41results about How to "Reduce hydrogen consumption" patented technology

The invention provides a hydrogen energy power system suitable for a magnetic suspension railway vehicle. The hydrogen energy power system comprises a hydrogen storage system, a hydrogen fuel cell system, a heat dissipation and cooling system, an air filter, a connector and an electronic control unit (ECU). The hydrogen storage system comprises a hydrogen storage control unit (HSU), the hydrogen fuel cell system comprises a power control unit (PCU), and the ECU is used for collecting and processing state information of each system and sending out a control instruction; the ECU is connected with the PCU and the HSU, and the ECU serves as a main control unit and is responsible for receiving an instruction from a vehicle or a train operator and coordinating work of the PCU and the HSU according to the current running state of the vehicle; and the ECU sends a power demand instruction to the PCU and sends a hydrogen supply instruction to the HSU so as to ensure that the fuel cell can output corresponding power according to needs. The engineering construction cost of the track in the project is reduced, the project construction time is saved, funds are saved, and the method is environment-friendly.

This invention relates to the field of petroleum refining and chemical engineering, and discloses a method for hydrogenating waste tire pyrolysis oil. The method includes the following steps: (1) in the presence of hydrogen, the waste tire pyrolysis oil raw material undergoes a gas-phase desulfurization reaction in a first gas-phase hydrogenation reactor to obtain a gas-phase desulfurization reaction product; (2) the gas-phase desulfurization reaction product is subjected to gas-liquid separation to obtain a gas-phase component and a liquid-phase component; (3) the liquid-phase component is pressurized and mixed with hydrogen, and then subjected to a liquid-phase dearomatics reaction in a second hydrogenation reactor to obtain a liquid-phase dearomatics reaction product; the nitrogen content in the waste tire pyrolysis oil raw material is 3000-10000 μg / g. This method uses waste tire pyrolysis oil from the middle distillate as raw material, achieving deep desulfurization while reducing the removal of nitrogen oxides and monocyclic aromatic hydrocarbon saturation. It also simplifies the overall process flow, reduces the reaction severity, and lowers energy and hydrogen consumption.

The invention relates to the field of oil refining and chemical engineering, and discloses a hydrogenation method of waste tire pyrolytic oil. The method comprises the following steps: (1) in the presence of hydrogen, carrying out a gas-phase desulfurization reaction on a waste tire pyrolytic oil raw material in a gas-phase first hydrogenation reactor to obtain a gas-phase desulfurization reaction product; (2) carrying out gas-liquid separation on the gas-phase desulfurization reaction product to obtain a gas-phase component and a liquid-phase component; (3) carrying out pressurization and hydrogen mixing on the liquid-phase component, and then carrying out a liquid-phase dearomatization reaction in a second hydrogenation reactor to obtain a liquid-phase dearomatization reaction product; in the waste tire pyrolytic oil raw material, the content of N is 3000-10000 [mu] g / g. According to the method, the waste tire pyrolytic oil of the middle fraction is taken as a raw material, deep desulfurization is realized, removal of nitrides and monocyclic aromatic hydrocarbon saturation are reduced, the technological process is simplified on the whole, the reaction severity is reduced, and energy consumption and hydrogen consumption are reduced.

The invention belongs to the technical field of hydrodesulfurization, and particularly relates to a butyl phosphonic acid modified magnesium-based hydrodesulfurization material and a preparation method thereof. The magnesium-based hydrodesulfurization material is prepared from the following raw materials: magnesium, carbon black and butyl phosphonic acid, and the preparation method comprises the following steps: adding the magnesium into the carbon black for ball milling; carrying out hydrotreating on a solid product obtained by ball milling; adding the hydrotreated solid product into butyl phosphonic acid for ball milling; and carrying out heat treatment on a solid product obtained by ball milling in the previous step to prepare the butyl phosphonic acid modified magnesium-based hydrodesulfurization material. Magnesium hydride in the magnesium-based hydrodesulfurization material is used as a high-activity hydrogen source for hydrodesulfurization of dibenzothiophene in an anthracene oil liquid phase, and high temperature and high pressure are not needed in the hydrodesulfurization process; the surface of magnesium hydride is modified by butyl phosphonic acid, so that dibenzothiophene molecules stand and are adsorbed on the surface of magnesium hydride, a direct hydrogenolysis desulfurization reaction is carried out, and a benzene ring is not subjected to hydrogenation saturation, so that the selectivity of the hydrodesulfurization reaction can be improved.

The present invention relates to a method for preparing low-carbon olefin raw materials by selective desulfurization and denitrogenation of diesel, wherein the diesel raw material oil is contacted with a selectively regulated hydrofining catalyst for hydrofining reaction, and the obtained refined oil is subjected to solvent extraction to obtain extracted oil rich in aromatics and raffinate oil rich in alkanes; wherein the raffinate oil is used as a high-quality raw material for steam cracking to produce ethylene, and the extracted oil can be directly used as a raw material for hydrocracking or catalytic cracking to produce high-octane gasoline or BTX light components. The present invention optimizes the raw materials and process structure of the existing device, not only fully utilizes various raw material resources, but also effectively solves the problem of diesel outlet and ethylene material shortage.

The invention provides a diesel oil hydrofining catalyst. The diesel oil hydrofining catalyst comprises a modified alumina carrier and an active component, the active component is an oxide of active metal, and the active metal comprises at least one of Co, Mo, Ni and W; the modified alumina carrier is alumina hydrothermally modified by ammonium fluoborate; the B / L acid value of the modified alumina carrier is 0.07 to 0.15; the specific surface area is 240-400 m < 2 > / g, and the pore volume is 0.55-0.80 mL / g. The diesel oil hydrofining catalyst containing the B acid can promote removal of sulfides with steric hindrance in distillate oil through a direct desulfurization reaction path and a hydroisomerization-direct desulfurization reaction path, promote adsorption and removal of nitrides, and reduce mutual inhibition effect in the removal process of the sulfides and the nitrides; and the diesel oil hydrofining catalyst has excellent hydrogenation activity.

This invention discloses a method for preparing aviation fuel with different functional components based on the directional dismantling of organic waste molecular structure, belonging to the field of organic waste recycling. The method uses waste plastics, waste rubber, and waste oils as raw materials, employing a vertically connected two-stage reactor. Multiple types of mixed organic waste are co-pyrolyzed in the first-stage reactor, and the pyrolysis volatilization products directly enter the second-stage reactor for gaseous catalytic hydrogenation, ultimately yielding a mixed aviation liquid fuel containing different functional components. This method utilizes the molecular structure of organic waste itself to prepare liquid fuel products such as isoalkanes and aromatics, replacing the isomerization and aromatization reactions in existing catalytic processes. It has advantages such as a simple process flow and simple catalytic reaction, and can quantitatively prepare mixed aviation fuel composed of two or more functional components from n-alkanes, isoalkanes, aromatics, and cycloalkanes according to actual applications.

The invention relates to a hydrogen fuel cell vehicle power distribution optimization method and device, and belongs to the technical field of hydrogen fuel cell vehicle power distribution.The method comprises the steps that demand power at the current moment is obtained; determining the life cycle stage of the hydrogen fuel cell engine according to the operation data of the hydrogen fuel cell engine; determining a hydrogen fuel cell engine power sequence and a power cell power sequence according to the hydrogen fuel cell engine power range, the maximum power change rate and the SOC threshold; and according to the hydrogen fuel cell engine power sequence and the power cell power sequence, carrying out demand power distribution. In the initial stage of the hydrogen fuel cell engine, the hydrogen fuel cell engine can operate in a wider power range, and in the middle stage or the last stage of the life cycle of the hydrogen fuel cell engine, the hydrogen fuel cell engine is limited in a narrower power range, so that the service life of the hydrogen fuel cell engine is prolonged.

The invention provides a hydrocracking catalyst, which is characterized in that a catalyst I is formed by mixing a Y molecular sieve, alumina and an adhesive to serve as a carrier and is loaded with nickel and tungsten, a catalyst II is formed by mixing a ZSM-5 molecular sieve, alumina and an adhesive to serve as a carrier and is loaded with cobalt and tungsten, and the catalyst I and the catalyst II are mixed to obtain the hydrocracking catalyst. Cobalt and tungsten are loaded on the ZSM-5 molecular sieve, so that the influence of aromatic hydrocarbon on alkane adsorption reaction is reduced, bond breaking and isomerization reaction of alkane are enhanced, the pour point of the transformer oil is remarkably reduced, and the yield of the transformer oil is increased; nickel and tungsten are loaded on the Y molecular sieve, so that the ring-opening cracking reaction of aromatic hydrocarbon is enhanced, the aromatic hydrocarbon content in the transformer oil can be remarkably reduced, and the stability and chromaticity of the transformer oil are improved. The composite catalyst gives consideration to indexes of the aromatic hydrocarbon content and the pour point of the transformer oil, can realize partitioned reinforcement of an aromatic hydrocarbon ring-opening reaction and a paraffin bond-breaking isomerization reaction, and can directly produce a qualified transformer oil product.

The invention discloses a solid acid catalyst as well as a preparation method and application thereof. The solid acid catalyst comprises the following components in percentage by mass on the basis of the weight of the catalyst: a) 50-98% of a silicon oxide carrier; b) 1%-30% of at least one metal selected from IVB group and IVA group in terms of corresponding metal oxide; c) 0.01%-10% of at least one of metals selected from the group VIB and the group VIII; d) 0.1% to 10% of sulfate ions; the ratio of the amount of the acid B to the amount of the strong acid L in the catalyst is (20: 1)-(1: 20). The catalyst is used for toluene disproportionation and transalkylation reaction, and has the characteristics of low reaction temperature, low hydrogen consumption and high conversion rate.

The application discloses a method for cracking tar into high value-added products, which adopts a route of separating light components by fractional distillation and then hydrogenating heavy components, so that the yield of target products can be affected by hydrogenation of naphthalene, methyl naphthalene and the like below 250 DEG C in the process of hydrocracking, and on the other hand, the components below 250 DEG C account for about 30% to 50%, so that the hydrogen consumption in the subsequent hydrocracking can be reduced by separating the components in advance. After the heavy fraction is subjected to hydrocracking, part of polycyclic aromatic hydrocarbons in the heavy fraction can be cracked into part of monocyclic aromatic hydrocarbons, which can be used for producing aromatic solvent oil, so that the light fraction in the hydrocracking product is separated and mixed into the light fraction generated by pre-fractionation, and the next step processing is carried out, so that the yield of high value-added products can be further improved.

The present invention provides a Fischer-Tropsch refined tail oil mild hydrogenation yield increasing method, which comprises: (1) introducing Fischer-Tropsch refined tail oil and a hydrogen-containing material flow into a first hydrogenation reactor, carrying out a hydrogenation reaction to obtain a first reaction effluent, and carrying out separation and fractionation on the first reaction effluent to obtain a first gas, light oil, medium distillate oil and heavy oil; (2) introducing the heavy oil and the hydrogen-containing material flow into an enhanced mass transfer mixer, mixing to obtain an emulsion containing microbubbles, carrying out hydrogenation reaction on the emulsion in a second hydrogenation reactor to obtain a second reaction effluent, and separating to obtain a second gas and product oil; wherein the hydrogenation reaction temperature in the first hydrogenation reactor and the second hydrogenation reactor is 290-340 DEG C, the volume space velocity in the first hydrogenation reactor and the second hydrogenation reactor is 0.1-2.0 h <-1 >, and the reaction pressure in the second hydrogenation reactor is 1.5-4.5 MPa; the volume fraction of microbubbles with the particle size being larger than or equal to 1 micron and smaller than 1 mm in the emulsion is larger than or equal to 65 According to the method disclosed by the invention, the medium distillate oil with high yield can be obtained under relatively mild conditions.

The present application relates to the field of processing inferior residual oil, and discloses a method for processing inferior residual oil, which comprises the following steps: (1) performing a mild catalytic cracking reaction on inferior residual oil I to obtain a mild catalytic cracking reaction product; (2) separating the mild catalytic cracking reaction product to obtain catalytic cracking heavy oil; (3) performing a hydrodesulfurization reaction on the catalytic cracking heavy oil to obtain a hydrodesulfurization reaction product; and (4) separating the hydrodesulfurization reaction product to obtain hydrogenated heavy oil. The method for processing inferior residual oil provided by the present application combines catalytic cracking heavy oil hydroprocessing and catalytic cracking, can maximize the production of light oil and low-sulfur marine fuel oil from inferior residual oil, and thus reduces the production cost of the light oil and low-sulfur marine fuel oil prepared by the method.

The utility model relates to the technical field of polycrystalline silicon production, in particular to a polycrystalline silicon tail gas recovery system and a polycrystalline silicon production system. The polycrystalline silicon tail gas recovery system comprises a filter, an electromagnetic pulse injection valve and a blowback gas bag, a hydrogen blowback pipeline is arranged between the electromagnetic pulse injection valve and the filter, the electromagnetic pulse injection valve is connected with the gas outlet end of the blowback gas bag, and the gas inlet end of the blowback gas bag is connected with a source hydrogen pipeline. And a pressure relief hole of the electromagnetic pulse injection valve is connected with a pressure relief hole exhaust pipeline. A hydrogen back-blowing pipeline is connected with an electromagnetic pulse injection valve, the gas inlet end of the electromagnetic pulse injection valve is connected with a back-blowing gas bag, a pressure relief hole of the electromagnetic pulse injection valve is connected with a pressure relief hole exhaust pipeline, after a system carries out one-time back-blowing operation, the pressure relief hole can be opened for pressure relief, then the pressure relief hole exhaust pipeline is closed, and hydrogen released from the pressure relief hole can be recycled through the pressure relief hole exhaust pipeline. Therefore, the safety of a production site is guaranteed, meanwhile, the hydrogen consumption can be reduced by recovering the hydrogen through the pressure relief hole exhaust pipeline, and the production cost of an enterprise is reduced.

The present invention discloses a hydrogen-air-water integrated heat exchange device, system and method for a fuel cell, which relates to the technical field of fuel cells, and includes a coolant heat exchange portion and a hydrogen heat exchange portion arranged in a shell, a compressed air inlet and a compressed air outlet are respectively arranged at both ends of the shell in the length direction, a water inlet and a water outlet are both connected to the coolant heat exchange portion, a hydrogen inlet and a hydrogen outlet are both connected to the hydrogen heat exchange portion, and a gas flow area for compressed gas to pass through is formed between the compressed air inlet and the compressed air outlet, and the gas flow area passes through the coolant heat exchange portion and the hydrogen heat exchange portion. The hydrogen-air-water integrated heat exchange device, system and method for a fuel cell provided by the present invention provides a highly integrated heat exchange device, which uses the heat generated by high-temperature compressed air and the engine when it is running to heat hydrogen, reduce the temperature of the high-temperature compressed air, reduce the influence of the external environment on the engine performance, and improve the engine's adaptability to a wide range of ambient temperatures.

The invention discloses a process for synthesizing natural gas through methanation of CO2-rich coke-oven gas. The process comprises the following steps: compressing coke-oven gas, pre-purifying, desulfurizing, carrying out CO2-rich conversion and three-stage methanation reaction, separating natural gas, extracting H2, and returning to prepare the natural gas meeting the national standard technical specification of the natural gas. According to the process, first-stage hot gas with water vapor circulation is adopted, the outlet temperature of a first-stage reactor and the CO + CO2 content of inlet gas are controlled, most of carbon in coke-oven gas reacts in the first-stage reactor, the second-stage reaction load and the third-stage reaction load are reduced, the catalyst dosage is reduced, and the process is suitable for high-carbon gas components and particularly suitable for CO2-rich environment gas; cO2 can be effectively converted into CO, the carbon utilization rate is increased, carbon emission is reduced, side reactions such as carbon deposition are reduced, the yield of methane is increased, and the catalyst special for methanation is long in service life and can stably run for a long time.

The invention belongs to the field of methanol synthesis, and discloses a methanol synthesis system and method. The system comprises a gasification unit, a carbon dioxide separation unit, a carbon dioxide boosting unit, a synthesis gas boosting unit, a first methanol synthesis unit, a second methanol synthesis unit and a water electrolysis unit. According to the method, hydrogen / oxygen production through water electrolysis, biomass gasification and methanol synthesis are coupled, so that the problems of low equilibrium conversion rate, high hydrogen consumption, high energy consumption and the like in traditional methanol production through biomass gasification are avoided, the challenge of raw material sources is solved, carbon emission is avoided, and the method has remarkable economic and social benefits.

The present invention discloses a one-stage series hydrocracking method. The method comprises the following steps: (1) mixing feedstock oil with hydrogen and then entering a hydrocracking pretreatment reactor for pre-reaction; (2) the pre-reaction effluent of step (1) enters a hydrocracking reactor for a first hydrocracking reaction; (3) the first hydrocracking reaction effluent in step (2) enters a catalytic reaction distillation tower for a second hydrocracking reaction and rectification to obtain corresponding products. The method can effectively solve the problem of timely separation of reaction products from the reaction zone, improve the yield of the target product, and at the same time improve the hydrocracking reaction efficiency and reduce the energy consumption of the device.

The invention discloses a joint production process for processing coked liquefied gas and coker diesel oil, which comprises the following steps: (1) coker diesel oil extracted from a side line of a fractionating tower of a coking device enters from the top of a first fixed bed reactor after being subjected to heat exchange and cooling; the coking liquefied gas with hydrogen sulfide removed enters the first fixed bed reactor from the middle lower part of the first fixed bed reactor for a thioetherification reaction; (2) a liquid-phase material flowing out of the bottom of the first fixed bed reactor is mixed with hydrogen and then enters a second fixed bed reactor for a gas-phase hydrogenation reaction; and (3) carrying out gas-liquid separation on the effluent of the second fixed bed reactor, pressurizing the separated liquid-phase component, feeding the pressurized liquid-phase component into a third fixed bed reactor, carrying out a liquid-phase hydrogenation reaction, and carrying out steam stripping and fractionation on the liquid-phase hydrogenation reaction product to obtain a refined product. According to the process, the two are deeply coupled to remove sulfides and olefins, so that the problems of olefin polymerization and processing difficulty increase caused by coking diesel storage are avoided, and the processing difficulty, hydrogen consumption and energy consumption of the device are reduced.

The present application relates to a molecular sieve composition, a preparation method thereof and application thereof. The molecular sieve composition of the present application comprises a mosaic molecular sieve of a TON structure molecular sieve and a 5A type molecular sieve. The molecular sieve composition of the present application has a dual function of adsorption and hydroisomerization.

This invention relates to the field of hydrocracking catalysts, and discloses a hydrocracking catalyst, its preparation method and application, and a method for hydrocracking treatment of residue oil. The hydrocracking catalyst contains molecular sieves, silicon-modified alumina, and active metal components. Optionally, the hydrocracking catalyst also contains alumina and / or additives. The content of the molecular sieve is 5-25 wt%, the content of the silicon-modified alumina is 30-60 wt%, and the content of the alumina is 0-20 wt%. The content of the active metal components, calculated as oxides, is 5-35 wt%, and the content of the additives, calculated as oxides, is 0-1.0 wt%. The catalyst provided by this invention has the advantages of large specific surface area, large pore volume, large pore size, and high metal content. When used in the hydrocracking treatment of residue oil, it not only exhibits high activity and good stability, but also improves naphtha selectivity, expands feedstock adaptability, and reduces hydrogen consumption.

This invention specifically relates to a distributed power management strategy for a hybrid electric propulsion system for electric aircraft, belonging to the field of aviation electrification. The system consists of a fuel cell, an energy storage battery, and a supercapacitor connected in parallel to a DC bus via a power converter. In this invention, each unit is independently controlled based on local information, eliminating the need for a communication network: the fuel cell adaptively switches between voltage and power modes according to the load power and battery state of charge, avoiding heavy or light load operation; the battery adjusts its steady-state operating point through a virtual resistance droop mechanism, absorbing steady-state power deficits or excess power; the supercapacitor absorbs dynamic power through a virtual capacitance droop mechanism, suppressing load fluctuations. This invention effectively suppresses the negative impacts of heavy / light loads, load fluctuations, and frequent start-stop cycles on fuel cell lifespan and efficiency, reduces hydrogen consumption, and improves overall system reliability.

The invention relates to a method and system for producing ethylene and propylene from heavy oil, and the method comprises the following steps: introducing heavy hydrocarbon oil into a supercritical extraction separation unit for supercritical extraction separation to respectively obtain light deasphalted oil, heavy deasphalted oil and deoiled asphalt; carrying out hydrotreating on the deoiled asphalt to obtain hydrogenated deoiled asphalt; introducing the heavy deasphalted oil and the hydrogenated deoiled asphalt into a first reactor to be in contact with a first catalytic conversion catalyst for a first catalytic conversion reaction; introducing the light deasphalted oil into a second reactor to contact with a second catalytic conversion catalyst for a second catalytic conversion reaction; wherein the first catalytic conversion catalyst and the second catalytic conversion catalyst contain MPZ hierarchical pore molecular sieves. According to the method disclosed by the invention, polycyclic aromatic hydrocarbon which is not easy to react can be saturated, the cracking property of the deoiled asphalt is improved, the generation of coke is reduced, and the yields of ethylene and propylene are improved.

This invention discloses a hydrocracking method. The hydrocracking method includes the following steps: mixing feedstock oil with hydrogen and then feeding the mixture into a hydrocracking pretreatment reactor for a pre-reaction; the pre-reaction effluent then enters a catalytic reactive distillation column for hydrocracking and distillation to obtain the corresponding product. This method effectively solves the problem of reaction products not being separated from the reaction zone in a timely manner, while simultaneously improving the yield of the target product and reducing the energy consumption of the equipment.

This invention belongs to the field of intelligent control technology for unmanned platform power and new energy, specifically relating to a power supply unit for deployment in extreme environments and its energy management method. The energy management method includes the following steps: S1, acquiring the current physical state vector of the system in real time through a multi-dimensional state sensing network; S2, inputting the state vector into the pre-trained deep Q-network main network inside the energy management controller, and selecting the action command with the highest Q value; S3, sending the action command to the DC / DC conversion module, instructing the DC / DC conversion module to prioritize controlling the sodium-ion battery pack to release a high-rate current, and to connect in parallel with the hydrogen fuel cell stack for high-power output to compensate for the physical sluggishness of the dynamic response of the hydrogen fuel cell; S4, dynamically adjusting the opening of the temperature-controlled proportional directional valve to directionally transport the collected waste heat to the heat exchange branch of the sodium-ion battery pack for heating and insulation.

The invention provides a hydrogen-electricity-heat multi-energy coupling method and system based on a multi-machine fuel cell, and belongs to the technical field of hydrogen-electricity-heat multi-energy coupling, and the method comprises the steps: collecting the sum of the actual output power of all galvanic piles at the current moment, and a user-side electrical load; outputting the sum of the reference output power of all the electric piles through a total fuzzy logic PID controller by taking the user-side electric load as an input reference value and the sum of the actual output power of all the electric piles as an input control value; the sum of the reference output power of all the electric piles is input into an efficiency optimal power distribution model, and the number of the electric piles needing to be started and the reference output power are output; the reference output power and the actual output power value of each galvanic pile serve as an input reference value and a control value respectively, galvanic pile gas flow is output through a sub-fuzzy logic PID controller of an electromagnetic valve corresponding to the galvanic pile, and the gas flow of a pipeline where the galvanic pile is located is controlled. According to the invention, power distribution and waste heat recovery management of the multi-machine fuel cell system are realized.

The invention provides a composite hydrocracking catalyst, which is prepared by mixing a ZSM-5 molecular sieve and alumina-loaded nickel and molybdenum as a catalyst I and a Beta molecular sieve and alumina-loaded cobalt and molybdenum as a catalyst II. According to the present invention, the indexes of the aromatic hydrocarbon content and the pour point of the transformer oil can be considered, and the aromatic hydrocarbon ring-opening reaction and the alkane bond-breaking isomerization reaction can be subjected to the partition strengthening so as to reduce the aromatic hydrocarbon content and the pour point in the hydrocracking diesel oil, such that the qualified transformer oil product can be directly produced by using the conventional hydrocracking means.

The invention belongs to the technical field of control, and particularly relates to an online identification method and system for the optimal efficiency of a multi-stack hydrogen fuel cell system, and the method comprises the steps: firstly obtaining the output current and output voltage of each hydrogen fuel cell during operation, and the real-time data of the real-time power demand of a power grid; calculating the real-time output power and efficiency of each hydrogen fuel cell according to the obtained real-time data; identifying the relationship between the efficiency of each hydrogen fuel cell and the output power based on a forgetting factor recursive least square method; and finally, solving the output power of each hydrogen fuel cell with the highest system efficiency by taking the system efficiency as an optimization target and combining a KKT condition, thereby improving the energy utilization efficiency of the whole system when the multi-stack hydrogen fuel cell system is in centralized operation for power generation, reducing the hydrogen consumption of the system, enabling the system to operate in a high-efficiency working area for most of the time, and reducing the energy consumption of the system. The system service life is prolonged and the system maintenance cost is saved.

The invention discloses a method for reducing deep cracking of a C2 + side chain in a hydrodealkylation reaction of alkyl aromatic hydrocarbon. The method comprises a step of contacting an alkyl aromatic hydrocarbon raw material with an aromatic hydrocarbon catalytic hydrodealkylation catalyst in the presence of hydrogen, and a polar compound and a gas oxidant are added into a reaction system. The method provided by the invention improves the BTX selectivity of the product, solves the problem of deep cracking of C2 + gas-phase light hydrocarbon in the traditional technical process of preparing benzene by catalytic hydrogenation of heavy aromatics, improves the additional value of the gas-phase product, reduces the hydrogen consumption of the device, improves the operation stability of the catalyst, and further improves the economic benefit of the device.

The application discloses a method for hydrocracking of wax oil, wherein the wax oil raw material is treated by a hydrofining catalyst and then reacts under the action of a hydrocracking catalyst, and the hydrocracking catalyst contains 10-50%, preferably 20-40% of B-Y heteroatom molecular sieve based on the weight of the hydrocracking catalyst. The method for hydrocracking of wax oil has the advantages of high reaction activity, high product liquid yield, low hydrogen consumption, high aromatic potential of heavy naphtha, high smoke point of aviation kerosene, low BMCI value and dry point of tail oil, etc.