Integrated technology and device for electro-reduction based on chemical absorption method

Abstract

Integrated technology and device for electro-reduction based on chemical absorption method belong to the field of electro-catalytic reduction and carbon capture technology. The device comprises a spray type absorption tower, a water pump, a buffer tank in front of the pool, an electrolytic cell and a buffer tank behind the pool. The integrated system of the present application integrates the chemical absorption method and the electrochemical reduction CO2 technology, simplifies the overall process of CO2 resource utilization, and makes the desorption and conversion of CO2 in situ in an electrolytic cell. The carbonized liquid formed in the carbon capture process is further utilized, thus making up for the deficiency of the chemical absorption method and building a complete technical chain. Compared with the mainstream CO2 capture-utilization (CCU) system, the present application is more advanced and realizes efficient and collaborative operation in the same space-time dimension. The present application fundamentally reduces the overall energy consumption and equipment cost of the integrated system, and can induce the formation of CO2 adducts through organic amine intermediates, so as to bend the CO2 configuration and reduce the overpotential of the electrochemical CO2 reduction reaction.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of electrocatalytic reduction and carbon capture, and particularly relates to an integrated technology and device for electro-reduction based on a chemical absorption method. BACKGROUND

[0002] The chemical absorption method is a technology for separating CO2 from a gas mixture through a chemical reaction, and is an important role for improving CO2 capture efficiency, reducing cost, and achieving the "double carbon" goal. It is the most feasible post-combustion carbon capture technology and has shown great industrial application prospects.

[0003] Ammonia decarbonization, as a typical chemical absorption method, has many advantages that traditional monoethanolamine (MEA) absorption methods do not have, such as strong CO2 absorption capacity, low absorption reaction heat, low corrosion, and low price, which helps to form an integrated system for energy cascade utilization and integrated removal of various pollutants.

[0004] The ammonia decarbonization technology generally has low CO2 absorption rate, serious ammonia escape, and high energy consumption for desorption and regeneration.

[0005] The mainstream CO2 capture-utilization (CCU) system is a kind of CCU technology that focuses on realizing effective utilization of CO2 by integrating capture and conversion processes, effectively improving energy utilization efficiency, and reducing global carbon emissions.

[0006] The mainstream CCU system needs to complete the "capture-regeneration-separation" whole process to obtain high-purity CO2 for subsequent catalytic reduction, but its energy consumption cost is high and the process is complex. SUMMARY

[0007] The present application provides an integrated technology and device for electro-reduction based on a chemical absorption method to solve the above problems.

[0008] The technical solution adopted by the present application is as follows:

[0009] An integrated technology and device for electro-reduction based on a chemical absorption method, comprising a spray absorption tower, and a water pump machine one, a pre-tank buffer tank, an electrolytic cell, a post-tank buffer tank, and a water pump machine two connected in sequence through a hose and a tower bottom rich liquid outlet of the spray absorption tower; the water outlet of the water pump machine two is connected back to the lean liquid inlet of the spray absorption tower through a hose.

[0010] Compared with the prior art, the present application has the following beneficial effects:

[0011] The application integrates the chemical absorption method and the electrochemical reduction CO2 technology through an integrated system, simplifies the overall process of CO2 resource utilization, and makes the desorption and conversion of CO2 in-situ in an electrolytic cell, so that the carbonated liquid (containing abundant bicarbonate ions, HCO3 - ) formed by the carbon capture process is continuously utilized, thereby making up for the shortcomings of the chemical absorption method and constructing a complete technical chain, which is more advanced than the mainstream CO2 capture-utilization (CCU) system, and realizes efficient and coordinated operation in the same space-time dimension. The application fundamentally reduces the overall energy consumption and equipment cost of the integrated system, and can induce the formation of CO2 adducts through organic amine intermediates, so that the CO2 configuration is bent, thereby reducing the overpotential of the electrochemical CO2 reduction reaction. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 is a structural schematic diagram of the application;

[0013] Figure 2 is a spray type absorption tower section view of the application;

[0014] Figure 3 is a structural schematic diagram of the electrolytic cell of the application;

[0015] Figure 4 is a structural schematic diagram of the electrolytic cell without electrolytic cell cover plate of the application;

[0016] Figure 5 is a bottom liquid flow section view of the electrolytic cell of the application;

[0017] Figure 6 is a structural schematic diagram of the electrolytic cell cover plate of the application;

[0018] Figure 7 is a structural schematic diagram of the anode side shell of the application;

[0019] Figure 8 is a structural schematic diagram of the cathode side shell of the application;

[0020] Figure 9 is a structural schematic diagram of the anode electrode plate of the application;

[0021] Figure 10 is a structural schematic diagram of the cathode electrode plate of the application;

[0022] Figure 11is the electrocatalytic reduction characteristic diagram of ammonium bicarbonate under the condition of no CO2 bubbling; wherein: (a) is a three-electrode experimental system; (b) is a mechanism diagram of the Br element modified Ag-based catalyst for reducing NH4HCO3 to CO2; (c) is the result of the halogen element synergistic electrocatalytic reduction of NH4HCO3; (d) is a comparison diagram of CO faradic efficiency before and after Br element modification; (e) is a Tafel diagram of the trace Br modified Ag catalyst;

[0023] Figure 12 is a structure-activity relationship diagram between the structure of the metal-based catalyst and the electrocatalytic selective reduction of CO2; wherein: (a) is a Ce-Cu electrode catalyzing the reduction of CO2 to C2H4; (b) is an Au-CNT catalytic electrode synthesis process; (c) is a Vo-SnO2 electrode catalyzing the reduction of CO2 to HCOOH; (d) is the intermediate free energy DFT calculation result of the Vo-SnO2 electrode catalyzing the reduction of CO2; (e) is the promotion effect of the Au-CNT catalytic electrode on the selectivity of CO2 reduction;

[0024] 1, spray type absorption tower; 2, water pump machine 1; 3, pool front buffer tank; 4, electrolytic cell; 5, pool back buffer tank; 6, hose; 7, tower top cover; 8, flue gas outlet; 9, top demisting layer; 10, liquid distributor; 11, lean liquid inlet; 12, upper layer filler; 13, liquid redistribution device; 14, lower layer filler; 15, tower bottom cover; 16, flue gas inlet; 17, tower bottom rich liquid outlet; 18, electrolyte inlet; 19, electrolyte outlet; 20, anode side shell; 21, cathode side shell; 22, electrolytic cell cover plate; 23, reduced gas outlet hole; 24, water pump machine 2; 25, fastener; 26, anode chamber; 27, anode chamber side wall pipeline; 28, ion exchange membrane; 29, spacer chamber; 30, spacer plate hole; 31, cathode chamber side wall pipeline; 34, cathode chamber; 35, spacer plate; 36, joint; 37, membrane gap; 38, cathode electrode port; 39, anode electrode port; 40, oxygen outlet hole; 41, cathode electrode plate; 42, cathode joint; 43, electrode plate hole; 44, anode electrode plate; 45, anode joint. DETAILED DESCRIPTION

[0025] In order to better understand the purpose, structure and function of the present application, the present application will be described in further detail below in combination with the drawings.

[0026] The present application relates to a kind of integrated system design of post-combustion carbon capture and utilization, specifically related to a kind of system integration for post-combustion by chemical absorbent absorption carbon dioxide (CO2) into carbonized liquid and be equipped with catalyst electrolytic cell equipment electrolytic reduction into C1, C2 Such as energy class reduction product technical device research and development.

[0027] The chemical absorbent of the present invention is any chemical absorbent that has CO2 absorption capacity and can promote the formation of bicarbonate ions (HCO3-) during the absorption process;

[0028] Alkylamine solutions, as a typical example of chemical absorbents, achieve effective CO2 capture by generating bicarbonate or carbonate. Specifically, the category of alkylamine solutions encompasses a range of common and widely adopted solvents in industry, such as MEA (monoethanolamine), DEA (diethanolamine), MDEA (methyldiethanolamine), and DIPA (diisopropanolamine).

[0029] The catalyst of this invention can be any catalyst that can promote the catalytic conversion of CO2 and HCO3- into carbon-containing reducing liquids (such as methanol and formic acid) and reducing gases (such as carbon monoxide and methane) in an electrolytic cell, such as: a) metal and its oxide derivative catalysts: copper (Cu), silver (Ag), copper oxide (CuO), cuprous oxide (Cu2O), etc.

[0030] b) Alloy catalysts: Cu-Sn alloys, Au-Pb alloys, etc.;

[0031] c) Transition metal nitrides and phosphides: nitrides and phosphides of molybdenum (Mo), cobalt (Co), nickel (Ni), etc.

[0032] d) Nanostructured materials: metal nanoparticles deposited on carbon nanotubes (CNTs), graphene, and two-dimensional layered materials, etc.

[0033] e) Organic and hybrid catalysts: conjugated microporous polymers (CMPs), porphyrin and phthalocyanine derivatives, organometallic frameworks (OMFs) and metal-organic frameworks (MOFs), etc.

[0034] f) Semiconductor materials: CdS, CdSe, ZnO, TiO2 and other photocatalysts.

[0035] like Figure 1 As shown, the present invention provides an integrated technology and device for electroreduction utilization based on chemical absorption, including a spray absorption tower 1, and a water pump 2, a buffer tank 3 before the pool, an electrolytic cell 4, a buffer tank 5 after the pool, and a water pump 24 connected in sequence to the rich liquid outlet 17 at the bottom of the spray absorption tower 1 via a hose 6; the outlet of the water pump 24 is connected back to the lean liquid inlet 11 of the spray absorption tower 1 via the hose 6.

[0036] The steps for assembling the integrated device are as follows:

[0037] Step 1: build the spray absorption tower 1, the top and bottom of the spray absorption tower 1 are provided with electrolyte flow inlet and outlet, the bottom of the spray absorption tower 1 is connected with the hose 6;

[0038] Step 2: connect the hose 6 obtained in step 1 to the water inlet of the water pump machine 1 2, then continue to connect the hose 6 to the water outlet of the water pump machine 1 2;

[0039] Step 3: connect the hose 6 obtained in step 2 to the liquid inlet on the side of the bottom of the pre-pool buffer tank 3, then connect the hose 6 to the liquid outlet on the side of the top of the pre-pool buffer tank 3;

[0040] Step 4: connect the hose 6 obtained in step 3 to the electrolyte liquid inlet 18 on the side of the bottom of the integrated electrolytic cell 4 (herein, a single electrolytic cell of the integrated electrolytic cell 4 is shown), then connect the hose 6 to the electrolyte liquid outlet 19 of the integrated electrolytic cell 4, and connect the oxygen gas outlet hole 40 and the reducing gas outlet hole 23 on the side of the top of the integrated electrolytic cell 4 to the oxygen gas storage system and the reducing gas storage system respectively;

[0041] Step 5: connect the hose 6 obtained in step 4 to the separation liquid inlet on the side of the bottom of the post-pool buffer tank 5, then connect the hose 6 to the top of the post-pool buffer tank 5, and connect the reducing liquid outlet on the bottom of the post-pool buffer tank 5 to the reducing liquid storage system;

[0042] Step 6: connect the hose 6 obtained in step 5 to the water inlet of the water pump machine 2 24, and then connect the hose 6 to the water outlet of the water pump machine 2 24;

[0043] Step 7: connect the hose 6 obtained in step 6 to the liquid inlet 11 on the side of the top of the spray absorption tower 1.

[0044] According to the above seven steps in order, the ICCU system of the application can be assembled, and details are shown in Figure 1 .

[0045] The ICCU system assembled by the above method can be used as a post-combustion carbon capture and resource recycling energy conversion device, which converts the excess power sent by a renewable energy power grid into flammable gas and alcohol liquid, and constitutes the core hub of source, network, load and storage.

[0046] As shown in Figure 2 , the spray absorption tower 1 comprises a tower top cover 7, a liquid distributor 10, an upper layer of fillers 12, a liquid redistribution device 13, a lower layer of fillers 14, a tower bottom cover 15, a lower layer of filler layer cylinder, a middle layer of cylinder, an upper layer of filler layer cylinder and a top layer of cylinder;

[0047] The tower bottom cover 15 is installed on the support, and the lower layer of filler layer cylinder, the middle layer cylinder, the upper layer of filler layer cylinder, the top layer cylinder and the tower top cover 7 are sequentially installed on the tower bottom cover 15 from bottom to top by the inner recessed joint 36,

[0048] The tower bottom cover 15 is installed on the support, and the lower layer of filler layer cylinder, the middle layer cylinder, the upper layer of filler layer cylinder, the top layer cylinder and the tower top cover 7 are sequentially installed on the tower bottom cover 15 from bottom to top by the inner recessed joint 36,

[0049] The tower bottom cover 15 is installed on the support, and the lower layer of filler layer cylinder, the middle layer cylinder, the upper layer of filler layer cylinder, the top layer cylinder and the tower top cover 7 are sequentially installed on the tower bottom cover 15 from bottom to top by the inner recessed joint 36,

[0050] The spray type absorption tower 1 adopts a bottom-up building mode, and comprises the following steps:

[0051] Step 1: first, the tower bottom cover 15 is installed on the support, then the lower layer of filler layer cylinder is butted to the tower bottom cover 15 along the joint 36, then the joint 36 is fastened by the screw device, and finally the lower layer of filler 14 is uniformly poured on the grid plate at the bottom of the lower layer of cylinder;

[0052] Step 2: on the basis of step 1, the middle layer cylinder is installed on the lower layer of filler layer cylinder along the joint 36, then the liquid redistribution device 13 is fixed on the inner wall of the middle layer cylinder, and finally the joint 36 is fastened by the screw device;

[0053] Step 3: on the basis of step 2, the upper layer of filler layer cylinder is installed on the middle layer cylinder along the joint 36, then the joint 36 is fastened by the screw device, and finally the upper layer of filler 12 is uniformly poured on the grid plate at the bottom of the upper layer of cylinder;

[0054] Step 4: on the basis of step 3, the top layer cylinder is installed on the upper layer of filler layer cylinder along the joint 36, then the liquid distribution device 10 is fixed on the inner wall of the top layer cylinder, and finally the joint 36 is fastened by the screw device;

[0055] Step 5: on the basis of step 4, the tower top cover 7 is installed on the upper layer of cylinder along the joint 36, and then the joint 36 is fastened by the screw device;

[0056] The application adopts the design of the upper convex and lower concave joint 36 between the lower filler layer cylinder, the middle layer cylinder, the upper filler layer cylinder, the top layer cylinder, the tower top cover 7 and the tower bottom cover 15, compared with the traditional flat joint, has the following advantages: 1, the joint 36 is more stable and convenient when the two devices are connected, and is more convenient for later fastening; 2, the liquid will not seep out of the joint 36 in the process of spraying and flowing from top to bottom, which is beneficial to the maintenance of the absorption tower and the stability of the surrounding environment; 3, the gas will be less seeped out of the joint 36 when flowing from bottom to top, which is beneficial to the full absorption of the flue gas and the external maintenance of the environmental stability.

[0057] As shown in Figures 3 to 10 The electrolytic cell 4 includes a shell, an electrolyte inlet 18, an electrolyte outlet 19, an anode electrode plate 44, a cathode electrode plate 41 and an ion exchange membrane 28; the shell is provided with the electrolyte inlet 18 and the electrolyte outlet 19 on the right side of the lower end, and the electrolyte inlet 18 and the electrolyte outlet 19 are arranged in front and back; a plurality of anode electrode plates 44 and cathode electrode plates 41 are arranged and installed in the shell from right to left in turn, and the anode joint 45 of the anode electrode plate 44 and the cathode joint 42 of the cathode electrode plate 41 respectively pass through the shell, the rear end of the anode electrode plate 44 and the front end of the cathode electrode plate 41 are both provided with vertically arranged electrode plate holes 43, the adjacent anode electrode plate 44 and cathode electrode plate 41 are provided with the ion exchange membrane 28, and the ion exchange membrane 28 is higher than the anode electrode plate 44 and the cathode electrode plate 41, and forms a closed space with the adjacent ion exchange membrane 28;

[0058] A plurality of anode chamber side wall pipes 27 are sequentially arranged on the front side wall of the shell from right to left, the inlet of each anode chamber side wall pipe 27 is arranged on the left side of the corresponding anode electrode plate 44, and the outlet of each anode chamber side wall pipe 27 is arranged on the right side of the next anode electrode plate 44;

[0059] The left side of the outermost cathode electrode plate 41 is provided with a partition plate 35, the chamber between the partition plate 35 and the shell is a partition chamber 29, and the rear side of the partition plate 35 is provided with a partition plate hole 30 for connecting the anode chamber 26 and the cathode chamber 34;

[0060] A plurality of cathode chamber side wall pipes 31 are sequentially arranged on the rear side wall of the shell from left to right, the inlet of each cathode chamber side wall pipe 31 is arranged on the right side of the corresponding cathode electrode plate 41, and the outlet of each cathode chamber side wall pipe 31 is arranged on the left side of the next cathode electrode plate 41;

[0061] From right to left, the shell and the nearest ion exchange membrane 28 form an anode chamber 26, then the two ion exchange membranes 28 are sequentially arranged as a cathode chamber 34 and an anode chamber 26 in turn, and finally the leftmost ion exchange membrane 28 and the partition plate 35 form a cathode chamber 34;

[0062] The anode chamber 26 and the cathode chamber 34 are arranged in the direction of gravity, with the upper side being the anode gas chamber and the lower side being the anode liquid chamber and the cathode liquid chamber. An oxygen outlet 40 is installed at the anode gas chamber, and a reducing gas outlet 23 is installed at the cathode gas chamber.

[0063] The electrolyte can submerge the anode electrode plate 44 and the cathode electrode plate 41, but will not be higher than the bottom of the oxygen outlet 40 and the reducing gas outlet 23. Meanwhile, the oxygen outlet 40 and the reducing gas outlet 23 are located at the top of the electrolytic cell shell 4.

[0064] like Figure 3 As shown, the housing includes an anode-side outer shell 20, a cathode-side outer shell 21, and an electrolytic cell cover plate 22; the anode-side outer shell 20 and the cathode-side outer shell 21 are joined together front and back, and the electrolytic cell cover plate 22 is sealed and installed on the anode-side outer shell 20 and the cathode-side outer shell 21. When the anode-side outer shell 20, the cathode-side outer shell 21, and the electrolytic cell cover plate 22 are connected to each other, they are all joined together through a recessed joint 36.

[0065] like Figures 3 to 10 As shown, the front wall of the anode-side housing 20 has multiple anode electrode ports 39, and the rear wall of the cathode-side housing 21 has multiple cathode electrode ports 38. The anode electrode plate 44 has an anode connector 45 at one end and an electrode plate channel 43 at the other end. The anode connector 45 of the anode electrode plate 44 extends out of the anode electrode port 39. The cathode electrode plate 41 has a cathode connector 42 at one end and an electrode plate channel 43 at the other end. The cathode connector 42 of the cathode electrode plate 41 extends out of the cathode electrode port 38. The anode connector 45 is connected to the anode of the external pulse power supply, and the cathode connector 42 is connected to the cathode of the external pulse power supply.

[0066] like Figures 4 to 6 As shown, corresponding to the front, back and top sides of each ion exchange membrane 28, multiple membrane slits 37 are opened on the anode-side shell 20, the cathode-side shell 21 and the electrolytic cell cover plate 22.

[0067] like Figure 3 , Figure 4 As shown, the anode-side outer shell 20, the cathode-side outer shell 21, and the electrolytic cell cover plate 22 are all connected by fasteners 25.

[0068] The construction method of a single electrolytic cell 4 in an integrated electrolytic cell includes the following steps:

[0069] Step 1: Insert the anode connector 45 on the anode electrode plate 44 and the cathode connector 42 on the cathode electrode plate 41 into the anode electrode port 39 of the anode side housing 20 and the cathode electrode port 38 of the cathode side housing 21, respectively.

[0070] Step 2: On the basis of Step 1, the anode side shell 20 and the cathode side shell 21 are combined along the opening and closing of the joint 36, and

[0071] Step 3: On the basis of Step 2, the ion exchange membrane 28 is inserted along the membrane gap 37 respectively;

[0072] Step 4: On the basis of Step 3, the electrolytic cell cover plate 22 is installed along the joint 36 from top to bottom on the joint 36 of the anode side shell 20 and the cathode side shell 21;

[0073] Step 5: On the basis of Step 4, the screw hole of the fastener 25 is fastened by a screw or the like, and then the anode of the external pulse power is connected to the anode joint 45 of the electrolytic cell, and the cathode of the external pulse power is connected to the cathode joint 45 of the electrolytic cell.

[0074] Through the sequential installation of the above five steps, the single electrolytic cell 4 of the integrated electrolytic cell of the application is stably completed, and then only the single electrolytic cell 4 needs to be connected in parallel to form the integrated electrolytic cell.

[0075] Compared with the prior art, the integrated electrolytic cell of the application has the following advantages in electrolytic cell installation:

[0076] 1. The integrated electrolytic cell of the application adopts the joint 36 treatment at the coincident joint surface of the anode side shell 20, the cathode side shell 21 and the electrolytic cell cover plate 22, which makes the integrity of the electrolytic cell 4 better after forming, and reduces the probability of problems such as liquid leakage and gas leakage;

[0077] 2. The integrated electrolytic cell of the application fixes the spatial position of the ion exchange membrane 28 by inserting the ion exchange membrane 28 into the membrane gap 37, effectively fixes the position of the ion exchange membrane 28, and effectively separates the cathode chamber 34 from the anode chamber 26 and the cathode gas chamber from the anode gas chamber, avoiding the turbulent mixing between the gas phase products and the liquid phase products, avoiding the adverse phenomenon of reducing the yield of the oxidation reaction of the cathode reduction product close to the anode plate, and being conducive to the product separation and liquid enrichment regeneration treatment in the later stage;

[0078] The system operation of the application is operated through the following technical process: including the following steps:

[0079] Step 1, the flue gas from the factory enters the inside of the bottom cover 15 of the spray absorption tower through the flue gas inlet 16 on the side of the bottom cover, and flows from bottom to top through the lower packing layer 14, the middle liquid redistributor 13, the upper packing layer 12, the upper liquid distributor 10, and the top demisting layer 9, and then reaches the inside of the top cover 7 of the spray absorption tower, and then flows out from the top flue gas outlet 8, and the flue gas that has reached the emission standard is discharged. The electrolyte lean liquid flows into the upper part of the spray absorption tower from the lean liquid inlet 11, and is uniformly sprayed from the upper liquid distributor 10 to the upper packing layer 12, and the lean liquid uniformly wets the surface of the packing, and then flows into the liquid redistributor 13, and is collected by the liquid redistributor 13 and uniformly sprayed to the lower packing layer 14 again, and the sprayed liquid continues to wet the surface of the packing and then flows into the inside of the bottom cover 15 of the spray absorption tower, and finally the electrolyte rich liquid is formed and flows out from the bottom rich liquid outlet of the tower; Figure 2 ;

[0080] Step 2, the electrolyte rich liquid obtained in step 1 is pressurized into the pre-pool buffer tank 3 by the water pump 2, and the carbonization degree of the carbonized liquid in the rich liquid is buffered to a suitable range. Then, the carbonized liquid rich liquid flows out from the pre-pool buffer tank 3 and flows into the electrolyte inlet 18 of the integrated electrolysis cell 4;

[0081] Step 3, the electrolyte flowing in from the electrolyte inlet 18 is guided to the anolyte chamber 26, and after external pulse current is introduced, the electrolyte undergoes intermittent oxidation reaction on the surface of the anode electrode plate 44 to generate O2 and H + , O2 enters the gas chamber of the anode chamber 26, the gas chamber is externally connected to an oxygen storage system, H + passes through the ion exchange membrane 28 into the liquid chamber of the cathode chamber 34 to achieve charge balance. Under the action of the liquid flow, the electrolyte flows through the anode chamber 26, the electrode plate channel 43, the next anode chamber 26, the anode chamber side wall pipe 27, the interval chamber 29, and the interval plate channel 30 into the cathode chamber 34 in sequence. Then, CO3 - in the electrolyte undergoes a balance exchange phenomenon near the surface of the cathode electrode plate to generate CO2 and is adsorbed on the surface of the cathode electrode plate 41, and then undergoes intermittent reduction reaction under the action of the externally connected pulse current to generate C + and H2 and other gas-liquid phase reduction products. H2 and the gas phase reduction products enter the gas chamber of the cathode chamber 34 from the liquid chamber, and the gas chamber is externally connected to a reduction gas storage chamber. The electrolyte after the reduction reaction continues to flow through the electrode plate channel 43, the next cathode chamber 34, the cathode chamber side wall pipe 31, and the next cathode chamber 34, and finally flows out from the electrolyte outlet 19 to form a mixed liquid of electrolyte lean liquid and alcohol liquid phase reduction products;

[0082] Step 4, the mixed liquid obtained in step 3 is introduced into the post-pool buffer tank 5, and the mixed liquid is separated into electrolyte lean liquid and alcohol liquid phase reduction product by the molecular sieve in the tank. The electrolyte lean liquid after separation flows out from the regeneration liquid outlet at the top of the post-pool buffer tank, forming a regeneration liquid, and the alcohol liquid phase reduction product after separation flows out from the reduction liquid outlet at the bottom of the post-pool buffer tank 5 and flows into the reduction liquid phase product storage system.

[0083] Step 5, the regeneration liquid obtained in step 4 is pressurized and transported by the water pump machine 2 4, and flows into the inside of the spray absorption tower 1 through the lean liquid inlet 11 of the spray absorption tower 1.

[0084] The continuous circulation of the above five steps constitutes the sustainable reflux process of the ICCU system. Compared with the prior art, the present application has the following advantages:

[0085] (1) The present application combines the spray absorption tower with the integrated electrolytic cell 4 in a system integration manner, and comprehensively uses multiple technical features such as separation of flue gas by the spray absorption tower, chemical absorption of CO2 by the chemical absorbent (ammonia water), and electrochemical reduction of CO2 by the electrolytic cell, thereby developing a perfect ICCU system.

[0086] (2) The number of integrated electrolytic cells 4 in the present application can be increased or decreased in quantity according to the actual production cycle benefit, which is very suitable for industrial large-scale operation control.

[0087] (3) The flow paths of the electrolyte in the single electrolytic cell 4 in the present application in the cathode chamber 34 and the anode chamber 26 are connected. Compared with the traditional electrolytic cell in which the cathode chamber 34 and the anode chamber 26 are not connected, the electrolytic cell 4 designed in the present application has a spacing chamber 29 on the opposite side of the electrolyte. The electrolyte flows into the anode chamber 26 from the electrolyte inlet 18, flows into the cathode chamber 34 through the spacing chamber 29, and then flows out of the cathode chamber 34 from the electrolyte outlet 19, thereby realizing full reduction of the electrolyte, and improving the total efficiency of the electro-reduction and the efficiency of the rich liquid regeneration. In the traditional electrolytic cell, only the electrolyte in the cathode chamber can participate in the reduction reaction.

[0088] (4) The flow direction of the electrolyte in the single electrolytic cell 4 in the present application is single, i.e. only from the anode chamber 26 to the cathode chamber 34, thereby ensuring that the alcohol liquid phase reduction product generated in the electrolyte after participating in the reduction reaction will not enter the anode chamber 26, and thereby preventing the reduction product from being oxidized, and ensuring the normal output of the alcohol liquid phase reduction product.

[0089] Example 1:

[0090] The inventors and their team studied the structure-activity relationship between the structure of the catalytic electrode and the reduction characteristics of ammonium bicarbonate under the condition of CO2-free bubbling. The three-electrode experimental system used for on-line gas-phase product monitoring is shown in Figure 11 a. The results of the study show that halogen element modified Ag catalysts can promote the process of ammonium bicarbonate reduction to CO Figure 11 c), among which the effect of Br modification is more significant Figure 11 b, d). The modification effect of Br mainly comes from the inhibition of proton adsorption and hydrogen evolution reaction on the electrode surface, and the fundamental reason is that Br changes the electronic state and structure of the Ag substrate and forms a chemical bond with Ag in the Helmholtz plane. In addition, trace Br on the Ag substrate also has a positive contribution to the electrochemical reduction selectivity and catalytic activity of ammonium bicarbonate. This provides a theoretical basis and experimental guarantee for exploring the influence mechanism of the surface morphology of the catalyst on the CO2 reduction reaction in the invention of this project. The Tafel plot of the trace Br modified Ag catalyst shows that the carbon source actually participating in the reduction reaction is CO2 gas produced by the decomposition of NH4HCO3 rather than bicarbonate ions Figure 11 e), which provides theoretical support for exploring the dynamic balance mechanism and kinetic characteristics between bicarbonate and CO2 in this project.

[0091] Example 2:

[0092] The inventors and their team have carried out a series of studies on the influence mechanism of the structure of metal-coupled catalysts or modified metal catalysts on the selective electrocatalytic reduction of CO2. The current research shows that the reduction process of bicarbonate is likely to start from the equilibrium conversion to CO2, i.e. the actual reactant participating in the reduction process is CO2, so the research results on the selective reduction of CO2 can be used to guide the study of the reduction process of ammonium bicarbonate. The inventors and their team have developed a series of catalytic electrodes with high selectivity based on metal-based catalysts, including Ce-Cu catalytic electrode, Au-CNT catalytic electrode, Vo-SnO2 catalytic electrode, Cu-Bi catalytic electrode, etc. (some results are shown in Figure 12 a-c). Among them, the black porous SnO2 nanoelectrode shows high reactivity and selectivity for the reduction of CO2 to formate, and further DFT calculation reveals that the introduction of oxygen vacancies can reduce the adsorption energy of intermediates and promote the selective mechanism of CO2 directional reduction to formate Figure 12d); provide a theoretical basis and experimental support for exploring the competition reaction regulation mechanism of the electrocatalytic ammonium bicarbonate liquid product in this project. The synthesis process of the metal complex on the appropriate carrier induces the charge transfer between the gold nanoclusters and the carbon nanotubes, forming the relatively electron-rich state of the gold active site, greatly promoting the selective activation process of CO2; provide theoretical support and experimental basis for exploring the real active site of the functional carbon material carrier participating in the reaction in this project Figure 12 e).

[0093] The application adopts a chemical absorption method carbon capture technology, which has high carbon capture efficiency, stable temperature control, large carbon capture amount, and the product is directly used for subsequent reaction, reducing the temperature loss caused by NH4HCO3 phase change recovery;

[0094] The application adopts the electrochemical reduction CO2 technology, which uses the property of integrated electrolytic cell 4 working at room temperature to electrochemically reduce CO2, which is suitable for large-scale commercial operation;

[0095] The number of the integrated electrolytic cell 4 can be configured according to actual conditions, which can well adapt to the peak and trough of the power grid, has a large adjustable range of energy storage, and has strong operability.

[0096] The spray type absorption tower 1 uses a liquid redistributor 13, which can collect the absorption liquid flowing down the upper layer of fillers and then uniformly distribute it to the lower layer of fillers, avoiding the adverse situation of uneven liquid distribution caused by long filler layer and filler blockage;

[0097] The CO2 absorption liquid of the application is an amine substance, which has high CO2 absorption capacity, but is not limited to amine substances;

[0098] The electrode working environment belongs to room temperature environment, and the electrolyte can flow from the anode chamber 26 to the cathode chamber 34, avoiding the oxidation reaction of the cathode product flowing to the anode plate;

[0099] The shell of the single electrolytic cell 4 has a joint 36, and the corresponding joints 36 can perfectly fit, reducing the risk of liquid and gas leakage;

[0100] The anode chamber side wall pipe 27 is arranged on the anode side electrolytic cell shell 20 of the integrated electrolytic cell 4, and the cathode chamber side wall pipe 31 is arranged on the cathode side electrolytic cell shell 21, which facilitates the electrolyte flow through pipe between the two anode chambers 26 and the two cathode chambers 34;

[0101] The integrated electrolytic cell 4 is provided with a spacing chamber 29 between the cathode chamber 34 and the anode chamber 26, which increases the spatial distance between the anode chamber 26 and the cathode chamber 34, avoids the reverse flow of the alcohol liquid phase product in the cathode chamber 34 to the anode chamber 26, and thus ensures the stable generation of the alcohol reduction product;

[0102] The anode plate 44 and the cathode plate 41 of the integrated electrolytic cell 4 contain plate holes 43 on the opposite sides of the anode joint 42 and the cathode joint 45, respectively, so that the electrolyte can flow from one side to the other side of the plate, prolonging the electrolysis distance of the electrolyte and allowing the electrolyte to be fully electrolyzed.

[0103] The pH value of the electrolyte needs to be maintained in the range of 8-9.

[0104] The present application combines the advantages of chemical absorption of CO2 in the absorption tower and electrochemical reduction of CO2 in the integrated electrolytic cell, uses ammonia and other chemical absorbents as the absorption liquid, adjusts the concentration of the chemical absorbent (ammonia), the absorption temperature, the concentration of carbon dioxide, the pulse current and other parameters, realizes the cyclic conversion of the absorption liquid and the electrolyte, and further realizes the double carbon goal of cyclic carbon capture and reduction of the ICCU system, fundamentally solves the problem of complex electrolyte sources and the lack of integrated systems. The integrated technology and device for electro-reduction based on the chemical absorption method (ICCU) developed by the present application can be operated efficiently and sustainably; under the premise that the parameters of the system are properly configured, no additional absorption liquid (electrolyte lean liquid) is needed during system operation; the equipment belongs to a post-combustion carbon capture device, so it does not need to modify the architectural structure of the flue gas emission facilities at factories and other places, and only needs to add the inventive device at the appropriate flue gas emission position to complete the installation; the spray type absorption tower and the shell structure of the integrated electrolytic cell of the equipment are treated with joints 36, which are not easy to leak internal gas and liquid, and are very friendly to the ecological environment; the gaseous and liquid phase reduction materials produced by the invention can be separated and used as energy storage raw materials, which is conducive to ensuring national energy security.

[0105] It can be understood that the present application is described by some embodiments, and those skilled in the art know that various changes or equivalent replacements can be made to these features and embodiments without departing from the spirit and scope of the present application. In addition, these features and embodiments can be modified to adapt to specific conditions and materials under the guidance of the present application without departing from the spirit and scope of the present application. Therefore, the present application is not limited by the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of the present application are within the scope of the present application.

Claims

1. An integrated device for electroreduction and utilization based on chemical absorption, characterized in that: The system includes a spray absorption tower (1), and a water pump (2), a buffer tank (3), an electrolytic cell (4), a buffer tank (5), and a water pump (24) connected in sequence to the rich liquid outlet (17) at the bottom of the spray absorption tower (1) via a hose (6). The outlet of the water pump (24) is connected back to the lean liquid inlet (11) of the spray absorption tower (1) via a hose (6). The electrolytic cell (4) includes a shell, an electrolyte inlet (18), an electrolyte outlet (19), an anode electrode plate (44), a cathode electrode plate (41), and an ion exchange membrane (28). An electrolyte inlet (18) and an electrolyte outlet (19) are provided on the lower right side of the shell, and the electrolyte inlet (18) and electrolyte outlet (19) are arranged one in front of the other. Multiple anode electrode plates (44) and cathode electrode plates (41) are arranged in a crisscross pattern from right to left within the shell. 4) The anode connector (45) and the cathode connector (42) of the cathode electrode plate (41) respectively protrude from the shell. Vertically arranged electrode plate channels (43) are opened at the rear end of the anode electrode plate (44) and the front end of the cathode electrode plate (41). An ion exchange membrane (28) is provided between adjacent anode electrode plates (44) and cathode electrode plates (41). The ion exchange membrane (28) is higher than the anode electrode plate (44) and cathode electrode plate (41) and forms a closed space with the adjacent ion exchange membrane (28). The front sidewall of the housing has multiple anode chamber sidewall pipes (27) arranged from right to left. The inlet of each anode chamber sidewall pipe (27) is located on the left side of the corresponding anode electrode plate (44), and the outlet of each anode chamber sidewall pipe (27) is located on the right side of the next anode electrode plate (44). A spacer plate (35) is installed on the left side of the outermost cathode electrode plate (41). The cavity between the spacer plate (35) and the shell is a spacer chamber (29). The spacer plate (35) has multiple spacer channels (30) at the end of the cathode side shell (21) to connect the anode chamber (26) and the cathode chamber (34). The rear sidewall of the housing has multiple cathode chamber sidewall pipes (31) arranged from left to right. The inlet of each cathode chamber sidewall pipe (31) is located on the right side of the corresponding cathode electrode plate (41), and the outlet of each cathode chamber sidewall pipe (31) is located on the left side of the next cathode electrode plate (41). From right to left, the anode chamber (26) is between the shell and the nearest ion exchange membrane (28). Then, the cathode chamber (34) and the anode chamber (26) are arranged alternately between the two ion exchange membranes (28). Finally, the cathode chamber (34) is between the leftmost ion exchange membrane (28) and the spacer (35). The anode chamber (26) and the cathode chamber (34) are arranged in the direction of gravity, with the upper side being the anode gas chamber and the lower side being the anode liquid chamber and the cathode liquid chamber. An oxygen outlet (40) is installed at the anode gas chamber, and a reducing gas outlet (23) is installed at the cathode gas chamber.

2. The integrated electroreduction and utilization device for chemical absorption according to claim 1, characterized in that: The spray absorption tower (1) includes a tower top cover (7), a liquid distributor (10), upper packing (12), a liquid redistributor (13), lower packing (14), a tower bottom cover (15), a lower packing layer cylinder, a middle cylinder, an upper packing layer cylinder, and a top cylinder; The tower bottom cover (15) is installed on the support, and the lower packing layer cylinder, the middle cylinder, the upper packing layer cylinder, the top cylinder, and the tower top cover (7) are installed on the tower bottom cover (15) from bottom to top. The bottom cover (15) is connected to the lower packing layer cylinder, the lower packing layer cylinder to the middle cylinder, the middle cylinder to the upper packing layer cylinder, the upper packing layer cylinder to the top cylinder, and the top cylinder to the top cover (7) through recessed joints (36). A flue gas inlet (16) is provided on the side of the bottom cover (15), a rich liquid outlet (17) is provided at the bottom of the bottom cover (15), the lower packing layer is filled with lower packing (14), a liquid redistributor (13) is fixedly installed in the middle layer, the upper packing layer is filled with upper packing (12), a liquid distributor (10) is fixedly installed in the top layer, a lean liquid inlet (11) is provided on the top layer, and the lean liquid inlet (11) is connected to the liquid distributor (10), a top demister (9) is installed inside the top cover (7), and a flue gas outlet (8) is provided at the top of the top cover (7).

3. The integrated electroreduction and utilization device based on chemical absorption method according to claim 1, characterized in that: The housing includes an anode-side shell (20), a cathode-side shell (21), and an electrolytic cell cover (22); the anode-side shell (20) and the cathode-side shell (21) are joined together front and back, and the electrolytic cell cover (22) is sealed and installed on the anode-side shell (20) and the cathode-side shell (21). When the anode-side shell (20), the cathode-side shell (21), and the electrolytic cell cover (22) are connected to each other, they are joined together through a recessed seam (36).

4. The integrated electroreduction and utilization device based on chemical absorption method according to claim 3, characterized in that: Multiple anode electrode ports (39) are opened on the front side wall of the anode side shell (20), and multiple cathode electrode ports (38) are opened on the rear side wall of the cathode side shell (21). An anode electrode plate (44) is provided with an anode connector (45) at one end and an electrode plate channel (43) at the other end. The anode connector (45) of the anode electrode plate (44) passes through the anode electrode port (39). A cathode electrode plate (41) is provided with a cathode connector (42) at one end and an electrode plate channel (43) at the other end. The cathode connector (42) of the cathode electrode plate (41) passes through the cathode electrode port (38). The anode connector (45) is connected to the anode of an external pulse power supply, and the cathode connector (42) is connected to the cathode of an external pulse power supply.

5. The integrated electroreduction and utilization device based on chemical absorption method according to claim 4, characterized in that: For each ion exchange membrane (28), a plurality of membrane slits (37) are made on the front, back and top sides of the anode side shell (20), the cathode side shell (21) and the electrolytic cell cover plate (22).

6. The integrated electroreduction and utilization device based on chemical absorption method according to claim 3, characterized in that: The anode-side shell (20), the cathode-side shell (21), and the electrolytic cell cover (22) are all connected by fasteners (25).

7. The integrated electroreduction and utilization device based on chemical absorption method according to claim 3, characterized in that: Multiple electrolytic cells (4) are connected in parallel to form an integrated electrolytic cell, which is set between the front buffer tank (3) and the rear buffer tank (5).

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