Biomass-green hydrogen double-drive multi-element energy conversion system and operation mode

Abstract

The invention provides a biomass-green hydrogen double-drive multi-element energy conversion system and an operation mode, and relates to the technical field of biomass energy and green hydrogen conversion and utilization, the biomass-green hydrogen double-drive multi-element energy conversion system comprises a biomass conversion unit, an LNG comprehensive heat exchange unit, a hydrogen production unit, a methanol synthesis unit and a fuel cell power generation unit; the hydrogen production unit is used for electrolyzing water to produce green hydrogen; the biomass conversion unit utilizes green hydrogen to convert biomass into synthesis gas and / or biodiesel and / or biological aviation fuel; the fuel cell power generation unit uses synthesis gas and green hydrogen to generate power and waste heat; the LNG comprehensive heat exchange unit is located between the biomass conversion unit and the hydrogen production unit, and cold energy of LNG is used for heat exchange so as to improve the energy efficiency of the system; and the methanol synthesis unit is used for generating methanol by utilizing the synthesis gas and the LNG reformed by the water vapor. According to the method, deep integration and efficient conversion of biomass and green hydrogen are achieved, output and value extension of diversified energy products are promoted, and comprehensive benefits and sustainable development potential are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass energy and green hydrogen conversion and utilization, and in particular to a biomass-green hydrogen dual-drive multi-energy conversion system and operation mode. Background Art

[0002] With the continuous growth of global energy demand and the increasing awareness of environmental protection, the development of clean and sustainable energy conversion technology has become the focus of current scientific and technological research. The consumption of traditional fossil energy has not only aggravated environmental pollution, but also led to a sharp increase in greenhouse gas emissions, which has a profound impact on the global climate. Therefore, exploring and utilizing renewable energy, such as biomass energy and hydrogen energy, has become an important way to solve the energy crisis and environmental protection problems.

[0003] As a widely available and highly renewable energy source, biomass energy conversion and utilization technology is gaining increasing attention. Through chemical or biological conversion methods, biomass can be converted into high value-added energy products, such as biodiesel and biojet fuel, which not only have environmental advantages, but can also replace traditional fossil fuels to a certain extent and reduce the impact on the environment.

[0004] At the same time, green hydrogen, as an important component of the future energy system, has a broad application prospect. Green hydrogen is hydrogen produced by electrolyzing water through renewable energy (such as solar energy and wind energy), which has the characteristics of zero emission and no pollution. Combining green hydrogen with biomass energy can build a more efficient and environmentally friendly energy conversion network.

[0005] However, there are still many challenges in the conversion and utilization of biomass energy and green hydrogen. For example, the energy efficiency and product selectivity in the biomass conversion process need to be improved; the high storage and transportation costs of green hydrogen limit its widespread application. Therefore, it is particularly important to develop an energy conversion network that can efficiently and flexibly utilize biomass energy and green hydrogen.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] One of the objectives of the present invention is to provide a biomass-green hydrogen dual-drive multi-energy conversion system that can achieve deep integration and efficient conversion of biomass and green hydrogen, effectively promoting the output and value extension of diversified energy products.

[0008] The second purpose of the present invention is to provide an operating mode of a biomass-green hydrogen dual-drive multi-energy conversion system, which can significantly improve the comprehensive benefits and sustainable development potential of the overall energy system, and provide strong support for building a green, low-carbon, efficient and safe energy system.

[0009] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0010] In the first aspect, a biomass-green hydrogen dual-drive multi-energy conversion system includes a biomass conversion unit, an LNG comprehensive heat exchange unit, a hydrogen production unit, a methanol synthesis unit and a fuel cell power generation unit;

[0011] The hydrogen production unit is used to electrolyze water to produce green hydrogen;

[0012] The biomass conversion unit converts the biomass into synthesis gas and / or biodiesel and / or biojet fuel using green hydrogen;

[0013] The fuel cell power generation unit utilizes synthesis gas and green hydrogen to generate electricity and waste heat;

[0014] The LNG comprehensive heat exchange unit is located between the biomass conversion unit and the hydrogen production unit, and utilizes the cold energy of LNG for heat exchange to improve the energy efficiency of the system;

[0015] The methanol synthesis unit uses the synthesis gas and the LNG reformed by water steam from the LNG comprehensive heat exchange unit as raw material components to carry out catalytic reaction to synthesize methanol.

[0016] Furthermore, the biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a solar wind-solar complementary unit to convert renewable energy into electric energy for electrolysis of water in the hydrogen production unit;

[0017] The biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a waste heat utilization unit, a first liquid storage unit, a second liquid storage unit, an energy storage unit and a hydrogen storage unit;

[0018] The waste heat utilization unit is used to comprehensively utilize the waste heat generated in the fuel cell power generation unit;

[0019] The waste heat utilization unit includes a lithium bromide unit and a screw expander power generation equipment;

[0020] The first liquid storage unit is used to store biodiesel and / or bio-jet fuel generated by the biomass conversion unit;

[0021] The second liquid storage unit is used to store methanol synthesized by the methanol synthesis unit;

[0022] The energy storage unit is used to store the electric energy generated by the waste heat through the screw expander;

[0023] The hydrogen storage unit is used to store excess green hydrogen.

[0024] Further, the biomass conversion unit includes a hydrodeoxygenation & cracking / isomerization reactor, and a gasifier;

[0025] The hydrodeoxygenation & cracking / isomerization reactor is used to produce biodiesel and / or biojet fuel;

[0026] The gasifier is used for gasification and decomposition to generate synthesis gas.

[0027] Furthermore, the LNG integrated heat exchange unit includes an LNG vaporizer and an LNG heat exchanger.

[0028] Furthermore, the hydrogen production unit includes a water electrolysis device and a compressor.

[0029] Furthermore, the methanol synthesis unit includes a steam reforming converter and a methanol synthesis device.

[0030] Furthermore, the fuel cell power generation unit includes a desulfurization device and a SOFC generator set.

[0031] Furthermore, the biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a water purification unit for treating wastewater generated by the biomass conversion unit and / or the SOFC generator set, and recycling the purified water for electrolysis of water to produce green hydrogen and / or steam reforming LNG;

[0032] The water purification unit includes water purification treatment equipment.

[0033] In a second aspect, an operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system as described in any one of the above items comprises the following steps:

[0034] The green hydrogen produced by the hydrogen production unit is transported to the biomass conversion unit and the fuel cell power generation unit, the biomass is sent to the biomass conversion unit to be converted into synthesis gas and / or biodiesel and / or bio-jet fuel, the obtained synthesis gas is supplied to the methanol synthesis unit and the fuel cell power generation unit, the synthesis gas and green hydrogen are used to generate electricity and waste heat in the fuel cell power generation unit, LNG is input into the LNG integrated heat exchange unit, the cold energy of LNG is used for heat exchange, and the LNG after heat exchange is reformed with water vapor to undergo catalytic reaction with the synthesis gas in the methanol synthesis unit to synthesize methanol.

[0035] Furthermore, the operation mode also includes the following steps:

[0036] In the waste heat utilization unit, part of the waste heat generated by the SOFC unit of the fuel cell power generation unit is reused through the lithium bromide unit to achieve cooling and heating, and the remaining waste heat is used to generate electricity through the screw expander, and the generated electricity is input into the energy storage unit for standby.

[0037] Compared with the prior art, the present invention has at least the following beneficial effects:

[0038] The biomass-green hydrogen dual-drive multi-energy conversion system provided by the present invention uses biomass and green hydrogen as raw materials, and forms a multi-energy output module through conversion, which can produce energy products such as biodiesel and / or bio-jet fuel as needed; at the same time, the present invention uses green hydrogen and methane generated by biomass gasification to supply to the SOFC of the fuel cell power generation unit for power generation, and the generated high-temperature waste heat can be fully utilized through the lithium bromide unit and the screw expander power generation equipment, realizing the recycling and efficient conversion of energy; in addition, the system of the present invention provides cold energy heat exchange through LNG input, and the LNG after heat exchange can be used as a methanol synthesis raw material through steam reforming, further enriching the types of energy products and enhancing the flexibility of the system; in addition, the remaining green hydrogen can be stored in the hydrogen storage module. In short, the present invention has made significant breakthroughs in the deep integration and efficient conversion of biomass and green hydrogen, and effectively promoted the output and value extension of diversified energy products.

[0039] The operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system provided by the present invention can significantly improve the comprehensive benefits and sustainable development potential of the overall energy system, and provide strong support for building a green, low-carbon, efficient and safe energy system. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A schematic diagram of the structure of a biomass-green hydrogen dual-drive multi-energy conversion system provided in one embodiment of the present invention;

[0042] Figure 2 A schematic diagram of the principle of a biomass-green hydrogen dual-drive multi-energy conversion system provided for one embodiment of the present invention. DETAILED DESCRIPTION

[0043] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] According to a first aspect of the present invention, a biomass-green hydrogen dual-drive multi-energy conversion system is provided. Figure 1, including biomass conversion unit, LNG integrated heat exchange unit, hydrogen production unit, methanol synthesis unit and fuel cell power generation unit;

[0045] Among them, the hydrogen production unit is used to electrolyze water to produce green hydrogen;

[0046] In the present invention, the biomass conversion unit converts biomass into syngas and / or biodiesel and / or biojet fuel using green hydrogen;

[0047] Furthermore, the fuel cell power generation unit uses syngas and green hydrogen to generate electricity and waste heat;

[0048] The LNG integrated heat exchange unit is located between the biomass conversion unit and the hydrogen production unit, and uses the cold energy of LNG for heat exchange to improve the system energy efficiency;

[0049] At the same time, the methanol synthesis unit uses the synthesis gas and LNG reformed by steam from the LNG integrated heat exchange unit as raw material components to synthesize methanol through catalytic reaction.

[0050] The biomass-green hydrogen dual-drive multi-energy conversion system provided by the present invention uses biomass and green hydrogen as raw materials, and forms a multi-energy output module through conversion, which can produce energy products such as biodiesel and / or bio-jet fuel as needed; at the same time, the present invention uses green hydrogen and methane generated by biomass gasification to supply to the SOFC of the fuel cell power generation unit for power generation, and the generated high-temperature waste heat can be fully utilized through the lithium bromide unit and the screw expander power generation equipment, thereby realizing the recycling and efficient conversion of energy; in addition, the system of the present invention provides cold energy heat exchange through LNG input, and the LNG after heat exchange can be used as a methanol synthesis raw material through steam reforming, further enriching the types of energy products and enhancing the flexibility of the system; in addition, the remaining green hydrogen can be stored in the hydrogen storage module.

[0051] In summary, the present invention has made significant breakthroughs in the deep integration and efficient conversion of biomass and green hydrogen, effectively promoting the output and value extension of diversified energy products.

[0052] In a preferred embodiment, the biomass conversion unit includes but is not limited to a hydrodeoxygenation & cracking / isomerization reactor, and a gasifier; wherein the hydrodeoxygenation & cracking / isomerization reactor is used to convert liquid biomass into biodiesel and / or bio-jet fuel, and the gasifier is used to convert solid biomass into synthesis gas, thereby being able to "tailor" according to raw materials and needs to achieve a full set of biomass utilization.

[0053] It should be noted that there is no specific restriction on the biomass raw materials used in the biomass conversion unit, which can be subdivided into agricultural waste (including crop straw, rice straw, wheat straw and corn stalks) and oil biomass (including vegetable oil, animal oil and waste oil).

[0054] In the present invention, the hydrodeoxygenation & cracking / isomerization reactor can adopt two sets of process schemes when preparing biodiesel and bio-jet kerosene; wherein, the process scheme for preparing biodiesel is as follows: the catalyst used is Ni-Mo / SAPO-11, the mass ratio of biomass oil and catalyst can be 1:(0.05-0.07), the silicon-aluminum ratio can be 280, the Ni loading can be 8%-10%, the Mo loading can be 0.5%-1%, the reaction temperature can be 320°C-360°C, and the reaction pressure can be 5Mpa-10Mpa; the process scheme for preparing bio-jet kerosene is as follows: the catalyst used is core-shell Ni / ZSM-5 / SAPO-5, the mass ratio of biomass oil and catalyst can be 1:(0.1-0.2), the Ni loading can be 6%-8.5%, the silicon-aluminum ratio can be 340, the reaction temperature can be 300°C-340°C, and the reaction pressure can be 5Mpa-7Mpa.

[0055] In the present invention, the temperature of the gasifier can be 1000° C. to 1200° C., and the pressure of the gasifier can be 0.5 MPa to 1.5 MPa, which is more conducive to gasifying and decomposing solid biomass into synthesis gas.

[0056] By adopting the above-mentioned specific process parameters, not only can the conversion efficiency of biomass oil be significantly improved, but also the waste of resources can be effectively avoided, providing strong technical support for the sustainable utilization and conversion of biomass resources.

[0057] In a preferred embodiment, the hydrogen production unit includes but is not limited to water electrolysis equipment and a compressor. The hydrogen production unit mainly produces hydrogen in an electrolyzer to achieve the purpose of generating hydrogen by electrolyzing water.

[0058] The electrolytic cell performs alkaline water electrolysis, the operating temperature can be between 80°C and 90°C, and the operating pressure can be between 0.5MPa and 2.5MPa.

[0059] In a preferred embodiment, the biomass-green hydrogen dual-drive multi-energy conversion system can also be provided with a solar wind-solar complementary unit. Figure 1 , to convert renewable energy into electrical energy for water electrolysis in hydrogen production units.

[0060] In the present invention, the solar wind-solar complementary unit includes a power generation system consisting of a wind turbine, a solar cell array, an intelligent controller, a battery pack, a multifunctional inverter, cables, and supporting and auxiliary parts.

[0061] The solar wind and solar complementary unit can convert renewable energy into electricity for hydrogen production unit. It uses lithium-ion battery energy storage system. When the total electricity generated by the system (solar and wind energy) exceeds 1.2 times the current demand of the water electrolyzer, the charging process is started; when the energy storage system reaches the set charging upper limit of 90% capacity, the charging process is stopped to prevent overcharging from causing damage to the battery. The power demand of the water electrolyzer is monitored in real time through EMS. When the total electricity generated by the system is less than 0.9 times the current demand of the water electrolyzer, the discharge process is started; when the energy storage system reaches the set capacity of 10%, the discharge process is stopped to prevent over-discharge from causing damage to the battery.

[0062] In a preferred embodiment, the biomass-green hydrogen dual-drive multi-energy conversion system can also be provided with a waste heat utilization unit, a liquid storage unit I, a liquid storage unit II, an energy storage unit and a hydrogen storage unit. Figure 1 .

[0063] The waste heat utilization unit is used for comprehensive utilization of waste heat generated in the fuel cell power generation unit; the waste heat utilization unit includes but is not limited to lithium bromide units and screw expander power generation equipment; the liquid storage unit I is used to store biodiesel and / or bio-jet fuel generated by the biomass conversion unit; the liquid storage unit II is used to store methanol synthesized by the methanol synthesis unit; the energy storage unit is used to store the electrical energy generated by the waste heat through the screw expander power generation; the hydrogen storage unit is used to store excess green hydrogen.

[0064] In the present invention, the liquid storage unit can use an internal floating roof tank, the hydrogen storage unit can use a Type IV hydrogen storage tank (a polymer liner and a fully composite material outer gas tank); the energy storage unit can use a battery energy storage device (centralized, 1500V).

[0065] In a preferred embodiment, the LNG integrated heat exchange unit includes but is not limited to an LNG vaporizer and an LNG heat exchanger.

[0066] In the present invention, the LNG integrated heat exchange unit utilizes a heat exchanger to implement efficient heat exchange between the cold energy of the LNG main pipeline and the heat exchange network of multiple energy conversion units (including a hydrogen production unit, a biomass conversion unit, and a fuel cell power generation unit), thereby achieving effective recovery of cold energy and transfer of heat energy, and promoting efficient operation of the entire system.

[0067] In a preferred embodiment, the methanol synthesis unit includes but is not limited to gas purification equipment, a steam reforming converter, a methanol synthesis reactor, and product separation and purification equipment to achieve the purpose of converting natural gas into methanol.

[0068] In the present invention, the reaction temperature of the steam reforming converter can be 800°C to 900°C, and the reaction pressure can be 4Mpa to 5Mpa; the reaction temperature of the methanol synthesis reactor can be 230°C to 280°C, and the reaction pressure can be 2Mpa to 4Mpa; wherein the catalyst used in the methanol synthesis reactor can be Cu-ZnO-CeO2 / Al2O3, wherein the molar ratio of Cu, Zn, and Al can be 1:1:2.8, and the amount of CeO2 added can be between 0.5% and 1.5%.

[0069] By adopting the above-mentioned specific process parameters, not only the conversion efficiency of methanol is significantly improved, but also the energy consumption of the entire synthesis process is effectively reduced, providing a more economical and efficient technical path for the industrial production of methanol.

[0070] In a preferred embodiment, the fuel cell power generation unit includes but is not limited to a desulfurization device and a SOFC power generation unit.

[0071] Among them, the SOFC generator set can use an anode support and a Ni-ZrO-carbon fiber composite matrix, and the operating temperature can be 650°C to 750°C.

[0072] The SOFC generator set reacts as follows:

[0073] Anode reaction:

[0074] H2+O 2- →H2O+2e

[0075] CO+O 2- →CO2+2e -

[0076] Cathode reaction: O2+4e - →2O 2-

[0077] Overall reaction: H2+CO+O2→H2O+CO2+electricity.

[0078] In a preferred embodiment, the biomass-green hydrogen dual-drive multi-energy conversion system can also be provided with a water purification unit. Figure 1 , used to treat wastewater generated by biomass conversion units and / or SOFC power generation units, and to recycle the purified water for electrolysis of water to produce green hydrogen and / or steam reforming LNG.

[0079] The water purification unit includes but is not limited to water purification treatment equipment, which may specifically be composed of a pretreatment device, a core purification device (coagulation tank, sedimentation tank and filtration tank) and a control system (PLC controller and human-machine interface).

[0080] The biomass-green hydrogen dual-drive multi-energy conversion system of the present invention has achieved the following beneficial effects:

[0081] (1) Deep integration of clean energy resources: By building a biomass-green hydrogen dual-driven multi-energy comprehensive conversion network, we innovatively combine biomass, a renewable resource, with green hydrogen, a zero-carbon emission energy carrier, to achieve deep integration of the two clean energy sources. This not only broadens the boundaries of energy utilization, but also promotes the optimization of the energy structure, providing a cleaner and more efficient solution for the energy sector.

[0082] (2) Efficient conversion and diversified output: Flexible adjustment according to market demand can produce a variety of high value-added energy products including biodiesel and bio-jet fuel. Diversified energy output not only meets the specific energy needs of different industries, but also improves the economy and flexibility of energy utilization. At the same time, biomass gasification and the generation of green hydrogen synthesis gas provide a stable and reliable fuel source for solid oxide fuel cells (SOFCs), achieving efficient conversion and utilization of energy.

[0083] (3) Plant power generation and waste heat utilization: The synthesis gas generated by biomass gasification and green hydrogen is used to supply SOFC for plant power generation, which not only reduces the dependence on traditional fossil energy, but also reduces the loss in the energy conversion process through the efficient power generation process of SOFC. In addition, the waste heat generated by SOFC is fully utilized to further improve the energy utilization efficiency of the entire system and achieve "full utilization" of energy.

[0084] (4) LNG cold energy utilization and methanol synthesis: LNG input provides cold energy heat exchange and is used as a raw material for producing methanol. The low-temperature cold energy of LNG is cleverly utilized, providing an additional energy-saving approach for methanol synthesis. This not only reduces the cost of methanol production, but also improves the overall energy efficiency of the entire energy conversion system.

[0085] (5) Green hydrogen storage and energy system flexibility: The remaining green hydrogen can enter the hydrogen storage module, providing the system with a flexible means of energy regulation; as a clean and efficient energy storage medium, the storage of green hydrogen not only enhances the energy storage capacity of the system, but also improves the system's ability to cope with fluctuations in energy demand, ensuring the stability and reliability of energy supply.

[0086] In summary, the present invention has made significant breakthroughs in the deep integration and efficient conversion of biomass and green hydrogen, and has promoted the output and value extension of diversified energy products. The present invention significantly improves the comprehensive benefits and sustainable development potential of the overall energy system by optimizing the energy structure, improving energy utilization efficiency, reducing production costs, and enhancing system flexibility, providing strong support for building a green, low-carbon, efficient and safe energy system.

[0087] According to a second aspect of the present invention, there is provided an operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system as described in any one of the above, comprising the following steps:

[0088] The green hydrogen produced by the hydrogen production unit is transported to the biomass conversion unit and the fuel cell power generation unit, the biomass is sent to the biomass conversion unit to be converted into synthesis gas and / or biodiesel and / or bio-jet fuel, the obtained synthesis gas is supplied to the methanol synthesis unit and the fuel cell power generation unit, the synthesis gas and green hydrogen are used to generate electricity and waste heat in the fuel cell power generation unit, LNG is input into the LNG integrated heat exchange unit, the cold energy of LNG is used for heat exchange, and the LNG after heat exchange is reformed with water vapor to undergo catalytic reaction with the synthesis gas in the methanol synthesis unit to synthesize methanol.

[0089] The operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system provided by the present invention can significantly improve the comprehensive benefits and sustainable development potential of the overall energy system, and provide strong support for building a green, low-carbon, efficient and safe energy system.

[0090] In a preferred embodiment, the operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system of the present invention further includes the following steps:

[0091] In the waste heat utilization unit, part of the waste heat generated by the SOFC unit of the fuel cell power generation unit is reused through the lithium bromide unit to achieve cooling and heating, and the remaining waste heat is used to generate electricity through the screw expander, and the generated electricity is input into the energy storage unit for standby.

[0092] A typical operation mode of a biomass-green hydrogen dual-drive multi-energy conversion system. The operation principle is shown in Figure 2 , including the following steps:

[0093] (1) Startup of the hydrogen production unit: Start the water electrolysis equipment and use the electricity generated by renewable energy (such as solar energy and wind energy) to electrolyze water to produce green hydrogen. The resulting green hydrogen is transported to the biomass conversion unit and the fuel cell power generation unit through pipelines for use, and the remaining green hydrogen is stored in the hydrogen storage unit for standby use;

[0094] (2) Start-up of the biomass conversion unit: biomass raw materials (such as crop straw, forestry waste, and bio-oil) are fed into the biomass conversion unit, and the gasification equipment or hydrodeoxygenation & cracking / isomerization unit is started according to demand to convert the biomass raw materials into synthesis gas and / or biodiesel and / or bio-jet fuel. The purified synthesis gas is divided into two parts: one part is supplied to the SOFC power generation unit, and the other part is used as a raw material for methanol synthesis. The synthesized biodiesel and / or bio-jet fuel is fed into the liquid storage unit.

[0095] (3) Liquid storage unit startup: The synthesized biodiesel and bio-jet fuel are stored in the liquid storage unit, and liquid storage preparations are made in advance for the methanol synthesis unit;

[0096] (4) Start-up of SOFC power generation unit: The purified synthesis gas and green hydrogen are fed into the SOFC generator set to generate electricity, while generating high-temperature waste heat. The electricity generated can be supplied to the plant or sold to the grid;

[0097] (5) Start-up of the waste heat utilization unit: The high-temperature waste heat generated by SOFC is utilized in two ways. On the one hand, the superheated exhaust gas generated by the SOFC unit in the fuel cell power generation unit is reused through the lithium bromide unit for cooling and heating of the entire system network. On the other hand, the remaining superheated exhaust gas is used to generate electricity through the screw expander and enters the energy storage device for backup;

[0098] (6) Start-up of LNG integrated heat exchange unit: LNG is fed into the LNG integrated heat exchange unit, and the cold energy of LNG is used for heat exchange to improve the energy efficiency of the system; the LNG after heat exchange can be used as raw material or further processed into other products;

[0099] (7) Start-up of methanol synthesis unit: The purified synthesis gas and LNG after steam reforming are used as raw material components of the methanol synthesis unit to synthesize methanol through catalytic reaction; the generated methanol can be used as fuel, chemical raw material or further processed into other products;

[0100] (8) Start-up of the hydrogen storage unit: The remaining green hydrogen is stored in the hydrogen storage unit by compression, liquefaction, etc. The hydrogen storage unit can provide hydrogen to other units as needed.

[0101] The present invention is further described below by way of examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or directly purchased from the market.

[0102] Example 1

[0103] A biomass-green hydrogen dual-drive multi-energy conversion system, the structural diagram is shown in Figure 1 See the schematic diagram for the principle Figure 2 , mainly composed of biomass conversion unit, hydrogen production unit, LNG comprehensive heat exchange unit, methanol synthesis unit, fuel cell power generation unit, waste heat utilization unit and storage unit;

[0104] Among them, the storage unit includes a liquid storage unit, a hydrogen storage unit and an energy storage unit.

[0105] In this embodiment, the hydrogen production unit is used to electrolyze water to produce green hydrogen. The produced green hydrogen is transported to the biomass conversion unit and the fuel cell power generation unit through pipelines for use, and the remaining green hydrogen can enter the hydrogen storage unit for standby use;

[0106] The biomass conversion unit converts biomass into synthesis gas and / or biodiesel and / or biojet fuel using green hydrogen. The biomass conversion unit includes a hydrodeoxygenation & cracking / isomerization reactor, and a gasifier;

[0107] The biomass conversion unit can "tailor" the treatment method according to the characteristics and needs of the raw materials. One is to send agricultural waste raw materials into the gasifier to produce synthesis gas (reaction temperature 850℃, reaction pressure 4.2Mpa) after pretreatment to achieve efficient resource conversion; the other is to classify and utilize oil biomass raw materials according to their specific chemical properties after pretreatment. If the carbon chain length of the raw material is moderate (oils and fats between 14 and 18 carbon atoms), it is suitable as a raw material for biodiesel because it has good combustion performance and environmental protection characteristics; if the carbon chain of the oil is longer (the carbon number exceeds a certain limit), it is more suitable as a raw material for bio-jet fuel, because long-chain fatty acids can generate hydrocarbon compounds suitable for aviation fuel requirements under specific conversion conditions;

[0108] It should be noted that the material of the hydrodeoxygenation & cracking / isomerization reactor is S31603. When preparing biodiesel, Ni-Mo / SAPO-11 catalyst (Ni loading 10%, Mo loading 0.5%) is used, the mass ratio of biomass oil and catalyst is 1:0.06, the reaction temperature is 340°C, and the reaction pressure is 7.5Mpa; when preparing bio-jet fuel, core-shell Ni / ZSM-5 / SAPO-5 catalyst (Ni loading 8%) is used, the mass ratio of biomass oil and catalyst is 1:0.12, the silicon-aluminum ratio is 340, the reaction temperature is 320°C, and the reaction pressure is 6.5Mpa.

[0109] The fuel cell power generation unit uses syngas and green hydrogen to generate electricity and high-temperature waste heat. The fuel cell power generation unit uses a SOFC unit to use green hydrogen and syngas as raw materials to power the entire system network. The SOFC unit uses an anode support and a Ni-ZrO-carbon fiber composite matrix with an operating temperature of 720°C;

[0110] It should be noted that the water electrolysis hydrogen production device in the hydrogen production unit is connected to the hydrodeoxygenation & cracking / isomerization reactor and the SOFC unit through pipelines, thereby providing green hydrogen as a raw material;

[0111] The waste heat utilization unit utilizes the high-temperature waste heat generated by SOFC in two ways. On the one hand, the superheated exhaust gas generated by the SOFC unit in the fuel cell power generation unit is reused through the lithium bromide unit for cooling and heating of the entire system network. On the other hand, the remaining superheated exhaust gas is used to generate electricity through the screw expander and enters the energy storage device for backup.

[0112] The LNG integrated heat exchange unit uses a heat exchanger to efficiently exchange the cold energy of the LNG main pipeline with the heat exchange network of multiple energy conversion units (including hydrogen production units, biomass conversion units, and fuel cell power generation units), achieving effective recovery of cold energy and heat energy transfer, and promoting efficient operation of the entire system;

[0113] The methanol synthesis unit includes gas purification equipment, steam reforming converter, methanol synthesis reactor, product separation and purification equipment, and uses the LNG reformed by steam from the synthesis gas and LNG comprehensive heat exchange unit as a raw material component to perform catalytic reaction to synthesize methanol;

[0114] It should be noted that the catalyst used in the methanol synthesis reactor (material S31603) is Cu-ZnO-CeO2 / Al2O3, in which the molar ratio of Cu, Zn and Al is 1:1:2.8, the amount of CeO2 added is 0.6% (mass fraction), the temperature of the methanol synthesis reactor is 270°C, and the pressure is 3.5Mpa.

[0115] Example 2

[0116] This embodiment provides a biomass-green hydrogen dual-drive multi-energy conversion system, which is different from Embodiment 1 only in that a water purification unit is further provided in this embodiment to treat wastewater generated by the biomass conversion unit and / or the SOFC generator set, and to circulate the purified water back for electrolysis of water to produce green hydrogen and / or steam reforming LNG;

[0117] The rest of the structure is the same as that of Example 1.

[0118] Example 3

[0119] This embodiment provides a biomass-green hydrogen dual-drive multi-energy conversion system, which is different from the first embodiment only in that a solar wind-solar complementary unit is also provided in this embodiment to supply power to the hydrogen production unit and the fuel cell power generation unit, and can convert unstable and fluctuating electric energy into a stable and reliable power supply;

[0120] The rest of the structure is the same as that of Example 1.

[0121] Example 4

[0122] This embodiment is an operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system of Example 1, including the following steps:

[0123] (1) Startup of the hydrogen production unit: Start the water electrolysis equipment and use the electricity generated by renewable energy (such as solar energy and wind energy) to electrolyze water to produce green hydrogen. The resulting green hydrogen is transported to the biomass conversion unit and the fuel cell power generation unit through pipelines for use, and the remaining green hydrogen is stored in the hydrogen storage unit for standby use;

[0124] (2) Start-up of the biomass conversion unit: biomass raw materials (such as crop straw, forestry waste, and bio-oil) are fed into the biomass conversion unit, and the gasification equipment or hydrodeoxygenation & cracking / isomerization unit is started according to demand to convert the biomass raw materials into synthesis gas and / or biodiesel and / or bio-jet fuel. The purified synthesis gas is divided into two parts: one part is supplied to the SOFC power generation unit, and the other part is used as a raw material for methanol synthesis. The synthesized biodiesel and / or bio-jet fuel is fed into the liquid storage unit.

[0125] (3) Liquid storage unit startup: The synthesized biodiesel and bio-jet fuel are stored in the liquid storage unit, and liquid storage preparations are made in advance for the methanol synthesis unit;

[0126] (4) Start-up of SOFC power generation unit: The purified synthesis gas and green hydrogen are fed into the SOFC generator set to generate electricity, while generating high-temperature waste heat. The electricity generated can be supplied to the plant or sold to the grid;

[0127] (5) Start-up of the waste heat utilization unit: The high-temperature waste heat generated by SOFC is utilized in two ways. On the one hand, the superheated exhaust gas generated by the SOFC unit in the fuel cell power generation unit is reused through the lithium bromide unit for cooling and heating of the entire system network. On the other hand, the remaining superheated exhaust gas is used to generate electricity through the screw expander and enters the energy storage device for backup;

[0128] (6) Start-up of LNG integrated heat exchange unit: LNG is fed into the LNG integrated heat exchange unit, and the cold energy of LNG is used for heat exchange to improve the energy efficiency of the system; the LNG after heat exchange can be used as raw material or further processed into other products;

[0129] (7) Start-up of methanol synthesis unit: The purified synthesis gas and LNG after steam reforming are used as raw material components of the methanol synthesis unit to synthesize methanol through catalytic reaction; the generated methanol can be used as fuel, chemical raw material or further processed into other products;

[0130] (8) Start-up of the hydrogen storage unit: The remaining green hydrogen is stored in the hydrogen storage unit by compression, liquefaction, etc. The hydrogen storage unit can provide hydrogen to other units as needed.

[0131] Comparative Example 1

[0132] The only difference between this comparative example and Example 1 is that no biomass conversion unit is provided in this comparative example;

[0133] The rest of the structure is the same as that of Example 1.

[0134] Compared with Example 1, the system of this comparative example cannot achieve deep integration and efficient conversion of biomass and green hydrogen.

[0135] Comparative Example 2

[0136] The difference between this comparative example and Example 1 is that no LNG comprehensive heat exchange unit is provided in this comparative example;

[0137] The rest of the structure is the same as that of Example 1.

[0138] Compared with Example 1, the system of this comparative example cannot effectively recover cold energy and transfer heat energy, which is not conducive to promoting the efficient operation of the entire system.

[0139] Comparative Example 3

[0140] The difference between this comparative example and Example 1 is that no fuel cell power generation unit is provided in this comparative example;

[0141] The rest of the structure is the same as that of Example 1.

[0142] Compared with Example 1, the system of this comparative example is unable to generate electricity and high-temperature waste heat, which is not conducive to promoting the output and value extension of diversified energy products.

[0143] In summary, the present invention has made significant breakthroughs in the deep integration and efficient conversion of biomass and green hydrogen, and has promoted the output and value extension of diversified energy products. The present invention has significantly improved the comprehensive benefits and sustainable development potential of the overall energy system by optimizing the energy structure, improving energy utilization efficiency, reducing production costs, and enhancing system flexibility, providing strong support for building a green, low-carbon, efficient and safe energy system.

[0144] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A biomass-green hydrogen dual-drive multi-energy conversion system, characterized in that: It includes biomass conversion unit, LNG integrated heat exchange unit, hydrogen production unit, methanol synthesis unit and fuel cell power generation unit; The hydrogen production unit is used to electrolyze water to produce green hydrogen; The biomass conversion unit converts biomass into synthesis gas and / or biodiesel and / or biojet fuel using green hydrogen; The fuel cell power generation unit utilizes synthesis gas and green hydrogen to generate electricity and waste heat; The LNG comprehensive heat exchange unit is located between the biomass conversion unit and the hydrogen production unit, and utilizes the cold energy of LNG for heat exchange to improve the energy efficiency of the system; The methanol synthesis unit uses the synthesis gas and the LNG reformed by water steam from the LNG comprehensive heat exchange unit as raw material components to carry out catalytic reaction to synthesize methanol.

2. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 1 is characterized in that: The biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a solar wind-solar complementary unit to convert renewable energy into electric energy for electrolysis of water in the hydrogen production unit; The biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a waste heat utilization unit, a first liquid storage unit, a second liquid storage unit, an energy storage unit and a hydrogen storage unit; The waste heat utilization unit is used to comprehensively utilize the waste heat generated in the fuel cell power generation unit; The waste heat utilization unit includes a lithium bromide unit and a screw expander power generation equipment; The first liquid storage unit is used to store biodiesel and / or bio-jet fuel generated by the biomass conversion unit; The second liquid storage unit is used to store methanol synthesized by the methanol synthesis unit; The energy storage unit is used to store the electric energy generated by the waste heat through the screw expander; The hydrogen storage unit is used to store excess green hydrogen.

3. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 1 is characterized in that: The biomass conversion unit includes a hydrodeoxygenation & cracking / isomerization reactor, and a gasifier; The hydrodeoxygenation & cracking / isomerization reactor is used to produce biodiesel and / or biojet fuel; The gasifier is used for gasification and decomposition to generate synthesis gas.

4. The biomass-green hydrogen dual-drive multi-energy conversion system according to any one of claims 1 to 3, characterized in that: The LNG comprehensive heat exchange unit includes an LNG vaporizer and an LNG heat exchanger.

5. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 4 is characterized in that: The hydrogen production unit comprises a water electrolysis device and a compressor.

6. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 1 is characterized in that: The methanol synthesis unit comprises a steam reforming converter and a methanol synthesis device.

7. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 1 is characterized in that: The fuel cell power generation unit comprises a desulfurization device and a SOFC power generation unit.

8. The biomass-green hydrogen dual-drive multi-energy conversion system according to claim 7 is characterized in that: The biomass-green hydrogen dual-drive multi-energy conversion system is also provided with a water purification unit for treating wastewater generated by the biomass conversion unit and / or the SOFC generator set, and recycling the purified water for electrolysis of water to produce green hydrogen and / or steam reforming LNG; The water purification unit includes water purification treatment equipment.

9. An operation mode of the biomass-green hydrogen dual-drive multi-energy conversion system according to any one of claims 1 to 8, characterized in that: The following steps are involved: The green hydrogen produced by the hydrogen production unit is transported to the biomass conversion unit and the fuel cell power generation unit, the biomass is sent to the biomass conversion unit to be converted into synthesis gas and / or biodiesel and / or bio-jet fuel, the obtained synthesis gas is supplied to the methanol synthesis unit and the fuel cell power generation unit, the synthesis gas and green hydrogen are used to generate electricity and waste heat in the fuel cell power generation unit, LNG is input into the LNG integrated heat exchange unit, the cold energy of LNG is used for heat exchange, and the LNG after heat exchange is reformed with water vapor to undergo catalytic reaction with the synthesis gas in the methanol synthesis unit to synthesize methanol.

10. The operating method according to claim 9, characterized in that: The operation mode also includes the following steps: In the waste heat utilization unit, part of the waste heat generated by the SOFC unit of the fuel cell power generation unit is reused through the lithium bromide unit to achieve cooling and heating, and the remaining waste heat is used to generate electricity through the screw expander, and the generated electricity is input into the energy storage unit for standby.

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