CN205329170U - Multi -chambered diaphragm electrolysis device that is carbon dioxide electroreduction carbon monoxide - Google Patents

Abstract

The utility model relates to a multi-chamber diaphragm electrolysis device for electrically reducing carbon dioxide to carbon monoxide, belonging to the technical field of carbon dioxide resource utilization. The electrolytic cell of this device is divided into multiple electrode chambers by perfluorosulfonic acid ion exchange membranes, forming a multi-chamber diaphragm electrolytic cell with cathode chambers and anode chambers arranged alternately. The top of the chamber is equipped with a water inlet, and the organic composite electrolyte solution containing a large amount of carbon dioxide flowing out of the gas absorption tower flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the organic composite electrolyte solution with a lower concentration of carbon dioxide in the upper part of the cathode chamber The composite electrolyte is returned to the top of the gas absorption tower through the catholyte circulation device. The side of the gas absorption tower is provided with a carbon dioxide inlet, and the top of the cathode chamber is connected to the gas storage tank through a pipeline. The multi-chamber diaphragm electrolysis device provided by the utility model can continuously and efficiently electrically reduce carbon dioxide to carbon monoxide.

Description

A multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide

technical field

The utility model relates to a multi-chamber diaphragm electrolysis device for electrically reducing carbon dioxide to carbon monoxide, belonging to the technical field of carbon dioxide resource utilization.

Background technique

Converting carbon dioxide into useful chemicals and realizing the recycling of carbon resources is a practical problem that needs to be solved urgently in the field of energy and environment. Syngas is a widely used basic chemical raw material, and its main components are carbon monoxide and hydrogen. At present, syngas is mainly produced by fossil fuels, but fossil fuels are non-renewable, and a large amount of carbon dioxide will be emitted during use, leading to greenhouse gas effects and global warming. Therefore, exploring non-fossil fuel sources The production method of synthesis gas has become an important research topic. This utility model uses carbon dioxide and water as raw materials to prepare synthesis gas, and uses renewable electric energy as electrolytic electric energy to electrolyze carbon dioxide and water into carbon monoxide and hydrogen, and then mix the obtained carbon monoxide and hydrogen together to produce synthesis gas. Syngas is used to produce downstream chemical products such as methanol, paraffin, and polyurethane.

To prepare syngas with carbon dioxide, water and renewable electric energy as the basic elements, the core key problem that needs to be solved is: the continuous and efficient electroreduction of carbon dioxide to carbon monoxide.

Contents of the invention

In order to continuously and efficiently electrically reduce carbon dioxide to carbon monoxide, the utility model provides a multi-chamber diaphragm electrolysis device for electrically reducing carbon dioxide to carbon monoxide, as shown in Figure 1, the utility model is realized through the following technical solutions: using perfluorosulfonic The ion-exchange membrane separates the electrolytic cell into multiple electrode chambers, forming a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately. The organic composite electrolyte dissolved in a large amount of carbon dioxide is used as the catholyte, and the aqueous solution containing the supporting electrolyte is For the anolyte, the electrode material with high selectivity for the electrolysis of carbon dioxide to carbon monoxide is used as the cathode, and the inert electrode is used as the anode, which together constitute a multi-chamber diaphragm electrolytic cell. During the electrolysis reaction, water undergoes an oxidation reaction on the anode to generate hydrogen ions and oxygen. The hydrogen ions migrate to the electrolyte in the cathodic chamber through the mass transfer process, and participate in the carbon dioxide electroreduction reaction to generate carbon monoxide. Since the carbon dioxide electroreduction reaction itself generates water, the water can undergo an electroreduction reaction on the cathode, resulting in the generation of hydrogen on the cathode.

The organic composite electrolyte contains four functional components: an organic solvent, an organic supporting electrolyte, a proton conduction enhancer and an electrocatalyst.

The organic solvent is one of propylene carbonate, N-methylpyrrolidone, diethyl carbonate or a mixed solvent of arbitrary proportions; the organic supporting electrolyte is one of quaternary ammonium salt, choline chloride or Two mixed electrolytes in any proportion; the proton conduction enhancer is one of trifluoromethylethanol, methanol and phenol or a mixture of any proportion; the electrocatalyst is a metal porphyrin compound, a metal phthalocyanine compound , tricarbonyl-2,4'-bipyridine metal halides, and one or more mixtures in arbitrary proportions of imidazole ionic liquids.

As the quaternary ammonium salt of the organic supporting electrolyte in the organic composite electrolyte, its chemical structural formula is:

R ₁ , R ₂ , R ₃ , R ₄ are C ₁ -C ₅ hydrocarbon chains; X ^- is CF ₃ SO ₃ ^- , ClO ₄ ^- , (CF ₃ SO ₂ ) ₂ N ^- , CF ₃ COO ^- , H ₂ PO ₄ ^- , HCO ₃ ^- , Cl ^- , HSO ₄ ^- , Br ^- ;

As the choline chloride of the organic supporting electrolyte in the organic composite electrolyte, its chemical structural formula is:

As the metalloporphyrin compound of the electrocatalyst in the organic composite electrolyte, its chemical structural formula is:

M ₁ is iron or cobalt element, R ₁ , R ₂ , R ₃ , R ₄ are hydrogen atoms or C ₁ -C ₅ hydrocarbon chains, or benzene substituents;

As the metal phthalocyanine compound of the electrocatalyst in the organic composite electrolyte, its chemical structural formula is:

M ₂ is iron, manganese or copper element;

As the tricarbonyl-2,4'-bipyridine metal halide of the electrocatalyst in the organic composite electrolyte, its chemical structural formula is:

M ₃ is manganese or rhenium, X is Cl, Br or I, R ₁ and R ₂ are hydrogen atoms or C ₁ -C ₅ hydrocarbon chains;

As the electrocatalyst of the imidazole ionic liquid in the organic composite electrolyte, its chemical structural formula is:

R ₁ and R ₂ are C ₁ -C ₅ hydrocarbon chains; M and N are hydrogen atoms or functional groups connected to the hydrocarbon chains, and the functional groups are: -CN, -NH ₂ or -OH; X ^- is (CF ₃ SO ₂ ) ₂ N ^- , CF ₃ COO ^- , CF ₃ SO ₃ ^- , HCO ₃ ^- , HSO ₄ ^- , H ₂ PO ₄ ^- , Br ^- , Cl ^- .

The supporting electrolyte in the anolyte is one or more of potassium bicarbonate, sodium bicarbonate, potassium dihydrogen phosphate, sodium dihydrogen phosphate, potassium hydrogen phosphate, sodium hydrogen phosphate, potassium sulfate, sodium sulfate or sulfuric acid Mixtures in any proportion.

The anode is an iridium oxide coated titanium anode, an IrO ₂ ·Ta ₂ O ₅ coated titanium anode, a glassy carbon electrode or a graphite electrode.

The cathode is any one of Cu, Au, Ag, Zn electrodes, or an alloy of the above metals.

A multi-chamber diaphragm electrolysis method for electroreducing carbon dioxide to carbon monoxide, its specific implementation steps are as follows:

Step 1, dissolve the organic supporting electrolyte into the organic solvent to obtain an organic electrolyte solution of 0.1-3.0 mol/L, add a proton conductivity enhancer to the organic electrolyte solution according to the required concentration of 0.1-0.4 mol/L, and then Add electrocatalyst at a concentration of 0.01-0.2mol/L to obtain an organic composite electrolyte. Dissolve carbon dioxide in the organic composite electrolyte to make the concentration 0.09-0.21mol/L. The resulting solution is injected into the cathode chamber of the diaphragm electrolytic cell. An aqueous solution with a supporting electrolyte concentration of 0.1-2mol/L is injected into the anode chamber of the diaphragm electrolytic cell;

Step 2, turn on the electrolysis power supply, control the electrolysis voltage to 3.6-4.3V, and carry out the electrolysis reaction under normal temperature and pressure conditions. At this time, the water undergoes an electro-oxidation reaction on the anode to generate hydrogen ions and oxygen, and the generated hydrogen ions undergo The perfluorosulfonic acid ion exchange membrane migrates to the cathode and participates in the electroreduction reaction of carbon dioxide to generate carbon monoxide. Since water is generated in the carbon dioxide electroreduction reaction itself, a certain amount of water is contained in the catholyte, and the water undergoes an electroreduction reaction on the cathode to generate hydrogen gas. Therefore, hydrogen gas is by-produced on the cathode. The cathode gas phase reaction product is collected in a gas storage tank for the production of downstream products. In order to make the carbon dioxide electroreduction reaction proceed continuously and stably, this utility model adopts the catholyte circulation technology: the carbon dioxide is passed into the gas absorption tower, and the organic composite electrolyte is used to dissolve and absorb the carbon dioxide. When the carbon dioxide concentration reaches or is close to saturation , inject this organic composite electrolyte solution containing a large amount of carbon dioxide into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, and at the same time, the organic composite electrolyte solution on the upper part of the cathode chamber of the multi-chamber diaphragm electrolytic cell flows out from the cathode chamber automatically, This organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration is reinjected into the cathode chamber of the multi-chamber diaphragm electrolytic cell bottom, thus forming the catholyte circulation. The speed at which the organic composite electrolyte flows into and out of the cathode chamber of the multi-chamber diaphragm electrolytic cell is controlled, so that the carbon dioxide electroreduction reaction can be carried out continuously and stably.

A multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide:

The device includes a gas absorption tower 1, a cathode 2, an anode 3, a gas storage tank 4, a perfluorosulfonic acid ion exchange membrane 5, an electrolytic cell and a catholyte circulation device, and the electrolytic cell is divided into multiple parts by the perfluorosulfonic acid ion exchange membrane 5 Two electrode chambers constitute a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately, the bottom of the cathode chamber and the anode chamber are respectively provided with a cathode 2 and an anode 3, the top of the anode chamber is provided with a water inlet, and the gas absorption tower 1 The outflowing organic composite electrolyte dissolved in a large amount of carbon dioxide flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the organic composite electrolyte dissolved in a lower concentration of carbon dioxide in the upper part of the cathode chamber returns to the gas through the catholyte circulation device. The top of the absorption tower 1 and the side of the gas absorption tower 1 are provided with a carbon dioxide inlet, and the top of the cathode chamber is connected with the gas storage tank 4 through a pipeline.

Compared with the prior art, the utility model has the following technical advantages:

(1) In the multi-chamber diaphragm electrolysis device proposed by this utility model, the electroreduction reaction of carbon dioxide can be carried out in the organic composite electrolyte, and at the same time, the electrooxidation reaction of water can be carried out in the aqueous solution. Since carbon dioxide is a non-polar molecule and has good solubility in organic composite electrolyte, electroreduction of carbon dioxide in organic composite electrolyte can increase the current density of carbon dioxide electroreduction reaction;

(2) In the multi-chamber diaphragm electrolysis device proposed by this utility model, the electrolyte in the cathodic chamber is an organic composite electrolyte, which contains four functional components: organic solvent, organic supporting electrolyte, proton conductivity enhancer and electrode. catalyst. The organic solvent used in this utility model has a strong ability to dissolve carbon dioxide, the supporting electrolyte used has high electrochemical stability, and the proton conductivity enhancer used can promote hydrogen ions in the organic electrolyte and ion exchange membrane. The electrocatalyst used can reduce the overpotential of the carbon dioxide electroreduction reaction. Therefore, the electroreduction of carbon dioxide in the above-mentioned organic composite electrolyte can effectively increase the current density of the electroreduction reaction of carbon dioxide while reducing the overpotential of the electroreduction reaction of carbon dioxide;

(3) This utility model adopts catholyte circulation technology, which can make the carbon dioxide electroreduction reaction proceed in a continuous and stable state. Catholyte circulation is realized in this way: In the carbon dioxide absorption tower, the organic composite electrolyte is used to dissolve and absorb carbon dioxide. When the concentration of carbon dioxide reaches or is close to saturation, the organic composite electrolyte dissolved in a large amount of carbon dioxide is injected into the cathode of the multi-chamber diaphragm electrolytic cell. At the bottom of the chamber, at the same time, the organic composite solution on the upper part of the cathode chamber continuously flows out from the cathode chamber, and this organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained The organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration is reinjected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, thereby forming a catholyte circulation. By controlling the speed at which the organic composite electrolyte flows into and out of the cathode chamber of the multi-chamber membrane electrolytic cell, the carbon dioxide electroreduction reaction can be carried out in a continuous and stable state.

(4) The multi-chamber diaphragm electrolysis device proposed by this utility model is easy to realize industrial application. For example, the production capacity of the multi-chamber diaphragm electrolysis device can be improved by increasing the number of electrode chambers, increasing the volume of the electrode chambers and enlarging the electrode area.

Description of drawings

Figure 1 is a schematic diagram of a multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide according to the present invention.

In the figure: 1-gas absorption tower, 2-cathode, 3-anode, 4-gas storage tank, 5-perfluorosulfonic acid ion exchange membrane.

detailed description

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described further.

Example 1

A multi-chamber diaphragm electrolysis method for electroreducing carbon dioxide to carbon monoxide: use a perfluorosulfonic acid ion exchange membrane to separate the electrolytic cell into multiple electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately. The liquid is an organic composite electrolyte dissolved in carbon dioxide. The electrolyte in the anode chamber is an aqueous solution containing a supporting electrolyte. The cathode adopts a metal electrode with high selectivity for the electrolysis of carbon dioxide to produce carbon monoxide. The anode is an inert electrode. During the electrolysis reaction, there is a Carbon monoxide is produced, and hydrogen is produced as a by-product.

The organic composite electrolyte contains four functional components: an organic solvent, an organic supporting electrolyte, a proton conduction enhancer and an electrocatalyst.

The organic solvent is propylene carbonate; the organic support electrolyte is tetrabutylammonium perchlorate quaternary ammonium salt; the proton conduction enhancer is trifluoromethyl ethanol; and the electrocatalyst is iron-containing porphyrin compound.

The supporting electrolyte of the anolyte is sulfuric acid.

The anode is an IrO ₂ ·Ta ₂ O ₅ coated titanium anode, and the cathode is Au.

The implementation steps are as follows:

Step 1, dissolve the organic supporting electrolyte in the organic solvent to obtain a 3.0mol/L organic electrolyte, add a proton conductivity enhancer to the organic electrolyte at a required concentration of 0.1mol/L, and then add a proton conductivity enhancer at a required concentration of 0.01 mol/L was added to the electrocatalyst to obtain an organic composite electrolyte, and carbon dioxide was dissolved in the organic composite electrolyte to make the concentration reach 0.09mol/L. The aqueous solution of L is injected into the anode compartment of the diaphragm electrolytic cell as the anolyte;

Step 2, turn on the electrolysis power supply, control the electrolysis voltage to 4.3V, under normal temperature and pressure conditions, when the electrolysis reaction is carried out for 2 hours, the measured current density of generating carbon monoxide is 430A/m ² , and the current efficiency of generating carbon monoxide is 91 %; during the electrolysis reaction, the catholyte is always in a circulating state, and the organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration flowing out of the gas absorption tower is injected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolysis device, and at the same time , the organic composite electrolyte in the upper part of the cathode chamber continuously flows out from the cathode chamber, and this organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained gas contains saturated or close to The organic composite electrolyte with a saturated carbon dioxide concentration is reinjected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, thereby forming a catholyte circulation. The speed at which the catholyte flows into and out of the cathode chamber of the multi-chamber diaphragm electrolytic cell is controlled, so that the carbon dioxide electroreduction reaction can be carried out in a continuous and stable state.

As shown in Figure 1, the multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide consists of a gas absorption tower 1, a cathode 2, an anode 3, a gas storage tank 4, a perfluorosulfonic acid ion exchange membrane 5, an electrolytic cell and The catholyte circulation device uses a perfluorosulfonic acid ion exchange membrane 5 to separate the electrolytic cell into a plurality of electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately, and the bottoms of the cathode chamber and the anode chamber are respectively arranged There are cathode 2 and anode 3, the top of the anode chamber is provided with a water inlet, the organic composite electrolyte dissolved in carbon dioxide flowing out of the gas absorption tower 1 flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the upper part of the cathode chamber is dissolved The organic composite electrolyte with carbon dioxide is returned to the top of the gas absorption tower 1 through the catholyte circulation device. The side of the gas absorption tower 1 is provided with a carbon dioxide inlet, and the top of the cathode chamber is connected to the gas storage tank 4 through a pipeline.

Example 2

A multi-chamber diaphragm electrolysis method for electroreducing carbon dioxide to carbon monoxide: use a perfluorosulfonic acid ion exchange membrane to separate the electrolytic cell into multiple electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately. The liquid is an organic composite electrolyte dissolved in carbon dioxide. The electrolyte in the anode chamber is an aqueous solution containing a supporting electrolyte. The cathode adopts a metal electrode with high selectivity for the electrolysis of carbon dioxide to prepare carbon monoxide. The anode is an inert electrode. During the electrolysis reaction, there is a Carbon monoxide is produced, and hydrogen is produced as a by-product.

The organic composite electrolyte contains four functional components: an organic solvent, an organic supporting electrolyte, a proton conduction enhancer and an electrocatalyst.

The organic solvent is N-methylpyrrolidone; the organic supporting electrolyte is choline chloride; the proton conductivity enhancer is methanol; the electrocatalyst is 1-butyl-3-methylimidazole trifluoromethyl Sulfonate.

The supporting electrolyte of the anolyte is sodium sulfate.

The anode is a graphite electrode, and the cathode is Ag.

The implementation steps are as follows:

Step 1, dissolve the organic supporting electrolyte in an organic solvent to obtain a 0.1mol/L organic electrolyte, add a proton conductivity enhancer to the organic electrolyte at a required concentration of 0.4mol/L, and then add a proton conductivity enhancer at a required concentration of 0.2 mol/L is added to the electrocatalyst to obtain an organic composite electrolyte, and carbon dioxide is dissolved in the organic composite electrolyte to make the concentration reach 0.21mol/L. The aqueous solution is injected into the anode chamber of the diaphragm electrolytic cell as the anolyte;

Step 2, turn on the electrolysis power supply, control the electrolysis voltage to 3.6V, under normal temperature and pressure conditions, when the electrolysis reaction is carried out for 2 hours, the measured current density for generating carbon monoxide is 410A/m ² , and the current efficiency for generating carbon monoxide is 93 %; during the electrolysis reaction, the catholyte is always in a circulating state, and the organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration flowing out of the gas absorption tower is injected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolysis device, and at the same time , the organic composite electrolyte in the upper part of the cathode chamber continuously flows out from the cathode chamber, and this organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained gas contains saturated or close to The organic composite electrolyte with a saturated carbon dioxide concentration is reinjected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, thereby forming a catholyte circulation. The speed at which the catholyte flows into and out of the cathode chamber of the multi-chamber diaphragm electrolytic cell is controlled, so that the carbon dioxide electroreduction reaction can be carried out in a continuous and stable state.

As shown in Figure 1, the multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide consists of a gas absorption tower 1, a cathode 2, an anode 3, a gas storage tank 4, a perfluorosulfonic acid ion exchange membrane 5, an electrolytic cell and The catholyte circulation device uses a perfluorosulfonic acid ion exchange membrane 5 to separate the electrolytic cell into a plurality of electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately, and the bottoms of the cathode chamber and the anode chamber are respectively arranged There are cathode 2 and anode 3, the top of the anode chamber is provided with a water inlet, the organic composite electrolyte dissolved in carbon dioxide flowing out of the gas absorption tower 1 flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the upper part of the cathode chamber is dissolved The organic composite electrolyte with carbon dioxide returns to the top of the absorption tower 1 through the catholyte circulation device. The side of the gas absorption tower 1 is provided with a carbon dioxide inlet, and the top of the cathode chamber is connected to the gas storage tank 4 through a pipeline.

Example 3

A multi-chamber diaphragm electrolysis method for electroreducing carbon dioxide to carbon monoxide: use a perfluorosulfonic acid ion exchange membrane to separate the electrolytic cell into multiple electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately. The liquid is an organic composite electrolyte dissolved in carbon dioxide. The electrolyte in the anode chamber is an aqueous solution containing a supporting electrolyte. The cathode adopts a metal electrode with high selectivity for the electrolysis of carbon dioxide to prepare carbon monoxide. The anode is an inert electrode. During the electrolysis reaction, there is a Carbon monoxide is produced, and hydrogen is produced as a by-product.

The organic composite electrolyte contains four functional components: an organic solvent, an organic supporting electrolyte, a proton conduction enhancer and an electrocatalyst.

The organic solvent is diethyl carbonate; the organic support electrolyte is tetrabutylammonium perchlorate quaternary ammonium salt; the proton conduction enhancer is phenol; and the electrocatalyst is iron phthalocyanine.

The supporting electrolyte of the anolyte is potassium bicarbonate.

The anode is a glassy carbon electrode, and the cathode is a Cu/Zn alloy electrode.

The implementation steps are as follows:

Step 1, dissolve the organic supporting electrolyte in the organic solvent to obtain a 0.2mol/L organic electrolyte, add a proton conductivity enhancer to the organic electrolyte at a required concentration of 0.4mol/L, and then add a proton conductivity enhancer at a required concentration of 0.03 mol/L of electrocatalyst is added to obtain an organic composite electrolyte, carbon dioxide is dissolved in the organic composite electrolyte to make the concentration reach 0.11mol/L, the resulting solution is injected into the cathode chamber of the diaphragm electrolytic cell, and the concentration of the supporting electrolyte is 0.3mol/L The aqueous solution of L is injected into the anode compartment of the diaphragm electrolytic cell as the anolyte;

Step 2, turn on the electrolysis power supply, control the electrolysis voltage to 4.3V, under normal temperature and pressure conditions, when the electrolysis reaction is carried out for 2 hours, the measured current density of generating carbon monoxide is 430A/m ² , and the current efficiency of generating carbon monoxide is 93 %; during the electrolysis reaction, the catholyte is always in a circulating state, and the organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration flowing out of the gas absorption tower is injected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolysis device, and at the same time , the organic composite electrolyte in the upper part of the cathode chamber continuously flows out from the cathode chamber, and this organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained gas contains saturated or close to The organic composite electrolyte with a saturated carbon dioxide concentration is reinjected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, thereby forming a catholyte circulation. The speed at which the catholyte flows into and out of the cathode chamber of the multi-chamber diaphragm electrolytic cell is controlled, so that the carbon dioxide electroreduction reaction can be carried out in a continuous and stable state.

As shown in Figure 1, the multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide consists of a gas absorption tower 1, a cathode 2, an anode 3, a gas storage tank 4, a perfluorosulfonic acid ion exchange membrane 5, an electrolytic cell and The catholyte circulation device uses a perfluorosulfonic acid ion exchange membrane 5 to separate the electrolytic cell into a plurality of electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately, and the bottoms of the cathode chamber and the anode chamber are respectively arranged There are cathode 2 and anode 3, the top of the anode chamber is provided with a water inlet, the organic composite electrolyte dissolved in carbon dioxide flowing out of the gas absorption tower 1 flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the upper part of the cathode chamber is dissolved The organic composite electrolyte with carbon dioxide is returned to the top of the gas absorption tower 1 through the catholyte circulation device. The side of the absorption tower 1 is provided with a carbon dioxide inlet, and the top of the cathode chamber is connected to the gas storage tank 4 through a pipeline.

Example 4

A multi-chamber diaphragm electrolysis method for electroreducing carbon dioxide to carbon monoxide: use a perfluorosulfonic acid ion exchange membrane to separate the electrolytic cell into multiple electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately. The liquid is an organic composite electrolyte dissolved in carbon dioxide. The electrolyte in the anode chamber is an aqueous solution containing a supporting electrolyte. The cathode adopts a metal electrode with high selectivity for the electrolysis of carbon dioxide to produce carbon monoxide. The anode is an inert electrode. During the electrolysis reaction, there is a Carbon monoxide is produced, and hydrogen is produced as a by-product.

The organic composite electrolyte contains four functional components: an organic solvent, an organic supporting electrolyte, a proton conduction enhancer and an electrocatalyst.

The organic solvent is a mixture of diethyl carbonate and N-methylpyrrolidone with a mass ratio of 1:1; Choline mixture; the proton conduction enhancer is a mixture of trifluoromethylethanol, methanol and phenol with a mass ratio of 1:1:1; the electrocatalyst is copper phthalocyanine and tricarbonyl-2 with a mass ratio of 1:1 , 4'-dipyridine manganese chloride mixture.

The supporting electrolyte is a mixture of potassium dihydrogen phosphate, sodium dihydrogen phosphate and potassium hydrogen phosphate with a mass ratio of 1:1:1.

The anode is an iridium oxide coated titanium anode, and the cathode is a Cu electrode.

The implementation steps are as follows:

Step 1, dissolve the organic supporting electrolyte in an organic solvent to obtain a 2.8mol/L organic electrolyte, add a proton conductivity enhancer to the organic electrolyte at a required concentration of 0.3mol/L, and then add a proton conductivity enhancer at a required concentration of 0.2 mol/L is added to the electrocatalyst to obtain an organic composite electrolyte, and carbon dioxide is dissolved in the organic composite electrolyte to make the concentration reach 0.21mol/L. The aqueous solution is injected into the anode chamber of the diaphragm electrolytic cell as the anolyte;

Step 2, turn on the electrolysis power supply, control the electrolysis voltage to 4.0V, under normal temperature and pressure conditions, when the electrolysis reaction is carried out for 2 hours, the measured current density of generating carbon monoxide is 493A/m ² , and the current efficiency of generating carbon monoxide is 94 %; during the electrolysis reaction, the catholyte is always in a circulating state, and the organic composite electrolyte containing saturated or close to saturated carbon dioxide concentration flowing out of the gas absorption tower is injected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolysis device, and at the same time , the organic composite electrolyte in the upper part of the cathode chamber continuously flows out from the cathode chamber, and this organic composite electrolyte containing a lower concentration of carbon dioxide is reintroduced into the gas absorption tower for dissolving and absorbing carbon dioxide, and the obtained gas contains saturated or close to The organic composite electrolyte with a saturated carbon dioxide concentration is reinjected into the bottom of the cathode chamber of the multi-chamber diaphragm electrolytic cell, thereby forming a catholyte circulation. The speed at which the catholyte flows into and out of the cathode chamber of the multi-chamber diaphragm electrolytic cell is controlled, so that the carbon dioxide electroreduction reaction can be carried out in a continuous and stable state.

As shown in Figure 1, the multi-chamber diaphragm electrolysis device for electroreducing carbon dioxide to carbon monoxide consists of a gas absorption tower 1, a cathode 2, an anode 3, a gas storage tank 4, a perfluorosulfonic acid ion exchange membrane 5, an electrolytic cell and The catholyte circulation device uses a perfluorosulfonic acid ion exchange membrane 5 to separate the electrolytic cell into a plurality of electrode chambers to form a multi-chamber diaphragm electrolytic cell in which the cathode chamber and the anode chamber are arranged alternately, and the bottoms of the cathode chamber and the anode chamber are respectively arranged There are cathode 2 and anode 3, the top of the anode chamber is provided with a water inlet, the organic composite electrolyte dissolved in carbon dioxide flowing out of the absorption tower 1 flows into the bottom of the cathode chamber through the pipeline of the catholyte circulation device, and the upper part of the cathode chamber is dissolved with The organic composite electrolyte of carbon dioxide is returned to the top of the gas absorption tower 1 through the catholyte circulation device. The side of the absorption tower 1 is provided with a carbon dioxide inlet, and the top of the cathode chamber is connected to the gas storage tank 4 through a pipeline.

The specific implementation of the utility model has been described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned implementation. Various changes are made.

Claims (1)

1. one kind by multicell diaphragm electrolysis apparatus that carbon dioxide electroreduction is carbon monoxide, it is characterized in that: device includes absorption column of gas (1), negative electrode (2), anode (3), air accumulator (4), perfluorinated sulfonic acid ion exchange membrane (5), electrolyzer and catholyte liquid circulating device, perfluorinated sulfonic acid ion exchange membrane (5) is adopted to divide the cell into multiple electrode chamber, constitute the multicell diaphragm cell of cathode chamber and anode chamber's interphase distribution, the bottom of cathode chamber and anode chamber is respectively equipped with negative electrode (2) and anode (3), top, anode chamber is provided with the entrance of water, the organic composite electrolyte dissolved with carbon dioxide flowed out in absorption column of gas (1) is flowed into the bottom of cathode chamber by the pipeline of catholyte liquid circulating device, cathode chamber top returns to the top of absorption column of gas (1) dissolved with the organic composite electrolyte of carbon dioxide by catholyte liquid circulating device, the side of absorption column of gas (1) is provided with carbon dioxide entrance, the top of cathode chamber is connected with air accumulator (4) by pipeline。