A system and method for producing methanol and fresh water based on seawater and biomass

Abstract

The present application relates to a kind of system and method for preparing methanol and co-production fresh water based on seawater and biomass.The present application includes: biomass processing unit, electrolytic water coupling low-temperature distillation integrated system and methanol preparation unit, the electrolytic water coupling low-temperature distillation integrated system includes alkaline electrolytic cell unit, oxygen separation cooling unit, hydrogen separation cooling unit, hydrogen purification cooling unit, lye filtration circulation unit and seawater desalination unit.The present application directly introduces seawater into electrolytic water coupling low-temperature distillation integrated system, and the prepared oxygen is supplied to biomass processing unit, and the final product is effectively utilized, with small floor area;By setting the alkaline electrolytic cell with good flow guide effect, a water-blocking boss is arranged at the lye inlet, so that the water is uniformly introduced into the reaction area.In the reaction area, a flow guide plate is arranged, so that the water flow can uniformly pass through the reaction area, so that the lye flow is more smooth, can tolerate high electric density, and further improves the efficiency of the device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of biomass and seawater development and utilization, in particular, and especially relates to a seawater and biomass based methanol co-production fresh water system and method. BACKGROUND

[0002] At present, in the global and China's energy structure, fossil fuels such as coal and oil occupy a dominant position in the power industry, and the consumption of coal and natural gas is very large, and thermal power generation has become the main source of harmful gas emissions, which threatens energy development and the ecological environment. Biomass energy can be converted into conventional solid, liquid and gaseous fuels, which is inexhaustible and inexhaustible, and is a renewable energy source, and is also the only renewable carbon source.

[0003] Hydrogen energy is considered as the most potential clean energy in the 21st century. Using green electricity generated by renewable energy such as solar energy and wind energy to drive water electrolysis reaction to produce hydrogen gas is of great significance to solve the energy shortage problem and achieve the "double carbon" goal. In the current water electrolysis hydrogen production technology, alkaline water electrolysis has low cost and relatively mature technology, and is the most widely used hydrogen production technology, occupying a dominant position. The Global Hydrogen Production Water Report released by the International Renewable Energy Agency (IRENA) shows that the current mainstream hydrogen production method needs fresh water, mainly concentrated in the hydrogen production and cooling processes. Every production of 1 kilogram of blue hydrogen needs to consume about 32.2 liters of fresh water, and in green hydrogen production, the fresh water consumption of alkaline water electrolysis hydrogen production process for producing 1 kilogram of hydrogen gas is expected to be 22.3 liters. But the global fresh water resources are extremely limited, and the large-scale promotion and application of water electrolysis hydrogen production technology will undoubtedly exacerbate the problem of fresh water shortage.

[0004] Methanol is also known as "liquid sunlight". In 2018, the Chinese Academy of Sciences established a "liquid sunlight" special group to study methanol fuel. The special group believes that methanol can be divided into five generations according to its source, and the fourth generation is biomass methanol, also known as green methanol. SUMMARY

[0005] According to the above technical problems, a seawater and biomass based methanol co-production fresh water system and method is provided. The present application can realize low-cost treatment of biomass waste, save the land area of the biomass treatment device, and realize efficient production of methanol.

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

[0007] The system for producing methanol and fresh water based on seawater and biomass comprises a biomass treatment unit, an electrolytic water coupling low-temperature distillation integrated system and a methanol preparation unit, the electrolytic water coupling 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 liquid filtration circulation unit and a seawater desalination unit, seawater to be treated is collected in the electrolytic water coupling low-temperature distillation integrated system, the seawater desalination unit is used for heating seawater, removing impurities by steam and producing fresh water and concentrated seawater to be collected after condensation; the output end of the seawater desalination unit is connected with the alkaline electrolytic cell unit, the fresh water in the alkaline electrolytic cell unit is decomposed into hydrogen and oxygen under the action of direct current, the hydrogen enters the hydrogen separation cooling unit and the oxygen enters the oxygen separation cooling unit; the hydrogen purification cooling unit is used for completing hydrogen purification, the alkali liquid filtration circulation unit is used for completing forced circulation of alkali liquid in the alkaline electrolytic cell unit and the hydrogen separation cooling unit and the oxygen separation cooling unit, the biomass treatment unit is connected with oxygen of the electrolytic water coupling low-temperature distillation integrated system, the biomass treatment unit obtains biomass, combusts with oxygen to generate carbon dioxide, the output end of the biomass treatment unit is connected to the methanol preparation unit, and hydrogen of the electrolytic water coupling low-temperature distillation integrated system is also delivered to the methanol preparation unit.

[0008] Further, the seawater enters the seawater desalination unit or enters the hydrogen separation cooling unit and the oxygen separation cooling unit.

[0009] Further, the hydrogen outlet of the alkaline electrolytic cell unit is connected with the hydrogen separation cooling unit, the oxygen outlet of the alkaline electrolytic cell unit is connected with the oxygen separation cooling unit, the alkali liquid inlet of the alkaline electrolytic cell unit is connected with 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 with 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 connected with 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 with the hydrogen separation cooling unit.

[0010] Further, the seawater 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 connecting port, a seawater inlet, a concentrated seawater outlet, a fresh water outlet, and an alkali liquid circulation pipe. The vacuum system connecting port is connected to the vacuum system. The seawater inlet is directly connected to seawater or an oxygen separation cooling unit / hydrogen separation cooling unit. The concentrated seawater outlet is used to collect concentrated seawater. The alkali liquid circulation pipe is used to exchange heat between high-temperature alkali liquid and seawater, reduce the temperature of the alkali liquid, and make seawater reach the evaporation temperature to evaporate into water vapor. The water vapor is condensed by the condenser. The water receiving plate is used to receive condensed water drops. The output end of the water receiving plate is connected to the fresh water outlet. The wire mesh separator is arranged in the device cylinder and is used to separate large droplets and impurities in the water vapor.

[0011] Further, the alkaline electrolytic cell unit comprises a cathode end plate and an anode end plate. 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. The cathode end plate, the bipolar plates, and the anode end plate each comprise a plate body. Positioning holes, fastening holes, alkali liquid inlets, gas-liquid outlets, and flow guide assemblies are arranged at corresponding positions of the plates. The flow guide assemblies of the cathode end plate and the anode end plate are arranged on the inner side close to the bipolar plates. The flow guide assembly of the bipolar plate is arranged on one side thereof. A flow channel for the communication of the alkali liquid inlets and the gas-liquid outlets is arranged at the middle position of the end face of the plate body. The flow guide assembly divides the flow channel in a preset form. The flow guide assembly specifically comprises a barrier mechanism, a pressure boosting mechanism, and a flow guide mechanism. The barrier mechanism is arranged on the side of the alkali liquid inlet. The flow guide mechanism is arranged on the side of the alkali liquid outlet. The pressure boosting mechanism is arranged between the barrier mechanism and the flow guide mechanism.

[0012] Further, the barrier mechanism comprises a liquid blocking table. The width of the liquid blocking table is not greater than the diameter of the alkali liquid inlet. The liquid blocking table protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate. The pressure boosting mechanism comprises a pressure boosting table arranged in the flow channel and connecting the left and right side walls. The pressure boosting table is a complete arc without discontinuity. The pressure boosting table protrudes from the flow channel by a preset distance but does not exceed the end face of the plate body of the plate. The protruding distance is less than the thickness of the barrier mechanism and the flow guide mechanism. The flow guide mechanism is located at the central position of the plate body and comprises a plurality of flow guide plates arranged in parallel along the main direction of the flow channel.

[0013] Further, the alkaline electrolytic cell unit comprises end plates, a plurality of electrolytic cell units composed of single-pole plates or double-pole plates are arranged between the end plates on both sides; a barrier is arranged between adjacent electrolytic cell units; the end plates and the pole plates each comprise a plate body, and a positioning hole, a fastening hole, an alkali inlet and a gas-liquid outlet are arranged at corresponding positions of each plate; a flow guide mechanism is arranged on the pole plate, a bottom position of an end face of the end plate is provided with an alkali tank of a preset form, an alkali shunt area is arranged at the bottom of the pole plate, and a flow channel communicating the alkali shunt area and the gas-liquid outlet is arranged above the alkali shunt area, and the flow channel is divided in a preset form by the flow guide assembly.

[0014] Further, when the pole plate is a single-pole plate, a plurality of bosses are arranged between adjacent flow guide plates / flow guide plates and the end portions of the flow channels at the inlet end of the flow channels of the flow guide plates of the single-pole plate, and all the bosses are arranged in a preset pattern; a plurality of bosses are arranged between adjacent flow guide plates / flow guide plates and the end portions of the flow channels at the outlet end of the flow channels of the flow guide plates of the single-pole plate, and all the bosses are arranged in a preset pattern; when the pole plate is a double-pole plate, a plurality of bosses are arranged in front of and behind the inlet of the flow channel of the double-pole plate, and all the bosses are arranged in a preset pattern; the end of the flow channel of the double-pole plate is provided with two gas-liquid confluence outlets which are separated, and a terminal post is arranged at the pole plate cylinder frame of the double-pole plate.

[0015] Further, the seawater desalination unit is further connected with a fresh water storage unit for storing excess fresh water.

[0016] A method for producing methanol and fresh water based on seawater and biomass, comprising the following steps:

[0017] The electrolytic water coupling low-temperature distillation integrated system is connected with a seawater source and a biomass treatment unit, and the seawater and biomass are used to produce methanol and fresh water, wherein,

[0018] The seawater is directly delivered to the seawater desalination unit to produce fresh water, separate concentrated seawater, or is delivered to the seawater desalination unit after passing through an oxygen separation cooling unit and a hydrogen separation cooling unit, and the seawater can play an auxiliary cooling role in the oxygen separation cooling unit and the hydrogen separation cooling unit;

[0019] The fresh water in the alkaline electrolytic cell unit is decomposed into hydrogen and oxygen under the action of direct current;

[0020] The oxygen outlet of the alkaline electrolytic cell unit delivers oxygen and alkali to the oxygen separation cooling unit to perform gas-liquid separation;

[0021] The hydrogen outlet of the alkaline electrolytic cell unit delivers hydrogen and alkali to the hydrogen separation cooling unit to perform gas-liquid separation, and the hydrogen and a small amount of water after preliminary purification are further purified in the hydrogen purification cooling unit to a hydrogen content of ≥99.99%;

[0022] The lye filtering circulation unit separates the lye in the oxygen separation cooling unit and the hydrogen separation cooling unit by pumping, and after cooling by the seawater desalination unit, the lye is finally delivered to the alkaline electrolytic cell unit to complete the cooling and forced circulation of the lye;

[0023] The heat emitted by the lye when cooled in the seawater desalination unit is used to heat seawater under negative pressure to produce fresh water, which is delivered to the hydrogen separation module to supplement the raw material fresh water for electrolysis, and also to assist in realizing hydrogen gas washing and cooling;

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

[0025] The hydrogen gas discharged from the hydrogen purification cooling unit and the CO2 discharged from the biomass treatment unit jointly enter the methanol preparation unit to prepare methanol.

[0026] Compared with the prior art, the present application has the following advantages: the traditional biomass methanol production process requires a large amount of oxygen, and occupies a large area. The present application directly introduces seawater into the water electrolysis coupling low-temperature distillation integrated system, and supplies the oxygen prepared to the biomass treatment unit, so that the final product is effectively utilized, and the area occupied is small. The water electrolysis coupling low-temperature distillation integrated system uses the lye to be cooled to heat seawater under negative pressure, so that the lye is cooled, and the heat emitted by the lye when cooled is also utilized. The fresh water generated by the seawater desalination unit is supplied to the alkaline electrolytic cell unit as the raw material for water electrolysis to alleviate the dependence on fresh water resources. The seawater and biomass are finally completely converted into high-concentration hydrogen, oxygen, fresh water, methanol, and high-concentration sea salt. The alkaline electrolytic cell with good flow guiding effect is provided, a water blocking boss is arranged at the lye inlet to make the water flow uniformly in the reaction area, and a flow guide plate is arranged in the reaction area to make the water flow uniformly through the reaction area, so that the lye flows more smoothly, can withstand high current density, and further improves the efficiency of the device. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

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

[0029] Figure 2 It is a schematic diagram of the single-pole plate electrolytic cell structure of embodiment 1 of the present application.

[0030] Figure 3 Fig. 1 is a schematic view of a front view of the present application. Figure 2

[0031] Figure 4 Fig. 2 is a schematic view of a side view of the present application. Figure 2

[0032] Figure 5 Fig. 3 is a schematic view of a top view of the present application. Figure 2

[0033] Figure 6 Fig. 4 is a schematic view of an end plate structure of the present application.

[0034] Figure 7 Fig. 5 is a schematic view of a single pole plate structure of the present application.

[0035] Figure 8 Fig. 6 is a schematic view of a double pole plate structure of the present application.

[0036] Figure 9 Fig. 7 is a schematic view of a side view of a single pole plate and a double pole plate of the present application.

[0037] Figure 10 Fig. 8 is a schematic view of an overall structure of the present application.

[0038] Figure 11 Fig. 9 is a schematic view of a front view of the present application. Figure 10

[0039] Figure 12 Fig. 10 is a schematic view of a side view of the present application. Figure 10

[0040] Figure 13 Fig. 11 is a schematic view of a top view of the present application. Figure 10

[0041] Figure 14 Fig. 12 is a schematic view of a double pole plate structure of the present application.

[0042] Figure 15 Fig. 13 is a schematic view of a front view of the present application. Figure 14

[0043] Figure 16 Fig. 14 is a schematic view of an A-A sectional view of the present application. Figure 6

[0044] Fig. 15 is a schematic view of a gasket structure of the present application. Figure 17

[0045] Fig. 16 is a schematic view of a structure of the present application after installing a gasket A. Figure 18

[0046] Fig. 17 is a schematic view of a structure of the present application after installing a gasket B. Figure 19 Fig. 18 is a schematic view of a structure of the present application after installing a gasket B.​​​​​​​

[0047] Figure: 1, first lye inlet; 2, gas-liquid confluence total outlet; 3, end plate; 4, first terminal post; 5, flat gasket; 6, T-shaped gasket; 7, first support post; 8, nut; 9, monopolar plate; 10, insulating gasket; 11, bolt; 12, first positioning hole; 13, fastening hole; 14, lye tank; 15, second lye inlet; 16, gas-liquid confluence total outlet groove; 17, first sealing groove; 18, second positioning hole; 19, boss; 20, lye shunt area; 21, lye flow-through inlet hole; 22, hydrogen outlet hole or oxygen outlet hole; 23, first flow guide plate; 24, third positioning hole; 25, second terminal post; 26, first liquid blocking table; 27, second flow guide plate; 28, lye flow-through hole; 29, second sealing groove; 30, second support post; 31, fourth positioning hole; 32, hydrogen outlet hole or oxygen outlet hole; 33, third flow guide plate; 34, pressure boosting table; 35, second liquid blocking table; 36, third lye inlet; 37, pressure measuring screw; 38, fastening hole; 39, pressure measuring post. DETAILED DESCRIPTION

[0048] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The technical solutions in the embodiments of the present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0049] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The description of the at least one exemplary embodiment is actually only illustrative, but not intended to limit the present application and its application or use in any way. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0050] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present application. As used herein, the singular form is intended to include the plural form, unless the context clearly indicates otherwise, and furthermore, it should be understood that when the terms "comprise" and / or "include" are used in the specification, there is a feature, step, operation, device, component and / or combination thereof.

[0051] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all suitable modifications and equivalents can be resorted to falling within the scope of the application. Unless otherwise indicated herein, the contents of all patents, patent applications, publications, and test methods cited herein are hereby incorporated by reference in their entirety for all purposes.

[0052] In the description of the present application, it is to be understood that the orientation or positional relationships indicated by terms such as "front", "back", "up", "down", "left", "right", "lateral", "vertical", "horizontal", "top", "bottom", and the like are generally based on the orientation or positional relationships shown in the drawings, and are merely intended to facilitate the description and simplify the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the scope of protection of the present application. The orientation terms "inner", "outer" refer to the inner and outer relative to the contour of the components themselves.

[0053] For the convenience of description, spatial relative terms such as "over", "above", "upper surface", "upper", and the like can be used herein to describe the spatial positional relationship of one device or feature with respect to other devices or features as shown in the drawings. It should be understood that the spatial relative terms are intended to include different orientations in use or operation in addition to the orientation of the devices described in the drawings. For example, if the devices in the drawings are inverted, the device described as "above" or "over" other devices or structures will be positioned "below" or "under" the other devices or structures. Thus, the exemplary term "above" can include both "above" and "below" orientations. The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein are interpreted accordingly.

[0054] In addition, it should be noted that the use of the terms "first", "second", and the like do not have a special meaning, and are used only to facilitate the distinction between the corresponding parts, and therefore cannot be construed as limiting the scope of protection of the present application.

[0055] As Figure 1As shown, the embodiment of the present application discloses a system for producing methanol and fresh water based on seawater and biomass, which comprises a biomass treatment unit, an electrolytic water coupling low-temperature distillation integrated system and a methanol preparation unit, the electrolytic water coupling 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, the electrolytic water coupling low-temperature distillation integrated system collects seawater to be treated, the seawater desalination unit is used for heating seawater, and after steam is impurity-removed and condensed, fresh water and concentrated seawater to be collected are generated; the output end of the seawater desalination unit is connected with the alkaline electrolytic cell unit, fresh water in the alkaline electrolytic cell unit is decomposed into hydrogen and oxygen under the action of direct current, hydrogen and alkali solution enter the hydrogen separation cooling unit, and oxygen and alkali solution enter the oxygen separation cooling unit; the hydrogen purification cooling unit is used for completing hydrogen purification, the alkali solution filtration circulation unit is used for completing forced circulation of alkali solution in the alkaline electrolytic cell unit and the hydrogen separation cooling unit and the oxygen separation cooling unit, the biomass treatment unit is connected with oxygen of the electrolytic water coupling low-temperature distillation integrated system, the biomass treatment unit obtains biomass, and after combustion reaction with oxygen, carbon dioxide is generated, the output end of the biomass treatment unit is connected to the methanol preparation unit, and hydrogen of the electrolytic water coupling low-temperature distillation integrated system is also delivered to the methanol preparation unit.

[0056] In the figure, the baseline is the electrolytic water coupling low-temperature distillation integrated system.

[0057] The hydrogen-deuterium gas purification cooling unit therein deoxidizes hydrogen, trace oxygen and trace water entering the same through a catalytic reaction, removes water and other impurities by using a molecular sieve adsorption principle, and finally purifies hydrogen to ≥99.99%.

[0058] In the embodiment, 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, and the direct current can be directly connected externally or the power supply can be completed by converting alternating current into direct current.

[0059] Seawater enters the seawater desalination unit or enters the hydrogen separation cooling unit and the oxygen separation cooling unit. The seawater entering the hydrogen separation cooling unit and the oxygen separation cooling unit can further complete the role of heat exchange using seawater.

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

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

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

[0063] In the embodiment, the biomass treatment unit can be a reaction chamber only for providing a reaction site for biomass combustion, or can be a complete biomass energy generation system. The output electric energy can be supplied to the electrolysis process of the electrolysis water coupled low-temperature distillation integrated system to realize the input of electric power. When the biomass treatment unit is large enough, the generated electric energy can also be transmitted to the power grid and connected to the grid. The reaction site of the methanol preparation unit adjusts the pressure and temperature, and synthesizes methanol by using hydrogen and carbon dioxide. In addition, the biomass treatment unit can further include a pre-treatment process such as anaerobic treatment, which can be realized by using the existing technology. In the embodiment, the water generated by the biomass treatment unit can also be supplied to the seawater desalination unit preparation unit as a water source for supplement, further improving the utilization rate of the product.

[0064] A method for producing methanol and fresh water based on seawater and biomass, comprising the following steps:

[0065] The electrolysis water coupled low-temperature distillation integrated system is connected to a seawater source and a biomass treatment unit, and the seawater and biomass are used to produce methanol and fresh water, wherein

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

[0067] The freshwater in the alkaline electrolysis cell unit is decomposed into hydrogen and oxygen under the action of direct current;

[0068] The oxygen outlet of the alkaline electrolysis cell unit transports oxygen and alkali liquor into the oxygen separation cooling unit for gas-liquid separation;

[0069] The hydrogen outlet of the alkaline electrolysis cell unit transports hydrogen and alkali liquor into the hydrogen separation cooling unit for gas-liquid separation, and the hydrogen and a small amount of water after preliminary purification are transported into the hydrogen purification cooling unit for further purification to a hydrogen content of ≥99.99%;

[0070] The alkali liquor filtration circulation unit extracts alkali liquor from the oxygen separation cooling unit and the hydrogen separation cooling unit, and after cooling by the seawater desalination unit, the alkali liquor is finally transported to the alkaline electrolysis cell unit to complete the cooling and forced circulation of the alkali liquor;

[0071] The heat emitted by the alkali liquor when cooled in the seawater desalination unit is used to heat seawater under negative pressure to produce freshwater, and the produced freshwater is transported to the hydrogen separation module to supplement the raw material freshwater for electrolysis, and also to assist in realizing hydrogen gas washing and cooling;

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

[0073] The hydrogen gas discharged from the hydrogen purification cooling unit and the CO2 discharged from the biomass treatment unit are jointly transported into the methanol preparation unit to prepare methanol.

[0074] Example 1

[0075] As Figures 2-9As shown, the electrolytic cell used in this embodiment of the invention can withstand high electrical density, achieving miniaturization and lightweighting of the cell body, significantly reducing the floor space. It includes an end plate 3, with several electrolytic cell units composed of single or double electrodes arranged between the end plates on both sides; a barrier is provided between adjacent electrolytic cell units, specifically an insulating gasket 10 in this embodiment; both the end plate and the electrode plate include a plate body, with a first positioning hole 12, a fastening hole 13, an alkali inlet, and a gas-liquid outlet provided at corresponding positions on each plate; a flow guiding mechanism is provided on the electrode plate, and an alkali tank of a preset form is opened at the bottom of the end face of the end plate, with an alkali diversion area 20 provided at the bottom of the electrode plate, and a flow channel connecting the alkali diversion area and the gas-liquid outlet provided above the alkali diversion area, the flow channel being divided in a preset form by the flow guiding component. During assembly, the positioning holes are used to install and position each plate. After adjusting the positional relationship of each plate, the bolts 11 and nuts 8 passing through the fastening holes are used to clamp the plate with a preset preload. Flat washers 5 and T-shaped washers 6 are provided in between. Of course, the mounting bolts are fitted with insulating sleeves. Figure 1 The diagram shows the basic components of a single-plate electrolytic cell (9). A diaphragm is located in the middle of the cell, with an anode plate and a cathode plate on either side. The cell is filled with electrolyte. Direct current is applied to the two electrodes, resulting in oxygen evolution at the anode and hydrogen evolution at the cathode. The produced oxygen and hydrogen are output through a gas-liquid junction outlet. At this point, a first terminal 4 is connected to the single-plate.

[0076] like Figures 5-8 As shown, both the end plate and the electrode plate are provided with sealing grooves. The sealing groove of the end plate is located on the inner side, dividing the inner side of the end plate into a plate body and a plate frame through the sealing groove. The outermost ring of the electrode plate is provided with a sealing groove, and the plate body is located inside the plate frame. Multiple sets of sealing grooves are arranged circumferentially, protruding beyond a predetermined distance from the plate body and plate frame. Several positioning holes are formed on the plate body, and several fastening holes are formed along the circumference of the plate frame. The sealing grooves are multiple tightly surrounding the plate, with at least two grooves. In this embodiment, five sealing grooves are provided. A second positioning hole 18, matching the position of the plate body positioning hole on the end plate, is formed at the non-flow channel position of the single electrode plate. A third positioning hole 24, matching the position of the plate body positioning hole on the end plate, is formed at the non-flow channel position of the bipolar plate.

[0077] The alkali inlet is arranged outside the end plate, in this embodiment, the first alkali inlet 1 is arranged at the center of the end plate; the end plate is limited by the horizontal center line or the upper position of the center line by a predetermined distance, the lower half of the end plate is provided with the alkali tank 14, the top center of the alkali tank is provided with the second alkali inlet 15 connected with the first alkali inlet 1, the bottom center of the alkali tank is provided with the alkali flow hole 28, the top of the upper limit is provided with the gas-liquid confluence general outlet 2, the periphery of the gas-liquid confluence general outlet is provided with the groove structure, a plurality of first sealing grooves 17 surrounding the groove are arranged outside the gas-liquid confluence general outlet groove 16, a plurality of sealing grooves horizontally arranged are further arranged above the alkali tank.

[0078] Further, the first support column 7 is arranged at the bottom of the plate frame of the end plate, so as to complete the stable installation of the device.

[0079] Further, the bottom of the polar plate is provided with the arc-shaped alkali shunt area matching the bottom of the alkali tank of the end plate, a plurality of alkali flow inlet holes 21 are arranged on the arc-shaped alkali shunt area, the first liquid blocking table 26 is arranged above the alkali flow inlet hole, the width of the liquid blocking table is not greater than the diameter of the alkali flow inlet hole, the liquid blocking table protrudes from the flow channel by a predetermined distance but does not exceed the end surface of the plate body of the polar plate, and the flow guide mechanism comprises a plurality of first flow guide plates 23 arranged in parallel along the longitudinal direction of the polar plate.

[0080] Further, the flow guide plate of the single polar plate comprises the upper end, the middle section and the lower end connected in sequence, the distance between the upper end and the lower end of the end flow guide plate to the side wall of the flow channel is less than the distance between the middle section of the end flow guide plate to the side wall of the flow channel, and the distance between the upper end and the lower end of the adjacent flow guide plates is less than the distance between the middle sections of the adjacent flow guide plates, that is, the diameter / width of the middle section is less than the diameter / width of the upper end and / or the lower end, and the end of the flow channel of the single polar plate is provided with the gas-liquid confluence outlet, that is, the hydrogen outlet hole or the oxygen outlet hole 22.

[0081] Further, the flow guide plate is in a symmetrical structure along the direction perpendicular to the flow channel, the top surface of the upper end of the flow guide plate is an arc surface with a predetermined curvature, and the bottom surface of the lower end of the flow guide plate is an arc surface with a predetermined curvature.

[0082] Further, a plurality of bosses 19 are arranged between the adjacent flow guide plates / flow guide plates and the end of the flow channel at the inlet end of the flow channel of the flow guide plate of the single polar plate, and all the bosses are arranged in a predetermined pattern; a plurality of bosses are arranged between the adjacent flow guide plates / flow guide plates and the end of the flow channel between the end of the flow channel and the lower end of the gas-liquid confluence general outlet at the outlet end of the flow channel of the flow guide plate of the single polar plate, and all the bosses are arranged in a predetermined pattern. In this embodiment, the connection of the bosses forms the outer arc surface and the inner arc surface, and the arc surfaces take the center of the plate body as the center of the arc.

[0083] Further, the flow channel of the bipolar plate is blocked by the flow guide plate, and a plurality of bosses are arranged before and after the flow channel inlet of the second flow guide plate 27 of the bipolar plate, and all the bosses are arranged in a predetermined pattern. In this embodiment, the connection of each boss forms an outer arc surface and an inner arc surface, and the arc surfaces have the plate body center as the arc center. The flow channel end of the bipolar plate is provided with two gas-liquid confluence outlets which are blocked, and the second terminal post 25 is arranged at the polar plate cylinder frame of the bipolar plate as the direct current power line contact point. A pressure measuring column 39 is arranged on each electrolytic cell unit for daily detection of abnormal conditions of the electrolytic cell. The pressure measuring column is directly connected to the monopolar plate and protrudes from the monopolar plate body by a predetermined distance to facilitate detection.

[0084] Embodiment 2

[0085] As shown in Figures 10-19 different from embodiment 1, the electrolytic cell of embodiment 2 of the application comprises 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, which can be a diaphragm or a baffle, is arranged between adjacent electrolytic cell units. The cathode end plate, the bipolar plate and the anode end plate each comprise a plate body, and a fourth positioning hole 31, a fastening hole 38, a third alkali inlet 36, a gas-liquid outlet 32 (i.e. an alkali and hydrogen outlet or an alkali and oxygen outlet) and a flow guide assembly are arranged at the 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, and the flow guide assembly of the bipolar plate is arranged on one side. A flow channel for communication between the alkali inlet and the gas-liquid outlet is arranged at the middle position of the end surface of the plate body. The flow guide assembly divides the flow channel in a predetermined form. The flow guide assembly specifically comprises a blocking mechanism, a pressure increasing mechanism and a flow guide mechanism. The blocking mechanism is arranged on the alkali inlet side, the flow guide mechanism is arranged on the alkali outlet side, and the pressure increasing mechanism is arranged between the blocking mechanism and the flow guide mechanism. The node terminal 37 is connected to the bipolar plate.

[0086] Further, the cathode end plate, the bipolar plate and the anode end plate are divided into a plate body and a plate frame by a second sealing groove 29. The plate body is arranged inside the plate frame. The sealing grooves are arranged in multiple groups in the circumferential direction. The sealing grooves protrude from the plate body and the plate frame by a predetermined distance. A plurality of positioning holes are arranged on the plate body. A plurality of mounting holes are arranged on the plate frame in the circumferential direction.

[0087] Further, the blocking mechanism comprises a second liquid blocking table 35. The width of the liquid blocking table is not greater than the diameter of the alkali inlet. The liquid blocking table protrudes from the flow channel by a predetermined distance but does not exceed the end surface of the plate body of the plate.

[0088] Further, the pressure increasing mechanism comprises a pressure increasing platform 34 connecting the left and right side walls in the flow channel, which is an arc-shaped structure without any discontinuity, and protrudes from the flow channel by a predetermined distance, but does not exceed the end surface of the plate body of the plate, and the protruding distance is less than the thickness of the blocking mechanism and the flow guiding mechanism.

[0089] Further, the flow guiding mechanism is located at the center of the plate body, and comprises a plurality of third flow guiding plates 33 arranged in parallel along the main direction of the flow channel.

[0090] Further, the flow guiding plate comprises an upper end portion, a middle section and a lower end portion connected in sequence, the distance between the upper end portion and the lower end portion of the end portion flow guiding plate and the side wall of the flow channel is less than the distance between the middle section of the end portion flow guiding plate and the side wall of the flow channel, and the distance between the upper end portion and the lower end portion of adjacent flow guiding plates is less than the distance between the middle sections of adjacent flow guiding plates.

[0091] Further, the flow guiding plate has a symmetrical structure along the direction perpendicular to the flow channel, the top surface of the upper end portion of the flow guiding plate is an arc surface or a flat section with a predetermined curvature or inclination, the bottom surface of the lower end portion of the flow guiding plate is an arc surface or a flat section with a predetermined curvature or inclination, and all the flow guiding plates are arranged to be symmetrically arranged with the center line of the flow channel as the axis between the two flow guiding plates at the center position; the top surface of the upper end portion and the bottom surface of the lower end portion of each flow guiding plate as a whole have a trend of removing the predetermined curvature of the arc section of the flow channel with the center of the plate as the center.

[0092] Further, a groove for mounting a gasket is formed on the end surface near the flow channel of the plate body, and the middle position of the main flow channel is not grooved, the shape of the groove matches the gasket, the gasket comprises a first gasket and a second gasket, the first gasket and the second gasket each comprise an upper piece and a lower piece, the upper piece and the lower piece are arranged above and below the middle position which is not grooved respectively, the lower part of the upper piece and the upper part of the lower piece are arc surfaces with the same curvature as the trend of the curvature of the end portion of the flow guiding plate, the first gasket can cover part of the end portion of the flow guiding plate, the second gasket is arranged above the first gasket and can cover the complete end portion of the flow guiding plate, and the thickness of the second gasket matches the thickness of the sealing groove of the plate body.

[0093] Further, the second support column 30 is arranged at the bottom of the plate frame of the predetermined plate, a pressure measuring screw 37 is arranged on each electrolytic cell unit for daily detection of abnormal conditions of the electrolytic cell, and a terminal post is arranged on the cathode end plate and the anode end plate when direct current power supply is used, which serves as a direct current power supply line contact point.

[0094] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit the present application; although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the technical solutions recorded in the above embodiments can be modified, or some or all of the technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A system for producing methanol and fresh water co-production based on seawater and biomass, characterized in that, include: The system comprises a biomass treatment unit, an integrated system for electrolysis coupled with low-temperature distillation, and a methanol preparation unit. The integrated system includes an alkaline electrolyzer unit, an oxygen separation and cooling unit, a hydrogen separation and cooling unit, a hydrogen purification and cooling unit, an alkaline solution filtration and circulation unit, and a seawater desalination unit. The system collects seawater to be treated. The seawater desalination unit heats the seawater, removes impurities with steam, and condenses the steam to produce fresh water and concentrated seawater to be collected. The output of the seawater desalination unit is connected to the alkaline electrolyzer unit, where the fresh water is decomposed into hydrogen gas under the action of direct current. Oxygen, hydrogen, and alkali solution enter the hydrogen separation and cooling unit, while oxygen and alkali solution enter the oxygen separation and cooling unit. The hydrogen purification and cooling unit is used to purify the hydrogen. The alkali solution filtration and circulation unit is used to force the circulation of alkali solution in the alkaline electrolysis cell unit, the hydrogen separation and cooling unit, and the oxygen separation and cooling unit. The biomass treatment unit is connected to the oxygen in the water electrolysis coupled low-temperature distillation integrated system. After obtaining biomass, the biomass treatment unit reacts with oxygen to generate carbon dioxide. The output of the biomass treatment unit is connected to the methanol preparation unit, and the hydrogen from the water electrolysis coupled low-temperature distillation integrated system is also supplied to the methanol preparation unit. The alkaline electrolytic cell unit includes a cathode end plate and an anode end plate, and several 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; the cathode end plate, bipolar plate and anode end plate all include a plate body, and positioning holes, fastening holes, alkali inlet, gas-liquid outlet and flow guiding components are provided at corresponding positions on each plate; the flow guiding components of the cathode end plate and the anode end plate are opened on the inner side near the bipolar plate, and the flow guiding components of the bipolar plate are opened on one side, and a flow channel for connecting the alkali inlet and the gas-liquid outlet is opened at the middle position of the end face of the plate body; the flow guiding components divide the flow channel in a preset form; the flow guiding components specifically include a barrier mechanism, a pressurizing mechanism and a flow guiding mechanism; the barrier mechanism is arranged on the alkali inlet side, the flow guiding mechanism is arranged on the alkali outlet side, and the pressurizing mechanism is arranged between the barrier mechanism and the flow guiding mechanism; The blocking mechanism includes a liquid-blocking platform, the width of which is no greater than the diameter of the alkali inlet. The liquid-blocking platform protrudes beyond the flow channel by a predetermined distance but does not exceed the end face of the plate body of the plate it is located on. The pressurizing mechanism includes a pressurizing platform connected to the left and right side walls in the flow channel. The pressurizing platform is a complete and uninterrupted arc shape. The pressurizing platform protrudes beyond the flow channel by a predetermined distance but does not exceed the end face of the plate body of the plate it is located on, and the protruding distance is less than the thickness of the blocking mechanism and the flow guiding mechanism. The flow guiding mechanism is located at the center of the plate body and includes several flow guiding plates arranged parallel to the main direction of the flow channel.

2. The system for co-production of methanol and fresh water from seawater and biomass according to claim 1, wherein, Seawater enters the seawater desalination unit or the hydrogen separation and cooling unit or the oxygen separation and cooling unit.

3. The system for co-production of methanol and fresh water from seawater and biomass according to claim 1, wherein, The hydrogen outlet of the alkaline electrolytic cell unit is connected with a hydrogen separation and cooling unit, the oxygen outlet of the alkaline electrolytic cell unit is connected with an oxygen separation and cooling unit, the alkali inlet of the alkaline electrolytic cell unit is connected with a seawater desalination unit, the oxygen separation and cooling unit separates oxygen and alkali by a gas-liquid separation method, the hydrogen separation and cooling unit separates hydrogen and alkali by a gas-liquid separation method, the hydrogen outlet of the hydrogen separation and cooling unit is connected with a hydrogen purification and cooling unit, the alkali outlets of the oxygen separation and cooling unit and the hydrogen separation and cooling unit are connected with an alkali filtration and circulation unit to provide high-temperature alkali to be cooled, and the fresh water outlet of the seawater desalination unit is connected with the hydrogen separation and cooling unit.

4. The system for co-production of methanol and fresh water from seawater and biomass according to claim 1, wherein, The seawater desalination unit comprises a device cylinder, a vacuum pumping system, a condenser, a water receiving plate and a wire mesh separator, the device cylinder is provided with a vacuum pumping system connecting port, a seawater inlet, a concentrated seawater outlet, a fresh water outlet and an alkali circulation pipe, the vacuum pumping system connecting port is connected with the vacuum pumping system, the seawater inlet is directly connected with seawater or connected with the oxygen separation and cooling unit and the hydrogen separation and cooling unit, the concentrated seawater outlet is used for collecting concentrated seawater, and the alkali circulation pipe is used for heat exchange between high-temperature alkali and seawater to reduce the alkali temperature and make seawater evaporate into water vapor at evaporation temperature, the water vapor is condensed by the condenser, and the water receiving plate is used for receiving condensed water drops, and the output end of the water receiving plate is connected with the fresh water outlet, and the wire mesh separator is arranged in the device cylinder and used for separating large droplets and impurities in the water vapor.

5. The system for co-production of methanol and fresh water from seawater and biomass according to claim 1, wherein, The seawater desalination unit is further connected with a fresh water storage unit for storing excess fresh water.

6. The method for co-production of methanol and fresh water from seawater and biomass according to any one of claims 1 to 5, wherein, The method comprises the following steps: The electrolytic water coupling low-temperature distillation integrated system is connected with a seawater source and a biomass treatment unit, and seawater and biomass are used to produce methanol and co-produce fresh water, wherein The seawater is directly transported to the seawater desalination unit to produce fresh water and separate concentrated seawater, or is transported to the seawater desalination unit after passing through the oxygen separation and cooling unit and the hydrogen separation and cooling unit, and the seawater can play an auxiliary cooling role in the oxygen separation and cooling unit and the hydrogen separation and cooling unit; The fresh water in the alkaline electrolytic cell unit is decomposed into hydrogen and oxygen under the action of direct current; The oxygen outlet of the alkaline electrolytic cell unit transports oxygen and alkali to the oxygen separation and cooling unit to perform gas-liquid separation; The hydrogen outlet of the alkaline electrolytic cell unit transports hydrogen and alkali to the hydrogen separation and cooling unit to perform gas-liquid separation, the hydrogen and a small amount of water after preliminary purification are transported to the hydrogen purification and cooling unit for further purification, and the hydrogen content is ≥99.99%; The alkali filtration and circulation unit extracts alkali from the oxygen separation and cooling unit and the hydrogen separation and cooling unit, and after cooling by the seawater desalination unit, the alkali is finally transported to the alkaline electrolytic cell unit to complete the cooling and forced circulation of the alkali; The heat emitted by the alkali during cooling in the seawater desalination unit is used to heat seawater under negative pressure to produce fresh water, and the produced fresh water is transported to the hydrogen separation module to supplement the raw material fresh water for electrolysis and also to assist in realizing hydrogen washing and cooling; The biomass treatment unit uses oxygen generated by water electrolysis to burn the biomass to produce a certain amount of CO2. The hydrogen purified and cooled unit discharges hydrogen gas into the methanol preparation unit together with CO2 discharged from the biomass treatment unit to prepare methanol. The hydrogen purified and cooled unit discharges hydrogen gas into the methanol preparation unit together with CO2 discharged from the biomass treatment unit to prepare methanol.

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