95%~100% purified methane gas. After cracking at 1800~2200K for 1~10ms, the reaction is terminated by rapid quenching for 0.5~3ms, effectively reducing acetylene decomposition loss. Example data shows that using the method and system provided in this application, the natural gas conversion rate can reach 92%~95%, and the acetylene yield is 83%~87.5%, which is significantly higher than the yield (30%~33%) and conversion rate (83%) of the natural gas partial oxidation method. The process does not introduce oxygen throughout, and the cracked gas contains only acetylene, hydrogen, carbon black and a small amount of unreacted methane, without impurities such as CO / CO2. The product composition is more concentrated, providing a basis for subsequent separation simplification.

[0074] 2. The method and system for producing acetylene and hydrogen from natural gas based on turbine cracking provided in this application utilizes a quenching and waste heat recovery unit to recover the high-temperature waste heat of the cracked gas, which is directly used for preheating purified methane gas (523~823K), achieving thermal energy recycling and reducing external energy consumption. The turbine device directly converts mechanical energy into cracking heat energy, avoiding the energy dispersion and waste problems in plasma and electric arc methods. According to the comparative data of the embodiments and comparative examples, the specific energy consumption for acetylene production in this application is 7.8~8.3kWh / kg, which is 12.6%~17.9% lower than that of the plasma method (9.5kWh / kg). Although the surface energy consumption of the natural gas partial oxidation method is lower (3.2kWh / kg), this process requires a large amount of pure oxygen, and nearly two-thirds of the natural gas is used for combustion heating and does not participate in acetylene generation. Considering the effective utilization rate of raw materials, the actual energy consumption of this invention is more advantageous.

[0075] 3. The method and system for high-efficiency natural gas to acetylene and hydrogen based on turbine cracking provided in this application can stably produce high-concentration, pressure-stabilized purified methane gas through a feedstock pretreatment step, providing uniform feed conditions for subsequent turbine cracking and reducing interference from impurities. Gas separation employs a mature "absorption-desorption-pressure swing adsorption" process, which is reliable and easily implemented. The entire process is adaptable to 800~2000 Nm³ / h environments. 3 The raw material flow rate range is / h (the flow rate of the example covers this range and the yield remains stable). It can maintain stable product yield and purity under different loads. The equipment investment and operating energy consumption of the separation unit are significantly reduced compared with the natural gas partial oxidation method, which is convenient for industrial scale-up or small and medium-sized deployment.

[0076] 4. The method and system for producing acetylene and hydrogen from natural gas based on turbine cracking provided in this application eliminates the need for calcium carbide production, completely avoiding the problems of high energy and water consumption and large amounts of solid waste emissions from calcium carbide slag. No harmful gases such as hydrogen sulfide or phosphine are generated during the production process. According to the test data from the examples, the carbon black content in the gas after gas-solid separation is ≤10 mg / Nm³. 3 The solid byproduct carbon black can be recycled, achieving "zero emissions of waste residue"; the cooling and carbon removal of the turbine unit uses inert gases such as nitrogen, which do not cause secondary pollution and meet the requirements of green production.

[0077] 5. The method and system for high-efficiency natural gas to acetylene and hydrogen based on turbine pyrolysis provided in this application are designed for ultra-high temperature conditions of 1800~2200K, and adopt a double-shell structure, anti-carbon deposit coating and cooling system, which can effectively extend the service life of the equipment under harsh conditions. Each system unit is connected in an orderly manner along the process flow path, and is equipped with a "high temperature resistant sensor array + collaborative control" design, which can collect parameters such as temperature and pressure in real time and adjust the rotor speed and interstage flow field, effectively mitigating the impact of parameter fluctuations on the reaction. The online carbon removal and backflushing dust removal mechanism can specifically solve the carbon deposition problem. Compared with the current situation of plasma method requiring frequent shutdown for carbon removal, the maintenance frequency of this invention is significantly reduced, which is more suitable for the needs of continuous industrial production. Attached Figure Description

[0078] Figure 1 This is a schematic diagram of the process of the efficient natural gas-to-acetylene and hydrogen production system based on turbine cracking, as described in this application.

[0079] Figure 2 This is a schematic diagram of the turbine device of this application.

[0080] Figure 3 This is a schematic diagram of the turbine heater in Embodiment 1 of this application.

[0081] Figure 4 This is a schematic diagram of the turbine reactor in Embodiment 1 of this application.

[0082] In the diagram: 10 - Raw material pretreatment unit;

[0083] 20 - Preheating unit;

[0084] 30-Turbine cracking reaction unit; 31-Turbine heater; 32-Turbine reactor; 33-Outer structure; 34-Inner structure; 35-Turbine working fluid inlet; 36-Turbine working fluid outlet; 37-Rotor shaft; 371-Rotor hub; 38-Drive device; 39-Flow guiding device; 310-Rotor blade; 311-Diffusion blade; 312-Interstage diffusion channel;

[0085] 40 - Quenching device; 41 - Quenching medium injection hole;

[0086] 50 - Waste heat recovery device;

[0087] 61-Cyclone separator; 62-Bag filter; 63-Scrubber; 64-Electrostatic precipitator;

[0088] 71-Absorption tower; 72-Desorption tower; 73-Pressure swing adsorption device. Detailed Implementation

[0089] In the following description, with reference to the accompanying drawings, we provide a detailed description relating to various aspects of the disclosed embodiments.

[0090] In this description, the terms "upstream" or "front" and "downstream" or "back" refer to the direction of reactant flow. For example, the term "downstream" or "back" refers to the direction along the flow direction, while the term "upstream" or "front" refers to the direction opposite to the flow direction.

[0091] To overcome the drawbacks of existing technologies such as partial oxidation and plasma pyrolysis, this invention provides a novel and efficient method and system for producing acetylene from natural gas.

[0092] 1.1 A High-Efficiency Method for Producing Acetylene and Hydrogen from Natural Gas Based on Turbine Cracking

[0093] This application first provides a method for producing acetylene and hydrogen from natural gas based on turbine cracking, comprising the following steps:

[0094] S1. Pretreatment step: Pretreatment of raw natural gas to obtain high-concentration purified methane gas with a methane concentration of 95%~100%;

[0095] S2. Preheating step: Preheat the purified methane gas to 523-823 K;

[0096] S3. Turbine heating and cracking step: The preheated purified methane gas is introduced into the turbine cracking reaction unit. The energy input of the turbine is adjusted by controlling the rotor speed of the turbine device in the turbine cracking reaction unit, so that the purified methane gas is heated to 1800~2200K within 1~10ms, and cracking reaction is carried out at this temperature for 1~10ms to generate cracked gas containing acetylene, hydrogen and carbon black.

[0097] S4. Quenching and waste heat recovery step: The pyrolysis gas is quenched and rapidly cooled to below 800 K within 0.5~3ms to terminate the acetylene decomposition reaction, and waste heat is recovered, finally cooled to 300~400 K.

[0098] S5. Separation Steps: The gas mixture after quenching and waste heat recovery is subjected to gas-solid separation and gas separation in sequence to obtain solid carbon black, acetylene product and hydrogen product respectively.

[0099] This application represents a significant advancement in the field of natural gas-to-acetylene technology by constructing a highly efficient and coherent process pathway of "turbine heating and cracking - instantaneous quenching - energy recovery." This scheme achieves rapid heating and cracking of methane within milliseconds, followed immediately by quenching to terminate side reactions (quenching occurs without delay after 1-10 ms of cracking). This effectively promotes the selective formation of acetylene and inhibits its decomposition, thus simultaneously achieving high methane conversion and high acetylene yield without the need for catalysts or the introduction of oxygen. Furthermore, the integrated design of using quenching waste heat for feedstock preheating significantly improves the thermal energy utilization efficiency of the process and reduces overall energy consumption. The organic integration of each step gives this scheme the combined advantages of a short process flow, high product selectivity, and excellent energy efficiency, providing a feasible new technological pathway for the green and low-carbon production of acetylene.

[0100] Furthermore, in step S1 of the above method, the pretreatment specifically includes: desulfurizing, dehydrating and removing heavy hydrocarbons from the raw material natural gas, and stabilizing the pressure to 0.5~1.5 atm; by deeply purifying the raw material and stabilizing the pressure of the raw gas to 0.5~1.5 atm, highly pure, stable and uniform feed conditions are created for the subsequent core turbine cracking reaction unit. The specific effects of this technology are as follows: First, deep desulfurization and dehydration fundamentally eliminate the corrosion of high-temperature components by sulfides and the risk of water vapor participating in side reactions at extreme temperatures, directly ensuring the long-term operational life and safety of the turbine unit (especially the rotor blades) in the turbine cracking reaction unit. Second, the removal of heavy hydrocarbons ensures that the feed is mainly methane, which not only makes the cracking reaction path more singular and controllable and improves the selectivity of acetylene, but also avoids the generation of too much tar or more complex solid deposits from the cracking of heavy hydrocarbons, reducing the carbon removal load of the system. Finally, stabilizing the pressure in a moderate range of 0.5~1.5 atm satisfies the specific requirements of the turbine cracking reaction unit for the inlet pressure (such as providing initial conditions for subsequent supersonic flow), and also serves as a stable operating boundary, enabling a smooth connection of pressure and materials between the entire precursor process and the core cracking unit, laying a solid foundation for the overall stable operation and precise control of the system.

[0101] Furthermore, in step S4 of the above method, the cooling rate of the quenching treatment is 1000~1500 K / ms. The cooling rate of the quenching treatment is 1000~1500 K / ms, which ensures that the cracked gas is rapidly cooled from the reaction temperature (1800~2200 K) to below 800 K in a very short time (0.5~3 ms), thereby efficiently terminating the acetylene decomposition reaction and controlling the acetylene decomposition rate to ≤3.5%. This high-speed quenching feature directly locks in a high acetylene yield, avoids the yield loss of traditional methods, and at the same time reduces energy loss and side reaction risks through rapid cooling, thereby improving the reliability and economy of the process.

[0102] Furthermore, in step S4 of the above method, the quenching medium used in the quenching treatment is selected from at least one of water, nitrogen, circulating oil, or cold methane gas. The selection of one or more of these media provides the system with flexibility and reliability to cope with different operating conditions: water, with its high specific heat capacity and latent heat of vaporization, can achieve rapid heat absorption and cooling; nitrogen, as an inert gas, can avoid product contamination; circulating oil is suitable for medium-temperature recovery systems; and cold methane gas enables the self-circulation of raw materials. This multi-media selection mechanism allows the system to optimize the quenching scheme in real time according to changes in the temperature, flow rate, and composition of the cracked gas. This ensures that the quenching rate is stably maintained at 1000~1500 K / ms, while effectively preventing local overcooling or equipment corrosion during the quenching process through media characteristic matching. From an operational perspective, this ensures that the acetylene decomposition rate is always ≤3.5%.

[0103] Furthermore, in step S4 of the above method, the heat recovered in the quenching and waste heat recovery steps is used to preheat the purified methane gas in step S2; using the quenching waste heat to preheat the purified methane gas achieves closed-loop utilization of energy within the system. This design uses the high-temperature waste heat of the cracked gas as a preheating heat source, replacing external energy sources and directly reducing the total energy consumption of the system.

[0104] Furthermore, in step S5 of the above method, the carbon black content in the gas after gas-solid separation is ≤10mg / Nm³. 3 The carbon black content in the gas after gas-solid separation is limited to ≤10 mg / Nm³. 3 This provides a crucial guarantee for the efficient separation of high-purity acetylene and hydrogen. This indicator ensures extremely high gas cleanliness entering subsequent gas separation units, effectively preventing wear, blockage, and contamination of the adsorbent, absorption solvent, or precision separation equipment by solid particles. This significantly improves the final purity of the acetylene and hydrogen products while reducing system maintenance frequency and operating costs. This strict carbon content control directly reduces the interference of carbon black on subsequent processes, ensuring the stability of the entire process and product yield.

[0105] Furthermore, in step S5 of the above method, gas separation includes absorption, desorption, and pressure swing adsorption (PSA) operations, sequentially separating acetylene, hydrogen, and methane-rich gas. First, acetylene is efficiently separated through selective absorption using an absorption solvent. Then, high-purity acetylene is recovered through desorption. Finally, hydrogen is purified from the remaining gas using PSA to obtain methane-rich tail gas. This process design fully utilizes the advantage of the simple composition of the cracked gas (mainly acetylene, hydrogen, and methane, without complex impurities such as CO). Through precise coordination between steps, efficient and high-purity separation of acetylene and hydrogen is achieved under mild operating conditions. Simultaneously, the effective recovery of methane-rich gas allows for recycling as fuel or feedstock, improving the resource utilization and economic efficiency of the entire process and fundamentally simplifying the complex separation processes required in traditional partial oxidation methods due to CO content.

[0106] Furthermore, in step S5 of the above method, the absorption solvent used in the absorption operation is selected from one or more of N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, and methanol. The selection of the absorption solvent from one or more of N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, and methanol provides a crucial guarantee for the efficient and selective separation of acetylene. These absorption solvents have been widely verified in industrial practice to have high solubility and selectivity for acetylene. For example, NMP and DMF, due to their strong polarity and affinity for the acetylene molecular structure, can efficiently absorb acetylene under mild pressure conditions (0.4~0.6 MPa), while effectively suppressing the co-dissolution of light components such as hydrogen and methane. In addition, the composability of the absorption solvents (such as the mixed use of NMP and DMF) endows the system with the ability to regulate fluctuations in the composition of the cracked gas, balancing solubility and selectivity through optimized ratios. Furthermore, these absorbent solvents all possess excellent thermal stability and regeneration characteristics. For example, DMF can efficiently release acetylene and be recycled during the desorption stage (0.1~0.2 MPa, 320~350K), reducing operating energy consumption and absorbent solvent replenishment costs. This characteristic directly supports the requirement of acetylene product purity ≥99.5%, and its high technological maturity ensures the stable operation and economic efficiency of the separation unit.

[0107] Furthermore, in step S5 of the above method, the adsorbent used in the pressure swing adsorption operation is an activated carbon-molecular sieve composite adsorbent. This adsorbent is a conventional commercial adsorbent that can be directly purchased from the market, and this invention has not modified it in any way. The activated carbon-molecular sieve composite adsorbent combines the preferential physical adsorption characteristics of activated carbon for methane with the deep sieving ability of molecular sieves for trace impurities in hydrogen. Through the synergistic effect of pore size and surface properties, under the periodic pressure change conditions of pressure swing adsorption defined in this invention (adsorption stage 0.4~0.6 MPa, desorption stage 0.03~0.08 MPa, temperature 300~350K), high selective separation of hydrogen and methane is achieved, ultimately yielding high-purity hydrogen product and methane-rich gas.

[0108] Furthermore, in step S5 of the above method, the operating pressure of the absorption operation is 0.4~0.6 MPa and the temperature is 260~290 K; the operating pressure of the desorption operation is 0.1~0.2 MPa and the temperature is 320~350 K. Here, pressure and temperature are synergistically optimized to ensure that the absorption operation achieves high-capacity and high-selectivity acetylene absorption under moderate pressure and relatively low temperature, while simultaneously enabling stable regeneration of the absorbent solvent under gentle decompression and moderate heating. This significantly reduces energy loss and equipment stress caused by drastic pressure fluctuations or sudden temperature changes, and effectively maintains the structural stability and long-term adsorption performance of the absorbent solvent (such as N-methylpyrrolidone). Therefore, while ensuring high purity (≥99.5%) and high recovery rate of the acetylene product, the operational economy and reliability of the separation unit are improved.

[0109] Furthermore, in step S5 of the above method, the pressure swing adsorption operation includes two stages: the first stage is the adsorption stage, with an operating pressure of 0.4~0.6 MPa and a temperature of 300~350 K; the second stage is the desorption stage, with an operating pressure of 0.03~0.08 MPa and a temperature of 300~350 K. The first stage is adsorption under moderate pressure of 0.4~0.6 MPa and a temperature of 300~350 K. This condition ensures the effective separation selectivity of hydrogen and methane while avoiding the equipment load and energy consumption caused by excessive pressure. The second stage is desorption under deep pressure of 0.03~0.08 MPa and a similar temperature, which significantly reduces the energy consumption required for adsorbent regeneration and achieves efficient regeneration of the adsorbent by utilizing the pressure difference. This optimized pressure and temperature cycle not only ensures the high purity and high recovery rate of hydrogen products, but also significantly reduces the overall operating energy consumption of the separation unit. At the same time, the mild operating conditions help maintain the structural stability of the activated carbon-molecular sieve composite adsorbent, extend its service life, and further improve the overall economy and long-term operational reliability of the process of this invention.

[0110] 1.2 High-efficiency natural gas-to-acetylene and hydrogen system based on turbine cracking

[0111] This application further provides a system for implementing the above method, such as... Figure 1 As shown, the system includes components connected sequentially along the process flow path:

[0112] The raw material pretreatment unit 10 is used to pretreat the raw material natural gas to obtain high-concentration purified methane gas;

[0113] The preheating unit 20 is connected to the raw material pretreatment unit 10 and is used to preheat the purified methane gas.

[0114] The turbine cracking reaction unit 30 is provided with a purified methane gas inlet and a cracked gas outlet; its purified methane gas inlet is connected to the preheating unit 20 to receive the preheated purified methane gas, and uses the mechanical energy of the turbine to heat the purified methane gas and cause a cracking reaction to generate cracked gas; the cracked gas outlet is used to discharge the cracked gas; the turbine cracking reaction unit 30 includes a turbine heater 31 and a turbine reactor 32 connected in sequence in the fluid flow direction, and the turbine heater 31 and the turbine reactor 32 are composed of one or more sets of turbine devices.

[0115] The quenching and waste heat recovery unit has its inlet connected to the outlet of the pyrolysis gas, and is used to quench the pyrolysis gas and recover waste heat.

[0116] A gas-solid separation unit, connected to the quenching and waste heat recovery unit, is used to separate solid carbon black from the pyrolysis gas after quenching and waste heat recovery.

[0117] A gas separation unit, connected to the gas-solid separation unit, is used to separate acetylene and hydrogen products.

[0118] The system provided in this application systematically integrates and deeply coordinates units such as raw material pretreatment, preheating, turbine cracking, quenching and waste heat recovery, gas-solid separation, and gas separation along the process flow path, constructing a natural gas-to-acetylene and hydrogen production system that achieves efficient matching of material and energy flow and thus stable operation. The core innovation of this system lies in replacing the traditional heat source or catalyst system with a turbine cracking reaction unit, directly converting mechanical energy into cracking heat energy, thereby fundamentally avoiding the separation complexity, high energy consumption, and environmental problems inherent in traditional systems due to the introduction of oxygen or reliance on catalysts. Deep coordination among units (such as using quenching waste heat for raw material preheating and modular layout) achieves efficient coupling of matter and energy. This integrated innovation significantly optimizes the overall energy consumption of the system, ensuring not only stable operation and high product yield throughout the process but also significantly reducing energy consumption per unit product and plant investment costs. Ultimately, this system achieves multiple goals simultaneously—high process efficiency, clean products, and economical operation—through a highly integrated technical solution.

[0119] Furthermore, in the above system, the raw material pretreatment unit 10 includes a raw natural gas buffer and pressure stabilization device, a deep desulfurization device, a CO2 removal device, a heavy hydrocarbon separation device, and a fine dehydration device, used to remove impurities (such as sulfur, water, heavy hydrocarbons, CO2, etc.) from the raw natural gas to obtain high-concentration purified methane gas with a methane concentration of 95%~100%, and stabilize the pressure to 0.5~1.5 atm; the various devices of the raw material pretreatment unit achieve coordinated operation through interstage pressure regulation and energy recovery.

[0120] Furthermore, in the above system, the preheating unit 20 is selected from one or more of the following: shell and tube heat exchanger, porous medium-filled heat exchanger, finned tube heat exchanger, spiral plate heat exchanger, coaxial heat exchanger, and heat pipe heat exchanger. The heat source of the heat exchanger can be the quenched high-temperature mixed gas and other heat flows in the system.

[0121] In the above system, the turbine heater 31 and the turbine reactor 32 are composed of one or more turbine units; the structure of the turbine unit is described in [reference needed]. Figure 2 ,include:

[0122] The housing has a working fluid inlet 35 and a working fluid outlet 36 for the turbine device, and a flow channel connecting the working fluid inlet 35 and the working fluid outlet 36 is formed inside the housing.

[0123] The rotor shaft 37 is rotatably supported within the housing and configured to be connected to the drive unit 38;

[0124] The rotor hub 371 is fixedly sleeved on the rotor shaft 37;

[0125] At least three stages of blades are arranged sequentially in the flow channel within the housing along the axial direction of the rotor shaft 37. Each stage of blades includes, in the direction of fluid flow, a flow guiding device 39 fixed to the housing, a rotor blade 310 mounted on the rotor hub 371, and a diffuser blade 311 fixed to the housing.

[0126] Between two adjacent blade groups, an interstage diffusion channel 312 is formed between the outlet of the upper stage diffuser blade 311 and the inlet of the lower stage guide device 39; the flow cross-sectional area of ​​the interstage diffusion channel 312 varies along the fluid flow direction (the flow cross-sectional area expands along the fluid flow direction), and an interstage flow field adjustment mechanism (not shown in the figure) is provided therein to enhance the turbulent mixing and pressure recovery of the fluid (the pressure is restored to be consistent with the pressure of the working fluid inlet 35 of the turbine device), thereby providing the next stage blade group with uniform pressure and uniform flow field inlet conditions.

[0127] The rotor shaft 37, rotor hub 371, and rotor blades 310 of each stage together constitute the rotor of the turbine device.

[0128] The turbine cracking reaction unit 30 (including a turbine heater 31 and a turbine reactor 32 connected sequentially in the fluid flow direction) is the core of the aforementioned system. Its design is fundamentally aimed at efficiently addressing the inherent energy supply and thermal management challenges of the methane cracking to acetylene reaction. This unit, through the synergistic effect of multiple turbine stages, achieves a highly efficient process where an endothermic reaction is directly driven by mechanical energy. Its complete working principle follows the following physical and chemical logic:

[0129] 1. Energy Injection and Kinetic Energy Conversion: The drive unit 38 drives the rotor shaft 37 to rotate at high speed, and the multi-stage rotor blades 310 fixed on the rotor hub 371 do work on the flowing methane gas. This process continuously converts the mechanical energy of the turbine into the kinetic and pressure energy of the gas, accelerating the gas to a supersonic state. This step provides the initial energy form required to initiate the strong endothermic reaction.

[0130] 2. Shock Compression and Thermal Energy Conversion: When supersonic airflow enters the 311 channel of the diffuser blades, a compression shock wave (usually manifested as a bow shock wave) is generated at its leading edge due to the change in flow area. As the airflow crosses this shock wave surface, its velocity drops sharply, and its kinetic and pressure energy is irreversibly dissipated and converted into the internal energy of the gas according to the laws of thermodynamics. This causes the temperature to rise rapidly to the pyrolysis temperature (1800~2200K) within milliseconds. The core value of this mechanism lies in its ability to instantaneously provide the large amount of heat required for a strongly endothermic reaction, thereby efficiently driving the reaction towards the formation of acetylene.

[0131] 3. Flow Field Reshaping and Interstage Mixing: The gas heated by the shock wave enters the interstage diffusion channel 312. This channel, through a specific shape design and a built-in interstage flow field adjustment mechanism (such as a vortex generator), promotes a more uniform velocity and pressure distribution of the high-temperature gas flow and enhances turbulent mixing. This step ensures the uniformity of the reaction heat distribution, providing a stable and controllable thermal environment for the endothermic reaction and avoiding side reactions caused by local overheating or temperature unevenness.

[0132] 4. Flow Guidance and Multi-Stage Energy Superposition: The gas, after mixing and reforming, is guided by the flow guiding device 39 into the subsequent rotor blades 310. By repeating the cycle of "acceleration → shock wave heating → mixing and reforming → re-guidance", the gas achieves step-by-step energy superposition and precise temperature increase as it flows through the multi-stage turbine device. This multi-stage design meets the stringent requirements of strong endothermic reactions for continuous and stable heat energy supply, ensuring that the reaction system ultimately reaches and stabilizes at the optimal pyrolysis temperature window.

[0133] 5. Synergistic control of heating and reaction: This unit adopts a segmented design strategy of turbine heater 31 (front section) and turbine reactor 32 (rear section); turbine heater 31 focuses on rapidly heating the gas to the reaction temperature to overcome the endothermic barrier of the reaction; turbine reactor 32 provides the necessary residence time and thermal environment for methane molecules to complete the endothermic process of cracking by maintaining an ultra-high temperature field; by independently adjusting the parameters of each section, the system achieves precise control of heating rate and reaction time, thereby optimizing the path of the strongly endothermic reaction at the molecular level, and ultimately achieving high acetylene yield and suppressing excessive cracking.

[0134] Furthermore, in the turbine heater 31 and turbine reactor 32 of the above system, the turbine housing adopts a double-shell structure, consisting of, from the outside to the inside: an outer layer structure 33 made of heat-resistant steel (mainly responsible for structural support and sealing), an inner layer structure 34 made of ceramic matrix composite material or high-temperature resistant ceramic lining (directly facing the ultra-high temperature pyrolysis gas flow, responsible for heat bearing and corrosion resistance), and a multi-layer thermal barrier coating covering the working surface of the inner layer structure (further improving the resistance to extreme temperatures, not shown in the figure); the high-temperature resistant ceramic lining is alumina-based ceramic or silicon carbide-based ceramic, etc., the ceramic matrix composite material is SiC / SiC composite material or Al2O3 / Al2O3 composite material, and the thermal barrier coating is yttrium-stabilized zirconia (YSZ) coating or YSZ / Al2O3 composite coating; in order to cope with the ultra-high temperature environment in the turbine pyrolysis reaction unit, this application has implemented a systematic active cooling design for key components (including rotor blades 310, diffuser blades 311 and shell interlayers in the turbine housing, etc.). This design achieves effective thermal protection based on the principle of convection heat transfer by prefabricating specific cavities and conduit structures inside the component and introducing cooling fluids such as nitrogen or steam.

[0135] Furthermore, in the above system, the rotor shaft 37 extends outside the housing and is connected to the drive unit 38 via a drive shaft and coupling. The output power of the drive unit 38 is regulated by a power actuator, which receives external control commands and acts as the final actuator to precisely control the rotor speed. The drive unit 38 can be selected from an electric motor, a gas turbine, or a steam turbine, with its primary energy source preferably being renewable and clean energy sources such as solar and wind power.

[0136] Furthermore, in the turbine heater 31 and turbine reactor 32 of the above system, the core functional component of the turbine device is the blade assembly, which is arranged sequentially along the axial direction of the rotor shaft 37. In the direction of fluid flow, each stage of the blade assembly follows the basic principle of "guided flow - work - diffusion". Specifically, each stage of the blade assembly includes, in terms of structure, a guide device 39, a rotor blade 310, and a diffuser blade 311 arranged sequentially in the flow channel inside the turbine device housing. The three are arranged upstream to downstream along the direction of fluid flow. Among them, the guide device 39 is fixedly installed in the housing. Its specific structure can preferably be a guide blade in the form of a cascade, or a streamlined Laval nozzle. The Laval nozzle can be, for example, a cascade nozzle, a perforated nozzle, or a rectangular nozzle, mainly serving to regulate the flow field and guide the fluid to flow in a preset direction. The rotor blade 310 is an impact rotor blade, installed on the circular rotor hub 371. The upper part consists of rotating power components of the turbine unit, numbering at least three rows, forming the core structure of the impeller. It is used to convert the mechanical energy of the turbine into the kinetic energy of the fluid, thereby realizing the conversion of the fluid's kinetic energy into internal energy and providing energy for the heating of methane gas. The diffuser blade 311 is fixed to the shell and located downstream of the rotor blade 310. Its flow channel configuration is expansion-shaped, mainly responsible for slowing down the fluid, thereby realizing the further conversion of the fluid's kinetic energy into pressure energy and internal energy. At the same time, the outlet of the diffuser blade 311 is connected to the interstage diffusion channel 312 of the next stage blade group, providing stable fluid inlet conditions for the next stage blade group.

[0137] To ensure the long-term operational stability of the turbine unit in high-temperature, carbon-deposits-prone environments, this invention features targeted designs for the materials and surface treatments of key components such as the guide vane 39, rotor blades 310, and diffuser blades 311. The substrates of the guide vane 39, rotor blades 310, and diffuser blades 311 can be made of high-temperature alloys or ceramic matrix composites to ensure high-temperature strength. Preferably, to obtain superior high-temperature resistance and thermal shock resistance, the substrate material can be a ceramic matrix composite, such as SiC / SiC composite or Al2O3 / Al2O3 composite.

[0138] To further suppress carbon soot deposition and extend maintenance cycles, an anti-carbon deposit coating is applied to the surface of all blade substrates. This coating is preferably a Pt-Al coating, a YSZ / Al2O3 composite coating, or an Al2O3-SiO2 composite coating, which combines good adhesion with high-temperature stability, to form a dense protective layer on the substrate surface and effectively block carbon soot adhesion.

[0139] To ensure the long-term stable operation of the turbine pyrolysis reaction unit in ultra-high temperature environments (e.g., 1800K~2200K), efficient cooling of its key high-temperature components is necessary. Specifically, discrete cooling holes can be provided on the surfaces of the flow guide device 39, rotor blades 310, and diffuser blades 311; alternatively, the flow guide device 39, rotor blades 310, and diffuser blades 311 themselves can be fabricated into porous structures using sintering technology. These cooling holes are conventional film cooling hole structures for high-temperature alloy / ceramic matrix composite blades, with pore diameter, porosity, and circumferential / axial spacing all being existing known parameters in the field of fluid machinery for ultra-high temperature pyrolysis conditions. They are used to introduce cooling media to form film cooling or porous divergent cooling. During operation, cooling media (such as inert gas or steam) are introduced into the cavities or pores inside the flow guide device 39, rotor blades 310, and diffuser blades 311. The cooling media is ejected in jet form through the discrete cooling holes or uniformly seeps out through the porous structure, thereby forming a film cooling layer that isolates the high-temperature fluid on the blade surface or achieving porous media divergent cooling. This cooling solution not only enables precise temperature control of the aforementioned key high-temperature components, but the resulting gas film layer can also effectively inhibit the formation and adhesion of carbon deposits.

[0140] Furthermore, in some specific embodiments, by optimizing the design of the number of turbine stages and the rotational speed, precise control of the pyrolysis process can be achieved. Specifically, the turbine heater 31 can be configured to include 9 to 11 blade stages. By controlling the rotor speed within the range of 8000 to 24000 rpm, it can ensure that the purified methane gas is rapidly heated from a preheating temperature of 523 K to the target pyrolysis initiation temperature of 1800 K within an extremely short time of 1 to 10 ms. Subsequently, the methane gas enters the turbine reactor 32, which receives the heating effect from the turbine heater 31. The turbine reactor 32 can be configured to include 5 to 9 blade stages. At a rotational speed of 8000 to 24000 rpm, it can stably maintain the temperature of the pyrolysis zone within the pyrolysis temperature range of 1800 K to 2200 K, thereby ensuring a high acetylene yield and suppressing side reactions.

[0141] Inside the casing, an interstage diffusion channel 312 is formed between adjacent blade groups along the fluid flow direction. The inlet of the interstage diffusion channel 312 is the outlet of the previous stage diffusion blade 311, and the outlet is the inlet of the next stage guide device 39. The flow cross-sectional area of ​​the interstage diffusion channel 312 adapts to the fluid flow direction (the flow cross-sectional area expands along the fluid flow direction, and its diffusion angle and cross-sectional area change ratio adopt conventional existing technical parameters of interstage diffusion channels of turbine devices in this field). An interstage flow field adjustment mechanism (not shown in the figure) is provided inside it. The interstage flow field adjustment mechanism is an active disturbance device or a vortex generator. The two work together to enhance the turbulent mixing and pressure recovery of the reaction fluid (the pressure is restored to be consistent with the pressure of the working fluid inlet 35 of the turbine device), thereby providing the next stage blade group with uniform pressure and uniform flow field inlet conditions.

[0142] It should be noted that the aforementioned active disturbance device and eddy current generator are existing commonly used mechanisms in the field of fluid flow field regulation. This invention does not improve them, but only integrates them into the interstage diffusion channel to achieve flow field homogenization and pressure recovery.

[0143] To achieve rapid termination of the cracked gas reaction and efficient energy recovery, the quenching and waste heat recovery unit includes a quenching device 40 and a waste heat recovery device 50 arranged in series. The quenching device 40 is directly connected to the cracked gas outlet of the turbine cracking reaction unit 30 and is used to perform millisecond-level quenching treatment on the high-temperature cracked gas to terminate the acetylene decomposition reaction and avoid side reactions. In some specific embodiments, the quenching device 40 is a quenching medium injection structure, with 4 to 6 pairs of quenching medium injection holes 41 evenly arranged on the circumference surrounding the cracked gas flow channel. The quenching medium is selected from water, nitrogen, circulating oil, or cold methane gas. At least one of the quenching medium forms an atomized jet through a quenching medium injection hole, which mixes thoroughly with the cracked gas and rapidly cools it, thereby achieving rapid termination of the cracking reaction. The waste heat recovery device 50 is connected to the quenching device 40, receiving the pre-quenched cracked gas and recovering its sensible heat. In some specific embodiments, the waste heat recovery device 50 is a porous media-filled heat exchanger, which may use alumina ceramic balls as the heat storage medium. When the cracked gas flows through the porous media bed, it undergoes efficient heat exchange with the heat storage medium, achieving efficient recovery of the sensible heat of the cracked gas. The recovered heat can be used for the preheating process of purifying methane gas. Regarding the thermal integration method of the waste heat recovery device 50, there are two main embodiments:

[0144] In some embodiments, the waste heat recovery device 50 is an independent heat exchange device, and the heat recovered by it is transferred to the preheating unit 20 or other heat-using links of the system through an intermediate heat medium (such as heat transfer oil).

[0145] In other embodiments, the waste heat recovery device 50 and the preheating unit 20 are integrated into a combined heat exchanger, for example, using a shell-and-tube or plate-and-shell structure, so that the cracked gas and the raw material methane to be preheated can directly exchange heat in indirect contact, thereby improving heat exchange efficiency.

[0146] To ensure continuous and stable system operation, the waste heat recovery device 50 adopts a modular design with multiple heat exchangers connected in parallel and operates in a pulse-type waste heat recovery mode. By switching valves, each heat exchanger can work alternately, enabling maintenance operations of a single or partial heat exchanger without interrupting the overall process flow, thus achieving non-stop system maintenance.

[0147] In the above system, the gas-solid separation unit is connected to the quenching and waste heat recovery unit, receiving the gas-solid mixture cooled to 300~400K after quenching and waste heat recovery. Its core function is to remove solid carbon black particles from the mixture, ensuring that the carbon black content in the separated gas is ≤10mg / Nm³. 3 This provides clean raw material gas for the subsequent gas separation unit. The gas-solid separation unit can be composed of one or more of the following devices: cyclone separator, bag filter, electrostatic precipitator, and scrubbing tower. It can be flexibly configured according to the carbon black content, particle size distribution, and system operation requirements of the process conditions.

[0148] Figure 1The system shown in the diagram, which utilizes turbine cracking to produce acetylene and hydrogen from natural gas, employs a multi-stage combined structure for its gas-solid separation unit. Along the process flow path, a cyclone separator 61, a bag filter 62, and a scrubbing tower 63 are sequentially arranged. An electrostatic precipitator 64 is installed in the upper part of the scrubbing tower 63. The gas, purified through these multiple stages, is sent from the gas outlet of the scrubbing tower 63 to the subsequent gas separation unit. A coarse separation-fine separation-deep purification + terminal fine filtration integrated process achieves efficient removal of carbon black. The cyclone separator 61, as a primary coarse separator, utilizes centrifugal force to create a swirling flow in the gas-solid mixture. Large-diameter, high-density carbon black particles are thrown against the wall by centrifugal force and settle to the bottom for collection, achieving rapid separation of large carbon black particles. This initially reduces the carbon black content in the gas-solid mixture, effectively reducing the processing load on subsequent separation units. After cyclone separation... The gas after coarse separation in filter 61 enters bag filter 62 as a secondary fine separation device. Through the filtration and retention of the filter bags, suspended medium and small-diameter carbon black particles are removed from the gas, further improving carbon black separation efficiency and significantly reducing the carbon black content in the gas. The gas treated by bag filter 62 is then passed into scrubbing tower 63. The scrubbing liquid (including but not limited to water) in scrubbing tower 63 fully contacts the gas, removing trace amounts of fine carbon black while further cooling and washing the gas, and also buffering the airflow and stabilizing the flow field. The upper part of scrubbing tower 63 is equipped with an electrostatic precipitator 64, which uses the principle of electrostatic adsorption to perform terminal deep purification of the gas in scrubbing tower 63, completely removing the remaining ultrafine carbon black particles and ensuring that the carbon black content in the gas after multi-stage treatment by the gas-solid separation unit strictly meets the requirement of ≤10mg / Nm³. 3 According to the process requirements, the purified gas is directly sent from the gas outlet of the scrubbing tower to the subsequent gas separation unit for the separation and extraction of acetylene and hydrogen.

[0149] The solid carbon black collected from each unit can be recycled as a by-product after subsequent processing such as collection, drying, and granulation, thus realizing the resource-based disposal of process waste.

[0150] like Figure 1 As shown, in the above system, the gas separation unit is connected to the gas outlet of the scrubbing tower 63 of the gas-solid separation unit, and receives gas with a carbon black content ≤10mg / Nm³ after gas-solid separation. 3The core of this clean gas separation unit is used to efficiently separate and purify acetylene, hydrogen, and methane-rich gases from the gas mixture, yielding acetylene and hydrogen products respectively, while simultaneously recovering methane-rich gases. The gas separation unit includes an absorption tower 71, a desorption tower 72, and a pressure swing adsorption (PSA) device 73 arranged sequentially along the process flow path. The mixed gas is separated and purified through a combined "absorption-desorption-PSA" process. The absorption tower 71 is filled with a specialized absorption solvent, selected from one or more of N-methylpyrrolidone, dimethylformamide (DMF), acetone, and methanol. The mixed gas first enters the absorption tower 71 from the bottom. Inside the absorption tower 71, the mixed gas comes into countercurrent contact with the absorption solvent flowing downwards. During this process, a large amount of the acetylene component in the cracked gas is absorbed by the absorption solvent, while hydrogen, methane, and other difficult-to-dilute components are absorbed. Soluble or slightly soluble gases are discharged from the top of absorption tower 71, becoming hydrogen-rich tail gas; the solvent rich in acetylene flows out from the bottom of the tower and enters desorption tower 72; in desorption tower 72, by adjusting process parameters (heating and / or depressurization), the acetylene adsorbed in the absorption solvent is desorbed, realizing the purification of acetylene and the regeneration of the absorption solvent. The regenerated absorption solvent is discharged from the bottom of the desorption tower and can be recycled back to absorption tower 71 for continued use. The high-concentration acetylene obtained by desorption is collected from the top of desorption tower 72 as crude acetylene product, and after subsequent purification, it becomes the acetylene product; the hydrogen-rich tail gas discharged from the top of absorption tower 71 is further sent to pressure swing adsorption unit 73 for deep purification to obtain high-purity hydrogen product; pressure swing adsorption unit 73 usually contains multiple adsorption towers in parallel, and its core adopts an activated carbon-molecular sieve composite adsorbent bed. Specifically, the bed is composed of adsorbents with different adsorption characteristics, which are filled in sections: the inlet end is mainly filled with activated carbon to preferentially remove heavy hydrocarbons, carbon dioxide and some moisture; the outlet end is mainly filled with molecular sieves (such as 5A or 13X type) to deeply remove impurities such as nitrogen and methane. Utilizing the adsorption selectivity of the adsorbent for different gas components and the characteristic that the adsorption capacity changes with pressure, hydrogen and methane-rich gas are efficiently separated through adsorption, pressure equalization, desorption and rinsing processes. The purified hydrogen is then stabilized and purified to become the hydrogen product. The adsorbed methane-rich gas can be desorbed and recycled to the system preheating unit 20 or the turbine cracking reaction unit 30 to participate in the cracking reaction again, realizing the recycling of raw materials and improving the overall raw material utilization rate of the process.

[0151] In the specific implementation process, the operating pressure of the absorption tower is controlled at 0.4~0.6MPa and the operating temperature at 260~290K, the operating pressure of the desorption tower is controlled at 0.1~0.2MPa and the operating temperature at 320~350K; the operating pressure of the pressure swing adsorption unit is 0.4~0.6MPa and the temperature is 300~350K during the adsorption stage, and the operating pressure of the desorption stage is 0.03~0.08MPa and the temperature is 300~350K. By precisely controlling the process parameters of each unit, the separation purity and yield of acetylene and hydrogen are ensured.

[0152] The following provides specific examples.

[0153] Example 1

[0154] This embodiment describes a method for producing acetylene and hydrogen from natural gas based on turbine cracking. Figure 1 The system shown is a high-efficiency natural gas-to-acetylene and hydrogen production system based on turbine cracking. In this system, the turbine cracking reaction unit 30 includes a turbine heater 31 and a turbine reactor 32 connected sequentially in the fluid flow direction (each turbine heater 31 and turbine reactor 32 includes a set of turbine devices). The specific structures of the turbine heater 31 and turbine reactor 32 are as follows: Figure 3 , Figure 4 As shown, Figure 3 Medium turbine heater 31 and Figure 4 The structure of the turbine reactor 32 is basically the same, the only difference being that... Figure 3 The intermediate turbine heater 31 includes a 10-stage blade assembly. Figure 4 The turbine reactor 32 includes a 7-stage blade assembly. The turbine working fluid inlet 35 of the turbine heater 31 is the purified methane gas inlet of the turbine cracking reaction unit 30. The turbine working fluid outlet 36 of the turbine reactor 32 is the cracked gas outlet of the turbine cracking reaction unit 30. The quenching device 40 consists of 4 pairs of quenching medium injection holes 41 evenly arranged around the turbine working fluid outlet 36 of the turbine reactor 32.

[0155] The method includes the following steps:

[0156] S1. Pretreatment step: The flow rate is 1500 Nm 3 The natural gas feedstock is introduced into the feedstock pretreatment unit 10 at a rate of / h, and after being treated by desulfurization, dehydration and heavy hydrocarbon removal, it is purified methane gas with a methane concentration of 95% and then stabilized at 1 atm.

[0157] S2. Preheating step: Introduce purified methane gas, which has been stabilized to 1 atm, into preheating unit 20 and preheat it to 823 K;

[0158] S3. Turbine heating and cracking steps: Purified methane gas preheated to 823 K is introduced into the turbine cracking reaction unit 30. The rotor speeds of the turbine heater 31 and the turbine reactor 32 are controlled at 18000 rpm. The purified methane gas enters the turbine heater and is heated from 823 K to 1950 K in 3 ms. Then it enters the turbine reactor 32 and stays in the ultra-high temperature environment of 1950 K for about 3 ms to complete the cracking reaction of methane and generate cracked gas containing acetylene, hydrogen, carbon black and unreacted methane.

[0159] S4. Quenching and Waste Heat Recovery Step: After the cracked gas is discharged from the outlet of the turbine reactor 32, it immediately enters the quenching device 40 arranged adjacent to the outlet. In the quenching device 40, atomized water is injected into the cracked gas flow through four pairs of quenching medium injection holes 41 arranged evenly in a circle, so that it is rapidly quenched to about 800 K within 3 ms, thereby terminating the secondary decomposition reaction of acetylene. Subsequently, the cracked gas enters the waste heat recovery device 50 (a porous medium-filled heat exchanger, the filling medium is alumina ceramic balls), and is further cooled to 300 K. The recovered heat is used for the preheating of the purified methane gas in step S2.

[0160] S5. Separation Step: The gas mixture after quenching and waste heat recovery enters the gas-solid separation unit (a cyclone separator 61, a bag filter 62, and a scrubbing tower 63 arranged sequentially along the process flow path; the upper part of the scrubbing tower 63 is equipped with an electrostatic precipitator 64), yielding solid product carbon black with a carbon black content ≤10mg / Nm³. 3 The gas mixture enters the gas separation unit (the operating pressure of the absorption tower is controlled at 0.5 MPa and the operating temperature at 260 K; the operating pressure of the desorption tower is controlled at 0.1 MPa and the operating temperature at 340 K; the operating pressure of the pressure swing adsorption unit is 0.6 MPa and the operating temperature is 320 K in the adsorption stage, and the operating pressure of the desorption stage is 0.03 MPa and the operating temperature is 325 K), and acetylene product with a purity ≥99.5%, hydrogen product with a purity ≥99.5%, and methane-rich gas (including by-products such as ethylene and ethane) are separated to obtain acetylene product with a purity ≥99.5%, hydrogen product with a purity ≥99.5%, and methane-rich gas.

[0161] The method yielded an acetylene yield of 85%, an acetylene production energy consumption of 8.0 kWh / kg, and a natural gas conversion rate of 95% (see Table 1).

[0162] Example 2

[0163] The method for efficient natural gas to acetylene and hydrogen production based on turbine cracking in this embodiment is basically the same as that in Embodiment 1, except that steps S1 to S3 are as follows:

[0164] S1. Pretreatment step: The flow rate is 2000 Nm 3The natural gas feedstock is introduced into the feedstock pretreatment unit 10 at a rate of / h, and after being treated sequentially by desulfurization, dehydration and heavy hydrocarbon removal, it is purified methane gas with a methane concentration of 95% and then stabilized at 1.3 atm.

[0165] S2. Preheating step: Introduce purified methane gas, which has been stabilized at 1.3 atm, into preheating unit 20 and preheat it to 573 K;

[0166] S3. Turbine heating and cracking steps: Purified methane gas preheated to 573K is introduced into the turbine cracking reaction unit 30. The rotor speeds of the turbine heater 31 and the turbine reactor 32 are controlled at 24,000 rpm. The purified methane gas enters the turbine heater and is heated from 573K to 2150K in 3.5ms. Then it enters the turbine reactor 32 and stays in the ultra-high temperature environment of 2150K for about 2.5ms to complete the cracking reaction of methane and generate cracked gas containing acetylene, hydrogen, carbon black and unreacted methane.

[0167] The test results showed that the acetylene yield of this method was 87.5%, the specific energy consumption for acetylene production was 8.3 kWh / kg, and the natural gas conversion rate was 95% (see Table 1).

[0168] Example 3

[0169] The method for efficient natural gas to acetylene and hydrogen production based on turbine cracking in this embodiment is basically the same as that in Embodiment 1, except that steps S1 to S3 are as follows:

[0170] S1. Pretreatment steps: The flow rate is 800 Nm 3 The natural gas feedstock is introduced into the feedstock pretreatment unit 10 at a rate of / h, and after being treated sequentially by desulfurization, dehydration and heavy hydrocarbon removal, it is purified methane gas with a methane concentration of 95% and then stabilized at 0.6 atm.

[0171] S2. Preheating step: Introduce purified methane gas, which has been stabilized at 0.6 atm, into preheating unit 20 and preheat it to 723 K;

[0172] S3. Turbine heating and cracking steps: Purified methane gas preheated to 723K is introduced into the turbine cracking reaction unit 30. The rotor speeds of the turbine heater 31 and the turbine reactor 32 are controlled at 14000rpm. The purified methane gas is heated from 723K to 1800K in the turbine heater for 5ms, and then enters the turbine reactor 32 and stays in the ultra-high temperature environment of 1800K for about 3.5ms to complete the cracking reaction of methane, generating cracked gas containing acetylene, hydrogen, carbon black and unreacted methane.

[0173] The test results showed that the acetylene yield of this method was 83%, the specific energy consumption for acetylene production was 7.8 kWh / kg, and the natural gas conversion rate was 92% (see Table 1).

[0174] Comparative Example 1

[0175] This comparative example uses a 10MW rotating arc plasma torch system with a flux of 3000 Nm. 3 The entire plasma system was purged with nitrogen for 0.5 hours. After purging, the plasma arc was started. Once the system was running stably (operating power around 5MW), the flow rate was increased to 5000 Nm³ / h. 3 Hydrogen gas at a rate of / h is introduced into the plasma torch, nitrogen gas is shut off, and the operating power is increased to approximately 10MW. Then, natural gas (1500Nm³) is introduced. 3 A methane concentration of 95% ( / h) is introduced into the system for pyrolysis (pyrolysis temperature ≥1700K); water is atomized and sprayed into the pyrolysis gas to ensure full contact between the pyrolysis gas and water. The water absorbs heat and turns into water vapor, quenching the pyrolysis gas to below 500K. The quenched product enters the separation system (cyclone separator and bag filter). After gas-solid separation, solid products are separated, and the obtained gaseous products are separated by pressure swing adsorption to obtain hydrogen, acetylene, and by-products such as methane, ethylene, and ethane. The hydrogen is recycled into the plasma torch system, the acetylene enters the gas holder, and the by-products such as methane, ethylene, and ethane enter the corresponding collection devices.

[0176] Testing showed that the method yielded 85% acetylene, had an acetylene production energy consumption of approximately 9.5 kWh / kg, and achieved a natural gas conversion rate of 95% (see Table 1).

[0177] Comparative Example 2

[0178] This comparative example uses an industrial-grade natural gas partial oxidation reaction system with a flow rate of 1500 Nm³. 3 / h, with a methane concentration of 95% and a flow rate of 850 Nm³. 3 Pure oxygen (≥99.6% purity) is preheated to approximately 873K and 923K respectively. The preheated natural gas and oxygen are thoroughly mixed in a mixer at an oxygen-alkane ratio of 0.55, and then injected into a partial natural gas oxidation reactor. Partial oxidation combustion and pyrolysis reactions occur at 1773K, with a residence time of approximately 10ms. The high-temperature pyrolysis gas is immediately quenched to below 300K by a large amount of atomized water at the reactor outlet quenching ring, terminating the reaction. The cooled gas then sequentially enters a cyclone separator and an electrostatic precipitator to obtain a carbon content ≤15mg / Nm³. 3 The process gas then enters a solvent absorption tower, where crude acetylene is separated by countercurrent absorption. After desorption and distillation, the product acetylene (purity ≥99.0%) is obtained. The tail gas discharged from the top of the absorption tower, rich in hydrogen, carbon monoxide, and unreacted methane, is partially returned to the system as fuel, and the remainder is subjected to cryogenic separation or pressure swing adsorption to extract hydrogen (purity ≥99.5%) and carbon monoxide.

[0179] The test results showed that the acetylene yield of this method was approximately 32%, the specific energy consumption for acetylene production was 3.2 kWh / kg, and the conversion rate of methane in natural gas was approximately 83% (see Table 1).

[0180] Table 1. Core performance indicators of Examples 1-3 and Comparative Examples 1-2

[0181]

[0182] A comparison of the core performance indicators of Examples 1-3 of this invention with existing technologies (Comparative Example 1: Plasma Method, Comparative Example 2: Partial Oxidation Method) shows that: the methane conversion rate of this invention reaches 92%-95%, and the acetylene yield is 83%-87.5%, which is significantly improved compared with the partial oxidation method (conversion rate 83%, yield 32%), and is on par with the plasma method (conversion rate 95%, yield 85%), with better product selectivity; the specific energy consumption for acetylene production is 7.8-8.3 kWh / kg, which is 12.6%-17.9% lower than that of the plasma method (9.5 kWh / kg). Although the surface energy consumption of the partial oxidation method is 3.2 kWh / kg, it requires a large amount of pure oxygen and nearly two-thirds of the natural gas is used for combustion, so the actual effective energy consumption is higher than that of this invention.

[0183] A comparison of different process parameters of this invention shows that: rotor speed is positively correlated with pyrolysis temperature; the highest yield (87.5%) is achieved at 24,000 rpm and 2150 K, while the lowest energy consumption (7.8 kWh / kg) is achieved at 14,000 rpm and 1800 K. Parameters can be flexibly adjusted according to industrial needs to achieve a balance between yield and energy consumption; the feed flow rate is 800~2000 Nm³. 3 Within the range of / h, the yield fluctuation is ≤4.5%, adapting to the needs of different scales of production.

[0184] Furthermore, the acetylene and hydrogen products of this invention have a purity of ≥99.5%, and the pyrolysis gas is free of CO / CO2 impurities. The separation process is simplified, and it exhibits outstanding advantages in terms of cleanliness, product quality, and process adaptability.

[0185] To achieve precise, stable, and intelligent control of the entire turbine pyrolysis system, this invention further integrates a monitoring and collaborative control module (not shown in the figure). This module communicates with each process unit of the system and is primarily used to collect real-time data on the temperature, pressure, flow rate, and composition parameters of the reaction fluids within the system. Based on the detected data, it compares and analyzes the data with preset target values ​​and safety thresholds, dynamically adjusting process parameters to ensure the continuous and stable operation of the entire turbine pyrolysis-based natural gas-to-acetylene and hydrogen production system. Simultaneously, it optimizes the yield of pyrolysis products, reduces energy consumption, and extends equipment lifespan. The target values ​​are the optimal setpoints for each process parameter during normal system operation, determined comprehensively by considering pyrolysis product yield, equipment operating efficiency, and energy consumption optimization. The safety thresholds are critical parameter values ​​that ensure equipment safety and prevent process anomalies. They are preset based on the equipment material tolerance limits, process reaction safety boundaries, and long-term operating experience, and can be adaptively fine-tuned according to actual operating conditions to ensure the rationality and adaptability of parameter settings.

[0186] This module specifically includes a signal acquisition unit, a signal processing and controller communicatively connected to the signal acquisition unit, and an actuator drive unit connected to the signal processing and controller; the three work together to form a closed-loop control system of "data acquisition - logical decision-making - instruction execution". The signal acquisition unit is equipped with a high-temperature resistant sensor array arranged within the turbine cracking reaction unit 30, specifically implemented as follows:

[0187] The high-temperature sensor array specifically includes: a temperature sensing unit, comprising high-temperature thermocouples (range -200~2500K, accuracy ±1K) installed at the outlet of the rotor blades 310, the outlet of the interstage diffusion channel 312, and the outlet of the working fluid 36 of the turbine unit, for real-time monitoring of the temperature distribution of the reaction fluid at key locations; a pressure sensing unit, comprising high-frequency pressure transmitters (range 0~10MPa, accuracy ±0.01MPa, sampling frequency 10kHz) installed at the working fluid inlet 35, the working fluid outlet 36, and the outlet of the interstage diffusion channel 312 of the turbine unit, for real-time monitoring of the static pressure and total pressure distribution of the reaction fluid; and a flow sensing unit, comprising high-temperature thermocouples (range -200~2500K, accuracy ±1K) installed at the outlet of the rotor blades 310, the outlet of the interstage diffusion channel 312 ... working fluid 312 of the turbine unit. Ultrasonic flow meters (range 0~200kg / s, accuracy ±1%) at the inlet 35 and the working fluid outlet 36 of the turbine unit are used to monitor the flow distribution of the reaction fluid in real time, providing a basis for system mass and energy balance calculations; Component analysis unit: including an online mass spectrometer or infrared spectrometer installed at the working fluid outlet 36 of the turbine unit, used to analyze the components of the reaction fluid in real time, focusing on monitoring the acetylene and hydrogen content to provide feedback on product yield; Vibration sensing unit: piezoelectric vibration sensors (range 0~50μm, accuracy ±0.1μm, sampling frequency 20kHz) are arranged at the rotor shaft 37 and rotor hub 371 of the turbine unit to monitor the radial and axial amplitude distribution of the impeller in real time and promptly identify equipment malfunctions.

[0188] Signal Processing and Controller: This unit (such as an Industrial Control Computer (IPC) or Programmable Logic Controller (PLC)) is the intelligent hub of the module. It establishes bidirectional communication connections with all sensor and actuator drive units, and embeds control algorithms such as PID algorithm and Model Predictive Control (MPC). It is responsible for real-time processing, logical judgment and risk identification of various types of monitoring data collected, and generating accurate control commands to provide a basis for subsequent command execution.

[0189] Actuator drive unit: This unit is the drive interface for control commands, responsible for converting the command signals output by the signal processing and controller into action signals that can drive various actuators, thereby precisely acting on key parts of the system. The actuators specifically include: a power actuator unit for adjusting the output power of the drive device; an actuator for adjusting the interstage flow field adjustment mechanism (active disturbance device, eddy current generator); a control valve for controlling the on / off state of the inert gas pipeline; and a drive mechanism for the backflushing cleaning device, ensuring the efficient implementation of various control commands.

[0190] The signal processing and controller are configured to execute the following core control logic based on the comparison results of the detection data with preset target values ​​and safety thresholds, thereby achieving coordinated control of various parameters:

[0191] I. Rotor speed control based on temperature parameters

[0192] Based on the deviations between the temperatures of each fluid outlet (including the rotor blade 310 outlet, the interstage diffusion channel 312 outlet, and the turbine working fluid outlet 36) detected by the temperature sensing unit and the corresponding preset temperature target values, the signal processing and controller employs a PID algorithm or model predictive control (MPC) to drive the aforementioned power execution unit through the actuator drive unit, adjusting the output power of the drive unit, and thus dynamically adjusting the rotor speed. The control response time is ≤1ms, ensuring that the temperature fluctuation of each fluid outlet is ≤±5K, and always maintained within the temperature target value range. At the same time, combined with the fluid composition data at the turbine working fluid outlet 36 collected by the component analysis unit, if the acetylene and hydrogen components deviate from the preset component target values, the rotor speed is finely adjusted through the aforementioned power execution unit to optimize the yield of cracking products.

[0193] II. Coordinated Regulation of Flow Field and Rotation Speed ​​Based on Pressure Parameters

[0194] Based on the deviation between the outlet pressure of each fluid (including the outlet of the interstage diffusion channel 312 and the working fluid outlet 36 of the turbine unit) detected by the pressure sensing unit and the corresponding preset pressure target value, the signal processing and controller, through the actuator drive unit, drives the actuator of the interstage flow field adjustment mechanism to dynamically adjust the interstage flow field adjustment mechanism (active disturbance device, eddy current generator) in the interstage diffusion channel 312 to stabilize the interstage flow field; on the other hand, it simultaneously fine-tunes the rotor speed through the aforementioned power execution unit to effectively suppress the disturbance of the interstage flow field caused by the flow rate change, avoid the instability of the shock wave system caused by the pressure change, and provide stable inlet conditions for the next stage blade group.

[0195] III. Collaborative Optimization Based on Flow Feedforward

[0196] The signal processing and controller uses the reaction fluid flow data collected by the flow sensing unit at the turbine working fluid inlet 35 and turbine working fluid outlet 36 as the benchmark parameters for calculating the system's mass and energy balance, and coordinates the control settings of the rotor speed and the interstage flow field adjustment mechanism. The coordination optimization includes: using the reaction fluid flow data as a feedforward signal, while adjusting the rotor speed through the aforementioned power execution unit, simultaneously fine-tuning the interstage flow field adjustment mechanism (active disturbance device, eddy current generator) in the interstage diffusion channel 312 through the interstage flow field adjustment mechanism actuator, suppressing the disturbance of the interstage flow field caused by the flow change in advance, ensuring the stability of the flow field in the turbine pyrolysis reaction unit 30, and providing a stable process environment for the pyrolysis reaction.

[0197] IV. Carbon Deposition Risk Identification and Online Carbon Removal Control

[0198] Both the turbine units in the turbine heater 31 and the turbine reactor 32 are equipped with a carbon removal mechanism. This carbon removal mechanism includes multiple micro-holes pre-installed at the leading edge of the flow guide device 39, an inert gas pipeline connected to the micro-holes, and a control valve installed on the inert gas pipeline (the aperture and spacing of the micro-holes are conventional existing technical parameters for online carbon removal of fluid equipment, and they are connected to the inert gas pipeline to achieve pulse-type carbon removal). The signal processing and controller perform joint real-time analysis based on the vibration spectrum data collected by the vibration sensor and the pressure difference between the working fluid inlet 35 and the working fluid outlet 36 (the same turbine unit) of the turbine unit detected by the pressure sensing unit. When the vibration amplitude is detected to exceed the preset vibration safety threshold, or the pressure difference between the working fluid inlet 35 and the working fluid outlet 36 of the turbine unit exceeds the preset pressure difference safety threshold, it is determined that there is a risk of dynamic balance failure caused by non-uniform carbon buildup. The actuator drive unit immediately drives the carbon cleaning mechanism to perform online carbon cleaning operation: the control valve of the inert gas pipeline is opened, and an inert gas (such as N2, Ar) jet is injected in a pulse manner through the micro-holes at the leading edge of the guide device to physically purge and remove carbon buildup from the blade surface. At the same time, the rotor speed is dynamically adjusted through the aforementioned power execution unit to ensure stable operation of the equipment and avoid interference with the pyrolysis reaction caused by the carbon cleaning operation.

[0199] V. Backflushing and dust removal control of waste heat recovery device

[0200] When the waste heat recovery device 50 is a porous media-filled heat exchanger, the signal acquisition unit also includes a second pressure sensor for real-time monitoring of the pressure difference between the inlet and outlet of the porous media-filled heat exchanger (pressure difference transmitters are set at the inlet and outlet of the porous media-filled heat exchanger to realize real-time monitoring of the pressure drop of the fluid flowing through the porous media bed). The porous media-filled heat exchanger is also equipped with a backflushing cleaning device that is communicatively connected to the second pressure sensor. The signal processing and controller are further configured to: when the pressure difference between the inlet and outlet of the porous media-filled heat exchanger detected by the second pressure sensor exceeds a preset safety threshold, it is determined that carbon deposits have accumulated and blocked the porous media bed. Immediately, the actuator drive unit controls the backflushing cleaning device to start, and inert gas (nitrogen, argon, etc.) is pulsedly introduced into the porous media-filled heat exchanger to perform backflushing cleaning, quickly remove the carbon deposits in the bed, restore the flow capacity and heat exchange efficiency of the porous media-filled heat exchanger, and ensure the stable coordinated operation of the waste heat recovery device 50 and the turbine cracking reaction unit 30.

[0201] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent transformations or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A method for producing acetylene and hydrogen from natural gas based on turbine cracking, characterized in that, Includes the following steps: S1. Pretreatment step: Pretreatment of raw natural gas to obtain high-concentration purified methane gas with a methane concentration of 95%~100%; S2. Preheating step: Preheat the purified methane gas to 523-823 K; S3. Turbine heating and cracking step: The preheated purified methane gas is introduced into the turbine cracking reaction unit. The energy input of the turbine machinery is adjusted by controlling the rotor speed of the turbine cracking reaction unit, so that the purified methane gas is heated to 1800~2200K within 1~10ms, and a cracking reaction is carried out at this temperature for 1~10ms to generate cracked gas containing acetylene, hydrogen and carbon black. S4. Quenching and waste heat recovery step: The pyrolysis gas is quenched and rapidly cooled to below 800 K within 0.5~3ms to terminate the acetylene decomposition reaction, and waste heat is recovered, finally cooled to 300~400 K. S5. Separation Steps: The gas mixture after quenching and waste heat recovery is subjected to gas-solid separation and gas separation in sequence to obtain solid carbon black, acetylene product and hydrogen product respectively.

2. The method according to claim 1, characterized in that, The pretreatment in step S1 specifically includes: desulfurizing, dehydrating and removing heavy hydrocarbons from the raw natural gas, and stabilizing the pressure to 0.5~1.5 atm.

3. The method according to claim 1, characterized in that, In step S4, the quenching medium is selected from at least one of water, nitrogen, circulating oil or cold methane gas, and the heat recovered in the quenching and waste heat recovery steps is used to preheat the purified methane gas in step S2.

4. The method according to claim 1, characterized in that, In step S5, the carbon black content in the gas after gas-solid separation is ≤10 mg / Nm³. 3 Gas separation includes absorption, desorption, and pressure swing adsorption operations, which sequentially separate acetylene, hydrogen, and methane-rich gas.

5. The method according to claim 4, characterized in that, In step S5, the absorption solvent used in the absorption operation is selected from one or more of N-methylpyrrolidone, dimethylformamide, acetone, and methanol. The operating pressure of the absorption operation is 0.4~0.6 MPa and the temperature is 260~290 K. The operating pressure of the desorption operation is 0.1~0.2 MPa and the temperature is 320~350 K. The adsorbent used in the pressure swing adsorption operation is an activated carbon-molecular sieve composite adsorbent. The pressure swing adsorption operation includes two stages: the first stage is the adsorption stage, with an operating pressure of 0.4~0.6 MPa and a temperature of 300~350 K; the second stage is the desorption stage, with an operating pressure of 0.03~0.08 MPa and a temperature of 300~350 K.

6. A system for implementing the method for producing acetylene and hydrogen from natural gas based on turbine cracking as described in any one of claims 1 to 5, characterized in that, Including those connected sequentially along the process flow path: The feedstock pretreatment unit is used to pretreat the feedstock natural gas to obtain high-concentration purified methane gas; A preheating unit, connected to the raw material pretreatment unit, is used to preheat the purified methane gas. The turbine cracking reaction unit is equipped with a purified methane gas inlet and a cracked gas outlet; Its purified methane gas inlet is connected to the preheating unit to receive the preheated purified methane gas, and to raise the temperature of the purified methane gas and cause a cracking reaction to generate cracked gas through the mechanical energy of the turbine; the cracked gas outlet is used to discharge the cracked gas; the turbine cracking reaction unit includes a turbine heater and a turbine reactor connected in sequence in the direction of fluid flow, and the turbine heater and turbine reactor are composed of one or more sets of turbine devices. The quenching and waste heat recovery unit has its inlet connected to the outlet of the pyrolysis gas, and is used to quench the pyrolysis gas and recover waste heat. A gas-solid separation unit, connected to the quenching and waste heat recovery unit, is used to separate solid carbon black from the pyrolysis gas after quenching and waste heat recovery. A gas separation unit, connected to the gas-solid separation unit, is used to separate acetylene and hydrogen products.

7. The system according to claim 6, characterized in that, The turbine device includes A housing, wherein a working fluid inlet and a working fluid outlet for a turbine device are provided on the housing, and a flow channel connecting the working fluid inlet and the working fluid outlet of the turbine device is formed inside the housing; The rotor shaft is rotatably supported within the housing and configured to be connected to the drive unit; The rotor hub is fixedly sleeved on the rotor shaft; At least three stages of blades are arranged sequentially in the flow channel within the housing along the axial direction of the rotor shaft, wherein each stage of blades sequentially includes, in the direction of fluid flow: a flow guiding device fixed to the housing, a rotor blade mounted on the rotor hub, and a diffuser blade fixed to the housing. Between two adjacent blade groups, an interstage diffusion channel is formed between the outlet of the upper stage diffuser blade and the inlet of the lower stage guide device; the flow cross-sectional area of ​​the interstage diffusion channel varies along the fluid flow direction, and an interstage flow field adjustment mechanism is provided therein to enhance the turbulent mixing and pressure recovery of the fluid, thereby providing the next stage blade group with inlet conditions that are both pressure-uniform and flow-uniform. The rotor shaft, the rotor hub, and the rotor blades of each stage together constitute the rotor of the turbine device.

8. The system according to claim 7, characterized in that, The system also includes a monitoring and collaborative control module, which comprises: The signal acquisition unit includes a high-temperature resistant sensor array arranged in the turbine cracking reaction unit, used to monitor the temperature, pressure, flow rate and composition parameters of the reaction fluid in the system in real time. The signal processing and controller is communicatively connected to the signal acquisition unit. An actuator drive unit is connected to the signal processing and controller; The signal processing and controller is configured as follows: a) Based on the temperature and composition data of the reaction fluid in the turbine pyrolysis reaction unit, the output power of the drive device is adjusted by the actuator drive unit to control the rotor speed; b) Based on the pressure data of the reaction fluid in the turbine pyrolysis reaction unit, the interstage flow field adjustment mechanism is adjusted by the actuator drive unit to stabilize the interstage flow field; c) Using the reaction fluid flow rate data as a reference parameter for mass and energy balance calculation, the control settings of the rotor speed and the interstage flow field adjustment mechanism are optimized in a coordinated manner; the coordinated optimization includes: using the reaction fluid flow rate data as a feedforward signal, and simultaneously fine-tuning the interstage flow field adjustment mechanism when adjusting the rotor speed, so as to suppress the disturbance of the interstage flow field caused by the flow rate change.

9. The system according to claim 8, characterized in that, The high-temperature resistant sensor array includes The temperature sensing unit includes temperature sensors installed at the rotor blade outlet, the interstage diffusion channel outlet, and the working fluid outlet of the turbine unit, for real-time monitoring of the temperature distribution of the reaction fluid. The pressure sensing unit includes a first pressure sensor located at the working fluid inlet of the turbine unit, the working fluid outlet of the turbine unit, and the outlet of the interstage diffusion channel, for real-time monitoring of the static pressure and total pressure distribution of the reaction fluid. The flow sensing unit includes flow meters installed at the working fluid inlet and outlet of the turbine unit, for real-time monitoring of the flow distribution of the reaction fluid; The component analysis unit includes an online component analyzer located at the working fluid outlet of the turbine unit for real-time analysis of the composition of the reaction fluid.

10. The system according to claim 9, characterized in that, The signal acquisition unit also includes a vibration sensor for monitoring the rotor vibration state of the turbine device; The turbine device also includes a carbon removal mechanism; the carbon removal mechanism includes multiple micro-holes pre-set at the leading edge of the flow guide device, an inert gas pipeline communicating with the micro-holes, and a control valve disposed on the inert gas pipeline; The signal processing and controller is communicatively connected to the vibration sensor and is further configured to: Based on the vibration data collected by the vibration sensor and the pressure difference data between the working fluid inlet and outlet of the turbine unit, a joint analysis is performed to identify the risk of carbon buildup in the turbine cracking reaction unit. When a risk of carbon buildup is detected, the actuator drive unit drives the carbon removal mechanism to perform an online carbon removal operation.

11. The system according to claim 10, characterized in that, The signal processing and controller is also configured to automatically generate an early warning message and output a standardized offline carbon cleaning operation guide when it is determined that the carbon buildup has exceeded the online cleaning capacity based on the cumulative running time or real-time data trend, so as to guide maintenance personnel to stop the machine for thorough cleaning.

12. The system according to claim 7, characterized in that, The interstage flow field adjustment mechanism is an active disturbance device or an eddy current generator.

13. The system according to claim 8, characterized in that, The quenching and waste heat recovery unit includes a quenching device and a waste heat recovery device. The quenching device consists of 4-6 pairs of quenching medium injection holes evenly arranged circumferentially along the cracked gas outlet. The quenching medium is selected from at least one of water, nitrogen, circulating oil, or cold methane gas. The waste heat recovery device is a porous media-filled heat exchanger. The signal acquisition unit also includes a second pressure sensor for real-time monitoring of the inlet and outlet pressure difference of the porous media-filled heat exchanger. The porous media-filled heat exchanger is equipped with a backflushing cleaning device that is communicatively connected to the second pressure sensor. The signal processing and controller is configured to: when the inlet and outlet pressure difference of the porous media-filled heat exchanger exceeds a preset safety threshold, control the backflushing cleaning device to pulse-purge inert gas into the porous media-filled heat exchanger for backflushing cleaning.

14. The system according to claim 6, characterized in that, The raw material pretreatment unit includes a raw natural gas buffer and pressure stabilization device, a deep desulfurization device, a CO2 removal device, a heavy hydrocarbon separation device, and a fine dehydration device; the preheating unit is selected from one or more of shell-and-tube heat exchangers, porous media-filled heat exchangers, finned tube heat exchangers, spiral plate heat exchangers, shell-and-tube heat exchangers, and heat pipe heat exchangers; the gas-solid separation unit includes one or more of cyclone separators, bag filters, electrostatic precipitators, and scrubbing towers; the gas separation unit includes an absorption tower, a desorption tower, and a pressure swing adsorption device, wherein the absorption solvent used in the absorption tower is selected from one or more of N-methylpyrrolidone, dimethylformamide, acetone, and methanol, and the adsorbent used in the pressure swing adsorption device is an activated carbon-molecular sieve composite adsorbent.

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