A process for hydrogen production by diesel reforming

Abstract

A diesel reforming hydrogen production process belongs to the technical field of hydrocarbon steam reforming hydrogen production. At present, diesel steam reforming hydrogen production is restricted by thermodynamic carbon deposition caused by long carbon chain of diesel and poisoning, and diesel steam reforming hydrogen production has not broken through in practicability. The present application comprises the following steps: obtaining light components by diesel distillation separation, hydrogenation desulfurization, pre-reforming, steam reforming and purification; wherein the light components obtained by distillation separation are components with distillation range of 300 DEG C and below. The distillation separation of oil products is combined with reforming method, sulfur content in raw materials is reduced to the degree that can be tolerated by nickel-based catalyst through distillation separation, high hydrocarbons in raw materials are converted into C1 components through pre-reforming process, thereby avoiding thermal cracking and carbon deposition of diesel distillate in high temperature area of reforming reactor, and the pre-reforming reactor improves heat utilization efficiency of the reforming reactor, realizing diesel reforming hydrogen production.

Description

Technical Field

[0001] A diesel reforming process for hydrogen production belongs to the field of hydrocarbon steam reforming hydrogen production technology. Background Technology

[0002] Hydrogen production technology has a history of over a century. The water electrolysis process for hydrogen production was developed in 1905 and is now quite mature. However, this process consumes a lot of electricity and has high production costs, making it suitable only for small-scale hydrogen users. Natural gas steam reforming for hydrogen production was industrialized by Standard Oil Company in the United States in 1928. With the rise of industries such as synthetic ammonia and methanol, hydrocarbon steam reforming for hydrogen production has also developed rapidly. Over more than half a century of applied research, experts from various countries have conducted in-depth studies on reformer design, energy utilization, catalyst performance, and purification, making targeted improvements and refinements. This has led to the process becoming increasingly mature, flexible and convenient to operate, requiring less investment, and continuously reducing energy consumption. Therefore, it has been widely used in petrochemical enterprises and is now one of the most widely used hydrogen production methods in the world.

[0003] The principle of hydrocarbon steam reforming for hydrogen production is as follows: The raw hydrocarbons first undergo hydrogenation and desulfurization processes to remove toxic substances such as olefins, sulfur, and chlorine. Then, they are combined with steam and fed into a reformer to react and produce hydrogen and carbon monoxide. The intermediate product, carbon monoxide, is then reacted with steam to further produce hydrogen. The resulting product gas is finally purified to obtain high-purity hydrogen. This process allows for a wide range of raw material options, including natural gas, oilfield gas, various refinery gases, liquefied petroleum gas (LPG), naphtha, top-oil, and residue oil, all of which can be used after processing.

[0004] Diesel fuel has advantages such as high energy density and mature and convenient production, transportation, storage, and distribution processes. Using diesel fuel as a feedstock for hydrocarbon steam reforming to produce hydrogen is a competitive technology in the market. There are three process methods for producing hydrogen from diesel fuel: steam reforming, autothermal reforming, and oxidative reforming.

[0005] However, on the one hand, diesel fuel has a high content of benzene rings and organic sulfur compounds. These substances are easy to combine with the active components of the catalyst, causing poisoning of the reforming catalyst. That is, the existing industrial pre-conversion catalysts cannot tolerate the sulfur compounds contained in diesel fuel, and the catalyst activity decreases significantly. Usually, the catalyst loses its activity after 50 to 100 hours of operation.

[0006] On the other hand, the catalyst cannot tolerate the long-chain hydrocarbons and olefins in diesel fuel. The high carbon number of diesel fuel molecules makes it easy for carbon to accumulate on the surface or in the pores of the reforming catalyst during the reforming reaction, which leads to catalyst deactivation.

[0007] Currently, hydrogen production via diesel steam reforming is still in the research stage. Literature reports mainly focus on "high-efficiency" catalysts or reactor designs. However, due to the thermodynamic coking caused by the long carbon chains of diesel fuel and poisoning, diesel steam reforming for hydrogen production has not yet achieved a breakthrough in practicality. Therefore, it is necessary to develop new solutions from the perspectives of process and catalyst. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a diesel reforming hydrogen production process that avoids catalyst poisoning or blockage and deactivation during the diesel reforming hydrogen production process.

[0009] The technical solution adopted by the present invention to solve its technical problem is: a diesel reforming hydrogen production process, characterized by the following steps: diesel distillation separation to obtain light components, hydrodesulfurization, pre-conversion, steam reforming, and purification; wherein, the light components obtained by distillation separation are components with a distillation range of 300°C and below.

[0010] The invention establishes a process for cutting, desulfurizing, and pre-converting diesel fuel. The inventors noted that the main sulfur compounds and olefin components of diesel fuel primarily appear in the fractions above 300°C. This invention first utilizes distillation to cut the light and heavy components of diesel fuel. Diesel fuel has an initial boiling point of approximately 180°C and a final boiling point of approximately 370°C. Selecting the light component fractions below 300°C allows for the retention of over 70% of the diesel fuel components for subsequent reforming to produce hydrogen. Simultaneously, it cuts away the vast majority of sulfur compounds and olefins, reducing the sulfur compound content to approximately 2 ppm. Based on this, further hydrogenation and desulfurization are performed to achieve secondary purification, further reducing the olefin and sulfur compound content of the diesel fuel, achieving a sulfur compound content below 0.5 ppm.

[0011] The pre-conversion step enables the light components of diesel fuel to undergo a hydrocarbon steam conversion reaction, yielding process gas with a dry basis composition mainly consisting of methane, carbon monoxide, carbon dioxide, and hydrogen (primarily methane with a low hydrogen content). The effective components obtained after pre-conversion are then introduced into the steam reforming step, effectively avoiding the influence of sulfur compounds and long-chain hydrocarbons on the reforming catalyst, thus enabling continuous hydrogen production from diesel steam reforming.

[0012] However, the pre-conversion step is usually a high-nickel catalyst, which is extremely sensitive to sulfur. Therefore, it is difficult to apply to the reforming of diesel to produce hydrogen in the existing technology. However, after the diesel has undergone two purification steps of distillation and hydrodesulfurization, the content of sulfur compounds and olefin components entering the pre-conversion step is greatly reduced. This allows the pre-conversion step to be added to the process to carry out hydrocarbon steam reforming reaction, providing process gas for the steam reforming step in a long-term and stable manner, thereby obtaining hydrogen.

[0013] Preferably, in the hydrodesulfurization step, the light components pass sequentially through a hydroreactor and a desulfurization tank, which is filled with a dechlorinating agent and a desulfurizing agent for dry desulfurization.

[0014] The optimized hydrodesulfurization process can effectively remove most of the sulfur compounds from the light components.

[0015] More preferably, there are two desulfurization tanks, which are connected in series at the outlet of the hydrogenation reactor.

[0016] Two desulfurization tanks connected in series can be switched and replaced. When one of the desulfurization tanks becomes saturated, it can be removed from the process line and the adsorbent replaced to ensure the continuous operation of the process line.

[0017] More preferably, the inlet temperature of the hydrogenation reactor is 330~350℃, the outlet temperature is less than or equal to 390℃, and the hydrogen-to-oil volume ratio is controlled at 800~1200.

[0018] The bed temperature of the desulfurization tank varies with the outlet temperature of the hydrogenation reactor. Therefore, under the above conditions, the reaction conditions inside the hydrogenation reactor can be kept stable, while ensuring that the working temperature of the desulfurization tank is most suitable, so as to make full use of the sulfur capacity of the desulfurizing agent.

[0019] The hydrogenation catalyst used in the hydrogenation reactor is preferably a cobalt-molybdenum-nickel-based hydrogenation catalyst. Cobalt-molybdenum-nickel-based catalysts are less sensitive to sulfur components and exhibit better activity in catalyzing olefins and sulfur compounds. Simultaneously, a hydrogenation protectant is preferably included in the hydrogenation reactor. This protectant possesses high porosity, large pore volume, suitable specific surface area, and catalytic activity, removing metallic impurities and solid particles from the oil, mitigating catalyst poisoning and coking, and extending the service life of the main catalyst.

[0020] The light components from the hydrogenation reactor pass sequentially through a dechlorinating agent and a desulfurizing agent in the desulfurization tank. The preferred dechlorinating agent is a calcium-magnesium-potassium-based dechlorinating agent. The preferred desulfurizing agents are zinc oxide and copper-zinc-based desulfurizing agents. The medium first flows through the calcium-magnesium-potassium-based dechlorinating agent, then through the zinc oxide desulfurizing agent, and finally through the copper-zinc-based desulfurizing agent.

[0021] Preferably, the pre-conversion uses a high-nickel catalyst with a nickel oxide weight content of 35% or more. More preferably, a high-nickel catalyst with a nickel oxide weight content of 55% or more is used.

[0022] The lower the nickel content, the easier it is for the catalyst to lose its catalytic activity under the influence of sulfur and impurities. However, the catalyst production cost is low. High-nickel catalysts have a longer lifespan and higher catalytic activity, but the higher the nickel content, the higher the cost. Thanks to the aforementioned purification steps, this invention can efficiently utilize high-nickel conversion catalysts to obtain the highest hydrocarbon steam conversion reaction efficiency. Furthermore, it has a lower impact on nickel active centers and a smaller lifespan reduction. Therefore, it has lower requirements for high-nickel catalysts and is more adaptable.

[0023] Preferably, the pre-conversion adopts a pre-conversion reactor with an inlet temperature of 360~450℃, a water-to-carbon ratio controlled at 2.0~3.2, and an outlet temperature less than or equal to 520℃.

[0024] The diesel vapor preconversion reaction is an exothermic reaction. The above temperature control conditions can prevent high temperature or carbon deposition from damaging the preconversion catalyst, and the outlet temperature can be controlled by adjusting the water-to-carbon ratio, thereby controlling the temperature inside the reactor.

[0025] Preferably, the preconversion process alternates between two preconversion reactors connected in parallel.

[0026] Although the diesel fuel undergoes two purification processes, it still contains a certain amount of sulfur. Preconversion catalysts are typically extremely sensitive to sulfur, inevitably leading to catalyst activity loss. Two preconversion reactors are set up in parallel, one in operation and one on standby. This allows the reactor to be replaced when the activity of one reactor is too low, ensuring the continuous operation of the process line and timely catalyst replacement.

[0027] This invention effectively solves the problem that the conversion catalyst cannot withstand the high-grade hydrocarbons with a distillation range of 220°C or higher for a long time by setting up a pre-conversion reactor that is both operational and standby, as well as a subsequent desulfurization tank. It also solves the problem of sulfur poisoning of the conversion catalyst and extends the operating cycle of the entire unit.

[0028] Further preferred, a temperature difference of ≤10℃ between the pre-conversion inlet and outlet is used as the criterion for switching the pre-conversion reactor. This parameter is based on the fact that the pre-conversion reaction of higher hydrocarbons is an exothermic reaction, and the temperature difference directly reflects the activity of the catalyst.

[0029] At the end of the preconversion catalyst's use, the dry basis composition of the process gas can be analyzed to reveal C2 hydrocarbons (such as ethane and ethylene), and even C3 hydrocarbons (such as propane and propylene). When the above temperature difference occurs, it proves that the preconversion catalyst has low activity and the content of C2 and C3 hydrocarbons has increased. This also reminds the operators to pay attention to the operation of the preconversion reactor and the catalyst, and to make preparations in advance for switching the preconversion reactor.

[0030] Preferably, the pre-conversion and steam reforming processes are further subjected to a gas-liquid separation operation.

[0031] The pre-converted reaction gas is condensed through heat exchange to a temperature of 40-100℃, preferably 80-100℃. Because it is under pressure, water at 100℃ will not boil, and the initial boiling point of unreacted long-chain liquid hydrocarbons is much higher than this temperature. The higher temperature of the medium can reduce the size and operating costs of cooling equipment, and the separated gaseous medium contains more saturated water than at low temperatures, which can save subsequent steam.

[0032] The gas and liquid phases are then separated. The purpose of this gas-liquid separation is that during the later stages of pre-conversion catalyst use, the C-C bond breaking reaction of hydrocarbons becomes incomplete. If some unreacted liquid hydrocarbons enter the subsequent reforming reactor, their long carbon chains will cause rapid coking at high temperatures, resulting in irreversible damage to the steam reforming catalyst. Therefore, by implementing gas-liquid separation, these diesel components that did not react in the pre-conversion reactor are separated from the gas, along with unreacted water. The separated gas is then introduced into the steam reformer.

[0033] The separated liquid phase (containing oil and water) is further preferably introduced into a liquid re-separation process. The liquid re-separation process involves settling the liquid, with the lower water being introduced into a steam drum for use as process steam, while the upper oil can be introduced into a recombining tank as fuel.

[0034] In a further preferred embodiment, the gas phase after gas-liquid separation undergoes another desulfurization process. Generally, a zinc oxide desulfurizing agent is used for desulfurization before entering steam reforming, i.e., the gas is blown through a zinc oxide desulfurizing agent with an operating temperature below 400℃, as a backup to further ensure that the sulfur content of the gas entering steam reforming is low.

[0035] The high-temperature crude product gas obtained after steam reforming can be heat-recovered and used to generate steam: a dual-steam chamber is set up, with steam chamber b using fresh water and steam chamber a using recycled water. The steam generated by steam chamber a is used within this process unit and is not exported to avoid contaminating other equipment or devices that use steam; the steam produced by steam chamber b can be used within this process unit and can also be exported.

[0036] Preferably, the gas undergoes a CO conversion reactor before purification, and the gas after steam reforming is catalyzed by a high-temperature CO conversion catalyst.

[0037] After steam reforming to produce hydrogen, although the hydrogen content in the dry gas can reach about 70 vol%, some carbon monoxide can still be further converted into hydrogen. The CO high-temperature conversion catalyst is further preferably an iron-chromium-based catalyst, which is a commonly used carbon monoxide conversion catalyst. The hydrogen content in the converted product gas can reach 73 vol% or more.

[0038] After the converted product gas undergoes multiple heat exchange and condensation separations, the resulting condensate is introduced into steam drum a for reuse in steam generation. Depending on the hydrogen user's needs, hydrogen of varying purities can be obtained by combining PSA, VPSA, or other hydrogen purification equipment of different scales or purification precisions.

[0039] Preferably, the heavy components separated by distillation are used as fuel for diesel distillation or steam reforming.

[0040] Compared with existing technologies, the beneficial effects of this invention are as follows: it combines oil distillation and reforming, removing complex high-drying-point compounds and sulfur compounds from diesel fractions, retaining only compounds with lower dry points and simpler sulfur forms. Utilizing a pre-conversion process and catalyst with excellent conversion effects on higher hydrocarbons, diesel is converted into methane-rich gas at lower temperatures, thus avoiding thermal cracking and carbonization of diesel in the high-temperature region of the reforming reactor. Furthermore, the pre-conversion reactor improves the heat utilization efficiency of the reforming reactor, effectively reducing overall energy consumption. The hydrocarbons entering the reforming reactor, regardless of complexity or toxicity content, are significantly reduced compared to diesel, and can be processed using conventional reforming catalysts, achieving diesel reforming for hydrogen production. Detailed Implementation

[0041] The present invention will be further described below with reference to the embodiments, wherein Embodiment 1 is the preferred embodiment of the present invention.

[0042] Example 1 A diesel reforming process for hydrogen production, using military-grade diesel as feedstock, includes the following steps: 1) Distillation separation is performed on military diesel to obtain a fraction with a distillation range of less than or equal to 300℃ (this fraction accounts for approximately 78%~80% of the total feed amount of military diesel), which is then introduced into a hydrotreating reactor. The upper part of the hydrotreating reactor is filled with a hydrotreating protective agent, and the lower part is filled with a cobalt-molybdenum-nickel hydrotreating catalyst. The gas phase passes sequentially through the hydrotreating protective agent and the cobalt-molybdenum-nickel hydrotreating catalyst, with the hydrotreating protective agent accounting for 20% and the cobalt-molybdenum-nickel hydrotreating catalyst accounting for 80%. The hydrotreating protective agent can remove metal impurities and solid particles from the oil, slow down catalyst poisoning and carbonization, and extend the service life of the main catalyst. The inlet temperature of the hydrotreating reactor is controlled at 330~350℃ (through heat exchange and steam heating), and the outlet temperature is approximately 380℃, with a hydrogen-to-oil volume ratio of 800~1200. The light components passing through the hydrotreating reactor enter a desulfurization tank. There are two desulfurization tanks, connected in series at the outlet of the hydrotreating reactor, which can be alternately connected to the system to desulfurize the gas coming out of the hydrotreating reactor. The bottom of the desulfurization tank is filled with copper-zinc-based desulfurizer, the middle is filled with zinc oxide desulfurizer, and the top is filled with calcium-magnesium-potassium-based dechlorinator. The filling ratio from top to bottom is 1:3:1. The gas components to be treated pass through the calcium-magnesium-potassium-based dechlorinator, zinc oxide desulfurizer, and copper-zinc-based desulfurizer in sequence in the desulfurization tank.

[0043] 2) The gas after the above desulfurization process enters the pre-conversion reactor. The inlet temperature of the pre-conversion reactor is 420℃, and the outlet temperature is approximately 495℃; the carbon space velocity is 2000 h⁻¹. -1 The water-to-carbon ratio is controlled at 3.0; the inlet pressure is 3.05 MPa and the outlet pressure is 3.0 MPa; the catalyst used for pre-conversion is the Z505 high-nickel pre-conversion catalyst developed and sold by Sinopec Qilu Branch, with a nickel oxide content of 55%; the composition of the process gas obtained from pre-conversion is: methane 59.85%, carbon monoxide 0.79%, carbon dioxide 23.57%, and hydrogen balance.

[0044] 3) The pre-converted gas is condensed to a temperature of about 90°C after heat exchange, and then the gas and liquid are separated. The separated liquid phase enters the liquid re-separation process. After the liquid re-separation is allowed to stand, the water at the bottom is introduced into the steam drum a and can be used as process steam, while the oil at the top can be introduced into the recombining tank as fuel.

[0045] 4) The gas phase obtained from gas-liquid separation, after being desulfurized by zinc oxide desulfurizing agent, is mixed with steam and then enters the steam reforming reactor for hydrocarbon steam reforming to obtain hydrogen-rich gas. The reforming catalyst packed in the steam reforming reactor is the Z417 / Z418 alkali-promoted hydrocarbon steam reforming catalyst developed and sold by Sinopec Qilu Branch. The operating conditions of the steam reforming reactor are a carbon space velocity of 1000 h⁻¹. -1 When the water-to-carbon ratio is 3.2, the inlet pressure is 2.7 MPa, the outlet pressure is 2.6 MPa, and the outlet temperature is 810℃, the methane content of the process gas at the outlet of the steam reforming reactor is less than 7%.

[0046] 5) The process gas obtained after steam reforming enters the CO shift reactor, where the carbon monoxide in the process gas is further converted into hydrogen by the internal iron-chromium-based catalyst to obtain product gas. The carbon monoxide content at the outlet of the CO shift reactor is less than or equal to 2%.

[0047] 6) The obtained product gas is used in fuel cells. A two-stage PSA is set up. The first-stage PSA produces hydrogen with a purity of 99.9%. Then the hydrogen is fed into the second-stage PSA, which produces hydrogen with a purity of 99.999%. The exhaust gas from both PSAs is fed into the gas pipeline network as fuel.

[0048] The above process employs a dual steam system, namely two steam drums. One steam drum, b, provides fresh steam for heating and supplying gas to each stage, while the other steam drum, a, collects condensed process water, including condensate from the heat exchange after the pre-conversion stage and condensate obtained from heat recovery after the CO conversion reactor. The steam in steam drum b, which provides fresh steam, can be used in any other stage, while steam drum a, which collects condensed process water, only supplies gas to the two stages mentioned above (pre-conversion and conversion), thus recovering heat while avoiding pollution.

[0049] In the above preparation process, two parallel pre-conversion reactors are used alternately, with the temperature difference between the pre-conversion inlet and outlet ≤10℃ serving as the indicator for switching pre-conversion reactors. The pre-conversion reactor only needs to be replaced after running for more than 500 hours, while the reforming reactor needs to run for more than 35,000 hours.

[0050] The fuel for this process is PSA desorbed gas and diesel fraction with a distillation range greater than 300°C from step 1), with military diesel fuel used as a supplement for any shortfall. The operating temperature and outlet gas composition of various parts within the pre-conversion reactor, as well as the relationship between the pre-conversion reactor's operating time, are shown in Table 1 below.

[0051] Table 1 Monitoring of the pre-conversion reactor in the examples .

[0052] The data above shows that the pre-conversion catalyst exhibits high activity and activity stability during operation, and can operate stably for more than 500 hours.

[0053] Example 2 A diesel reforming hydrogen production process, based on Example 1, except that the pre-conversion catalyst in step 2) is replaced with the Z503 high-nickel catalyst developed and sold by Sinopec Qilu Branch, with a nickel oxide content of 50%, and other conditions are the same as in Example 1.

[0054] The pre-conversion reactor needs to be replaced only after it has been running for more than 500 hours, while the reforming reactor needs to be running for more than 35,000 hours.

[0055] Example 3 A diesel reforming hydrogen production process, based on Example 1, has the inlet temperature of the pre-conversion reactor set to 360°C, less than 520°C, while other conditions are the same as in Example 1.

[0056] The pre-conversion reactor needs to be replaced only after it has been running for more than 500 hours, while the reforming reactor needs to be running for more than 35,000 hours.

[0057] Comparative Example 1 A diesel reforming hydrogen production process, based on Example 1, except that step 1) does not involve a hydrogenation reactor, while other conditions are the same as in Example 1.

[0058] After the pre-conversion reactor operated for 100 hours, the C2 component in the exhaust gas exceeded 10 vol%, and the total sulfur was 1.7 mg / L. Upon unloading the pre-conversion catalyst, its sulfur content was found to be 0.46% (mass ratio), clearly indicating sulfur poisoning of the pre-conversion catalyst.

[0059] Comparative Example 2 A diesel reforming hydrogen production process, based on Example 1, except that step 1) does not include a desulfurization tank, while other conditions are the same as in Example 1.

[0060] After the pre-conversion reactor operated for 100 hours, the C2 component in the exhaust gas exceeded 10.5 vol%, and the total sulfur was 1.8 mg / L. Upon unloading the pre-conversion catalyst, its sulfur content was found to be 0.44% (mass ratio), clearly indicating sulfur poisoning of the pre-conversion catalyst.

[0061] Comparative Example 3 A diesel reforming process for hydrogen production, based on Example 1, except that step 1) does not involve distillation separation, and full-fraction oil is used for subsequent steps, while other conditions are the same as in Example 1.

[0062] The relationship between the operating temperature of various parts of the preconversion reactor and the composition of the outlet gas with the operating time of the preconversion reactor is shown in Table 2 below.

[0063] Table 2 Monitoring of the pre-conversion reactor in Comparative Example 3 .

[0064] The evaluation data above shows that when the pre-conversion catalyst is used to process the full-range military diesel, the temperature drops rapidly at 1 / 3 of the bed, indicating that the catalyst has undergone significant deactivation.

[0065] Comparative Example 4 A diesel reforming process for hydrogen production, based on Example 1, involves step 1) distillation to obtain a fraction with a distillation range less than or equal to 310°C (this fraction accounts for approximately 80-85% of the total feed amount of military diesel). The inlet temperature of the pre-conversion reactor is increased to 450°C, while other conditions remain the same as in Example 1. The temperature of the pre-conversion reactor is increased because: after raising the cut-off temperature, the amount of impurities such as sulfur entering the pre-conversion reactor increases, necessitating an increase in the inlet temperature to enhance the catalytic activity of the pre-conversion catalyst and ensure the normal progress of the reaction.

[0066] The relationship between the operating temperature of various parts of the preconversion reactor and the composition of the outlet gas with the operating time of the preconversion reactor is shown in Table 3 below.

[0067] Table 3 Monitoring of the pre-conversion reactor in Comparative Example 4 .

[0068] The evaluation data above shows that when the pre-conversion catalyst treats the fraction of military diesel with a distillation range of less than or equal to 310℃, the temperature at 1 / 3 of the bed still decreases slowly, indicating that the catalyst is slowly deactivated.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A diesel reforming process for hydrogen production, characterized in that, Includes the following steps: 1) Distillation separation of diesel fuel is performed to obtain a fraction with a distillation range of less than or equal to 300℃. This fraction is then introduced into a hydrotreating reactor for hydrotreating. The inlet temperature of the hydrotreating reactor is 330~350℃, and the outlet temperature is less than or equal to 390℃. The hydrogen-to-oil ratio is controlled at 800~1200. The light components after passing through the hydrotreating reactor enter the desulfurization tank. The bottom of the desulfurization tank is filled with copper-zinc based desulfurizing agent, the middle is filled with zinc oxide desulfurizing agent, and the top is filled with calcium-magnesium-potassium based dechlorinating agent. The gas components to be treated pass through the calcium-magnesium-potassium based dechlorinating agent, zinc oxide desulfurizing agent, and copper-zinc based desulfurizing agent in sequence in the desulfurization tank. 2) The gas that has undergone the above desulfurization enters the pre-conversion reactor; the pre-conversion uses a high-nickel catalyst with a nickel oxide weight content of 55% or more; 3) The pre-converted gas undergoes heat exchange and condensation, followed by gas-liquid separation; 4) The gas phase obtained from gas-liquid separation is desulfurized by zinc oxide desulfurizing agent, mixed with water vapor and then fed into a steam reforming reactor to carry out hydrocarbon steam conversion reaction to obtain process gas; 5) The process gas obtained after steam reforming enters the CO shift reactor, where carbon monoxide in the process gas is further converted into hydrogen to obtain product gas.

2. The diesel reforming hydrogen production process according to claim 1, characterized in that: There are two desulfurization tanks, which are connected in series at the outlet of the hydrogenation reactor.

3. The diesel reforming hydrogen production process according to claim 1, characterized in that: The inlet temperature of the pre-conversion reactor is 360~450℃, the water-to-carbon ratio is controlled at 2.0~3.2, and the outlet temperature is less than or equal to 520℃.

4. The diesel reforming hydrogen production process according to claim 1, characterized in that: The heavy components separated by distillation are used as fuel for diesel distillation or steam reforming.