System and method for preparing methanol and co-producing fresh water based on seawater and biomass

Abstract

The invention relates to a system and a method for preparing methanol and co-producing fresh water based on seawater and biomass. The device comprises a biomass treatment unit, an electrolyzed water coupling low-temperature distillation integrated system and a methanol preparation unit, wherein the electrolyzed water coupling low-temperature distillation integrated system comprises an alkaline electrolytic bath unit, an oxygen separation cooling unit, a hydrogen separation cooling unit, a hydrogen purification cooling unit, an alkali liquor filtering and circulating unit and a seawater desalination unit. Seawater is directly introduced into the electrolyzed water coupling low-temperature distillation integrated system, prepared oxygen is supplied to the biomass treatment unit, the final product is effectively utilized, and the occupied area is small; the alkaline electrolytic bath with a good flow guide effect is arranged, and the water blocking boss is arranged at the alkali liquor inlet, so that water enters a reaction area uniformly. The flow guide plate is arranged in the reaction area, so that the water flow can uniformly pass through the reaction area, the alkali liquor flows more smoothly and can tolerate high current density, and the efficiency of the device is further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of biomass and seawater development and utilization, and in particular to a system and method for producing fresh water by co-producing methanol from seawater and biomass. Background Art

[0002] At present, in the global and domestic energy structure, fossil fuels such as coal and oil dominate the power industry. The consumption of coal and natural gas is very large, and thermal power generation has become the main source of harmful gas emissions, posing a threat to energy development and the ecological environment. Biomass energy can be converted into conventional solid, liquid and gaseous fuels. It is inexhaustible and is a renewable energy source. It is also the only renewable carbon source.

[0003] Hydrogen energy is regarded as the clean energy with the greatest development potential in the 21st century. Using green electricity generated by renewable energy such as solar energy and wind energy to drive the electrolysis of water to produce hydrogen is of great significance to solving the problem of energy shortage and achieving the "dual carbon" goal. Among the current water electrolysis hydrogen production technologies, alkaline water electrolysis has a low cost and relatively mature technology. It is the most widely industrialized hydrogen production technology and occupies a dominant position. The "Global Water Use Report for Hydrogen Production" released by the International Renewable Energy Agency (IRENA) shows that the current mainstream hydrogen production methods in the world require fresh water, mainly concentrated in the two major processes of hydrogen production and cooling. About 32.2 liters of fresh water are required to produce 1 kilogram of blue hydrogen. In the production of green hydrogen, the amount of fresh water consumed by the alkaline water electrolysis hydrogen production process to produce 1 kilogram of hydrogen is estimated to be 22.3 liters. However, global fresh water resources are extremely limited, and the large-scale promotion and application of water electrolysis hydrogen production technology will undoubtedly aggravate the problem of fresh water shortage.

[0004] Methanol is also known as "liquid sunshine". In 2018, the Chinese Academy of Sciences established a "Liquid Sunshine" task force to study methanol fuel. The task force believes that methanol can be divided into five generations based on its source. The fourth generation is biomass methanol, also known as green methanol. Summary of the invention

[0005] According to the technical problems raised above, a system and method for producing fresh water based on seawater and biomass to produce methanol is provided. The present invention can achieve low-cost treatment of biomass waste, save the floor space of biomass treatment equipment, and achieve efficient production of methanol.

[0006] The technical means adopted by the present invention are as follows:

[0007] A desalination system based on the co-production of methanol from seawater and biomass, comprising: a biomass processing unit, an electrolytic water coupled low-temperature distillation integrated system and a methanol preparation unit, wherein the electrolytic water coupled low-temperature distillation integrated system comprises an alkaline electrolytic cell unit, an oxygen separation cooling unit, a hydrogen separation cooling unit, a hydrogen purification cooling unit, an alkali solution filtration circulation unit and a seawater desalination unit, wherein the electrolytic water coupled low-temperature distillation integrated system collects seawater to be treated, and the seawater desalination unit is used to heat the seawater, remove impurities with steam and condense to produce fresh water and concentrated seawater to be collected; the output end of the seawater desalination unit is connected to the alkaline electrolytic cell unit, and the fresh water in the alkaline electrolytic cell unit is directly Under the action of galvanic current, it is decomposed into hydrogen and oxygen, hydrogen and alkali liquid enter the hydrogen separation cooling unit, and oxygen and alkali liquid enter the oxygen separation cooling unit; the hydrogen purification cooling unit is used to complete the purification of hydrogen, and the alkali liquid filtration circulation unit is used to complete the forced circulation of alkali liquid in the alkaline electrolyzer unit and the hydrogen separation cooling unit and the oxygen separation cooling unit. The biomass processing unit is connected to the oxygen of the electrolysis water coupled low-temperature distillation integrated system. After the biomass processing unit obtains the biomass, it reacts with oxygen to generate carbon dioxide. The output end of the biomass processing unit is connected to the methanol preparation unit, and the hydrogen of the electrolysis water coupled low-temperature distillation integrated system is also transported to the methanol preparation unit.

[0008] Furthermore, the seawater enters a seawater desalination unit or a hydrogen separation cooling unit or an oxygen separation cooling unit.

[0009] Furthermore, the hydrogen outlet of the alkaline electrolyzer module is connected to the hydrogen separation cooling unit, the oxygen outlet of the alkaline electrolyzer module is connected to the oxygen separation cooling unit, the alkali liquid inlet of the alkaline electrolyzer module is connected to the seawater desalination unit, the oxygen separation cooling unit separates oxygen and alkali liquid by a gas-liquid separation method, the hydrogen separation cooling unit separates hydrogen and alkali liquid by a gas-liquid separation method, the hydrogen outlet of the hydrogen separation cooling unit is connected to the hydrogen purification cooling unit, the alkali liquid outlet of the oxygen separation cooling unit and the alkali liquid outlet of the hydrogen separation cooling unit are both connected to the alkali liquid filtration circulation unit to provide high-temperature alkali liquid to be cooled, and the fresh water outlet of the seawater desalination unit is connected to the hydrogen separation cooling unit.

[0010] Furthermore, the seawater desalination unit includes a device cylinder, a vacuum system, a condenser, a water receiving plate, and a wire mesh separator. The device cylinder is provided with a vacuum system connection port, a seawater inlet port, a concentrated seawater outlet port, a fresh water outlet, and an alkali solution circulation pipe. The device cylinder is connected to the vacuum system through the vacuum system connection port, and is directly connected to seawater or an oxygen separation cooling unit / hydrogen separation cooling unit through the seawater inlet port. The concentrated seawater outlet port is used to collect concentrated seawater. The alkali solution circulation pipe is used to exchange heat between high-temperature alkali solution and seawater, reduce the temperature of the alkali solution, and make the seawater reach the evaporation temperature and evaporate into water vapor. The water vapor is condensed by the condenser. The water receiving plate is used to receive condensed water droplets, and its output end is connected to the fresh water outlet. A wire mesh separator is arranged in the device cylinder, which is used to separate larger droplets and impurities in the water vapor.

[0011] Furthermore, the alkaline electrolytic cell unit includes a cathode end plate and an anode end plate, and a plurality of electrolytic cell units consisting of bipolar plates are arranged between the cathode end plate and the anode end plate; a barrier is arranged between adjacent electrolytic cell units; the cathode end plate, the bipolar plate and the anode end plate all include a plate body, and positioning holes, fastening holes, an alkali solution inlet, a gas-liquid outlet and a guide assembly are arranged at corresponding positions of each plate; the guide assembly of the cathode end plate and the anode end plate is opened on the inner side close to the bipolar plate, the guide assembly of the bipolar plate is opened on one side, and a flow channel for connecting the alkali solution inlet and the gas-liquid outlet is opened in the middle position of the end surface of the plate body, and the guide assembly divides the flow channel in a preset form, and the guide assembly specifically includes a barrier mechanism, a boosting mechanism and a guide mechanism, the barrier mechanism is arranged on the alkali solution inlet side, the guide mechanism is arranged on the alkali solution outlet side, and the boosting mechanism is arranged between the barrier mechanism and the guide mechanism.

[0012] Furthermore, the blocking mechanism includes a liquid blocking platform, the width of which is not greater than the diameter of the alkali solution inlet, and the liquid blocking platform protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate where it is located; the boosting mechanism includes a boosting platform connected to the left and right side walls and arranged in the flow channel, the boosting platform is a complete and uninterrupted arc, the boosting platform protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate where it is located, and the protruding distance is less than the thickness of the blocking mechanism and the guide mechanism; the guide mechanism is located at the center of the plate body, and includes a plurality of guide plates arranged in parallel along the main direction of the flow channel.

[0013] Furthermore, the alkaline electrolytic cell unit includes an end plate, and a plurality of electrolytic cell units consisting of monopolar plates or bipolar plates are arranged between the end plates on both sides; a barrier is arranged between adjacent electrolytic cell units; the end plate and the electrode plate both include a plate body, and positioning holes, fastening holes, alkali liquid inlets and gas-liquid outlets are arranged at corresponding positions of each plate; a flow guide mechanism is arranged on the electrode plate, and a preset alkali liquid tank is opened at the bottom position of the end surface of the end plate, an alkali liquid diversion area is arranged at the bottom of the electrode plate, and a flow channel connecting the alkali liquid diversion area and the gas-liquid outlet is arranged above the alkali liquid diversion area, and the flow channel is divided into a preset form by the flow guide component.

[0014] Furthermore, when it is a single-pole plate, at the inlet end of the flow channel of the guide plate of the single-pole plate, a number of bosses are arranged between adjacent guide plates / guide plates and the end of the flow channel, and all the bosses are arranged as a whole in a preset pattern; at the outlet end of the flow channel of the guide plate of the single-pole plate, a number of bosses are arranged between adjacent guide plates / guide plates and the end of the flow channel between the end flow channel to the flow channel at the lower end of the gas-liquid confluence total outlet, and all the bosses are arranged as a whole in a preset pattern; when it is a bipolar plate, a number of bosses are arranged before and after the flow channel inlet of the guide plate of the bipolar plate, and all the bosses are arranged as a whole in a preset pattern; two gas-liquid confluence outlets are arranged at the end of the flow channel of the bipolar plate and the two gas-liquid confluence total outlets are blocked, and a terminal is arranged at the plate cylinder frame of the bipolar plate.

[0015] Furthermore, the seawater desalination unit is also connected to a fresh water storage unit for storing excess fresh water.

[0016] A method for producing fresh water by co-producing methanol from seawater and biomass, comprising the following steps:

[0017] The electrolysis water coupling low temperature distillation integrated system is connected with the seawater source and biomass processing unit to start the co-production of fresh water from seawater and biomass to produce methanol.

[0018] The seawater is directly transported to the desalination unit for fresh water production and concentrated seawater separation, or enters the desalination unit after passing through the oxygen separation cooling unit and the hydrogen separation cooling unit. The seawater can play an auxiliary cooling role in the oxygen separation cooling unit and the hydrogen separation cooling unit.

[0019] Fresh water in the alkaline electrolyser unit is decomposed into hydrogen and oxygen by direct current;

[0020] The oxygen outlet of the alkaline electrolyzer unit transports oxygen and alkaline solution to the oxygen separation cooling unit for gas-liquid separation;

[0021] The hydrogen outlet of the alkaline electrolyzer unit transports hydrogen and alkali liquid to the hydrogen separation cooling unit for gas-liquid separation. The hydrogen and a small amount of water after preliminary purification enter the hydrogen purification cooling unit for further purification to a hydrogen content of ≥99.99%;

[0022] The alkali solution filtration circulation unit extracts alkali solution from the oxygen separation cooling unit and the hydrogen separation cooling unit, cools it in the seawater desalination unit, and finally transports it to the alkaline electrolyzer unit to complete the cooling and forced circulation of the alkali solution.

[0023] The heat released by the alkali solution during cooling in the desalination unit is used to heat the seawater under negative pressure to produce fresh water, which is then transported to the hydrogen separation module to supplement the raw fresh water used for electrolysis and also assist in hydrogen scrubbing and cooling.

[0024] The biomass processing unit uses oxygen generated by water electrolysis to burn biomass to produce a certain amount of CO2;

[0025] The hydrogen exhausted from the hydrogen purification cooling unit and the CO2 exhausted from the biomass processing unit enter the methanol preparation unit together for methanol preparation.

[0026] Compared with the prior art, the present invention has the following advantages: the traditional biomass methanol production process requires a large amount of oxygen to be stored and occupies a large area. The present invention directly introduces seawater into the electrolytic water coupled low-temperature distillation integrated system, and supplies the prepared oxygen to the biomass processing unit, so that the final product is effectively utilized and occupies a small area; the electrolytic water coupled low-temperature distillation integrated system uses the alkali solution to be cooled to heat the seawater in a negative pressure environment. While the alkali solution is cooled, the heat emitted when the alkali solution is cooled is also utilized. The fresh water generated by the seawater desalination unit is used as the electrolytic water raw material to supplement the alkaline electrolytic cell unit, alleviating the dependence on fresh water resources; so that the seawater and biomass are finally completely converted into high-concentration hydrogen, oxygen, fresh water, methanol, and high-concentration sea salt is separated. By setting an alkaline electrolytic cell with good diversion effect, a water-blocking boss is set at the inlet of the alkali solution to make the water inlet of the reaction area uniform. A guide plate is set in the reaction area so that the water flow can pass through the reaction area evenly, making the alkali solution flow more unobstructed, and can withstand high electrical density, further improving the efficiency of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0028] Figure 1 This is a schematic diagram of the fresh water co-production system based on seawater and biomass to produce methanol.

[0029] Figure 2 This is a schematic diagram of the structure of a monopolar plate electrolytic cell according to Example 1 of the present invention.

[0030] Figure 3 for Figure 2 Schematic diagram of the main view.

[0031] Figure 4 for Figure 2 Schematic side view of .

[0032] Figure 5 for Figure 2 Schematic top view of .

[0033] Figure 6 This is a schematic diagram of the end plate structure of Example 1 of the present invention.

[0034] Figure 7 This is a schematic diagram of the monopolar plate structure of Example 1 of the present invention.

[0035] Figure 8 This is a schematic diagram of the bipolar plate structure of Example 1 of the present invention.

[0036] Fig. 9 It is a side view of the monopolar plate and the bipolar plate of Example 1 of the present invention.

[0037] Fig.10 This is a schematic diagram of the overall structure of Example 2 of the present invention.

[0038] Fig.11 for Fig.10 main view.

[0039] Fig.12 for Fig.10 Side view of.

[0040] Fig.13 for Fig.10 Top view of the .

[0041] Fig.14 This is a schematic diagram of the bipolar plate structure of Example 2 of the present invention.

[0042] Fig.15 for Fig.14 main view.

[0043] Fig.16 for Figure 6 AA cross-section diagram.

[0044] Fig.17 This is a schematic diagram of the gasket structure of Example 2 of the present invention.

[0045] Fig.18 This is a schematic diagram of the structure after gasket A is installed in Example 2 of the present invention.

[0046] Fig.19 This is a schematic diagram of the structure after gasket B is installed in Example 2 of the present invention.

[0047] In the figure: 1, alkali liquid inlet; 2, gas-liquid confluence total outlet; 3, end plate; 4, terminal; 5, flat gasket; 6, T-type gasket; 7, support column; 8, nut; 9, single-pole plate; 10, insulating gasket; 11, bolt; 12, positioning hole; 13, fastening hole; 14, alkali liquid tank; 15, alkali liquid inlet; 16, gas-liquid confluence total outlet; 17, sealing groove; 18, positioning hole; 19, boss; 20, alkali liquid diversion area; 2 1. Alkali solution flow inlet; 22. Hydrogen outlet or oxygen outlet; 23. Guide plate; 24. Positioning hole; 25. Terminal block; 26. Liquid blocking platform; 27. Guide plate; 28. Alkali solution flow hole; 29. ​​Sealing groove; 30. Support column; 31. Positioning hole; 32. Hydrogen outlet or oxygen outlet; 33. Guide plate; 34. Pressurizing platform; 35. Liquid blocking platform; 36. Alkali solution inlet; 37. Pressure measuring screw; 38. Fastening hole; 39. Pressure measuring column. DETAILED DESCRIPTION

[0048] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0049] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0050] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0051] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0052] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0053] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0054] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0055] like Figure 1As shown, an embodiment of the present invention discloses a desalination water co-production system based on seawater and biomass to produce methanol, comprising: a biomass processing unit, an electrolytic water coupled low-temperature distillation integrated system and a methanol preparation unit, wherein the electrolytic water coupled low-temperature distillation integrated system comprises an alkaline electrolyzer unit, an oxygen separation cooling unit, a hydrogen separation cooling unit, a hydrogen purification cooling unit, an alkali solution filtration circulation unit and a seawater desalination unit, wherein the electrolytic water coupled low-temperature distillation integrated system collects seawater to be treated, and the seawater desalination unit is used to heat the seawater, remove impurities with steam and condense to produce fresh water and concentrated seawater to be collected; the output end of the seawater desalination unit is connected to the alkaline electrolyzer unit, and the alkaline electrolyzer unit The fresh water in the reactor is decomposed into hydrogen and oxygen under the action of direct current, and the hydrogen and alkali liquid enter the hydrogen separation cooling unit, and the oxygen and alkali liquid enter the oxygen separation cooling unit; the hydrogen purification cooling unit is used to complete the purification of hydrogen, and the alkali liquid filtration circulation unit is used to complete the forced circulation of alkali liquid in the alkaline electrolyzer unit and the hydrogen separation cooling unit and the oxygen separation cooling unit. The biomass processing unit is connected to the oxygen of the electrolysis water coupled low-temperature distillation integrated system. After obtaining the biomass, the biomass processing unit reacts with oxygen to generate carbon dioxide. The output end of the biomass processing unit is connected to the methanol preparation unit, and the hydrogen of the electrolysis water coupled low-temperature distillation integrated system is also transported to the methanol preparation unit.

[0056] In the figure, the baseline is the integrated system of water electrolysis coupled with low-temperature distillation.

[0057] The hydrogen-deuterium mixed gas purification cooling unit deoxygenates the incoming hydrogen, trace oxygen and trace water through catalytic reactions, and uses the molecular sieve adsorption principle to remove water and other impurities, ultimately purifying the hydrogen to ≥99.99%.

[0058] In this embodiment, the fresh water in the alkaline electrolytic cell is decomposed into one part of hydrogen and 1 / 2 part of oxygen under the action of direct current. The direct current can be directly connected to an external source, or the power supply can be completed by converting alternating current into direct current.

[0059] The seawater enters the desalination unit or the hydrogen separation cooling unit or the oxygen separation cooling unit. The seawater entering the hydrogen separation cooling unit or the oxygen separation cooling unit can further achieve the function of utilizing the seawater for heat exchange.

[0060] Furthermore, the hydrogen outlet of the alkaline electrolyzer module is connected to the hydrogen separation cooling unit, the oxygen outlet of the alkaline electrolyzer module is connected to the oxygen separation cooling unit, the alkali liquid inlet of the alkaline electrolyzer module is connected to the seawater desalination unit, the oxygen separation cooling unit separates oxygen and alkali liquid by a gas-liquid separation method, the hydrogen separation cooling unit separates hydrogen and alkali liquid by a gas-liquid separation method, the hydrogen outlet of the hydrogen separation cooling unit is connected to the hydrogen purification cooling unit, the alkali liquid outlet of the oxygen separation cooling unit and the alkali liquid outlet of the hydrogen separation cooling unit are both connected to the alkali liquid filtration circulation unit to provide high-temperature alkali liquid to be cooled, and the fresh water outlet of the seawater desalination unit is connected to the hydrogen separation cooling unit.

[0061] Furthermore, the seawater desalination unit includes a device cylinder, a vacuum system, a condenser, a water receiving plate, and a wire mesh separator. The device cylinder is provided with a vacuum system connection port, a seawater inlet port, a concentrated seawater outlet port, a fresh water outlet, and an alkali solution circulation pipe. The device cylinder is connected to the vacuum system through the vacuum system connection port, and is directly connected to seawater or an oxygen separation cooling unit / hydrogen separation cooling unit through the seawater inlet port. The concentrated seawater outlet port is used to collect concentrated seawater. The alkali solution circulation pipe is used to exchange heat between high-temperature alkali solution and seawater, reduce the temperature of the alkali solution, and make the seawater reach the evaporation temperature and evaporate into water vapor. The water vapor is condensed by the condenser. The water receiving plate is used to receive condensed water droplets, and its output end is connected to the fresh water outlet. A wire mesh separator is arranged in the device cylinder, which is used to separate larger droplets and impurities in the water vapor.

[0062] Furthermore, the seawater desalination unit is also connected to a fresh water storage unit for storing excess fresh water.

[0063] In this embodiment, the biomass processing unit used can be a reaction chamber that is only used to provide a reaction site for biomass combustion, or provide a complete set of biomass energy power generation system. The output electric energy can also be supplied to the electrolysis process of the electrolytic water coupled low-temperature distillation integrated system to realize the input of electricity. When the biomass processing unit is large enough, the generated electric energy can also be transmitted to the power grid for grid connection; the reaction site of the methanol preparation unit provides pressure and temperature adjustment, and methanol is synthesized using hydrogen and carbon dioxide. In addition, the biomass processing unit can also include a pre-treatment process, such as anaerobic treatment and other processes, which can be implemented using existing technologies. In this embodiment, the water generated by the biomass processing unit can also be passed into the seawater desalination unit preparation unit as a water source for supplementation, further improving the utilization rate of the product.

[0064] A method for producing fresh water by co-producing methanol from seawater and biomass, comprising the following steps:

[0065] The electrolysis water coupling low temperature distillation integrated system is connected with the seawater source and biomass processing unit to start the co-production of fresh water from seawater and biomass to produce methanol.

[0066] The seawater is directly transported to the desalination unit for fresh water production and concentrated seawater separation, or enters the desalination unit after passing through the oxygen separation cooling unit and the hydrogen separation cooling unit. The seawater can play an auxiliary cooling role in the oxygen separation cooling unit and the hydrogen separation cooling unit.

[0067] Fresh water in the alkaline electrolyser unit is decomposed into hydrogen and oxygen by direct current;

[0068] The oxygen outlet of the alkaline electrolyzer unit transports oxygen and alkaline solution to the oxygen separation cooling unit for gas-liquid separation;

[0069] The hydrogen outlet of the alkaline electrolyzer unit transports hydrogen and alkali liquid to the hydrogen separation cooling unit for gas-liquid separation. The hydrogen and a small amount of water after preliminary purification enter the hydrogen purification cooling unit for further purification to a hydrogen content of ≥99.99%;

[0070] The alkali solution filtration circulation unit extracts alkali solution from the oxygen separation cooling unit and the hydrogen separation cooling unit, cools it in the seawater desalination unit, and finally transports it to the alkaline electrolyzer unit to complete the cooling and forced circulation of the alkali solution.

[0071] The heat released by the alkali solution during cooling in the desalination unit is used to heat the seawater under negative pressure to produce fresh water, which is then transported to the hydrogen separation module to supplement the raw fresh water used for electrolysis and also assist in hydrogen scrubbing and cooling.

[0072] The biomass processing unit uses oxygen generated by water electrolysis to burn biomass to produce a certain amount of CO2;

[0073] The hydrogen exhausted from the hydrogen purification cooling unit and the CO2 exhausted from the biomass processing unit enter the methanol preparation unit together for methanol preparation.

[0074] Example 1

[0075] like Figures 2 to 9As shown, the electrolytic cell used in the embodiment of the present invention can withstand high electrical density, realize miniaturization and lightweight of the cell body, and significantly reduce the floor space, including an end plate 3, and a plurality of electrolytic cell units composed of monopolar plates or bipolar plates are arranged between the end plates on both sides; a barrier is arranged between adjacent electrolytic cell units, in this embodiment, specifically an insulating gasket 10; the end plate and the pole plate both include a plate body, and positioning holes 12, fastening holes 13, an alkali liquid inlet and a gas-liquid outlet are arranged at corresponding positions of each plate; a guide mechanism is arranged on the pole plate, and an alkali liquid tank of a preset form is opened at the bottom position of the end face of the end plate, an alkali liquid diversion area 20 is arranged at the bottom of the pole plate, and a flow channel connecting the alkali liquid diversion area and the gas-liquid outlet is arranged above the alkali liquid diversion area, and the flow channel is divided into a preset form by the guide component. During the assembly process, the installation and positioning of each plate is completed through the positioning holes. After the positional relationship of each plate is adjusted, the clamping with a preset preload force is completed through the bolts 11 and nuts 8 passing through the fastening holes, with flat washers 5 and T-shaped washers 6 arranged therebetween. Of course, the mounting bolts are covered with insulating sleeves. Figure 1 The most basic components of the monopolar plate 9 electrolytic cell are shown. There is a diaphragm in the middle of the electrolytic cell, and there are anode plates and cathode plates on both sides. The electrolytic cell is filled with electrolyte. Direct current is passed through the two electrodes, oxygen is precipitated at the anode, and hydrogen is precipitated at the cathode. The prepared oxygen and hydrogen are output respectively through the gas-liquid confluence total outlet 4. At this time, a terminal 4 is connected to the monopolar plate.

[0076] like Figures 5 to 8 As shown, both the end plate and the pole plate are provided with sealing grooves, and the sealing grooves of the end plate are provided on the inner side. The inner side of the end plate is divided into a plate body and a plate frame by the sealing grooves. The outermost circle of the pole plate is provided with sealing grooves, and the plate body is provided inside the plate frame. The sealing grooves are provided in multiple groups in the circumferential direction, and the sealing grooves protrude from the plate body and the plate frame by a preset distance. The plate body is provided with a plurality of positioning holes, and the plate frame is provided with a plurality of fastening holes along its circumference. The sealing grooves are multiple channels tightly surrounding the circumference, at least 2 channels. In this embodiment, 5 sealing grooves are provided. A positioning hole 18 matching the position of the positioning hole of the plate body of the end plate is provided at the non-flow channel position of the monopolar plate. A positioning hole 24 matching the position of the positioning hole of the plate body of the end plate is provided at the non-flow channel position of the bipolar plate.

[0077] An alkali liquid inlet is arranged on the outside of the end plate. In the present embodiment, the alkali liquid inlet 1 is arranged at the center of the end plate. The end plate is bounded by a horizontal midline or a preset distance above the midline, and the alkali liquid tank 14 is arranged on the lower half surface. An alkali liquid inlet 15 connected to the alkali liquid inlet 1 is arranged at the top center of the alkali liquid tank. An alkali liquid flow hole 28 is arranged at the bottom center of the alkali liquid tank. A gas-liquid confluence total outlet 16 is arranged at the top above the boundary. The periphery of the gas-liquid confluence total outlet is a groove structure, and a plurality of sealing grooves 17 surrounding the groove are arranged outside the gas-liquid confluence total outlet groove. A plurality of horizontally arranged sealing grooves are also arranged above the alkali liquid tank.

[0078] Furthermore, a support column 7 is provided at the bottom of the frame of the end plate to ensure stable installation of the device.

[0079] Furthermore, an arc-shaped alkali liquid diversion area matching the bottom of the end plate alkali liquid tank is provided at the bottom of the electrode plate, and a plurality of alkali liquid flow inlet holes 21 are provided on the arc-shaped alkali liquid diversion area, and a liquid blocking platform 26 is provided above the alkali liquid flow inlet holes. The width of the liquid blocking platform is not greater than the diameter of the alkali liquid flow inlet holes, and the liquid blocking platform protrudes from the flow channel by a preset distance but does not exceed the end surface of the plate body of the electrode plate. The flow guide mechanism includes a plurality of flow guide plates 23 arranged in parallel along the longitudinal direction of the electrode plate.

[0080] Furthermore, the guide plate of the monopolar plate includes an upper end, a middle section and a lower end connected in sequence, the distance between the upper end and the lower end of the end guide plate to the side wall of the flow channel is smaller than the distance between the middle section of the end guide plate to the side wall of the flow channel, the distance between the upper end and the lower end between adjacent guide plates is smaller than the distance between the middle sections between adjacent guide plates, that is, the diameter / width of the middle section is smaller than the diameter / width of the upper end and / or the lower end, and a gas-liquid confluence outlet, that is, a hydrogen outlet hole or an oxygen outlet hole 22, is provided at the end of the flow channel of the monopolar plate.

[0081] Furthermore, the guide plate has a symmetrical structure along a direction perpendicular to the flow channel, the top surface of the upper end of the guide plate is a curved surface with a preset curvature, and the bottom surface of the lower end of the guide plate is a curved surface with a preset curvature.

[0082] Furthermore, at the inlet end of the flow channel of the guide plate of the monopolar plate, a plurality of bosses 19 are arranged between adjacent guide plates / guide plates and the end of the flow channel, and all bosses are arranged as a whole in a preset pattern; at the outlet end of the flow channel of the guide plate of the monopolar plate, a plurality of bosses are arranged between adjacent guide plates / guide plates and the end of the flow channel between the end flow channel and the flow channel at the lower end of the gas-liquid confluence total outlet, and all bosses are arranged as a whole in a preset pattern. In this embodiment, after the connection of each boss, an outer arc surface and an inner arc surface are formed, and the arc surface takes the center of the plate body as the arc center.

[0083] Furthermore, the flow channel of the bipolar plate is blocked by the guide plate, and a number of bosses are provided before and after the flow channel entrance of the guide plate 27 of the bipolar plate, and all the bosses are arranged in a preset pattern as a whole; in this embodiment, after the connection of each boss, an outer arc surface and an inner arc surface are formed, and the arc surface takes the center of the plate body as the arc center. Two gas-liquid confluence outlets are provided at the end of the flow channel of the bipolar plate, and the two gas-liquid confluence total outlets are blocked, and a terminal 25 is provided at the plate cylinder frame of the bipolar plate as a DC power line connection point. A pressure measuring column 39 is provided on each electrolytic cell unit for daily detection of whether there is any abnormality in the electrolytic cell. The pressure measuring column is directly connected to the monopolar plate and protrudes from the monopolar plate body by a preset distance for easy detection.

[0084] Example 2

[0085] like Figures 10 to 19 As shown, as another embodiment different from Example 1, the electrolytic cell of Example 2 of the present invention includes a cathode end plate and an anode end plate, and a plurality of electrolytic cell units composed of bipolar plates are arranged between the cathode end plate and the anode end plate; a barrier is arranged between adjacent electrolytic cell units, which may be a diaphragm or a partition; the cathode end plate, the bipolar plate and the anode end plate all include a plate body, and positioning holes 31, fastening holes 38, an alkali liquid inlet 36, and a gas-liquid outlet (i.e., an alkali liquid and hydrogen outlet or an alkali liquid and oxygen outlet) 32 are arranged at corresponding positions of each plate. and a flow guide assembly; the flow guide assembly of the cathode end plate and the anode end plate is opened on the inner side close to the bipolar plate, the flow guide assembly of the bipolar plate is opened on one side, a flow channel for connecting the alkali liquid inlet and the gas-liquid outlet is opened in the middle of the end surface of the plate body, the flow guide assembly divides the flow channel in a preset form, the flow guide assembly specifically includes a blocking mechanism, a boosting mechanism and a flow guide mechanism, the blocking mechanism is arranged on the alkali liquid inlet side, the flow guide mechanism is arranged on the alkali liquid outlet side, and the boosting mechanism is arranged between the blocking mechanism and the flow guide mechanism. The bipolar plate is connected with a node terminal 37.

[0086] Furthermore, the cathode end plate, the bipolar plate and the anode end plate are divided into a plate body and a plate frame by a sealing groove 29. The plate body is arranged inside the plate frame. There are multiple groups of sealing grooves arranged in a circumferential direction. The sealing grooves protrude from the plate body and the plate frame by a preset distance. A number of positioning holes are opened on the plate body, and a number of mounting holes are opened on the plate frame along its circumference.

[0087] Furthermore, the blocking mechanism comprises a liquid blocking platform 35, the width of which is not greater than the diameter of the alkali solution inlet, and the liquid blocking platform protrudes from the flow channel by a preset distance but does not exceed the end surface of the plate body of the plate where it is located.

[0088] Furthermore, the boosting mechanism includes a boosting platform 34 connected to the left and right side walls and arranged in the flow channel. The boosting platform is a complete and uninterrupted arc. The boosting platform protrudes from the flow channel by a preset distance but does not exceed the end surface of the plate body of the plate where it is located, and the protruding distance is less than the thickness of the blocking mechanism and the guide mechanism.

[0089] Furthermore, the guide mechanism is located at the center of the plate body, and includes a plurality of guide plates 33 arranged in parallel along the main direction of the flow channel.

[0090] Furthermore, the guide plate includes an upper end, a middle section and a lower end connected in sequence, the distance between the upper end and the lower end of the end guide plate to the side wall of the flow channel is smaller than the distance between the middle section of the end guide plate to the side wall of the flow channel, and the distance between the upper end and the lower end between adjacent guide plates is smaller than the distance between the middle sections between adjacent guide plates.

[0091] Furthermore, the guide plate has a symmetrical structure along a direction perpendicular to the flow channel, the top surface of the upper end of the guide plate is a curved surface or a straight section with a preset curvature or inclination, and the bottom surface of the lower end of the guide plate is a curved surface or a straight section with a preset curvature or inclination. After all the guide plates are arranged, they are symmetrically arranged with the center line of the flow channel between the two guide plates at the center position as the axis; with the center of the plate as the arc center, the top surface of the upper end of each guide plate as a whole and the bottom surface of the lower end as a whole present a trend of removing the preset curvature of the flow channel arc segment.

[0092] Furthermore, a groove for installing a gasket is provided on the end surface near the flow channel of the plate body, and the middle position of the main flow channel is not grooved, and the shape of the groove matches the gasket. The gasket includes a first gasket and a second gasket, and the first gasket and the second gasket both include an upper piece and a lower piece, and the upper piece and the lower piece are respectively arranged above and below the middle position without a groove, and the lower part of the upper piece and the upper part of the lower piece are both arc surfaces, and the arc is the same as the arc of the overall trend of the end of the guide plate. The first gasket can cover part of the end of the guide plate, and the second gasket is arranged above the first gasket to cover the complete end of the guide plate. The thickness of the second gasket matches the thickness of the sealing groove of the plate body.

[0093] Furthermore, a support column 30 is provided at the bottom of the plate frame of the preset plate; a pressure measuring screw 37 is provided on each electrolytic cell unit for daily detection of whether there is any abnormality in the electrolytic cell. When DC power supply is adopted, terminal blocks are provided on the cathode end plate and the anode end plate as DC power line connection points.

[0094] 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 system for producing methanol from seawater and biomass to produce fresh water, characterized in that: include: A biomass treatment unit, an electrolytic water coupled low-temperature distillation integrated system and a methanol preparation unit, wherein the electrolytic water coupled low-temperature distillation integrated system comprises an alkaline electrolytic cell unit, an oxygen separation cooling unit, a hydrogen separation cooling unit, a hydrogen purification cooling unit, an alkali solution filtration circulation unit and a seawater desalination unit, wherein the electrolytic water coupled low-temperature distillation integrated system collects seawater to be treated, and the seawater desalination unit is used to heat the seawater, remove impurities with steam and condense to produce fresh water and concentrated seawater to be collected; the output end of the seawater desalination unit is connected to the alkaline electrolytic cell unit, and the fresh water in the alkaline electrolytic cell unit is decomposed into hydrogen under the action of direct current and oxygen, hydrogen and alkali liquid enter the hydrogen separation cooling unit, and oxygen and alkali liquid enter the oxygen separation cooling unit; the hydrogen purification cooling unit is used to complete the purification of hydrogen, the alkali liquid filtration circulation unit is used to complete the forced circulation of alkali liquid in the alkaline electrolyzer unit and the hydrogen separation cooling unit and the oxygen separation cooling unit, the biomass processing unit is connected to the oxygen of the electrolysis water coupled low-temperature distillation integrated system, after the biomass processing unit obtains the biomass, it reacts with oxygen to generate carbon dioxide, the output end of the biomass processing unit is connected to the methanol preparation unit, and the hydrogen of the electrolysis water coupled low-temperature distillation integrated system is also transported to the methanol preparation unit.

2. The system for producing methanol from seawater and biomass according to claim 1, characterized in that: The seawater enters the seawater desalination unit or the hydrogen separation cooling unit or the oxygen separation cooling unit.

3. The system for producing methanol from seawater and biomass according to claim 1, characterized in that: The hydrogen outlet of the alkaline electrolyzer module is connected to the hydrogen separation cooling unit, the oxygen outlet of the alkaline electrolyzer module is connected to the oxygen separation cooling unit, the alkali liquid inlet of the alkaline electrolyzer module is connected to the seawater desalination unit, the oxygen separation cooling unit separates oxygen and alkali liquid by a gas-liquid separation method, the hydrogen separation cooling unit separates hydrogen and alkali liquid by a gas-liquid separation method, the hydrogen outlet of the hydrogen separation cooling unit is connected to the hydrogen purification cooling unit, the alkali liquid outlet of the oxygen separation cooling unit and the alkali liquid outlet of the hydrogen separation cooling unit are both connected to the alkali liquid filtration circulation unit to provide high-temperature alkali liquid to be cooled, and the fresh water outlet of the seawater desalination unit is connected to the hydrogen separation cooling unit.

4. The system for producing methanol from seawater and biomass according to claim 1, characterized in that: The desalination unit comprises a device cylinder, a vacuum system, a condenser, a water receiving plate, and a wire mesh separator. The device cylinder is provided with a vacuum system connection port, a seawater inlet port, a concentrated seawater outlet port, a fresh water outlet port, and an alkali solution circulation pipe. The device cylinder is connected to the vacuum system through the vacuum system connection port, and is directly connected to seawater or an oxygen separation cooling unit / hydrogen separation cooling unit through the seawater inlet port. The concentrated seawater outlet port is used to collect concentrated seawater. The alkali solution circulation pipe is used to exchange heat between high-temperature alkali solution and seawater, reduce the temperature of the alkali solution, and make the seawater reach the evaporation temperature and evaporate into water vapor. The water vapor is condensed by the condenser. The water receiving plate is used to receive condensed water droplets, and its output end is connected to the fresh water outlet. A wire mesh separator is arranged in the device cylinder, which is used to separate larger droplets and impurities in the water vapor.

5. The system for producing methanol from seawater and biomass to produce fresh water according to claim 1, characterized in that: The alkaline electrolytic cell unit comprises a cathode end plate and an anode end plate, and a plurality of electrolytic cell units consisting of bipolar plates are arranged between the cathode end plate and the anode end plate; a barrier is arranged between adjacent electrolytic cell units; the cathode end plate, the bipolar plate and the anode end plate all comprise a plate body, and positioning holes, fastening holes, an alkali solution inlet, a gas-liquid outlet and a flow guide assembly are arranged at corresponding positions of each plate; the flow guide assembly of the cathode end plate and the anode end plate is arranged on the inner side close to the bipolar plate, the flow guide assembly of the bipolar plate is arranged on one side, a flow channel for connecting the alkali solution inlet and the gas-liquid outlet is arranged in the middle position of the end surface of the plate body, the flow guide assembly divides the flow channel in a preset form, and the flow guide assembly specifically comprises a barrier mechanism, a boosting mechanism and a flow guide mechanism, the barrier mechanism is arranged on the alkali solution inlet side, the flow guide mechanism is arranged on the alkali solution outlet side, and the boosting mechanism is arranged between the barrier mechanism and the flow guide mechanism.

6. The system for producing methanol from seawater and biomass to produce fresh water according to claim 1, characterized in that: The blocking mechanism includes a liquid blocking platform, the width of which is not greater than the diameter of the alkali solution inlet, and the liquid blocking platform protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate where it is located; the boosting mechanism includes a boosting platform arranged in the flow channel and connecting the left and right side walls, the boosting platform is a complete and uninterrupted arc, the boosting platform protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate where it is located, and the protruding distance is less than the thickness of the blocking mechanism and the guide mechanism; the guide mechanism is located at the center of the plate body, and includes a plurality of guide plates arranged in parallel along the main direction of the flow channel.

7. The system for producing methanol from seawater and biomass to produce fresh water according to claim 1, characterized in that: The alkaline electrolytic cell unit comprises an end plate, and a plurality of electrolytic cell units consisting of monopolar plates or bipolar plates are arranged between the end plates on both sides; a barrier is arranged between adjacent electrolytic cell units; the end plate and the electrode plate both comprise a plate body, and positioning holes, fastening holes, an alkali liquid inlet and a gas-liquid outlet are arranged at corresponding positions of each plate; a flow guide mechanism is arranged on the electrode plate, and an alkali liquid tank of a preset form is opened at the bottom position of the end surface of the end plate, an alkali liquid diversion area is arranged at the bottom of the electrode plate, a flow channel connecting the alkali liquid diversion area and the gas-liquid outlet is arranged above the alkali liquid diversion area, and the flow channel is divided into a preset form by the flow guide component.

8. The system for producing methanol from seawater and biomass to produce fresh water according to claim 1, characterized in that: When it is a single-pole plate, at the inlet end of the flow channel of the guide plate of the single-pole plate, a number of bosses are arranged between adjacent guide plates / guide plates and the end of the flow channel, and all the bosses are arranged as a whole in a preset pattern; at the outlet end of the flow channel of the guide plate of the single-pole plate, a number of bosses are arranged between adjacent guide plates / guide plates and the end of the flow channel between the end flow channel to the flow channel at the lower end of the gas-liquid confluence total outlet, and all the bosses are arranged as a whole in a preset pattern; when it is a bipolar plate, a number of bosses are arranged before and after the flow channel inlet of the guide plate of the bipolar plate, and all the bosses are arranged as a whole in a preset pattern; two gas-liquid confluence outlets are arranged at the end of the flow channel of the bipolar plate and the two gas-liquid confluence total outlets are blocked, and a terminal is arranged at the plate cylinder frame of the bipolar plate.

9. The system for producing methanol from seawater and biomass according to claim 1, characterized in that: The seawater desalination unit is also connected to a fresh water storage unit for storing excess fresh water.

10. A method for producing fresh water based on seawater and biomass to produce methanol according to any one of claims 1 to 9, characterized in that: The steps include: The electrolysis water coupling low temperature distillation integrated system is connected with the seawater source and biomass processing unit to start the co-production of fresh water from seawater and biomass to produce methanol. The seawater is directly transported to the desalination unit for fresh water production and concentrated seawater separation, or enters the desalination unit after passing through the oxygen separation cooling unit and the hydrogen separation cooling unit. The seawater can play an auxiliary cooling role in the oxygen separation cooling unit and the hydrogen separation cooling unit. Fresh water in the alkaline electrolyser unit is decomposed into hydrogen and oxygen by direct current; The oxygen outlet of the alkaline electrolyzer unit transports oxygen and alkaline solution to the oxygen separation cooling unit for gas-liquid separation; The hydrogen outlet of the alkaline electrolyzer unit transports hydrogen and alkali liquid to the hydrogen separation cooling unit for gas-liquid separation. The hydrogen and a small amount of water after preliminary purification enter the hydrogen purification cooling unit for further purification to a hydrogen content of ≥99.99%; The alkali solution filtration circulation unit extracts alkali solution from the oxygen separation cooling unit and the hydrogen separation cooling unit, cools it in the seawater desalination unit, and finally transports it to the alkaline electrolyzer unit to complete the cooling and forced circulation of the alkali solution. The heat released by the alkali solution during cooling in the desalination unit is used to heat the seawater under negative pressure to produce fresh water, which is then transported to the hydrogen separation module to supplement the raw fresh water used for electrolysis and also assist in hydrogen scrubbing and cooling. The biomass processing unit uses oxygen generated by water electrolysis to burn biomass to produce a certain amount of CO2; The hydrogen exhausted from the hydrogen purification cooling unit and the CO2 exhausted from the biomass processing unit enter the methanol preparation unit together for methanol preparation.

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