Non-catalytic and catalytic coupled synthesis gas preparation device and application thereof in preparation of synthesis gas

Abstract

The invention discloses a non-catalytic and catalytic coupling synthesis gas preparation device and application thereof to synthesis gas preparation, the device comprises a non-catalytic reactor, a catalytic reactor, a pre-catalytic reactor, a waste heat boiler, a plurality of heat exchangers, a connecting pipeline and the like, and the pre-catalytic reactor is also provided with a heat exchanger structure; a pre-catalytic reaction cavity is arranged between a cold end inlet and a hot end outlet of the pre-catalytic reactor; the heat exchanger is used for preheating oxygen and part of raw materials and feeding into the non-catalytic reactor; the rest of the raw materials are preheated again and then fed into the pre-catalytic reactor and the non-catalytic reactor, reactants of the pre-catalytic reactor are fed into the catalytic reactor for continuous reaction, reactants of the catalytic reactor are used for supplying heat to the pre-catalytic reactor, the heat exchanger and the waste heat boiler, and the waste heat boiler can be used for preparing raw material steam; and heat balance adjustment of the whole device can also be participated. The device is high in heat utilization rate and conversion rate, can adjust the hydrogen-carbon ratio of the synthesis gas, and is particularly suitable for preparing methanol synthesis gas from natural gas and the like.

Description

Technical Field

[0001] This invention relates to the fields of energy chemical engineering and catalytic reaction engineering, and in particular to an apparatus for the non-catalytic and catalytic coupling of natural gas to produce syngas. Background Technology

[0002] Natural gas is a clean fossil fuel primarily composed of methane and is one of the most economical raw materials for producing syngas. Syngas, a key feedstock in chemical processes such as methanol, ammonia synthesis, and Fischer-Tropsch synthesis, consists of hydrogen (H2) and carbon monoxide (CO). Generally, natural gas can be used to produce syngas through processes such as partial oxidation (POX), steam reforming (SMR), and autothermal reforming (ATR). Taking methanol syngas as an example, the main technical routes for producing methanol syngas from natural gas include non-catalytic conversion and catalytic conversion. Furthermore, the methanol syngas produced must meet the hydrogen-to-carbon ratio requirement, i.e., (H2-CO2) / (CO+CO2) = 2.05.

[0003] As a common non-catalytic conversion process, POX mainly converts natural gas into methanol syngas (H2+CO) through incomplete combustion. However, the methanol syngas produced by this method has a low hydrogen-to-carbon ratio, requiring the introduction of shift and decarbonization units to adjust the hydrogen-to-carbon ratio to meet the conditions for methanol production. In contrast, methanol syngas produced via catalytic conversion has a higher hydrogen-to-carbon ratio, and researchers are currently combining SMR and ATR to optimize the process. However, while optimizing the methanol syngas ratio, this method also introduces some new technical problems: firstly, the catalytic reaction requires a large amount of additional steam, and the large catalyst loading leads to high energy consumption in methanol synthesis and distillation; secondly, the high carbon dioxide content in the produced methanol syngas reduces methanol synthesis efficiency; and thirdly, the SMR process involves external heating through the combustion of natural gas, which produces carbon dioxide and nitrogen oxides (NOx). X The emissions of these substances contribute to the greenhouse effect and harm the ecological environment.

[0004] Chinese patent CN112533890A discloses a method for producing methanol, involving separating a methane feed stream into a first methane feed stream and a second methane feed stream. The first methane feed stream, an oxidant, and carbon dioxide produced from natural gas combustion are then fed into a burner to generate a heated gas stream containing a mixture of carbon dioxide and water vapor at 1200°C–1800°C. This heated gas stream and the second methane feed stream are then fed into a reformer for a reforming reaction to produce methanol synthesis gas. However, this method relies on the complete oxidation of the first methane feed stream to provide heat and water vapor for the catalytic reforming stage, while the production of methanol synthesis gas depends entirely on the catalytic reforming of the second methane feed stream. In other words, it does not address reducing the catalytic reaction and its steam consumption, nor does it consider recovering the heat from the product for preheating the feedstock.

[0005] Chinese patent CN106431834A discloses a combined conversion method for methanol production, achieving large-scale methanol production through a single-line process integrating a gas heating converter (GHR), a steam methane converter (SMR), and a partial oxidation converter (POX). The method involves splitting the feedstock into a first feed stream and a second feed stream. The first feed stream is mixed with steam and fed into the GHR and SMR operating in series. The second feed stream is mixed with converted gas from the SMR and fed into the POX along with oxygen. However, this method uses a 45:55 volume ratio of the first feed stream used for catalytic conversion to the second feed stream used for non-catalytic conversion, which does not significantly reduce the catalytic reaction and its steam consumption. Furthermore, the non-catalytic conversion effluent is only used for heat exchange, without steam recovery. Additionally, the SMR uses fuel gas for heating, resulting in fuel gas emissions that require desulfurization.

[0006] In summary, current syngas production technologies still suffer from drawbacks such as high consumption of materials like steam and catalysts. Furthermore, the greenhouse gases and harmful gases emitted during production also pose environmental risks. Therefore, there is an urgent need to develop a syngas production device suitable for a new syngas production technology. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a non-catalytic and catalytic coupled syngas production device and its application in syngas production. By improving the device composition, the non-catalytic conversion reaction and the catalytic conversion reaction are highly coupled, the use of reaction energy in the whole device is optimized, and the reaction device is more stable, reliable and easy to adjust.

[0008] The technical solution adopted by this invention to solve its technical problem is: a non-catalytic and catalytic coupled syngas production device, including a non-catalytic reactor and a catalytic reactor, and further including connecting pipelines and matching control valves, a pre-catalytic reactor, a waste heat boiler, and four heat exchangers, namely heat exchanger No. 1, heat exchanger No. 2, heat exchanger No. 3, and heat exchanger No. 4. The pre-catalytic reactor has the structure of a heat exchanger. Heat exchanger No. 1 is a raw material preheater. The raw material inlet is connected to the cold end inlet of heat exchanger No. 1. The hot end outlet of heat exchanger No. 1 is connected to the cold end inlet of heat exchanger No. 2. The hot end outlet of heat exchanger No. 2 is connected to the raw material inlet of the non-catalytic reactor and the cold end inlet of heat exchanger No. 3. The hot end outlet of heat exchanger No. 3 is connected to the pre-catalytic reactor. The cold end inlet of the reactor, the reactant outlet of the non-catalytic reactor, and the hot end outlet of the pre-catalytic reactor are all connected to the feed inlet of the catalytic reactor. The cold end inlet and hot end outlet of the pre-catalytic reactor are arranged as a pre-catalytic reaction chamber. The reactant outlet of the catalytic reactor is connected to the hot end inlet of the pre-catalytic reactor. The cold end outlet of the pre-catalytic reactor is connected to the hot end inlet of heat exchanger No. 3. The cold end outlet of heat exchanger No. 3 is connected to the hot end inlet of heat exchanger No. 2. The cold end outlet of heat exchanger No. 2 is connected to the heat source inlet of the waste heat boiler. The steam outlet of the waste heat boiler is connected to the cold end inlet of heat exchanger No. 3 and the feed inlet of the non-catalytic reactor, respectively. Heat exchanger No. 4 is an oxygen preheater, and its oxygen outlet is connected to the feed inlet of the non-catalytic reactor.

[0009] In the aforementioned device, the heat generated by the oxidation reaction in the non-catalytic reactor is supplied to the pre-catalytic reactor and the catalytic reactor. The pre-catalytic reactor can fully absorb the heat of syngas to partially catalyze the raw materials. The products from the non-catalytic reactor and the uncatalyzed portion from the pre-catalytic reactor continue to react in the catalytic reactor, thus achieving a very high syngas conversion rate. The material temperature of each reactor is regulated by a waste heat boiler and multiple heat exchangers to ensure that each reactor is in a stable state. The choice between reducing oxygen consumption or increasing steam supply can be made as needed. Reducing oxygen consumption can increase the syngas yield, while increasing steam supply will increase oxygen consumption and reduce the syngas yield. The heat of syngas can be fully utilized. The catalyst operates at a relatively constant temperature, is not prone to pulverization and deactivation, and has a significantly extended service life. In the later stages of the catalyst's life, the reaction temperature can be appropriately increased to maintain a high conversion rate. The gas flow rate, temperature, and composition in the device can always be maintained at a relatively constant state, which is beneficial to the stable production of downstream production units.

[0010] Preferably, the hot end inlet of the No. 1 heat exchanger is connected to the heat source outlet of the waste heat boiler, and the cold end outlet of the No. 1 heat exchanger is the synthesis gas outlet of the unit. That is, the synthesis gas from the No. 2 heat exchanger is sent to the No. 1 heat exchanger for preheating the raw materials.

[0011] Alternatively, the hot end inlet of heat exchanger No. 1 can be connected to the steam outlet of waste heat boiler, and the heat source outlet of waste heat boiler is the syngas outlet of the unit. That is, the steam generated by waste heat boiler is sent to heat exchanger No. 1 for preheating raw materials, and the syngas exiting heat exchanger No. 2 is sent to waste heat boiler to generate steam. The heat utilization rate is slightly lower than the aforementioned syngas preheating raw material scheme.

[0012] The present invention also provides the use of the above-described non-catalytic and catalytic coupled syngas production apparatus for producing syngas.

[0013] The applicable syngas production processes include methanol syngas produced from natural gas, ammonia syngas produced from coke oven gas, and hydrogen syngas produced from refinery dry gas.

[0014] The beneficial effects of this invention are as follows: In the above-mentioned device, the raw materials enter the pre-catalytic reactor and the non-catalytic reactor respectively. By adjusting the ratio of raw materials entering the pre-catalytic reactor and the non-catalytic reactor, the hydrogen-carbon ratio of the syngas can be adjusted, achieving heat balance throughout the catalyst's life cycle and maintaining a high conversion rate. The device does not produce greenhouse gases that need to be emitted. The waste heat boiler can not only be used to prepare raw material steam, but also participate in the regulation of the overall heat balance of the device, which is beneficial to stably control each reactor at a suitable reaction temperature and maintain the reaction in each reactor in a stable state, which is beneficial to the control of subsequent syngas treatment processes. Attached Figure Description

[0015] Figure 1 This is a process flow diagram of a non-catalytic and catalytic coupling process for producing syngas from hydrocarbon feed gas, provided in an embodiment of this application.

[0016] Figure 2 This is a schematic diagram of the non-catalytic and catalytic coupled syngas production apparatus of the present invention.

[0017] Figure 3 This is a schematic diagram of another embodiment of the non-catalytic and catalytic coupled syngas production device of the present invention.

[0018] The diagram is labeled as follows: 1-Heat exchanger No. 1, 2-Heat exchanger No. 2, 3-Heat exchanger No. 3, 4-Heat exchanger No. 4, 5-Oxygen inlet pipe, 6-Non-catalytic reactor, 7-Pre-catalytic reactor, 8-Catalytic reactor, 9-Waste heat boiler, 10-Steam main pipe, 11-Synthesis gas outlet pipe.

[0019] Note: In this specification, "raw material inlet" refers to the overall raw material inlet of the device, while "raw material outlet" refers to the raw material inlet of the reactor. Detailed Implementation

[0020] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] like Figure 2 As shown, the non-catalytic and catalytic coupled synthesis gas production apparatus of the present invention completes the synthesis of methanol from natural gas. The apparatus includes a non-catalytic reactor 6 and a catalytic reactor 8, as well as connecting pipelines and associated control valves, a pre-catalytic reactor 7, a waste heat boiler 9, and four heat exchangers: heat exchanger 1, heat exchanger 2, heat exchanger 3, and heat exchanger 4. The pre-catalytic reactor 7 has the structure of a heat exchanger, and its feed inlet is a natural gas inlet. The natural gas used should have undergone conventional treatment such as desulfurization.

[0022] The raw material inlet is connected to the cold end inlet of heat exchanger 1. The hot end outlet of heat exchanger 1 is connected to the cold end inlet of heat exchanger 2. The hot end outlet of heat exchanger 2 is connected to the raw material inlet of non-catalytic reactor 6 and the cold end inlet of heat exchanger 3. The hot end outlet of heat exchanger 3 is connected to the cold end inlet of pre-catalytic reactor 8. The reactant outlet of non-catalytic reactor 6 and the hot end outlet of pre-catalytic reactor 7 are both connected to the raw material inlet of catalytic reactor 8. A pre-catalytic reaction chamber is arranged between the cold end inlet and the hot end outlet of pre-catalytic reactor 7. The pre-catalytic reaction chamber is filled with the catalyst required to promote the reaction. The reactant outlet of catalytic reactor 8... The outlet of the pre-catalytic reactor 7 is connected to the hot end inlet of the pre-catalytic reactor 7. The cold end outlet of the pre-catalytic reactor 7 is connected to the hot end inlet of the No. 3 heat exchanger 3. The cold end outlet of the No. 3 heat exchanger 3 is connected to the hot end inlet of the No. 2 heat exchanger 2. The cold end outlet of the No. 2 heat exchanger 2 is connected to the heat source inlet of the waste heat boiler 9. The heat source outlet of the waste heat boiler 9 is connected to the hot end inlet of the No. 1 heat exchanger 1. The cold end outlet of the No. 1 heat exchanger 1 is the synthesis gas outlet of the unit. The steam outlet of the waste heat boiler 9 is connected to the cold end inlet of the No. 3 heat exchanger 3, the raw material inlet of the non-catalytic reactor 6, and the hot end inlet of the No. 4 heat exchanger 4. The hot end outlet of the No. 4 heat exchanger 4 is connected to the raw material inlet of the non-catalytic reactor 6.

[0023] The process of the non-catalytic and catalytic coupled synthesis gas production apparatus of the present invention for producing methanol synthesis gas from natural gas is as follows.

[0024] The preheated natural gas is split into a first feedstock gas and a second feedstock gas. The first feedstock gas and preheated oxygen are fed into a non-catalytic reactor 6 for a non-catalytic conversion reaction to produce a first syngas. The second feedstock gas and added steam are fed into a pre-catalytic reactor 7 for a pre-catalytic conversion reaction to produce a second syngas. The first and second syngas are then fed into a catalytic reactor 8 for a catalytic conversion reaction to produce a third syngas. The heat from the third syngas is recovered to obtain methanol syngas. This heat recovery is achieved through the pre-catalytic reactor, various heat exchangers, and a waste heat boiler. Syngas meeting the hydrogen-to-carbon ratio requirements for subsequent synthesis is sent out of the boundary area after heat recovery from the preheated feedstock gas.

[0025] The start-up process is as follows: For the initial start-up, a small amount of raw material natural gas or other hydrocarbon-containing gases are introduced as fuel through the furnace-baking function of the integrated burner (not the conventional configuration of a catalytic converter). This is ignited with the aid of oxygen, slowly raising the system temperature at a rate of 30°C / hour. For every 150°C increase, a 48-hour pause is applied until the system reaches 450°C. (No pause is required for subsequent start-ups). Once the unit stabilizes at 450°C (at which point the waste heat boiler has already produced steam), natural gas or other hydrocarbon-containing gases at 30% of the rated load are introduced, along with proportionally added steam. The system temperature continues to rise until it reaches the operating temperature of each reactor. At this point, a load increase operation is performed, adding natural gas first, followed by oxygen. After each increase, the entire unit temperature must reach the target and stabilize (the amount added should not exceed 10% of the rated load). This process is repeated until the system reaches its rated load.

[0026] In this invention, heat exchanger 4 is an oxygen preheater. Its heat source is saturated steam produced by a waste heat boiler. The oxygen is preheated and then introduced into the non-catalytic reactor. The heat released by the reaction is provided to the catalytic reactor and the pre-catalytic reactor along with the flow of reactants to maintain the catalytic reaction temperature. The pre-catalytic reactor has a heat exchanger structure. Its heat-absorbing medium cavity can be filled with catalyst to complete part of the catalytic reaction of the raw materials. Its heat-releasing medium cavity serves as a synthesis gas channel. Because of the partial catalytic reaction, the non-catalytic reactor can absorb more heat than conventional heat exchangers with a smaller overall structure. The remaining heat is used to generate steam through the waste heat boiler. The steam is then sent to the pre-catalytic reactor and the non-catalytic reactor as raw materials to generate synthesis gas. The steam that cannot be completely reacted in the pre-catalytic reactor can enter the catalytic reactor to continue the reaction. The heat of the synthesis gas can also be used to preheat the raw material gas or oxygen through other heat exchangers.

[0027] Specifically, in heat exchanger No. 1, the feed gas is initially preheated by low-temperature syngas; in heat exchanger No. 2, the feed gas is preheated again by medium-temperature syngas; in the non-catalytic reactor, the preheated feed gas natural gas and oxygen undergo partial oxidation to produce process gases such as hydrogen, carbon monoxide, and carbon dioxide. The oxidation reaction generates partial syngas that carries the heat of the system, which can promote the catalytic reaction in the catalytic reactor.

[0028] In the precatalytic reactor, preheated feedstock natural gas and added steam undergo a methane steam reforming reaction to produce process gases such as hydrogen, carbon monoxide, and carbon dioxide. The purpose of setting up a precatalytic reactor is to pre-process part of the catalytic conversion, thereby reducing the workload of the catalytic conversion. More importantly, it maximizes the utilization of the heat of the syngas through the heat absorption of the conversion process. Theoretically, a heat exchanger could also achieve the purpose of heat recovery, but due to the high temperature and large temperature difference of the syngas, it is extremely difficult to select a suitable heat exchanger. Using this type of reactor provides better heat exchange and reduces the load on the main catalytic reactor.

[0029] In the catalytic reactor, a catalytic conversion reaction occurs, converting all the unreacted methane. Because the syngas produced by catalytic conversion has a high hydrogen-to-carbon ratio, it neutralizes the problem of the low hydrogen-to-carbon ratio in the syngas produced by the non-catalytic conversion upstream. All the energy required for catalytic conversion is provided by the non-catalytic conversion, thus achieving the coupling of energy and materials.

[0030] The waste heat from the syngas exiting the pre-catalytic reactor is used to heat the steam in the waste heat boiler. The cold end temperature of heat exchanger No. 3 is higher than the hot end temperature of heat exchangers No. 1 and No. 2. The syngas exiting heat exchanger No. 2 enters the waste heat boiler to heat the boiler water to generate saturated steam. The saturated steam can be added to the pre-catalytic reactor as a reaction feedstock, or it can be fed into the non-catalytic reactor to improve the syngas conversion rate of the non-catalytic reactor. Moreover, the heat is utilized in multiple stages, resulting in high heat exchange efficiency, high energy utilization, and easy control and adjustment of the reaction temperature and conversion rate of each reactor.

[0031] Example 1:

[0032] A non-catalytic and catalytic coupled process for producing syngas from hydrocarbon feedstock gas, using natural gas as feedstock to produce methanol syngas, is shown in the attached process flow diagram. Figure 1 As shown, the specific steps include:

[0033] (S1) The preheated raw material gas is split into the first raw material gas and the second raw material gas;

[0034] In this embodiment, natural gas can be used as the feed gas. As shown in Table 1, the components of the feed gas include CH4, C2H6, C3H8, CO2, and N2, with CH4 having the highest volume percentage at 96.5%. The preheated feed gas is split into a first feed gas and a second feed gas at a volume ratio of 3.094:1. By adjusting the ratio of the first and second feed gas, the non-catalytic conversion reaction rate and the catalytic conversion reaction rate can be controlled. Before the reaction begins, the furnace is ignited and heated to 450°C using an integrated burner configured in the non-catalytic reactor. Subsequently, the feed gas is introduced for ignition and heating. After the reaction begins, the feed gas can be preheated twice using the heat recovered in step (S5), such as... Figure 2As shown, the raw gas passes through heat exchanger No. 1 and heat exchanger No. 2 in sequence. The first preheating through heat exchanger No. 1 brings the raw gas to about 220°C, and the second preheating through heat exchanger No. 2 raises the raw gas temperature from 220°C to 500-550°C.

[0035] (S2) The first raw material gas, water vapor and preheated oxygen are introduced into a non-catalytic reactor to carry out a non-catalytic conversion reaction to generate the first synthesis gas.

[0036] In this embodiment, the first raw material gas, water vapor, and preheated oxygen are continuously added to a non-catalytic reactor at a volume ratio of oxygen to the first raw material gas of 0.603:1 and a volume ratio of water vapor to the first raw material gas of 0.281:1. The reaction temperature is controlled at 1300℃±50℃ and the pressure at 3MPaG±1MPaG to carry out a non-catalytic conversion reaction and generate the first synthesis gas. Figure 2 As shown, the first raw material gas passes through heat exchanger 1 and heat exchanger 2 before being introduced into reactor 6 (non-catalytic reactor). Steam is generated by waste heat boiler 9 and introduced into reactor 6 (non-catalytic reactor) via steam main pipe 10. Oxygen is introduced through oxygen inlet pipe 5, preheated by heat exchanger 4, and then introduced into reactor 6 (non-catalytic reactor). The temperature of the first synthesis gas is 1300℃±50℃. The non-catalytic conversion reactions include oxidation reaction (reaction 1), conversion reaction (reactions 2 and 3), and shift reaction (reaction 4); the conversion rate of the non-catalytic conversion reactions is ≥99.9%.

[0037] CH4 + 3 / 2O2 → CO + 2H2O (Reaction 1)

[0038] CH4 + H2O → CO + 3H2 (Reaction 2)

[0039] CH4 + CO2 → 2CO + 2H2 (Reaction 3)

[0040] CO + H₂O → CO₂ + H₂ (Reaction 4)

[0041] Before the reaction begins, the non-catalytic reactor can be preheated by igniting the feed gas in the non-catalytic converter, raising the temperature to above 1000℃. After the reaction begins, the reaction temperature in the non-catalytic reactor is controlled at 1300℃±50℃, mainly maintained by the exothermic reaction; simultaneously, the heat in the non-catalytic converter can be transferred to other reactors for heat supply, maximizing the utilization of the system's internal heat. The oxygen in this step can be preheated using the heat recovered in step (S5), such as... Figure 2 As shown, oxygen is introduced through 5-Oxygen inlet pipe, and then passes through 4-Heat exchanger No. 4 to reach 220°C; the water vapor in this step can also be formed using the heat recovered in step (S5), such as... Figure 2 As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam, which is then introduced into the 6-non-catalytic reactor via the 10-steam main pipe for reaction. The preheating operation can shorten the start time of the non-catalytic conversion reaction. As shown in Table 2, O2 accounts for 99.6% of the volume of oxygen; the components of the first syngas include H2, CO, CO2, CH4, N2, and water vapor, with H2 and CO being the main components, accounting for 52.96% and 25.6% of the volume, respectively. Water vapor accounts for 18.29% of the first syngas, and CO2 accounts for 2.76%. Using the formula: hydrogen-to-carbon ratio = (H2-CO2) / (CO+CO2), the hydrogen-to-carbon ratio of the first syngas is calculated to be 1.77, which is low and does not meet the material ratio requirements for methanol synthesis.

[0042] (S3) The second raw material gas and the added water vapor are fed into the pre-catalytic reactor to carry out a pre-catalytic conversion reaction to generate the second syngas;

[0043] In this embodiment, the added steam and the second feed gas are prepared according to an H2O / C molar ratio of 2.745:1. The second feed gas and the added steam are continuously added to the pre-catalytic reactor, and the reaction temperature is controlled at 700℃±50℃ and the pressure at 3MPaG±1MPaG to carry out the pre-catalytic conversion reaction and generate the second syngas. Figure 2 As shown, the second raw material gas passes through heat exchanger 1 and heat exchanger 2, then through heat exchanger 3 before entering the pre-catalytic reactor 7. The supplementary steam is generated by waste heat boiler 9 and enters the pre-catalytic reactor 7 through heat exchanger 3. The temperature of the second synthesis gas is 700℃±50℃. The pre-catalytic conversion reaction includes a conversion reaction (reaction 5) and a shift reaction (reaction 6); the conversion rate of the pre-catalytic conversion reaction is 50%±5%.

[0044] CH4 + H2O → CO + 3H2 (Reaction 5)

[0045] CO + H₂O → CO₂ + H₂ (Reaction 6)

[0046] Before the reaction begins, the pre-catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the pre-catalytic reactor is controlled at 700℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The water vapor added in this step can be generated from the heat recovered in step (S5), such as... Figure 2As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam. This steam is then fed into the 7-precatalytic reactor via the 3-No. 3 heat exchanger for reaction. Since the temperature of the second feed gas may decrease after mixing with the added steam, the 3-No. 3 heat exchanger can be used to reheat the second feed gas to 500–550°C. This preheating operation can shorten the start time of the precatalytic conversion reaction. As shown in Table 3, the components of the second syngas include H2, CO, CO2, CH4, N2, and steam. The volume percentages of H2 and CO are 32.87% and 2.45%, respectively; steam accounts for 48.14% of the second syngas volume; CH4 accounts for 9.96%; and CO2 accounts for 6.48%. Using the following formula: hydrogen-carbon ratio = (H2-CO2) / (CO+CO2), the hydrogen-carbon ratio of the second syngas is calculated to be 2.96. This high hydrogen-carbon ratio can balance the low hydrogen-carbon ratio of the first syngas produced by the above non-catalytic conversion reaction.

[0047] (S4) The first syngas and the second syngas are fed into a catalytic reactor to carry out a catalytic conversion reaction to obtain the third syngas;

[0048] In this embodiment, the first syngas and the second syngas are continuously added to the catalytic reactor at a volume ratio of 2.163:1. The reaction temperature is controlled at 950℃±50℃ and the pressure at 3MPaG±1MPaG for further catalytic conversion, so that all unreacted CH4 is converted to generate the third syngas. Figure 2 As shown, the first syngas in reactor 6 (non-catalytic reactor) and the second syngas in reactor 7 (pre-catalytic reactor) are simultaneously fed into reactor 8 (catalytic reactor) to react and produce the third syngas. The temperature of the third syngas is ≥900℃. The catalytic conversion reaction includes a conversion reaction (reaction 7) and a shift reaction (reaction 8); the conversion rate of the catalytic conversion reaction is ≥90%.

[0049] CH4 + H2O → CO + 3H2 (Reaction 7)

[0050] CO + H₂O → CO₂ + H₂ (Reaction Equation 8)

[0051] Before the reaction begins, the catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the catalytic reactor is controlled at 950℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The preheating operation can shorten the start time of the catalytic conversion reaction. As shown in Table 4, the components of the third syngas include H2, CO, CO2, CH4, N2, and water vapor. The volume percentages of H2 and CO are 53.44% and 19.29%, respectively, water vapor accounts for 22.38%, CH4 accounts for 0.19%, and CO2 accounts for 4.54%. Using the following formula: hydrogen-to-carbon ratio = (H2-CO2) / (CO+CO2), the hydrogen-to-carbon ratio of the third syngas is calculated to be 2.05, which meets the material ratio requirements for subsequent methanol synthesis.

[0052] (S5) The heat of the third synthesis gas is recovered to obtain synthesis gas.

[0053] In this embodiment, the synthesized gas is methanol synthesis gas. Because the third synthesis gas has a high temperature (≥900℃) and contains a high amount of heat, it can be recovered for preheating of the feedstock gas and oxygen, as well as for the formation of water vapor. Figure 2 As shown, in this step, the third synthesis gas is sequentially fed into 7-pre-catalytic reactor, 3-heat exchanger No. 3, 2-heat exchanger No. 2, 9-waste heat boiler, and 1-heat exchanger No. 1 for heat recovery to obtain methanol synthesis gas.

[0054] In this process, the heat recovered by the pre-catalytic reactor (7) can be used for the pre-catalytic conversion reaction in step (S3); the heat recovered by the No. 3 heat exchanger can reheat the second feed gas in step (S3) to 500-550℃; the heat recovered by the No. 2 heat exchanger can be used for the secondary preheating of the feed gas in step (S1); the waste heat boiler performs process cooling, and the recovered heat is used to turn boiler water into steam. The generated steam can be used in steps (S2) and (S3) to participate in the reaction, or it can be used for the preheating of oxygen in step (S2), finally forming steam condensates; the heat recovered by the No. 1 heat exchanger can be used for the primary preheating of the feed gas in step (S1). In this embodiment, the third synthesis gas has the same composition and content as the final methanol synthesis gas, only differing in temperature, with the temperature of the third synthesis gas being higher than that of the methanol synthesis gas. Therefore, the hydrogen-to-carbon ratio of the methanol synthesis gas is consistent with that of the third synthesis gas, satisfying the material ratio conditions for subsequent methanol synthesis. The methanol synthesis gas after heat recovery is sent out of the boundary area.

[0055] The reaction processes in step (S2) and step (S3) are carried out simultaneously.

[0056] Among them, non-catalytic conversion reactions provide heat for catalytic conversion reactions and pre-catalytic conversion reactions, including:

[0057] (a) The heat generated by the non-catalytic conversion reaction is transferred to the catalytic reactor via the first syngas to provide primary heat for the catalytic conversion reaction;

[0058] (b) The unused primary heat from the catalytic conversion reaction is transferred to the pre-catalytic reactor via the third syngas to provide secondary heat for the pre-catalytic conversion reaction.

[0059] In this embodiment, a non-catalytic and catalytic coupling process for producing syngas from hydrocarbon feed gas is used. The syngas produced is methanol syngas. The hydrogen-to-carbon ratio of the methanol syngas is controlled by adjusting the volume ratio of the first feed gas to the second feed gas. The hydrogen-to-carbon ratio of the methanol syngas is not less than 2.05.

[0060] Throughout the preparation process, the addition of raw materials and the output of methanol syngas are continuous. In the non-catalytic reactor, the gas flow rate is fixed at 0.85 m / s ± 0.05 m / s, with the first raw material gas, water vapor, and preheated oxygen continuously added, and the first syngas continuously output. In the pre-catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the second raw material gas and supplemented water vapor continuously added, and the second syngas continuously output. In the catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the first and second syngas continuously input, and the third syngas continuously output. The third syngas undergoes heat recovery to continuously produce methanol syngas.

[0061] In this embodiment, methanol synthesis gas meeting the hydrogen-to-carbon ratio condition was prepared from natural gas by coupling non-catalytic conversion and catalytic conversion, while the heat of the product was recovered, resulting in a very high degree of heat recovery and utilization of the reaction system. Table 2 details the raw material and product components of the non-catalytic conversion reaction, Table 3 details the raw material and product components of the pre-catalytic conversion reaction, and Table 4 details the raw material and product components of the catalytic conversion reaction.

[0062] Table 1 Natural Gas Components

[0063]

[0064] Table 2. Components of feedstocks and products in non-catalytic conversion reactions

[0065]

[0066] Table 3. Components of feedstocks and products in the precatalytic conversion reaction

[0067]

[0068] Table 4. Components of feedstocks and products in catalytic conversion reaction

[0069]

[0070] This embodiment uses a non-catalytic and catalytic coupled process route to prepare methanol synthesis gas, and further synthesize methanol. The consumption of common engineering works at each stage is statistically analyzed, as shown in Table 5. Table 5 shows that the total oxygen consumption of the coupled process, methanol synthesis, and methanol distillation in the entire methanol preparation process is 6496 Nm³. 3 The total power consumption is 6398 kW·h, of which the coupled process generates only 260 kW·h of power. The steam consumption includes 4.0 t / h, 2.5 t / h, and 0.5 t / h, which are consumed at 2.0 t / h, -24.0 t / h, and 27.2 t / h, respectively, of which the coupled process generates only 2.0 t / h of steam. The total boiler water consumption is 33.2 t / h, of which the coupled process consumes 9.2 t / h. The total demineralized water consumption is 9.2 t / h, all of which is generated by the coupled process. The total circulating cooling water consumption is 1075 t / h.

[0071] Therefore, it can be seen that the oxygen consumption and electricity consumption generated in the methanol production process of this invention via the non-catalytic and catalytic coupled process route are 6496 Nm³, respectively. 3 / h and 6398kw.h.

[0072] Table 5. Public works consumption for methanol production via non-catalytic and catalytic coupled processes.

[0073] Example 2:

[0074] A non-catalytic and catalytic coupled process for producing syngas from hydrocarbon feedstock gas, using coke oven gas as feedstock to prepare ammonia syngas, is illustrated in the attached process flow diagram. Figure 1 As shown, the specific steps include:

[0075] (S1) The preheated raw material gas is split into the first raw material gas and the second raw material gas;

[0076] In this embodiment, coke oven gas can be used as the feed gas. As shown in Table 6, the components of the feed gas include CH4, C2H6, CO, CO2, H2, O2, and N2, with H2 having the highest volume percentage at 60.6%. The preheated feed gas is split into a first feed gas and a second feed gas at a volume ratio of 2.125:1. The non-catalytic conversion reaction rate and the catalytic conversion reaction rate can be controlled by adjusting the ratio of the first and second feed gas. Before the reaction begins, the furnace is ignited and heated to 450°C using an integrated burner configured in the non-catalytic reactor. Then, the feed gas is introduced for ignition and heating. After the reaction begins, the feed gas can be preheated twice using the heat recovered in step (S5), such as... Figure 2As shown, the raw gas passes through heat exchanger No. 1 and heat exchanger No. 2 in sequence. The first preheating through heat exchanger No. 1 brings the raw gas to about 220°C, and the second preheating through heat exchanger No. 2 raises the raw gas temperature from 220°C to 500-550°C.

[0077] (S2) The first raw material gas, water vapor and preheated oxygen are introduced into a non-catalytic reactor to carry out a non-catalytic conversion reaction to generate the first synthesis gas.

[0078] In this embodiment, the first raw material gas, water vapor, and preheated oxygen are continuously added to a non-catalytic reactor at a volume ratio of oxygen to the first raw material gas of 0.215:1 and a volume ratio of water vapor to the first raw material gas of 0.105:1. The reaction temperature is controlled at 1300℃±50℃ and the pressure at 3MPaG±1MPaG to carry out a non-catalytic conversion reaction and generate the first synthesis gas. Figure 2 As shown, the first raw material gas passes through heat exchanger 1 and heat exchanger 2 before being introduced into reactor 6 (non-catalytic reactor). Steam is generated by waste heat boiler 9 and introduced into reactor 6 (non-catalytic reactor) via steam main pipe 10. Oxygen is introduced through oxygen inlet pipe 5, preheated by heat exchanger 4, and then introduced into reactor 6 (non-catalytic reactor). The temperature of the first synthesis gas is 1300℃±50℃. The non-catalytic conversion reactions include oxidation reaction (reaction 1), conversion reaction (reactions 2 and 3), and shift reaction (reaction 4); the conversion rate of the non-catalytic conversion reactions is ≥99.9%.

[0079] CH4 + 3 / 2O2 → CO + 2H2O (Reaction 1)

[0080] CH4 + H2O → CO + 3H2 (Reaction 2)

[0081] CH4 + CO2 → 2CO + 2H2 (Reaction 3)

[0082] CO + H₂O → CO₂ + H₂ (Reaction 4)

[0083] Before the reaction begins, the non-catalytic reactor can be preheated by igniting the feed gas in the non-catalytic converter, raising the temperature to above 1000℃. After the reaction begins, the reaction temperature in the non-catalytic reactor is controlled at 1300℃±50℃, mainly maintained by the exothermic reaction; simultaneously, the heat in the non-catalytic converter can be transferred to other reactors for heat supply, maximizing the utilization of the system's internal heat. The oxygen in this step can be preheated using the heat recovered in step (S5), such as... Figure 2 As shown, oxygen is introduced through 5-Oxygen inlet pipe, and then passes through 4-Heat exchanger No. 4 to reach 220°C; the water vapor in this step can also be formed using the heat recovered in step (S5), such as... Figure 2 As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam, which is then introduced into the 6-non-catalytic reactor via the 10-steam main pipe for reaction. The preheating operation can shorten the start-up time of the non-catalytic conversion reaction. As shown in Table 7, O2 accounts for 99.6% of the volume of oxygen; the components of the first syngas include H2, CO, CO2, CH4, N2, and water vapor, with H2 and CO being the main components, accounting for 58.41% and 19.12% of the volume, respectively. Water vapor accounts for 18.53% of the volume of the first syngas, and CO2 accounts for 1.86% of the volume of the first syngas.

[0084] (S3) The second raw material gas and the added water vapor are fed into the pre-catalytic reactor to carry out a pre-catalytic conversion reaction to generate the second syngas;

[0085] In this embodiment, the added steam and the second feed gas are prepared at an H2O / C molar ratio of 2.5:1. The second feed gas and the added steam are continuously added to the pre-catalytic reactor, and the reaction temperature is controlled at 700℃±50℃ and the pressure at 3MPaG±1MPaG to carry out the pre-catalytic conversion reaction and generate the second syngas. Figure 2 As shown, the second raw material gas passes through heat exchanger 1 and heat exchanger 2, then through heat exchanger 3 before entering the pre-catalytic reactor 7. The supplementary steam is generated by waste heat boiler 9 and enters the pre-catalytic reactor 7 through heat exchanger 3. The temperature of the second synthesis gas is 700℃±50℃. The pre-catalytic conversion reaction includes a conversion reaction (reaction 5) and a shift reaction (reaction 6); the conversion rate of the pre-catalytic conversion reaction is 50%±5%.

[0086] CH4 + H2O → CO + 3H2 (Reaction 5)

[0087] CO + H₂O → CO₂ + H₂ (Reaction 6)

[0088] Before the reaction begins, the pre-catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the pre-catalytic reactor is controlled at 700℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The water vapor added in this step can be generated from the heat recovered in step (S5), such as... Figure 2As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam. This steam is then fed into the 7-precatalytic reactor via the 3-No. 3 heat exchanger for reaction. Since the temperature of the second feed gas may decrease after mixing with the added steam, the 3-No. 3 heat exchanger can be used to reheat the second feed gas to 500–550°C. This preheating operation can shorten the start time of the precatalytic conversion reaction. As shown in Table 8, the components of the second syngas include H2, CO, CO2, CH4, N2, and steam. The volume percentages of H2 and CO are 46.77% and 3.66%, respectively; steam accounts for 37.33% of the second syngas volume; CH4 accounts for 5.44%; and CO2 accounts for 5.27%.

[0089] (S4) The first syngas and the second syngas are fed into a catalytic reactor to carry out a catalytic conversion reaction to obtain the third syngas;

[0090] In this embodiment, the first syngas and the second syngas are continuously added to the catalytic reactor at a volume ratio of 1.669:1. The reaction temperature is controlled at 950℃±50℃ and the pressure at 3MPaG±1MPaG for further catalytic conversion, so that all unreacted CH4 is converted to generate the third syngas. Figure 2 As shown, the first syngas in reactor 6 (non-catalytic reactor) and the second syngas in reactor 7 (pre-catalytic reactor) are simultaneously fed into reactor 8 (catalytic reactor) to react and produce the third syngas. The temperature of the third syngas is ≥900℃. The catalytic conversion reaction includes a conversion reaction (reaction 7) and a shift reaction (reaction 8); the conversion rate of the catalytic conversion reaction is ≥90%.

[0091] CH4 + H2O → CO + 3H2 (Reaction 7)

[0092] CO + H₂O → CO₂ + H₂ (Reaction Equation 8)

[0093] Before the reaction begins, the catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the catalytic reactor is controlled at 950℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The preheating operation can shorten the start time of the catalytic conversion reaction. As shown in Table 9, the components of the third syngas include H2, CO, CO2, CH4, N2, and water vapor. The volume percentages of H2 and CO are 58.24% and 13.78%, respectively; water vapor accounts for 22.1% of the third syngas; CH4 accounts for 0.28%; and CO2 accounts for 3.86%.

[0094] (S5) The heat of the third synthesis gas is recovered to obtain synthesis gas.

[0095] In this embodiment, the synthesized gas is ammonia synthesis gas. Because the third synthesis gas has a high temperature (≥900℃) and contains a high amount of heat, it can be recovered for preheating of the feedstock gas and oxygen, as well as for the formation of water vapor. Figure 2 As shown, in this step, the third syngas is sequentially fed into 7-pre-catalytic reactor, 3-heat exchanger No. 3, 2-heat exchanger No. 2, 9-waste heat boiler, and 1-heat exchanger No. 1 for heat recovery to obtain syngas.

[0096] In this embodiment, the heat recovered by the pre-catalytic reactor (7) can be used for the pre-catalytic conversion reaction in step (S3); the heat recovered by the No. 3 heat exchanger can reheat the second raw material gas in step (S3) to 500-550℃; the heat recovered by the No. 2 heat exchanger can be used for the secondary preheating of the raw material gas in step (S1); the waste heat boiler performs process cooling, and the recovered heat is used to turn boiler water into steam. The generated steam can be used in steps (S2) and (S3) to participate in the reaction, or it can be used for the preheating of oxygen in step (S2), finally forming steam condensates; the heat recovered by the No. 1 heat exchanger can be used for the primary preheating of the raw material gas in step (S1). In this embodiment, the third synthesis gas has the same composition and content as the final synthesized ammonia, only differing in temperature, with the temperature of the third synthesis gas being higher than that of the ammonia synthesis gas. The synthesized ammonia gas after heat recovery is sent out of the boundary area.

[0097] The reaction processes in step (S2) and step (S3) are carried out simultaneously.

[0098] Among them, non-catalytic conversion reactions provide heat for catalytic conversion reactions and pre-catalytic conversion reactions, including:

[0099] (a) The heat generated by the non-catalytic conversion reaction is transferred to the catalytic reactor via the first syngas to provide primary heat for the catalytic conversion reaction;

[0100] (b) The unused primary heat from the catalytic conversion reaction is transferred to the pre-catalytic reactor via the third syngas to provide secondary heat for the pre-catalytic conversion reaction.

[0101] Throughout the preparation process, the addition of raw materials and the output of ammonia synthesis gas are continuous. In the non-catalytic reactor, the gas flow rate is fixed at 0.85 m / s ± 0.05 m / s, with the first raw material gas, water vapor, and preheated oxygen continuously added, and the first synthesis gas continuously output. In the pre-catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the second raw material gas and supplemented water vapor continuously added, and the second synthesis gas continuously output. In the catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the first and second synthesis gases continuously input, and the third synthesis gas continuously output. The third synthesis gas is then subjected to heat recovery to continuously produce ammonia synthesis gas.

[0102] In this embodiment, ammonia synthesis gas was prepared from coke oven gas by coupling non-catalytic conversion and catalytic conversion, while the heat of the products was recovered, resulting in a very high degree of heat recovery and utilization in the reaction system. Table 7 details the raw material and product components of the non-catalytic conversion reaction, Table 8 details the raw material and product components of the pre-catalytic conversion reaction, and Table 9 details the raw material and product components of the catalytic conversion reaction.

[0103] Table 6 Composition of Coke Oven Gas

[0104]

[0105] Table 7. Components of feedstocks and products in non-catalytic conversion reactions

[0106]

[0107] Table 8. Components of feedstocks and products in the precatalytic conversion reaction

[0108]

[0109] Table 9. Components of feedstocks and products in catalytic conversion reaction

[0110]

[0111] This embodiment uses a non-catalytic and catalytic coupled process route to prepare ammonia synthesis gas, and further prepares ammonia. The consumption of public works at each stage is statistically analyzed, as shown in Table 10. Table 10 shows that the total oxygen consumption in the entire ammonia synthesis process is 9493.7 Nm³. 3 The total power consumption is 11625.8 kW·h, of which the coupled process generates only 720 kW·h of power. The steam consumption includes 4.0 t / h and 0.5 t / h, which are consumed at -49.2 t / h and 13.8 t / h respectively, of which the coupled process generates only 10 t / h of steam. The total boiler water consumption is 81.5 t / h, of which the coupled process consumes 11.5 t / h. The total circulating cooling water consumption is 2973.1 t / h.

[0112] Therefore, it can be seen that the oxygen consumption and electricity consumption generated in the ammonia synthesis process of this invention via non-catalytic and catalytic coupled process routes are 9493.7 Nm³. 3 / h and 11625.8kw.h.

[0113] Table 10 Public works consumption for ammonia synthesis via non-catalytic and catalytic coupled processes.

[0114] Serial Number Public works unit coupling Transformation MDEA decarbonization Synthetic ammonia total 1 oxygen <![CDATA[Nm 3 / h]]> 9493.7 9493.7 2 nitrogen <![CDATA[Nm 3 / h]]> 29270.1 29270.1 3 electricity kw.h 720.0 1330.1 9575.7 11625.8 4 4.0 steam t / h 10.0 -19.6 -39.6 -49.2 5 0.5 steam t / h -9.1 22.9 13.8 6 Boiler water t / h 11.5 30.0 40.0 81.5 7 Circulating cooling water t / h 205.0 1009.0 1759.1 2973.1

[0115] Example 3:

[0116] A non-catalytic and catalytic coupled process for producing syngas from hydrocarbon feedstock gas, using refinery dry gas as feedstock to produce hydrogen syngas, is illustrated in the attached process flow diagram. Figure 1 As shown, the specific steps include:

[0117] (S1) The preheated raw material gas is split into the first raw material gas and the second raw material gas;

[0118] In this embodiment, refinery dry gas can be used as the feed gas. As shown in Table 11, the components of the feed gas include CH4, C2H6, C3H8, and C4H. 10 C5H 12 The feed gas consists of CO, CO2, H2, O2, and N2, with CH4 being the most abundant by volume at 38.12%. The preheated feed gas is split into a first feed gas and a second feed gas at a volume ratio of 2.333:1. The amounts of non-catalytic and catalytic conversion reactions can be controlled by adjusting the ratio of the first and second feed gas. Before the reaction begins, the furnace is ignited and heated to 450°C using an integrated burner in the non-catalytic reactor. The feed gas is then introduced for ignition and heating. After the reaction begins, the feed gas can be preheated twice using the heat recovered in step (S5), such as... Figure 2 As shown, the raw gas passes through heat exchanger No. 1 and heat exchanger No. 2 in sequence. The first preheating through heat exchanger No. 1 brings the raw gas to about 220°C, and the second preheating through heat exchanger No. 2 raises the raw gas temperature from 220°C to 500-550°C.

[0119] (S2) The first raw material gas, water vapor and preheated oxygen are introduced into a non-catalytic reactor to carry out a non-catalytic conversion reaction to generate the first synthesis gas.

[0120] In this embodiment, the first raw material gas, water vapor, and preheated oxygen are continuously added to a non-catalytic reactor at a volume ratio of oxygen to the first raw material gas of 0.437:1 and a volume ratio of water vapor to the first raw material gas of 0.219:1. The reaction temperature is controlled at 1300℃±50℃ and the pressure at 3MPaG±1MPaG to carry out a non-catalytic conversion reaction and generate the first synthesis gas. Figure 2 As shown, the first raw material gas passes through heat exchanger 1 and heat exchanger 2 before being introduced into reactor 6 (non-catalytic reactor). Steam is generated by waste heat boiler 9 and introduced into reactor 6 (non-catalytic reactor) via steam main pipe 10. Oxygen is introduced through oxygen inlet pipe 5, preheated by heat exchanger 4, and then introduced into reactor 6 (non-catalytic reactor). The temperature of the first synthesis gas is 1300℃±50℃. The non-catalytic conversion reactions include oxidation reaction (reaction 1), conversion reaction (reactions 2 and 3), and shift reaction (reaction 4); the conversion rate of the non-catalytic conversion reactions is ≥99.9%.

[0121] CH4 + 3 / 2O2 → CO + 2H2O (Reaction 1)

[0122] CH4 + H2O → CO + 3H2 (Reaction 2)

[0123] CH4 + CO2 → 2CO + 2H2 (Reaction 3)

[0124] CO + H₂O → CO₂ + H₂ (Reaction 4)

[0125] Before the reaction begins, the non-catalytic reactor can be preheated by igniting the feed gas in the non-catalytic converter, raising the temperature to above 1000℃. After the reaction begins, the reaction temperature in the non-catalytic reactor is controlled at 1300℃±50℃, mainly maintained by the exothermic reaction; simultaneously, the heat in the non-catalytic converter can be transferred to other reactors for heat supply, maximizing the utilization of the system's internal heat. The oxygen in this step can be preheated using the heat recovered in step (S5), such as... Figure 2 As shown, oxygen is introduced through 5-Oxygen inlet pipe, and then passes through 4-Heat exchanger No. 4 to reach 220°C; the water vapor in this step can also be formed using the heat recovered in step (S5), such as... Figure 2As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam, which is then introduced into the 6-non-catalytic reactor via the 10-steam main pipe for reaction. The preheating operation can shorten the start-up time of the non-catalytic conversion reaction. As shown in Table 12, O2 accounts for 99.6% of the volume of oxygen; the components of the first syngas include H2, CO, CO2, CH4, N2, and water vapor, with H2 and CO being the main components, accounting for 48.98% and 23.01% of the volume, respectively. Water vapor accounts for 18.29% of the volume of the first syngas, and CO2 accounts for 2.60% of the volume of the first syngas.

[0126] (S3) The second raw material gas and the added water vapor are fed into the pre-catalytic reactor to carry out a pre-catalytic conversion reaction to generate the second syngas;

[0127] In this embodiment, the added steam and the second feed gas are prepared according to an H2O / C molar ratio of 3:1. The second feed gas and the added steam are continuously added to the pre-catalytic reactor, and the reaction temperature is controlled at 700℃±50℃ and the pressure at 3MPaG±1MPaG to carry out the pre-catalytic conversion reaction and generate the second syngas. Figure 2 As shown, the second raw material gas passes through heat exchanger 1 and heat exchanger 2, then through heat exchanger 3 before entering the pre-catalytic reactor 7. The supplementary steam is generated by waste heat boiler 9 and enters the pre-catalytic reactor 7 through heat exchanger 3. The temperature of the second synthesis gas is 700℃±50℃. The pre-catalytic conversion reaction includes a conversion reaction (reaction 5) and a shift reaction (reaction 6); the conversion rate of the pre-catalytic conversion reaction is 50%±5%.

[0128] CH4 + H2O → CO + 3H2 (Reaction 5)

[0129] CO + H₂O → CO₂ + H₂ (Reaction 6)

[0130] Before the reaction begins, the pre-catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the pre-catalytic reactor is controlled at 700℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The water vapor added in this step can be generated from the heat recovered in step (S5), such as... Figure 2As shown, the 9-waste heat boiler can utilize the heat from the recovered syngas to convert boiler water into steam. This steam is then fed into the 7-precatalytic reactor via the 3-No. 3 heat exchanger for reaction. Since the temperature of the second feed gas may decrease after mixing with the added steam, the 3-No. 3 heat exchanger can be used to reheat the second feed gas to 500–550°C. This preheating operation can shorten the start time of the precatalytic conversion reaction. As shown in Table 13, the components of the second syngas include H2, CO, CO2, CH4, N2, and steam. The volume percentages of H2 and CO are 43.92% and 5.06%, respectively; steam accounts for 35.06% of the second syngas volume; CH4 accounts for 4.25%; and CO2 accounts for 7.23%.

[0131] (S4) The first syngas and the second syngas are fed into a catalytic reactor to carry out a catalytic conversion reaction to obtain the third syngas;

[0132] In this embodiment, the first syngas and the second syngas are continuously added to the catalytic reactor at a volume ratio of 1.501:1. The reaction temperature is controlled at 950℃±50℃ and the pressure at 3MPaG±1MPaG for further catalytic conversion, so that all unreacted CH4 is converted to generate the third syngas. Figure 2 As shown, the first syngas in reactor 6 (non-catalytic reactor) and the second syngas in reactor 7 (pre-catalytic reactor) are simultaneously fed into reactor 8 (catalytic reactor) to react and produce the third syngas. The temperature of the third syngas is ≥900℃. The catalytic conversion reaction includes a conversion reaction (reaction 7) and a shift reaction (reaction 8); the conversion rate of the catalytic conversion reaction is ≥90%.

[0133] CH4 + H2O → CO + 3H2 (Reaction 7)

[0134] CO + H₂O → CO₂ + H₂ (Reaction Equation 8)

[0135] Before the reaction begins, the catalytic reactor can be preheated by introducing high-temperature nitrogen gas. After the reaction begins, the reaction temperature in the catalytic reactor is controlled at 950℃±50℃, mainly heated by the oxidation reaction in the non-catalytic reactor. The preheating operation can shorten the start time of the catalytic conversion reaction. As shown in Table 14, the components of the third syngas include H2, CO, CO2, CH4, N2, and water vapor. The volume percentages of H2 and CO are 51.13% and 16.13%, respectively; water vapor accounts for 21.73% of the third syngas; CH4 accounts for 0.07%; and CO2 accounts for 5.12%.

[0136] (S5) The heat of the third synthesis gas is recovered to obtain synthesis gas.

[0137] In this embodiment, the synthesized gas is hydrogen synthesized gas. Because the third synthesized gas has a high temperature (≥900℃) and contains a high amount of heat, it can be recovered for preheating of the feedstock gas and oxygen, as well as for the formation of water vapor. Figure 2 As shown, in this step, the third syngas is sequentially fed into 7-pre-catalytic reactor, 3-heat exchanger No. 3, 2-heat exchanger No. 2, 9-waste heat boiler, and 1-heat exchanger No. 1 for heat recovery to obtain syngas.

[0138] In this embodiment, the heat recovered by the pre-catalytic reactor (7) can be used for the pre-catalytic conversion reaction in step (S3); the heat recovered by the third heat exchanger can reheat the second feed gas in step (S3) to 500-550°C; the heat recovered by the second heat exchanger can be used for the secondary preheating of the feed gas in step (S1); the waste heat boiler performs process cooling, and the recovered heat is used to turn boiler water into steam. The generated steam can be used in steps (S2) and (S3) to participate in the reaction, or it can be used for the preheating of oxygen in step (S2), finally forming steam condensates; the heat recovered by the first heat exchanger can be used for the primary preheating of the feed gas in step (S1). In this embodiment, the third syngas has the same composition and content as the final hydrogen syngas, only differing in temperature, with the third syngas having a higher temperature than the hydrogen syngas. The hydrogen syngas after heat recovery is sent out of the boundary area.

[0139] The reaction processes in step (S2) and step (S3) are carried out simultaneously.

[0140] Among them, non-catalytic conversion reactions provide heat for catalytic conversion reactions and pre-catalytic conversion reactions, including:

[0141] (a) The heat generated by the non-catalytic conversion reaction is transferred to the catalytic reactor via the first syngas to provide primary heat for the catalytic conversion reaction;

[0142] (b) The unused primary heat from the catalytic conversion reaction is transferred to the pre-catalytic reactor via the third syngas to provide secondary heat for the pre-catalytic conversion reaction.

[0143] Throughout the preparation process, the addition of raw materials and the output of hydrogen syngas are continuous. In the non-catalytic reactor, the gas flow rate is fixed at 0.85 m / s ± 0.05 m / s, with the first raw material gas, water vapor, and preheated oxygen continuously added, and the first syngas continuously output. In the pre-catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the second raw material gas and supplemented water vapor continuously added, and the second syngas continuously output. In the catalytic reactor, the gas flow rate is fixed at 0.7 m / s ± 0.05 m / s, with the first and second syngas continuously input, and the third syngas continuously output. The heat of the third syngas is recovered to continuously produce hydrogen syngas.

[0144] In this embodiment, hydrogen syngas was prepared from refinery dry gas by coupling non-catalytic conversion and catalytic conversion, while the heat of the product was recovered, resulting in a very high degree of heat recovery and utilization in the reaction system. Table 12 details the raw material and product components of the non-catalytic conversion reaction, Table 13 details the raw material and product components of the pre-catalytic conversion reaction, and Table 14 details the raw material and product components of the catalytic conversion reaction.

[0145] Table 11 Components of Refinery Dry Gas

[0146]

[0147] Table 12 Components of Feedstocks and Products in Non-Catalytic Conversion Reactions

[0148]

[0149] Table 13 Components of feedstocks and products in the precatalytic conversion reaction

[0150]

[0151] Table 14 Components of feedstocks and products in catalytic conversion reaction

[0152]

[0153] This embodiment uses a non-catalytic and catalytic coupled process route to prepare hydrogen syngas and further synthesize hydrogen. The public works consumption at each stage is statistically analyzed, as shown in Table 15. Table 15 shows that the total oxygen consumption during the entire hydrogen synthesis process is 18347.7 Nm³. 3The total power consumption is 3277.5 kW·h, of which the coupled process generates only 747 kW·h of power. The steam consumption includes 4.0 t / h and 0.5 t / h, which are consumed at -20.5 t / h and 33.7 t / h respectively, of which the coupled process consumes only 13.0 t / h of steam. The total boiler water consumption is 58.9 t / h, of which the coupled process consumes 13.9 t / h. The total circulating cooling water consumption is 2154.7 t / h.

[0154] Therefore, it can be seen that the oxygen consumption and electricity consumption during the hydrogen production process via the non-catalytic and catalytic coupling process route of this invention are 18347.7 Nm³. 3 / h and 3277.5kw.h.

[0155] Table 15 Public works consumption for hydrogen production via non-catalytic and catalytic coupled processes

[0156] Serial Number Public works unit coupling Transformation MDEA decarbonization PSA-H2 total 1 oxygen <![CDATA[Nm 3 / h]]> 18347.7 18347.7 2 electricity kw.h 747 2530.5 3277.5 3 4.0 steam t / h 13.0 -33.5 -20.5 4 0.5 steam t / h -9.9 43.6 33.7 5 Boiler water t / h 13.9 45.0 58.9 6 Circulating cooling water t / h 235.0 1919.7 2154.7

[0157] Comparative Example 1:

[0158] Comparative Example 1 uses a non-catalytic conversion process to produce methanol syngas, which is then further synthesized into methanol. The public works consumption at each stage is statistically analyzed, as shown in Table 16. The methanol production process based on the non-catalytic conversion route includes conversion, shift conversion, MDEA decarbonization, methanol synthesis, and methanol distillation stages. Conversion, shift conversion, and MDEA decarbonization are used to produce methanol syngas. As can be seen from Table 16, the total oxygen consumption is 10373 Nm³. 3 The total power consumption is 6598 kW·h, of which 602 kW·h is generated by the conversion and MDEA decarbonization processes. The steam consumption includes 4.0 t / h, 2.5 t / h, and 0.5 t / h, which are consumed at -34.5 t / h, -24 t / h, and 25.2 t / h, respectively. The total boiler water consumption is 69.4 t / h, of which 45.4 t / h is consumed by the conversion and shift conversion processes. The total demineralized water consumption is 45.5 t / h, all of which is generated by the shift conversion process. The total circulating cooling water consumption is 1159 t / h, of which 370 t / h is consumed by the shift conversion and MDEA decarbonization processes.

[0159] Therefore, it can be seen that the oxygen consumption and electricity consumption during the methanol production process via the non-catalytic conversion route of this invention are 10373 Nm³. 3 / h and 6598kw.h.

[0160] Table 16 Public works consumption for methanol production via non-catalytic conversion process.

[0161] Serial Number Public works unit Transformation Transformation MDEA decarbonization Methanol Synthesis Methanol distillation total 1 oxygen <![CDATA[Nm 3 / h]]> 10373 10373 2 electricity kw.h 372 230 5871 125 6598 3 4.0 steam t / h -37.6 3.1 -34.5 4 2.5 steam t / h -24.0 -24 5 0.5 steam t / h -1.5 1.9 24.8 25.2 6 Boiler water t / h 43.9 1.5 24.0 69.4 7 Desalinated water t / h 45.5 45.5 8 Circulating cooling water t / h 286 84 440 349 1159

[0162] Comparative Example 2:

[0163] Comparative Example 2 uses an SMR-ATR process to produce methanol syngas, which is then further synthesized into methanol. The utility consumption at each stage is shown in Table 17. The methanol production process based on the non-catalytic conversion route includes SMR, ATR, methanol synthesis, and methanol distillation stages, with SMR and ATR used to produce methanol syngas. Table 17 shows that the total oxygen consumption is 6504 Nm³. 3 The total power consumption is 7713 kW·h, of which 550 kW·h is generated by the SMR process; the steam consumption includes 4.0 t / h, 2.5 t / h, and 0.5 t / h, which are consumed at 5.1 t / h, -24 t / h, and 37.1 t / h, respectively; the total boiler water consumption is 38.1 t / h, of which 14.1 t / h is consumed by the ATR process; the total demineralized water consumption is 14.1 t / h, all of which is generated by the ATR process; the total circulating cooling water consumption is 789 t / h, of which no circulating cooling water is used in the SMR and ATR processes.

[0164] Therefore, it can be seen that the oxygen consumption and electricity consumption during the methanol production process via the non-catalytic conversion route of this invention are 6504 Nm³. 3 / h and 7713kw.h.

[0165] Table 17 Public works consumption for methanol production via SMR-ATR process.

[0166] Serial Number Public works unit SMR ATR Methanol Synthesis Methanol distillation total 1 oxygen <![CDATA[Nm 3 / h]]> 6504 6504 2 electricity kw.h 550 7001 162 7713 3 4.0 steam t / h 19.2 -14.1 5.1 4 2.5 steam t / h -24.0 -24 5 0.5 steam t / h 37.1 37.1 6 Boiler water t / h 14.1 24.0 38.1 7 Desalinated water t / h 14.1 14.1 8 Circulating cooling water t / h 440 349 789

[0167] In summary, under the premise of producing the same amount of methanol, the utility consumption of different process routes was statistically compared. As shown in Table 18, the feed gas consumption, oxygen consumption, and electricity consumption of the traditional non-catalytic conversion process route for methanol production are 15935 Nm³. 3 / h、10373Nm 3 / h, 6598kw.h, the feed gas consumption, oxygen consumption, and electricity consumption of the existing SMR series ATR process route are 17213Nm 3 / h、6504Nm 3 / h, 7713kw.h, the feed gas consumption, oxygen consumption, and electricity consumption of the non-catalytic and catalytic coupled process routes used in this invention are 14246Nm³, respectively. 3 / h、6496Nm 3 / h, 6398kw.h,

[0168] It can be seen that the raw material gas consumption, oxygen consumption, and electricity consumption of the non-catalytic and catalytic coupled process routes for methanol production in this invention are all lower than those of the non-catalytic conversion process route and the SMR-ATR process route. This indicates that the technical route used in this invention can greatly save materials and has obvious advantages over the prior art.

[0169] Table 18 Utility Consumption for Methanol Production via Different Process Routes

[0170]

[0171] like Figure 3 As shown, the steam produced by the waste heat boiler 9 can also be used as the initial preheating of the raw materials. The hot end inlet of the No. 1 heat exchanger 1 is connected to the steam outlet of the waste heat boiler 9. The hot end outlet of the No. 1 heat exchanger 1 is still connected to the cold end inlet of the No. 2 heat exchanger 2. The cold end outlet of the No. 1 heat exchanger 1 and the cold end outlet of the No. 4 heat exchanger 4 merge to discharge the steam condensate in a unified manner. The heat source outlet of the waste heat boiler 9 is the synthesis gas outlet of the device and is connected to the synthesis gas outlet pipe 11.

Claims

1. A non-catalytic and catalytic coupled synthesis gas production apparatus, comprising a non-catalytic reactor (6) and a catalytic reactor (8), characterized in that: It also includes connecting pipes and matching control valves, a pre-catalytic reactor (7), a waste heat boiler (9), and four heat exchangers, namely heat exchanger No. 1 (1), heat exchanger No. 2 (2), heat exchanger No. 3 (3), and heat exchanger No. 4 (4). The pre-catalytic reactor (7) has the structure of a heat exchanger. Heat exchanger No. 1 (1) is a raw material preheater. The raw material inlet is connected to the cold end inlet of heat exchanger No. 1 (1). The hot end outlet of heat exchanger No. 1 (1) is connected to the cold end inlet of heat exchanger No. 2 (2). The hot end outlet of heat exchanger No. 2 (2) is connected to the raw material inlet of the non-catalytic reactor (6) and the cold end inlet of heat exchanger No. 3 (3). The hot end outlet of heat exchanger No. 3 (3) is connected to the cold end inlet of the pre-catalytic reactor (8). The reactant outlet of the non-catalytic reactor (6) and the pre-catalytic reactor (7) are connected to the cold end inlet of the pre-catalytic reactor (8). The hot end outlet of reactor (7) is connected to the raw material inlet of catalytic reactor (8). The cold end inlet and hot end outlet of precatalytic reactor (7) are arranged as a precatalytic reaction chamber. The reactant outlet of catalytic reactor (8) is connected to the hot end inlet of precatalytic reactor (7). The cold end outlet of precatalytic reactor (7) is connected to the hot end inlet of heat exchanger No. 3 (3). The cold end outlet of heat exchanger No. 3 (3) is connected to the hot end inlet of heat exchanger No. 2 (2). The cold end outlet of heat exchanger No. 2 (2) is connected to the heat source inlet of waste heat boiler (9). The steam outlet of waste heat boiler (9) is connected to the cold end inlet of heat exchanger No. 3 (3) and the raw material inlet of noncatalytic reactor (6) respectively. Heat exchanger No. 4 (4) is an oxygen preheater, and its oxygen outlet is connected to the raw material inlet of noncatalytic reactor (6).

2. The non-catalytic and catalytic coupled syngas production apparatus as described in claim 1, characterized in that: The hot end inlet of the No. 1 heat exchanger (1) is connected to the heat source outlet of the waste heat boiler (9), and the cold end outlet of the No. 1 heat exchanger (1) is the synthesis gas outlet of the device.

3. The non-catalytic and catalytic coupled syngas production apparatus as described in claim 1, characterized in that: The hot end inlet of the No. 1 heat exchanger (1) is connected to the steam outlet of the waste heat boiler (9), and the heat source outlet of the waste heat boiler (9) is the synthesis gas outlet of the device.

4. The use of the non-catalytic or catalytic coupled syngas production apparatus according to claim 1, 2 or 3 for the production of syngas.

5. The non-catalytic or catalytic coupled synthesis gas production apparatus according to claim 1, 2 or 3 is used for producing methanol synthesis gas from natural gas.

6. The non-catalytic or catalytic coupled syngas production apparatus according to claim 1, 2 or 3 is used for preparing ammonia syngas from coke oven gas.

7. The non-catalytic or catalytic coupled syngas production apparatus according to claim 1, 2 or 3 is used for producing hydrogen syngas from refinery dry gas.

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