An integrated hydrogen production unit coupled with natural gas and methanol

Abstract

This invention relates to the field of hydrogen production technology and discloses an integrated hydrogen production device coupled with natural gas and methanol. This device produces high-purity hydrogen through the synergistic reforming of natural gas and methanol. The device includes: a raw material input unit comprising a natural gas compressor, a methanol pump, and a water treatment system, used to provide compressed natural gas, liquid methanol, and purified water, respectively; a pretreatment unit comprising a desulfurizer, a methanol vaporizer, and a steam generator, used to remove sulfides from the natural gas, convert methanol into gas, and generate high-pressure steam. In the third reaction zone, water-gas conversion and in-situ CO2 capture are performed using a WGS catalyst and adsorbent, achieving a CO conversion rate ≥95% and a CO2 capture rate ≥90%, which is 10–20% higher than post-treatment capture. TSA regeneration: a thermally coupled heat exchanger provides heat to drive TSA regeneration, releasing CO2 with a purity >95%, which is then transported to a CO2 collection tank. No external heat source is required, saving 10–15% of energy consumption.

Description

Technical Field

[0001] This invention relates to the field of hydrogen production technology, specifically to an integrated hydrogen production device that couples natural gas and methanol. Background Technology

[0002] Hydrogen, as a clean and efficient energy carrier, has broad application prospects in fuel cells, chemical synthesis, and energy storage. With the increasing global demand for low-carbon energy, efficient and environmentally friendly hydrogen production technologies have become a research hotspot. Steam reforming (SMR) and methanol steam reforming (MSR) are two mature hydrogen production technologies, using natural gas (mainly composed of methane) and methanol as feedstocks, respectively, to produce hydrogen-rich syngas through catalytic reactions. However, existing hydrogen production technologies have the following shortcomings:

[0003] In traditional hydrogen production units, after water-gas shift (WGS), CO2 and hydrogen are mixed and need to be separated by pressure swing adsorption (PSA). PSA has a high load (increasing the amount of gas processed by 30–40%) and does not achieve efficient in-situ capture of CO2. Summary of the Invention

[0004] This invention provides an integrated hydrogen production device that couples natural gas and methanol, solving the problems mentioned in the background art.

[0005] This invention provides the following technical solution: an integrated hydrogen production unit coupled with natural gas and methanol, used to produce high-purity hydrogen through the synergistic reforming of natural gas and methanol, the unit comprising:

[0006] The feedstock input unit includes a natural gas compressor, a methanol pump, and a water treatment system, which are used to provide compressed natural gas, liquid methanol, and purified water, respectively.

[0007] The pretreatment unit, including a desulfurizer, a methanol vaporizer, and a steam generator, is used to remove sulfides from natural gas, convert methanol into gas, and generate high-pressure steam.

[0008] A mixer is used to mix preheated natural gas, gaseous methanol, and steam to form a first feed stream and a second feed stream;

[0009] The mixed reaction-adsorption module has a cylindrical structure. The interior is divided into a first reaction region, a second reaction region, and a third reaction region by an outer thermal conductive wall and an inner thermal conductive wall. Furthermore, both the outer and inner thermal conductive walls are embedded with microchannels.

[0010] The first reaction zone is connected to the first feed outlet of the mixer via a pipe equipped with a regulating valve. Natural gas steam reforming is performed using a Ni-based catalyst at a temperature of 800–1000°C to generate the first syngas (CO + 3H2), which is then transported to the WGS reaction inlet of the third reaction zone via an internal pipe.

[0011] The second reaction zone is connected to the second feed outlet of the mixer via a pipe equipped with a regulating valve. Methanol vapor reforming is performed using a Cu-based catalyst at a temperature of 200–300°C to generate a second syngas (CO2 + 3H2), which is then transported to the third reaction zone through an internal pipe.

[0012] The third reaction zone is connected to the synthesis gas outlets of the first and second reaction zones via internal pipes. The TSA regeneration outlet is connected to the CO2 collection tank via a pipe equipped with a pneumatic valve. The gas outlet is connected to the cooler via a pipe. The water-gas shift reaction is carried out using WGS catalyst at a temperature of 200–400°C, and CO2 is captured in situ by an adsorbent to generate a hydrogen gas stream.

[0013] Microchannel heat exchanger network, including:

[0014] A preheating natural gas heat exchanger is connected by a pipeline to the hot-side exhaust outlet of the first reaction zone and the cold-side natural gas outlet of the desulfurizer. The preheating natural gas heat exchanger is used to preheat natural gas.

[0015] A vaporized methanol heat exchanger is connected by a pipeline to the exhaust hot-side outlet of the third reaction zone and the methanol cold-side inlet of the methanol vaporizer. The vaporized methanol heat exchanger is used for vaporizing methanol.

[0016] The heat exchanger is a plate and frame structure that can withstand high temperatures up to 1000℃. It is used to distribute the heat from the first reaction zone to the methanol reforming in the second reaction zone and the TSA regeneration in the third reaction zone.

[0017] The purification unit, including a cooler and a pressure swing adsorption device, is used to separate high-purity hydrogen from the output gas of the third reaction zone.

[0018] The cooler is connected to the gas outlet of the third reaction zone via a pipe.

[0019] The pressure swing adsorption device, connected to the outlet of the cooler via a pipeline, separates hydrogen gas with a purity of ≥99.99%.

[0020] CO2 collection tank, used to store high-purity CO2 released by the third reaction zone through TSA regeneration;

[0021] A burner is used to burn the residual gas from the pressure swing adsorption unit to provide auxiliary heat to the steam generator;

[0022] The burner is connected to the residual gas outlet of the pressure swing adsorption unit via a pipeline. After combustion, the auxiliary heat is transferred to the steam generator via a pipeline.

[0023] The PLC control system dynamically adjusts the feed ratio of natural gas and methanol, reaction conditions, and TSA cycle time by monitoring temperature, pressure, gas composition, and adsorbent status.

[0024] The hybrid reaction-adsorption module achieves synergistic effects of thermal coupling and in-situ CO2 capture through a microchannel heat exchanger network.

[0025] As a preferred technical solution of the present invention: the first reaction region is located in the outer layer and is filled with Ni / Al2O3 catalyst. The catalyst is doped with CeO2 to improve the sulfur resistance performance. Ni accounts for 10-20 wt% of the total mass of the catalyst, CeO2 accounts for 1-10 wt%, Al2O3 accounts for 70-85 wt%, and the operating pressure is 10-15 bar.

[0026] The second reaction zone is located in the middle layer and is filled with Cu / ZnO / Al2O3 catalyst to optimize hydrogen selectivity;

[0027] The third reaction zone is filled with a combination of Fe-Cr and Cu-Zn catalysts, wherein the Fe-Cr catalyst accounts for 50–70 wt% and the Cu-Zn catalyst accounts for 30–50 wt%, and the catalyst is filled in layers or mixed, in conjunction with CaO adsorbent or modified hydrotalcite adsorbent, with the adsorbent accounting for 20–40% of the reaction bed volume;

[0028] The combined catalyst covers a temperature range of 200–400℃, with a CO conversion rate of ≥95% and an H2 selectivity of ≥98%.

[0029] As a preferred technical solution of the present invention: the adsorbent in the third reaction zone captures CO2 at 200–400°C to form CaCO3 or adsorbed CO2;

[0030] During the regeneration stage, heat of 400–600°C is provided through a thermal coupling heat exchanger, releasing CO2 with a purity of >95% to the CO2 collection tank;

[0031] The TSA cycle time is 1–2 hours, which is dynamically adjusted by the PLC control system according to the adsorbent saturation and hydrogen demand.

[0032] The CO2 capture rate is ≥90%, which reduces the purification load of the subsequent pressure swing adsorption unit.

[0033] As a preferred technical solution of the present invention: the thermal coupling heat exchanger is connected to the exhaust outlet of the first reaction zone through a pipe, and the hot fluid in the thermal coupling heat exchanger circulates through the microchannel embedded in the outer and inner thermal conductive walls of the mixing reaction-adsorption module, transferring heat to the TSA regeneration reaction inlet of the second and third reaction zones, and the remaining heat flows back to the steam generator through a pipe.

[0034] As a preferred embodiment of the present invention, the PLC control system includes:

[0035] The sensors collect temperature, pressure, and gas composition data for the first, second, and third reaction zones, as well as the hydrogen purity of the pressure swing adsorption device and the CO2 concentration of the CO2 collection tank.

[0036] Based on the principles of minimizing hydrogen demand and energy consumption, the feed ratio of natural gas and methanol, the temperature of the first reaction zone, and the TSA cycle frequency are dynamically adjusted.

[0037] As a preferred embodiment of the present invention: the adsorbent in the third reaction region is CaO and modified hydrotalcite, wherein:

[0038] Doping CaO adsorbents with Al2O3 or ZrO2 improves their high-temperature stability.

[0039] Modified hydrotalcite doped with K2CO3 enhances CO2 adsorption capacity at 200–400℃;

[0040] The adsorbent is mixed with WGS catalyst for filling, which optimizes gas contact efficiency.

[0041] As a preferred embodiment of the present invention: the pressure swing adsorption device includes 4-6 adsorption beds, configured as follows:

[0042] Activated carbon or molecular sieves are used as adsorption materials to separate hydrogen from residual gases (CO, CH4, CO2).

[0043] Residual gases (CO, CH4, CO2) are transported to the burner through pipelines to provide auxiliary heat, or partially recovered to the mixer to improve the utilization rate of raw materials.

[0044] As a preferred embodiment of the present invention: the integrated hydrogen production unit coupled with natural gas and methanol adopts a modular design, wherein:

[0045] The hybrid reaction-adsorption module, microchannel heat exchanger network, and purification unit are integrated into a single containerized structure;

[0046] Modular configuration allows multiple R1 units to operate in parallel, and hydrogen production can be scaled up to 100–5000 Nm³. 3 / h;

[0047] Suitable for distributed applications, including hydrogen supply stations for fuel cell vehicles or energy systems in remote areas.

[0048] The present invention has the following beneficial effects:

[0049] 1. This integrated hydrogen production unit coupled with natural gas and methanol utilizes the waste heat from the exhaust gas in the first reaction zone to preheat natural gas via microchannels, achieving a heat recovery efficiency of ≥70%, which is 15–20% higher than traditional heat exchangers. The methanol vaporization heat exchanger utilizes the waste heat from the exhaust gas in the third reaction zone to vaporize methanol to 150–200℃ via microchannels, requiring a heat of 500–600 kJ / kg CH3OH. No external electric heating is required, saving approximately 5–10% of energy consumption.

[0050] The thermally coupled heat exchanger distributes heat from the first reaction zone to the TSA regeneration and steam generator in the second and third reaction zones through microchannels embedded in the outer and inner thermal conductive walls of the mixed reaction-adsorption module. It achieves a heat transfer efficiency of ≥80%, which is 20–30% higher than conventional heat exchangers, while reducing heat loss to 5–10%. The microchannel structure also increases the heat exchange area by 2–3 times compared to conventional heat exchangers.

[0051] 2. In this integrated hydrogen production unit coupled with natural gas and methanol, the first reaction zone uses a Ni / Al2O3 catalyst for natural gas reforming, with a methane conversion rate of ≥95%, generating the first syngas (CO+3H2).

[0052] The second reaction zone uses a Cu / ZnO / Al2O3 catalyst for methanol reforming, with H2 selectivity ≥98% and CO content <1%, which is superior to traditional MSR.

[0053] The third reaction zone uses WGS catalyst and adsorbent for water-gas conversion and in-situ CO2 capture, achieving a CO conversion rate of ≥95% and a CO2 capture rate of ≥90%, which is 10–20% higher than post-treatment capture.

[0054] TSA regeneration: A thermally coupled heat exchanger provides heat to drive TSA regeneration, releasing CO2 with a purity >95%, which is then transported to a CO2 collection tank. No external heat source is required, saving 10–15% of energy.

[0055] 3. This integrated hydrogen production unit that couples natural gas and methanol uses a thermal coupling heat exchanger embedded in the heat conduction wall of the mixed reaction-adsorption module unit to reduce the length of external pipes and reduce heat loss to 5-10%, making it more compact than traditional heat exchangers.

[0056] The modular design supports multiple hybrid reaction-adsorption module units connected in parallel (M1 and PSA1 are connected via stainless steel piping), and the output can be scaled up to 100–5000 Nm³. 3 / h is suitable for distributed applications. Attached Figure Description

[0057] Figure 1 This is a schematic diagram of a hydrogen production unit that couples natural gas and methanol.

[0058] Figure 2 This is a schematic diagram of the mixed reaction-adsorption module structure of the present invention;

[0059] Figure 3 This is a schematic diagram showing the connection between the third reaction region and the thermally coupled heat exchanger of the present invention.

[0060] In the diagram: 1. Natural gas compressor; 2. Desulfurizer; 3. Methanol pump; 4. Methanol vaporizer; 5. Water treatment system; 6. Steam generator; 7. Mixer; 8. First reaction zone; 9. Second reaction zone; 10. Third reaction zone; 11. Preheating natural gas heat exchanger; 12. Vaporizing methanol heat exchanger; 13. Thermal coupling heat exchanger; 14. Cooler; 15. Pressure swing adsorption device; 16. CO2 collection tank; 17. Burner; 18. PLC control system; 19. Mixed reaction-adsorption module. Detailed Implementation

[0061] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] Please see Figures 1-3 An integrated hydrogen production unit coupled with natural gas and methanol is used to produce high-purity hydrogen through the synergistic reforming of natural gas and methanol. The unit includes:

[0063] The raw material input unit includes a natural gas compressor 1, a methanol pump 3, and a water treatment system 5, which are used to provide compressed natural gas, liquid methanol, and purified water, respectively.

[0064] The pretreatment unit includes a desulfurizer 2, a methanol vaporizer 4, and a steam generator 6, which are used to remove sulfides from natural gas, convert methanol into gaseous state, and generate high-pressure steam.

[0065] Mixer 7 is used to mix preheated natural gas, gaseous methanol and steam to form a first feed stream and a second feed stream;

[0066] The mixed reaction-adsorption module 19 has a cylindrical structure. Its interior is divided into a first reaction region 8, a second reaction region 9, and a third reaction region 10 by an outer thermal conductive wall and an inner thermal conductive wall. Furthermore, both the outer and inner thermal conductive walls are embedded with microchannels.

[0067] The first reaction zone 8 is connected to the first feed outlet of the mixer 7 through a pipe equipped with a regulating valve. Natural gas steam reforming is carried out using a Ni-based catalyst at a temperature of 800–1000°C to generate the first syngas CO + 3H2, which is then transported through an internal pipe to the WGS reaction inlet of the third reaction zone 10.

[0068] TSA is an adsorption separation technology based on temperature changes. It adsorbs the target gas at a lower temperature and regenerates the adsorbent by desorption at a higher temperature, releasing the target gas in high purity.

[0069] During the adsorption stage, the adsorbent selectively captures CO2 at relatively low temperatures, such as 200–400℃; during the regeneration stage, by increasing the temperature, such as 400–600℃, the adsorbent releases CO2 and restores its adsorption capacity.

[0070] Its role in hydrogen production units:

[0071] TSA is mainly used in the third reaction zone 10 of the mixed reaction-adsorption module 19 to capture CO2 generated from the water gas shift reaction WGS in situ, CO + H2O → CO2 + H2.

[0072] The third reaction region 10 is achieved via TSA:

[0073] CO2 capture: At 200–400℃, adsorbents such as CaO form CaCO3, or modified hydrotalcite adsorbs CO2, with a capture rate of ≥90%, reducing the amount of CO2 entering the subsequent pressure swing adsorption unit 15.

[0074] CO2 release: At 400–600℃, the adsorbent is regenerated, releasing high-purity CO2 (>95%), which is then transported through pipeline to CO2 collection tank 16.

[0075] Hydrogen purification: In-situ CO2 capture improves hydrogen selectivity by ≥98% and reduces the load on pressure swing adsorption unit 15.

[0076] The second reaction zone 9 is connected to the second feed outlet of the mixer 7 through a pipe equipped with a regulating valve. Methanol steam reforming is carried out using a Cu-based catalyst at a temperature of 200–300°C to generate a second synthesis gas CO2 + 3H2, which is then transported to the third reaction zone 10 through an internal pipe.

[0077] The third reaction zone 10 is connected to the synthesis gas outlets of the first reaction zone 8 and the second reaction zone 9 through internal pipes. The TSA regeneration outlet is connected to the CO2 collection tank 16 through a pipe equipped with a pneumatic valve. The gas outlet is connected to the cooler 14 through a pipe. The water-gas shift reaction is carried out using WGS catalyst at a temperature of 200–400°C, and CO2 is captured in situ by an adsorbent to generate a hydrogen gas stream.

[0078] Microchannel heat exchanger network, including:

[0079] A preheating natural gas heat exchanger 11 is connected by a pipeline to the hot-side exhaust outlet of the first reaction zone 8 and the cold-side natural gas outlet of the desulfurizer 2. The preheating natural gas heat exchanger 11 is used to preheat natural gas.

[0080] A vaporization methanol heat exchanger 12 is connected by a pipe to the exhaust hot side outlet of the third reaction zone 10 and the methanol cold side inlet of the methanol vaporizer 4. The vaporization methanol heat exchanger 12 is used for vaporizing methanol.

[0081] The heat exchanger 13 is a plate and frame structure that can withstand high temperatures up to 1000℃. The heat exchanger 13 is used to distribute the heat from the first reaction zone 8 to the methanol reforming in the second reaction zone 9 and the TSA regeneration in the third reaction zone 10.

[0082] The preheating natural gas heat exchanger 11 and the vaporized methanol heat exchanger 12 are independent external heat exchangers. The thermally coupled heat exchanger 13 is integrated with the mixed reaction-adsorption module 19 through microchannels embedded in the outer and inner thermal conductive walls of the mixed reaction-adsorption module 19.

[0083] Both the outer and inner thermal conductive walls are connected to the thermally coupled heat exchanger 13. The outer thermal conductive wall mainly transfers heat to the second reaction region 9, and the inner thermal conductive wall transfers heat to the third reaction region 10. The microchannel network of the thermally coupled heat exchanger 13 spans the two thermal conductive walls.

[0084] The purification unit, including a cooler 14 and a pressure swing adsorption device 15, is used to output the gas from the third reaction zone 10 and separate high-purity hydrogen.

[0085] Cooler 14 is connected to the gas outlet of the third reaction zone 10 via a pipe;

[0086] The pressure swing adsorption device 15 is connected to the outlet of the cooler 14 via a pipeline to separate hydrogen gas with a purity of ≥99.99%.

[0087] CO2 collection tank 16 is used to store high-purity CO2 released by the third reaction zone 10 through TSA regeneration;

[0088] CO2 collection tank 16 is connected to the TSA regeneration outlet of the third reaction zone 10 through a pipeline to store CO2 with a purity >95%;

[0089] Burner 17 is used to burn the residual gas from pressure swing adsorption unit 15 to provide auxiliary heat to steam generator 6;

[0090] The burner 17 is connected to the residual gas outlet of the pressure swing adsorption device 15 through a pipe, and after combustion, the auxiliary heat is transferred to the steam generator 6 through a pipe.

[0091] The PLC control system 18 dynamically adjusts the feed ratio of natural gas and methanol, reaction conditions, and TSA cycle time by monitoring temperature, pressure, gas composition, and adsorbent status.

[0092] Among them, the mixed reaction-adsorption module 19 achieves synergistic effects of thermal coupling and in-situ CO2 capture through a microchannel heat exchanger network.

[0093] The first reaction region 8 is located in the outer layer and is filled with Ni / Al2O3 catalyst. The catalyst is doped with CeO2 to improve the sulfur resistance performance. Ni accounts for 10–20 wt% of the total mass of the catalyst, CeO2 accounts for 1–10 wt%, Al2O3 accounts for 70–85 wt%, and the operating pressure is 10–15 bar.

[0094] The second reaction zone 9 is located in the middle layer and is filled with Cu / ZnO / Al2O3 catalyst to optimize hydrogen selectivity;

[0095] The third reaction zone 10 is filled with a combination of Fe-Cr and Cu-Zn catalysts, wherein the Fe-Cr catalyst accounts for 50–70 wt% and the Cu-Zn catalyst accounts for 30–50 wt%, and the catalyst is filled in layers or mixed, along with CaO adsorbent or modified hydrotalcite adsorbent, with the adsorbent accounting for 20–40% of the reaction bed volume;

[0096] The combined catalyst covers a temperature range of 200–400℃, with CO conversion ≥95% and H2 selectivity ≥98%.

[0097] In the third reaction zone 10, the adsorbent captures CO2 at 200–400℃ to form CaCO3 or adsorbed CO2.

[0098] During the regeneration stage, heat of 400–600°C is provided through thermal coupling heat exchanger 13, releasing CO2 with a purity of >95% to CO2 collection tank 16;

[0099] The TSA cycle time is 1–2 hours, which is dynamically adjusted by the PLC control system 18 according to the adsorbent saturation and hydrogen demand.

[0100] The CO2 capture rate is ≥90%, which reduces the purification load of the subsequent pressure swing adsorption unit 15.

[0101] The thermal coupling heat exchanger 13 is connected to the exhaust outlet of the first reaction zone 8 through a pipe. The hot fluid inside the thermal coupling heat exchanger 13 circulates through the microchannels of the outer and inner thermal conductive walls of the embedded mixing reaction-adsorption module 19, transferring heat to the TSA regeneration reaction inlet of the second reaction zone 9 and the third reaction zone 10. The remaining heat flows back to the steam generator 6 through a pipe.

[0102] The PLC control system 18 includes:

[0103] The sensors collect temperature, pressure, and gas composition data for the first reaction zone 8, the second reaction zone 9, and the third reaction zone 10, as well as the hydrogen purity of the pressure swing adsorption device 15 and the CO2 concentration of the CO2 collection tank 16.

[0104] Based on the principles of minimizing hydrogen demand and energy consumption, the feed ratio of natural gas and methanol, the temperature of the first reaction zone 8, and the TSA circulation frequency are dynamically adjusted.

[0105] The adsorbents in the third reaction zone 10 are CaO and modified hydrotalcite, wherein:

[0106] Doping CaO adsorbents with Al2O3 or ZrO2 improves their high-temperature stability.

[0107] Modified hydrotalcite doped with K2CO3 enhances CO2 adsorption capacity at 200–400℃;

[0108] The adsorbent is mixed with WGS catalyst for filling, which optimizes gas contact efficiency.

[0109] CaO (calcium oxide): It captures CO2 at 200–400℃ through the carbonation reaction (CaO+CO2→CaCO3), and the high-temperature stability is improved by doping with Al2O3 or ZrO2. The cycle life is ≥1000 times.

[0110] Modified hydrotalcite: By doping with K2CO3 or Na2CO3, the CO2 adsorption capacity at 200–400℃ is enhanced (≥0.5mol / kg), making it suitable for medium and low temperature operation.

[0111] The adsorbent is mixed with or layered with WGS catalyst (Fe-Cr 50–70wt%, Cu-Zn 30–50wt%) to optimize gas contact efficiency.

[0112] Operating conditions:

[0113] Adsorption stage: 200–400℃, pressure 1–5 bar, CO2 capture rate ≥90%.

[0114] Regeneration stage: 400–600℃, heat is provided by thermally coupled heat exchanger 13 through microchannels embedded in the inner thermal conductive wall, releasing CO2.

[0115] The pressure swing adsorption device 15 includes 4–6 adsorption beds, configured as follows:

[0116] Activated carbon or molecular sieves are used as adsorption materials to separate hydrogen from residual gases CO, CH4, and CO2.

[0117] The residual gases CO, CH4, and CO2 are transported to burner 17 through pipelines to provide auxiliary heat, or partially recovered to mixer 7 to improve the utilization rate of raw materials.

[0118] The integrated hydrogen production unit, which couples natural gas and methanol, adopts a modular design, in which:

[0119] The mixed reaction-adsorption module 19, the microchannel heat exchanger network, and the purification unit are integrated into a single containerized structure;

[0120] Modular configuration allows multiple R1 units to operate in parallel, and hydrogen production can be scaled up to 100–5000 Nm³. 3 / h;

[0121] Suitable for distributed applications, including hydrogen supply stations for fuel cell vehicles or energy systems in remote areas.

[0122] Working principle: Natural gas, methanol, and purified water are supplied through a natural gas compressor 1, a methanol pump 3, and a water treatment system 5, respectively; sulfides are removed from the natural gas in a desulfurizer 2, methanol is converted into gas in a methanol vaporizer 4, and high-pressure steam is generated in a steam generator 6; preheated natural gas, gaseous methanol, and steam are mixed in a mixer 7 to form a first feed stream and a second feed stream; in the mixing reaction-adsorption module 19: in the first reaction zone 8, natural gas steam is reformed at 800–1000℃ with a Ni-based catalyst to generate a first syngas; in the second reaction zone 9, methanol steam is reformed at 200–300℃ with a Cu-based catalyst to generate a second syngas; in the third reaction... In zone 10, a water-gas shift reaction is carried out at 200–400℃ with a WGS catalyst, and CO2 is captured in situ by CaO or modified hydrotalcite adsorbent. The heat from the first reaction zone 8 is transferred to the TSA regeneration in the second reaction zone 9 and the third reaction zone 10 through a thermal coupling heat exchanger 13. The TSA regeneration temperature is 400–600℃, and high-purity CO2 is released to the CO2 collection tank 16. The output gas of the third reaction zone 10 is cooled by a cooler 14, and hydrogen with a purity ≥99.99% is separated by a pressure swing adsorption device 15. The reaction conditions are monitored by a PLC control system 18, and the feed ratio of natural gas and methanol, the reaction temperature, and the TSA cycle time are dynamically adjusted.

[0123] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0124] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An integrated hydrogen production unit coupled with natural gas and methanol, characterized in that: include: A mixed reaction-adsorption module (19), the mixed reaction-adsorption module (19) having a concentric region layout, including: The first reaction zone (8) is used for natural gas steam reforming. The second reaction zone (9) is used for methanol vapor reforming. And a third reaction zone (10) for water-gas conversion and in-situ capture of carbon dioxide, which is connected to the first reaction zone (8) and the second reaction zone (9) to receive their reaction products; And a microchannel heat exchanger network integrated inside the mixed reaction-adsorption module (19) is used to selectively transfer the heat generated in the first reaction zone (8) to the second reaction zone (9) to drive the methanol reforming reaction, and to the third reaction zone (10) to achieve the heating regeneration of the adsorbent. A raw material supply system connected to the mixed reaction-adsorption module (19) is used to provide reactants; A purification unit connected to the third reaction zone (10) is used to separate and purify hydrogen from the reaction products; Microchannel heat exchanger network, including: A preheating natural gas heat exchanger (11) is connected by a pipeline to the hot side exhaust outlet of the first reaction zone (8) and the cold side outlet of the natural gas of the desulfurizer (2). The preheating natural gas heat exchanger (11) is used to preheat natural gas. A vaporized methanol heat exchanger (12) is connected by a pipe to the exhaust hot side outlet of the third reaction zone (10) and the methanol cold side inlet of the methanol vaporizer (4). The vaporized methanol heat exchanger (12) is used to vaporize methanol. The heat exchanger (13) is a plate and frame structure and can withstand high temperatures up to 1000℃. The heat exchanger (13) is used to distribute the heat of the first reaction zone (8) to the methanol reforming of the second reaction zone (9) and the TSA regeneration of the third reaction zone (10). The adsorbent in the third reaction zone (10) captures CO2 at 200–400°C to form CaCO3 or adsorbed CO2. During the regeneration stage, heat of 400–600°C is provided through a thermally coupled heat exchanger (13), releasing CO2 with a purity of >95% to the CO2 collection tank (16). The TSA cycle time is 1–2 hours, which is dynamically adjusted by the PLC control system (18) according to the adsorbent saturation and hydrogen demand. The CO2 capture rate is ≥90%, which reduces the purification load of the subsequent pressure swing adsorption device (15); The heat exchanger (13) is connected to the exhaust outlet of the first reaction zone (8) through a pipe. The heat fluid inside the heat exchanger (13) circulates through the microchannels of the outer and inner heat conduction walls of the embedded mixing reaction-adsorption module (19) to transfer heat to the TSA regeneration reaction inlet of the second reaction zone (9) and the third reaction zone (10). The remaining heat flows back to the steam generator (6) through a pipe. The mixed reaction-adsorption module (19), microchannel heat exchanger network and purification unit are integrated into a single container structure.

2. The integrated hydrogen production device coupled with natural gas and methanol according to claim 1, characterized in that: The raw material supply system includes: The raw material input unit includes a natural gas compressor (1), a methanol pump (3), and a water treatment system (5), which are used to provide compressed natural gas, liquid methanol, and purified water, respectively. The pretreatment unit includes a desulfurizer (2), a methanol vaporizer (4), and a steam generator (6) for removing sulfides from natural gas, converting methanol into gaseous state, and generating high-pressure steam. A mixer (7) is used to mix preheated natural gas, gaseous methanol and steam to form a first feed stream and a second feed stream. The first feed stream is supplied to the first reaction zone (8) and the second feed stream is supplied to the second reaction zone (9).

3. The integrated hydrogen production device coupled with natural gas and methanol according to claim 2, characterized in that: It also includes: Cooler (14) is connected to the gas outlet of the third reaction zone (10) via a pipe; The pressure swing adsorption device (15) is connected to the outlet of the cooler (14) through a pipeline to separate hydrogen gas with a purity of ≥99.99%; CO2 collection tank (16) is used to store high-purity CO2 released by the third reaction zone (10) through TSA regeneration; Burner (17) for burning the residual gas from the pressure swing adsorption unit (15) to provide auxiliary heat to the steam generator (6). The PLC control system (18) dynamically adjusts the feed ratio of natural gas and methanol, reaction conditions and TSA cycle time by monitoring temperature, pressure, gas composition and adsorbent status.

4. The integrated hydrogen production device coupled with natural gas and methanol according to claim 3, characterized in that: The first reaction region (8) is located in the outer layer and is filled with Ni / Al2O3 catalyst. The catalyst is doped with CeO2 to improve sulfur resistance. Ni accounts for 10–20 wt% of the total mass of the catalyst, CeO2 accounts for 1–10 wt%, Al2O3 accounts for 70–85 wt%, and the operating pressure is 10–15 bar. The second reaction zone (9) is located in the middle layer and is filled with Cu / ZnO / Al2O3 catalyst to optimize hydrogen selectivity; The third reaction zone (10) is filled with a combination of Fe-Cr and Cu-Zn catalysts, wherein the Fe-Cr catalyst accounts for 50–70 wt% and the Cu-Zn catalyst accounts for 30–50 wt%, and is filled in layers or mixed, with CaO adsorbent or modified hydrotalcite adsorbent, the adsorbent accounting for 20–40% of the reaction bed volume; The catalyst filling the third reaction zone (10) covers a temperature range of 200–400℃, with CO conversion ≥95% and H2 selectivity ≥98%.

5. The integrated hydrogen production unit coupled with natural gas and methanol according to claim 4, characterized in that: The PLC control system (18) includes: The temperature, pressure, and gas composition data of the first reaction zone (8), the second reaction zone (9), and the third reaction zone (10) are collected by sensors, as well as the hydrogen purity of the pressure swing adsorption device (15) and the CO2 concentration of the CO2 collection tank (16). Based on the principles of minimizing hydrogen demand and energy consumption, the feed ratio of natural gas and methanol, the temperature of the first reaction zone (8), and the TSA cycle frequency are dynamically adjusted.

6. The integrated hydrogen production device coupled with natural gas and methanol according to claim 5, characterized in that: The adsorbent in the third reaction zone (10) is CaO and modified hydrotalcite, wherein: Doping CaO adsorbents with Al2O3 or ZrO2 improves their high-temperature stability. Modified hydrotalcite doped with K2CO3 enhances CO2 adsorption capacity at 200–400℃; The adsorbent is mixed with WGS catalyst for filling, which optimizes gas contact efficiency.

7. The integrated hydrogen production device coupled with natural gas and methanol according to claim 6, characterized in that: The integrated hydrogen production unit coupled with natural gas and methanol adopts a modular design, in which: The pressure swing adsorption device (15) comprises 4–6 adsorption beds, configured as follows: Activated carbon or molecular sieves are used as adsorption materials to separate hydrogen from residual carbon monoxide, methane, and carbon dioxide gases. Residual carbon monoxide, methane, and carbon dioxide gases are transported to the burner (17) through pipelines to provide auxiliary heat, or partially recovered to the mixer (7) to improve the utilization rate of raw materials.

Images