Water-saving process for preparing oil products / chemicals by high-efficiency low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis

Abstract

The invention discloses a water-saving process for preparing oil products / chemicals through high-efficiency low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis, and belongs to the technical field of chemical engineering. The water-saving process for preparing the oil product / chemical product through combination of low-carbon hydrocarbon reforming and Fischer-Tropsch synthesis sequentially comprises the steps of reforming reaction, synthesis gas purification, Fischer-Tropsch synthesis reaction and product separation, and gas-phase and water-phase products in the products can be recycled repeatedly. According to the water-saving process, a reforming reaction and a Fischer-Tropsch synthesis reaction are organically combined in a series connection manner, the water-saving process has the advantages of high efficiency, low energy consumption and low water consumption by optimizing reaction conditions and integrating the process, and the water-saving process is high in carbon utilization efficiency, low in emission, simple in overall process flow, convenient to operate and relatively high in product yield.

Description

Technical Field

[0001] The present invention relates to the field of chemical technology, and in particular to a water-saving process for producing oil products / chemicals by combining high-efficiency low-carbon hydrocarbon reforming with Fischer-Tropsch synthesis. Background Art

[0002] In recent years, countries around the world have increasingly stringent requirements for reducing greenhouse gas emissions, with methane being listed as the second most restricted greenhouse gas. Natural gas-related businesses, including oil and gas producers, coalbed methane producers, biogas recovery companies, and water treatment plant oxidized biogas, have all seen production and development restrictions due to methane emissions restrictions, severely impacting their operations and sustainable development. Oilfield associated gas, small natural gas reservoirs, biogas, and coalbed methane, among others, are difficult to utilize on a large scale due to their small scale, dispersed sources, and complex composition. Furthermore, these gases exist as gaseous molecules at ambient temperature and pressure, making their storage and transportation costs prohibitive. Further tapping the resource potential of these gases, achieving clean, efficient, low-carbon, and green utilization of industrial waste gas, and increasing reserves and production are essential for long-term, sustainable energy development.

[0003] Low-carbon hydrocarbons are reformed into carbon monoxide and hydrogen through an efficient integrated device for producing clean oils / chemicals. Carbon monoxide and hydrogen are further converted into high-value oils (gasoline, diesel, etc.) or chemicals (wax, alcohol, olefins, etc.) that are easy to transport through the Fischer-Tropsch synthesis reaction. This can not only significantly reduce storage and transportation costs, but also achieve effective high-value utilization of some industrial waste gases and garbage pyrolysis gases.

[0004] Low-carbon hydrocarbons are reformed into carbon monoxide and hydrogen through an efficient integrated device for producing clean oils / chemicals. Carbon monoxide and hydrogen are further converted into high-value oils (gasoline, diesel, etc.) or chemicals (wax, alcohol, olefins, etc.) that are easy to transport through the Fischer-Tropsch synthesis reaction. This can not only significantly reduce storage and transportation costs, but also achieve effective high-value utilization of some industrial waste gases and garbage pyrolysis gases.

[0005] The current low-carbon hydrocarbon conversion technology landscape features mainstream reforming pathways including steam reforming (SMR), partial oxidation reforming (POX), and dry reforming with carbon dioxide (DRM). Steam reforming is the most mature technology, but currently primarily used in hydrogen production, and still faces inherent drawbacks such as high water consumption, high carbon emissions, and energy efficiency bottlenecks. The complementary Fischer-Tropsch synthesis process, which catalytically converts synthesis gas (H2 / CO) into high-value-added oils and chemicals, is considered a core technology for the indirect utilization of natural gas resources. However, its limited carbon chain growth selectivity, resulting in excessive CO2 emissions and low atom economy, urgently require solutions.

[0006] In marginal natural gas fields, associated gas fields and biomass gas resource-rich areas, due to practical constraints such as the scarcity of freshwater resources and weak water treatment infrastructure, the development of a coupled process system with both low water consumption and high carbon efficiency has become a strategic need and technical necessity to solve the problem of regional resource mismatch and achieve clean conversion of unconventional natural gas.

[0007] Therefore, coupling low-carbon hydrocarbon reforming with the Fischer-Tropsch synthesis reaction to develop a water-saving process for producing oil products / chemicals through efficient low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis can achieve the combined circulation of water and carbon resources and energy recovery and utilization, which has important industrial application value. Summary of the Invention

[0008] In view of this, the technical problem to be solved by the present invention is to provide a water-saving process for producing oil products / chemicals by reforming low-carbon hydrocarbons combined with Fischer-Tropsch synthesis. The water-saving process has the advantages of high efficiency, low energy consumption, and low water consumption.

[0009] In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] The present invention provides a water-saving process for producing oil products / chemicals by reforming low-carbon hydrocarbons combined with Fischer-Tropsch synthesis, comprising the following steps:

[0011] (1) mixing a mixture of C1-C4 hydrocarbons and water vapor with a first catalyst for reforming reaction to obtain a synthesis gas containing CO, H2 and water vapor, wherein the temperature of the mixture is 400°C-650°C, and the molar ratio of CO to H2 in the synthesis gas is (1-3):1;

[0012] (2) cooling and purifying the synthesis gas and removing water to obtain purified synthesis gas;

[0013] (3) mixing the purified synthesis gas with a second catalyst to perform a Fischer-Tropsch synthesis reaction to generate relevant products;

[0014] (4) separating the product through a hot trap and a cold trap to obtain Fischer-Tropsch wax, an oil phase, an aqueous phase, and a gas phase;

[0015] (5) The water described in step (2) and the aqueous phase described in step (4) are converted into steam and circulated to step (1) as a reaction raw material, and the gas phase described in step (4) is circulated to the Fischer-Tropsch synthesis unit and the reforming reaction unit respectively, and the remaining gas phase is emptied.

[0016] In the water-saving process of the present invention, the related products of step (3) include but are not limited to C 19+ Long chain hydrocarbons, C 10 -C 20Mainly long-chain hydrocarbons, low-carbon olefins, C5-C9 light hydrocarbons, water, liquid oxygen-containing compounds, unreacted C1-C4 hydrocarbons, and unreacted purified synthesis gas.

[0017] Among them, the C 19+ Long-chain hydrocarbons include but are not limited to Fischer-Tropsch wax, heavy diesel, etc.;

[0018] The C 10 -C 20 The main long-chain hydrocarbons include but are not limited to naphtha, gasoline, light diesel, etc.;

[0019] The liquid oxygen-containing compounds include but are not limited to alcohol compounds and the like.

[0020] The present invention obtains Fischer-Tropsch wax, oil phase, water phase and gas phase by performing hot trap and cold trap separation on the above-mentioned related products.

[0021] The water-saving process includes reforming reaction, synthesis gas purification, Fischer-Tropsch synthesis reaction, and product separation in sequence, and the gas phase and water phase products in the products can be repeatedly circulated.

[0022] In addition, the water-saving process also includes raw material premixing and preheating treatment and energy recovery and utilization.

[0023] The raw material premixing and preheating treatment is to pass the mixed gas of C1-C4 hydrocarbons and water vapor into a gas premixing and preheating device for premixing and preheating, ensuring that the temperature of the mixed gas raw material reaches 400°C-650°C.

[0024] The energy recovery and utilization is to recover the heat released by the reforming reaction product synthesis gas, transfer the heat to the raw mixed gas through the gas premix preheater, and preliminarily preheat the low-temperature raw mixed gas to achieve energy recovery, reduce energy consumption and improve energy efficiency.

[0025] Preferably, the C1-C4 hydrocarbons include but are not limited to methane, ethane, propane, butane, ethylene, etc.

[0026] Preferably, the heat sink separation includes a first heat sink separation and a second heat sink separation;

[0027] Preferably, the temperature of the first heat trap separation is 180°C-220°C;

[0028] Preferably, the temperature of the second heat trap separation is 100°C-160°C.

[0029] Preferably, in step (1), the molar ratio of C1-C4 hydrocarbon to water vapor is 1:(0.5-7), more preferably 1:(1-3). In some specific embodiments of the present invention, it is preferably 1:1.5 or 1:2.

[0030] Preferably, in the present invention, the first catalyst in step (1) is selected from one or more of a noble metal-based catalyst, a non-noble metal-based catalyst and a composite oxide supported catalyst.

[0031] Preferably, the noble metal in the noble metal-based catalyst is selected from Rh, Ru, Pt, Pd or Ir;

[0032] Preferably, the non-noble metal in the non-noble metal-based catalyst is selected from Ni, Co or Fe;

[0033] Preferably, the composite oxide in the composite oxide supported catalyst is selected from LaNiO3 or SrTiO3.

[0034] Preferably, in the present invention, the temperature of the reforming reaction in step (1) is 600°C-950°C; more preferably 600°C-800°C; further preferably 600°C or 650°C.

[0035] Preferably, the pressure of the reforming reaction is 0-3.0 MPa.

[0036] By controlling and optimizing the Fischer-Tropsch synthesis reaction conditions of the above-mentioned water-saving process, the generation of methane is reduced, the water gas shift reaction is inhibited, and the generation of carbon dioxide is thereby reduced.

[0037] Preferably, in the present invention, the second catalyst in step (3) is selected from Fe-based catalysts, Co-based catalysts or Ru-based catalysts; more preferably, Fe-based catalysts or Co-based catalysts.

[0038] Preferably, the temperature of the Fischer-Tropsch synthesis reaction in step (3) is 180°C-400°C, more preferably 200°C-300°C. In some specific embodiments of the present invention, it is preferably 200°C or 270°C.

[0039] Preferably, the pressure of the Fischer-Tropsch synthesis reaction is 0-5.0 MPa; more preferably 2.0-5.0 MPa.

[0040] The present invention improves carbon efficiency through cyclic reaction. The gas phase in step (4) of the water-saving process can be divided into three batches, which are circulated to the Fischer-Tropsch synthesis unit and the reforming reaction unit respectively, and the remaining gas phase is evacuated. The proportion and gas volume of the gas phase (including C1-C4 hydrocarbons and unreacted purified synthesis gas) circulated to the reforming reaction and the Fischer-Tropsch synthesis reaction can be accurately controlled and adjusted by a flow controller according to actual conditions.

[0041] Preferably, in the present invention, the total circulation amount of the gas phase in step (5) accounts for 0%-100% of the total amount of the gas phase; more preferably, it is 50%-95%; further preferably, the total circulation amount of C1-C4 hydrocarbons and unreacted purified synthesis gas in the gas phase each accounts for 25% of the total amount of the gas phase; or, the circulation amount of C1-C4 hydrocarbons in the gas phase accounts for 45% of the total amount of the gas phase, and the circulation amount of unreacted purified synthesis gas in the gas phase accounts for 50% of the total amount of the gas phase.

[0042] Furthermore, the water in step (2) and the aqueous phase in step (4) are converted into steam and then circulated to step (1) as starting materials, thereby further reducing the consumption of fresh water and achieving the purpose of saving water resources.

[0043] Preferably, in the present invention, the equipment used in the water-saving process includes a safety explosion-proof system, an air cooling device, and a liquid level controller.

[0044] The equipment used in the water-saving process of the present invention is equipped with a safety explosion-proof system in key processes such as the reforming reaction and the Fischer-Tropsch synthesis reaction, which includes a nitrogen protection device and a safety pressure relief device to effectively prevent the occurrence of explosion accidents.

[0045] The nitrogen protection device is supplied with high-pressure nitrogen from a cylinder. This is used to replace the air within the device, acting as a catalyst shielding gas, and also for safety protection. When a temperature spike or a sharp rise in pressure occurs within the reforming reactor or Fischer-Tropsch synthesis reactor, the reactor safety valve and nitrogen line valve automatically open, allowing nitrogen to rapidly enter the reactor and block the reaction. The safety pressure relief device (i.e., a safety valve) is installed on the reforming reactor and Fischer-Tropsch synthesis reactor. When pressure rises sharply or nitrogen rushes in, the safety valve automatically opens to release pressure, preventing explosions caused by overpressure.

[0046] The equipment used in the water-saving process described in the present invention also includes an air cooling system, which is used to cool the reforming reaction products and the Fischer-Tropsch synthesis reaction products. The system adopts an air-conditioning external unit structure and uses air convection for cooling. It has high cooling efficiency and low energy consumption. It also avoids the coolant consumption caused by the use of a liquid cooling system, reduces the volume of the cooling system, and improves the compactness of the system.

[0047] The air cooling system is preferably an air conditioning external dry air cooling system, which includes an air cooler, a fan, a deflector, etc.

[0048] The air cooler adopts a finned tube structure to increase the heat exchange area and improve the cooling efficiency.

[0049] The fan is used to accelerate air flow and improve cooling efficiency.

[0050] The air guide cover is used to guide air flow, avoid hot air backflow, and improve cooling efficiency.

[0051] The water-saving process also includes equipment for liquid level controllers. These controllers are installed on both the hot and cold traps to monitor and control the liquid levels in real time, ensuring timely discharge of liquid products and safe and stable operation of the equipment, thereby improving automation and operational stability.

[0052] Compared with the prior art, the water-saving process for low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis to produce oil products / chemicals provided by the present invention comprises the following steps: (1) mixing a mixture of C1-C4 hydrocarbons and water vapor with a first catalyst for reforming reaction to obtain a synthesis gas containing CO, H2 and water vapor, wherein the temperature of the mixed gas is 400°C-650°C, and the molar ratio of CO and H2 in the synthesis gas is (1-3):1; (2) cooling and purifying the synthesis gas, removing water, and obtaining purified synthesis gas; (3) mixing the purified synthesis gas with a second catalyst for Fischer-Tropsch synthesis reaction to generate relevant products; (4) separating the products through a hot trap and a cold trap to obtain Fischer-Tropsch wax, an oil phase, an aqueous phase and a gas phase; (5) converting the water described in step (2) and the aqueous phase described in step (4) into steam and circulating them to step (1) as a reaction raw material, and circulating the gas phase described in step (4) to the Fischer-Tropsch synthesis unit and the reforming reaction unit respectively, and the remaining gas phase is discharged. The water-saving process of the present invention organically combines the reforming reaction and the Fischer-Tropsch synthesis reaction in a series manner. By optimizing the reaction conditions and process integration, the water-saving process has the advantages of high efficiency, low energy consumption, and low water consumption. It also has high carbon utilization efficiency and low emissions. The overall process flow is simple, the operation is convenient, and the product yield is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the water-saving process equipment structure for high-efficiency low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis to produce oil products / chemicals in the present invention, wherein 1 is a nitrogen raw gas feed port, 2 is a low-carbon hydrocarbon (C1-C4 hydrocarbon) raw gas feed port, 3 is a water vapor raw material feed port, 4 is a gas premixing preheater, 5 is a reforming reactor, 6 is a synthesis gas purification device, 7 is a Fischer-Tropsch synthesis reactor, 8-1, 8-2, and 8-3 are air cooling devices, 9-1 and 9-2 are heat traps, 10 is a cold trap, 11 is a light component collector, 12 is a water phase collector, and 13 is a steam generator. , 14-1 and 14-2 are safety valves, 15-1, 15-2 and 15-3 are liquid level controllers, 16 is a gas-liquid separator, 17 is a booster pump, and 18 is a heavy component collector; ① is the nitrogen protection gas inlet pipeline, ② is the low-carbon hydrocarbon feed gas inlet pipeline, ③ is the steam feed pipeline, ④ is the reforming reactor inlet pipeline, ⑤ is the reforming reactor outlet pipeline, ⑥ is the outlet pipeline after the reforming reaction and after passing through the preheater, ⑦ is the gas-liquid separator inlet pipeline, ⑧ is the synthesis gas purification unit inlet pipeline, ⑨ is the light component outlet pipeline, and ⑩ is the water phase outlet pipeline. It is the gas phase exhaust pipe. It is the water phase circulation reflux pipeline. It is a gas phase circulating reflux reforming reaction pipeline. Condensate circulation return pipeline, The gas phase is recycled back to the Fischer-Tropsch synthesis reaction pipeline. It is the air inlet pipeline of the Fischer-Tropsch synthesis reactor. Heavy component outlet pipeline. DETAILED DESCRIPTION

[0054] To further illustrate the present invention, the water-saving process for producing oils / chemicals by reforming low-carbon hydrocarbons combined with Fischer-Tropsch synthesis provided by the present invention is described in detail below with reference to examples.

[0055] Schematic diagram of the water-saving process equipment structure for the high-efficiency low-carbon hydrocarbon reforming combined with Fischer-Tropsch synthesis to produce oil products / chemicals according to the present invention, Figure 1 As shown, the process includes the following steps:

[0056] 1. Raw material pretreatment

[0057] Low-carbon hydrocarbons (C1-C4 hydrocarbons) and water vapor are used as raw materials and introduced into the gas premixing and preheating device 4 through the low-carbon hydrocarbon raw material gas feed port 2 and the water vapor raw material feed port 3 for premixing and preheating, ensuring that the raw material temperature reaches 400°C-650°C to meet the subsequent process requirements.

[0058] 2. Reforming reaction

[0059] The pretreated light hydrocarbons and a suitable amount of water vapor mixture enter the reforming reactor 5 through gas line (gas pipeline) ④, where a reforming reaction occurs in the presence of a catalyst to produce synthesis gas (CO and H2). By adjusting the ratio of water vapor to light hydrocarbons, the temperature and pressure of the reforming reactor, the ratio of heavy H2 / CO in the light hydrocarbon reforming product is maintained between 1.0 and 3.0 to meet the requirements of the Fischer-Tropsch synthesis reaction.

[0060] The gas generated by the reforming reaction enters the gas premixing preheater 4 through the gas path ⑤ to preheat the raw gas, reduce heat loss and improve energy efficiency.

[0061] 3. Syngas purification

[0062] The outlet gas flowing through the preheater after the reforming reaction enters the air cooling device 8-1 through the gas path ⑥ for further cooling to preliminarily remove water from the synthesis gas.

[0063] The cooled synthesis gas enters the gas-liquid separator 16 through the gas line ⑦, and after rough dehydration, enters the synthesis gas purification device 6 through the gas line ⑧ to further remove trace water in the synthesis gas, thereby obtaining dry and pure synthesis gas. It flows back to the steam generator 13 for recycling.

[0064] 4. Fischer-Tropsch synthesis reaction

[0065] The purified synthesis gas is pressurized by the booster pump 17 and then passes through the gas path The catalyst is fed into a Fischer-Tropsch synthesis reactor 7 to produce oil products and chemicals. The reaction conditions are as follows:

[0066] Reaction temperature: 180℃-400℃;

[0067] Reaction pressure: 0-5.0MPa;

[0068] Catalyst: Highly efficient Fischer-Tropsch synthesis catalyst with cobalt (Co), iron (Fe) or ruthenium (Ru) as active metal.

[0069] By optimizing the reaction conditions, the water vapor shift reaction is inhibited and the generation of carbon dioxide is reduced.

[0070] 5. Product Separation

[0071] The outlet material of the Fischer-Tropsch synthesis reaction enters the hot trap 9-1 for separation to obtain heavy components (such as Fischer-Tropsch wax, heavy diesel, etc.), and the remaining outlet material is cooled by the air cooling device 8-2 and then enters the hot trap 9-2 for separation to obtain light components (such as gasoline, light diesel, etc.). Then, the remaining outlet material is cooled by the air cooling device 8-3 and then enters the cold trap 10 for separation to obtain the water phase. The remaining gas is discharged through the gas path. 、 、 The heavy components are finally collected in the heavy component collector 18, the light components are finally collected in the light component collector 11, and the water phase is finally collected in the water phase collector 12. It flows back to the steam generator 13 for recycling.

[0072] 6. Gas phase circulation

[0073] The unreacted synthesis gas and gaseous hydrocarbons produced in the Fischer-Tropsch synthesis process are transported through the gas line 、 Circulate back to the Fischer-Tropsch synthesis reaction system and reforming reaction to react again, one of which is mixed with the synthesis gas and passed through the pressure pump 17 and the gas line It then re-enters the Fischer-Tropsch synthesis reactor 7 for conversion, and the other stream is mixed with the low-carbon hydrocarbon feed gas 2 and returned to the reforming reactor 5 through the premixing preheater 4 for reforming and recycling. The ratio and flow rate of the two circulating gases can be accurately controlled by the flow controller according to actual process requirements.

[0074] Example 1

[0075] 1. Using methane and water vapor as raw materials, adjust the molar ratio of water molecules to methane molecules to 1:1.5, and pass them into the gas premixing and preheating device for premixing and preheating to ensure that the raw material temperature reaches 600°C before entering the reforming reactor. Using a nickel-based catalyst, at a pressure of 0.1MPa, the reaction generates synthesis gas (H2 / CO=2.5).

[0076] 2. The cooled, dehydrated and purified synthesis gas is introduced into a Fischer-Tropsch synthesis reactor and reacted at 200°C and 3.0 MPa using a cobalt-based catalyst to produce oil products and chemicals.

[0077] 3. The reaction products are separated by the hot trap and cold trap described above, wherein the liquid products are wax, diesel, gasoline, oxygen-containing compounds and water, and 95% of the gaseous products are recycled, wherein a 50% stream of unreacted purified synthesis gas is mixed with the synthesis gas and pressurized and then re-enters the Fischer-Tropsch synthesis reactor for conversion, and another 45% stream of C1-C4 hydrocarbons is mixed with the newly added low-carbon hydrocarbon (C1-C4 hydrocarbon) feed gas and then returned to the reforming reactor through the premixing preheater for reforming and recycling.

[0078] 4. The aqueous phase produced during the reaction is recovered and recycled.

[0079] Example 2

[0080] 1. Using methane, ethylene and water vapor as raw materials, adjust the molar ratio of water molecules to carbon atoms to 1.5:1, and pass them into the gas premixing and preheating device for premixing and preheating to ensure that the raw material temperature reaches 650°C before entering the reforming reactor. Using a nickel-based catalyst, at a pressure of 0.5 MPa, the reaction generates synthesis gas (H2 / CO=2.5).

[0081] 2. The cooled, dehydrated and purified synthesis gas is fed into a Fischer-Tropsch synthesis reactor and reacted at 270°C and 3.0 MPa using an iron-based catalyst to produce oil products and chemicals.

[0082] 3. The reaction products are separated by hot traps and cold traps, and the liquid products are paraffin, diesel, gasoline, oxygen-containing compounds and water. 50% of the gaseous products are recycled, among which 25% of the unreacted purified synthesis gas is mixed with the synthesis gas and pressurized before re-entering the Fischer-Tropsch synthesis reactor for conversion, and the other 25% of the C1-C4 hydrocarbons is mixed with the newly added low-carbon hydrocarbon (C1-C4 hydrocarbon) feed gas and returned to the reforming reactor through the premixing preheater for reforming.

[0083] 4. The aqueous phase produced during the reaction is recovered and recycled.

[0084] The above embodiments are only intended to help understand the method and core concept of the present invention. It should be noted that, without departing from the principles of the present invention, a number of improvements and modifications may be made to the present invention by those skilled in the art, and such improvements and modifications also fall within the scope of protection of the claims of the present invention.

Claims

1. A water-saving process for producing oils / chemicals by reforming low-carbon hydrocarbons combined with Fischer-Tropsch synthesis, characterized in that: The following steps are involved: (1) mixing a mixture of C1-C4 hydrocarbons and water vapor with a first catalyst for reforming reaction to obtain a synthesis gas containing CO, H2 and water vapor, wherein the temperature of the mixture is 400°C-650°C, and the molar ratio of CO to H2 in the synthesis gas is (1-3):1; (2) cooling and purifying the synthesis gas and removing water to obtain purified synthesis gas; (3) mixing the purified synthesis gas with a second catalyst to perform a Fischer-Tropsch synthesis reaction to generate relevant products; (4) separating the product through a hot trap and a cold trap to obtain Fischer-Tropsch wax, an oil phase, an aqueous phase, and a gas phase; (5) The water described in step (2) and the aqueous phase described in step (4) are converted into steam and circulated to step (1) as a reaction raw material, and the gas phase described in step (4) is circulated to the Fischer-Tropsch synthesis unit and the reforming reaction unit respectively, and the remaining gas phase is emptied.

2. The water-saving process according to claim 1, characterized in that The heat trap separation includes a first heat trap separation and a second heat trap separation; The temperature of the first heat trap separation is 180°C-220°C; The temperature of the second heat trap separation is 100°C-160°C.

3. The water-saving process according to claim 1, characterized in that The molar ratio of C1-C4 hydrocarbon to water vapor in step (1) is 1:(0.5-7).

4. The water-saving process according to claim 1, characterized in that: In the step (1), the first catalyst is selected from one or more of a noble metal-based catalyst, a non-noble metal-based catalyst and a composite oxide-supported catalyst.

5. The water-saving process according to claim 1, characterized in that: The noble metal in the noble metal-based catalyst is selected from Rh, Ru, Pt, Pd or Ir; The non-noble metal in the non-noble metal-based catalyst is selected from Ni, Co or Fe; The composite oxide in the composite oxide supported catalyst is selected from LaNiO3 or SrTiO3.

6. The water-saving process according to claim 1, characterized in that: The temperature of the reforming reaction in step (1) is 600° C.-950° C.; The pressure of the reforming reaction is 0-3.0 MPa.

7. The water-saving process according to claim 1, characterized in that: The second catalyst in step (3) is selected from Fe-based catalysts, Co-based catalysts or Ru-based catalysts.

8. The water-saving process according to claim 1, characterized in that: The temperature of the Fischer-Tropsch synthesis reaction in step (3) is 180° C.-400° C.; The pressure of the Fischer-Tropsch synthesis reaction is 0-5.0 MPa.

9. The water-saving process according to claim 1, characterized in that: The total circulation amount of the gas phase in step (5) accounts for 0%-100% of the total amount of the gas phase.

10. The water-saving process according to claim 1, characterized in that: The equipment used in the water-saving process includes a safety explosion-proof system, an air cooling device, and a liquid level controller.

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