CN113174603A

CN113174603A - For capturing and electrolyzing CO2Compositions and methods of

Info

Publication number: CN113174603A
Application number: CN202110470001.2A
Authority: CN
Inventors: 萨希尔·加尔格; 李梦然; 托马斯·爱德华·拉福德; 王国雄; 维克多·鲁道夫; 王新东; 李建新; 吝章国; 常金宝; 李立业
Original assignee: HBIS Co Ltd
Current assignee: HBIS Co Ltd
Priority date: 2021-04-28
Filing date: 2021-04-28
Publication date: 2021-07-27
Also published as: WO2022227146A1

Abstract

The present disclosure discloses a method for capturing and electrolyzing CO₂Compositions and methods of (1). The composition comprises the following components in percentage by mass: 2-60 wt% of amino alcohol compound and 40-98 wt% of alcohol solvent, wherein the composition further comprises 50-500 ppm of chelating agent based on the total weight of the composition. For capturing and electrolyzing CO according to the present disclosure₂Can capture CO₂Can also be used as electrolyte for making CO₂And (4) electrolyzing. In addition, the compositions of the non-aqueous systems of the present disclosure can greatly improve the CO faradaic efficiency. Furthermore, the method for capturing and electrolyzing CO according to the invention₂The method can reduce the cost of controlling the emission of carbon dioxide.

Description

For capturing and electrolyzing CO2Compositions and methods of

Technical Field

The invention relates to a method for capturing and electrolyzing CO₂And more particularly to a method for capturing and electrolyzing CO₂And a method for capturing and electrolyzing CO₂The method of (1).

Background

Reducing carbon emissions is a challenging problem worldwide, but also brings great market opportunities. In 2013, the total amount of global carbon dioxide emission exceeds 320 hundred million tons, and 28 percent of the total amount of global carbon dioxide emission comes from China. As the largest energy consuming industry in the manufacturing industry, the steel industry emits more than 5% of the total emission of carbon dioxide (about 4.5 million tons of CO)₂). For example, in a typical blast furnace route-based steel mill, the production of one ton of steel requires the emission of about two tons of CO₂。

Separation of CO from flue gas or blast furnace gas using existing gas-liquid absorption techniques₂Will be in CO₂Capture and Sequestration (CCS) process or CO₂The capture and utilization (CCU) process incurs significant economic and energy losses. Capture and storage solutions require suitable geological storageLayer to store CO₂And the reservoir must be close to the production site to minimize costs. With on-site CO capture₂And direct conversion to other chemicals, the CCU process has the potential to provide a low cost, efficient way to offset the reduction of CO in production plants₂Part of the cost of the discharge. The key challenge is to develop a method that can capture both CO and CO₂Can also be used as CO₂A solvent for the electrolyte of the electrolysis.

Disclosure of Invention

The purpose of the disclosure is to provide a method for capturing CO₂Can also be used as CO₂Electrolytic electrolyte compositions.

It is an object of the present disclosure to provide a method for reducing CO in carbon intensive manufacturing processes and/or power or heat generation processes₂And (4) a discharge technology.

According to an aspect of the present disclosure, there is provided a method for capturing and electrolyzing CO₂The composition comprises the following components in percentage by mass: 2-60 wt% of amino alcohol compound and 40-98 wt% of alcohol solvent,

wherein the composition further comprises from 50ppm to 500ppm of a chelating agent, based on the total weight of the composition.

According to embodiments of the present disclosure, the aminoalcohol compound may include at least one of an ethanolamine compound and an aminocyclitol compound.

According to embodiments of the present disclosure, the ethanolamine-based compound may include at least one of monoethanolamine, diethanolamine, and triethanolamine.

According to embodiments of the present disclosure, the aminocyclitol compound can include at least one of aminocyclopentanol, aminocyclohexanol, and aminocycloheptanol.

According to embodiments of the present disclosure, the ethanolamine-based compound may be monoethanolamine, and the purity of the monoethanolamine may be 99.5 wt% to 98 wt%.

According to an embodiment of the present disclosure, the alcohol solvent may include at least one of methanol, ethanol, propanol, and butanol.

According to embodiments of the present disclosure, the chelating agent may include ethylenediaminetetraacetic acid.

According to embodiments of the present disclosure, the composition may further include 1ppm to 10000ppm of piperazine based on the total weight of the composition.

According to embodiments of the present disclosure, the composition may further include at least one of propylene carbonate, dimethyl ether, polyethylene glycol, acetonitrile, and dimethylformamide.

According to another aspect of the present disclosure, there is provided a method of capturing and electrolyzing CO₂The method of (2), said method comprising the steps of: to include CO₂With the composition described above, to obtain a composition comprising CO₂And mixtures of said compositions; will comprise CO₂And the composition is supplied as an electrolyte to an electrolysis device, wherein the electrolysis device comprises an anode, a cathode, and an ion-conducting membrane disposed between the anode and the cathode; and electrifying the anode and the cathode to electrolyze CO₂。

According to an embodiment of the present disclosure, the cathode may include at least one of silver, nickel, cobalt, zinc, palladium, tin, bismuth, mercury, lead, and copper. The cathode may be a metal foil, a porous metal, or may be a composite electrode with a catalyst supported on porous carbon or a polymeric material.

According to embodiments of the present disclosure, the anode may comprise one of graphite, a noble metal catalyst based dimensionally stable anode, a foam electrode, and a non-noble metal electrode.

According to an embodiment of the present disclosure, the energizing step may be performed at a predetermined temperature (e.g., normal or low temperature) under the condition of stirring the electrolyte.

For capturing and electrolyzing CO according to the present disclosure₂Can capture CO₂Can also be used as electrolyte for making CO₂Electrolyze and can increase CO₂The conversion efficiency of (a). Further, for capturing and electrolyzing CO according to the present disclosure₂The composition of (a) can reduce the requirement for the purity of monoethanolamine. In addition, the compositions of the non-aqueous systems of the present disclosure can greatly improve the faradaic efficiency of CO. Further, for capturing and electrolyzing CO according to the present disclosure₂Can reduceThe cost of controlling carbon dioxide emission is low.

Drawings

The foregoing and/or other features and aspects of the inventive concept will become apparent and appreciated from the following description of the exemplary embodiments, taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic diagram illustrating a method for capturing and electrolyzing CO according to an embodiment of the disclosure₂A flow chart of the method of (1).

FIG. 2 is a graph showing converted H of examples 1 to 5₂And a graph of faradaic efficiency of CO.

FIG. 3 is a graph showing converted H of reference example 1, example 6, and example 7₂Graph of faradaic efficiency.

Fig. 4 is a graph showing faradaic efficiency of the converted CO of reference example 1, example 6, and example 7.

Figure 5 is a graph showing the faradaic efficiency of CO in compositions with varying amounts of EDTA added.

Detailed Description

The embodiments are described below in order to explain the present invention by referring to the figures. This invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

The invention provides a method for capturing and electrolyzing CO₂The composition comprises the following components in percentage by mass: 2-60 wt% of amino alcohol compound and 40-98 wt% of alcohol solvent, wherein the composition further comprises 50-500 ppm of chelating agent based on the total weight of the composition.

In embodiments of the present disclosure, aminoalcohol-based compounds may refer to compounds that include an amino group and a hydroxyl group, for example, compounds that include a primary amine group, a secondary amine group, a tertiary amine group, or a cyclic amine group, as well as a hydroxyl group. Specifically, according to embodiments of the present disclosure, the amino alcohol compound may include at least one of an ethanolamine compound and an aminocyclitol compound.

According to embodiments of the present disclosure, the ethanolamine-based compound may include at least one of monoethanolamine, diethanolamine, and triethanolamine; however, embodiments of the present disclosure are not limited thereto. Preferably, the ethanolamine-based compound is Monoethanolamine (MEA).

The purity of monoethanolamine greatly affects the faradaic efficiency of CO, and preferably, the purity of monoethanolamine may be 99.5 wt% to 98 wt%.

According to embodiments of the present disclosure, the aminocyclitol compound may include at least one of aminocyclopentanol, aminocyclohexanol, and aminocycloheptanol; however, embodiments of the present disclosure are not limited thereto.

In embodiments of the disclosure, the aminoalcohol-based compound is present in the range of 2 wt% to 60 wt%, for example, in the range of 5 wt% to 55 wt%, 10 wt% to 50 wt%, 15 wt% to 45 wt%, 20 wt% to 40 wt%, 25 wt% to 35 wt%, or any range defined by the numerical values given above, for example, in the range of 20 wt% to 35 wt%, 35 wt% to 50 wt%, or 15 wt% to 25 wt%. Preferably, the content of amino alcohol-based compound may be in the range of 26 wt% to 32 wt%, more preferably, may be 30 wt%.

In embodiments of the present disclosure, the alcoholic solvent may refer to an alcoholic compound containing one or more hydroxyl groups.

According to an embodiment of the present disclosure, the alcohol solvent may include at least one of methanol, ethanol, propanol (e.g., isopropanol), and butanol; however, embodiments of the present disclosure are not limited thereto. In an embodiment of the present disclosure, preferably, the alcohol solvent may include methanol.

In embodiments of the present disclosure, the content of the alcohol solvent may be in the range of 40 wt% to 98 wt%, for example, 40 wt% to 95 wt%, 45 wt% to 90 wt%, 50 wt% to 85 wt%, 55 wt% to 80 wt%, 60 wt% to 75 wt%, or 65 wt% to 70 wt%, or any range defined by the above-given numerical values, for example, 50 wt% to 80 wt%, 55 wt% to 75 wt%, or 65 wt% to 75 wt%. Preferably, the content of the alcohol solvent may be in the range of 68 wt% to 72 wt%, and more preferably, may be 70 wt%.

Further, in embodiments of the present disclosure, the composition does not include water as a solvent.

In the art, when using the use of KHCO in the art₃As CO₂In the conventional method of trapping the solvent, K is 5 wt%₂CO₃In the aqueous solution, the capturing solvent can capture only 0.0056mol of CO per mol of the capturing solvent₂. However, in the examples of the present disclosure, by using an alcohol amine compound and an alcohol compound of a non-aqueous solvent as a mixture of solvents, the composition has sufficiently high CO₂Capacity for Capture (e.g., capable of capturing 0.5mol to 0.55mol CO per 1 mol composition₂) It is significantly superior to the existing above-mentioned conventional methods.

Furthermore, the compositions according to the present disclosure have CO Faradaic Efficiencies (FE) as high as 72%.

In CO₂The purity of the alcamines is very demanding during the electrolysis, in particular, the Faradaic Efficiency (FE) of the CO of the MEA example with a purity of more than 99.5% is significantly higher than the faradaic efficiency of the CO of the MEA example with a purity of 98% under the same conditions, taking Monoethanolamine (MEA) as an example.

In order to reduce the purity requirement for the alcamines, the inventors propose to add a chelating agent to the mixture of alcamines and the alcoholic solvent.

In embodiments of the present disclosure, the chelating agent may include ethylenediaminetetraacetic acid. Further, the chelating agent is present in an amount ranging from 50ppm to 500ppm, such as from 70ppm to 470ppm, from 90ppm to 450ppm, from 110ppm to 430ppm, from 130ppm to 410ppm, from 150ppm to 390ppm, from 170ppm to 370ppm, from 190ppm to 350ppm, from 210ppm to 330ppm, from 230ppm to 310ppm, from 250ppm to 330ppm, from 270ppm to 310ppm, or any range defined by the values given above, such as from 130ppm to 250ppm, from 170ppm to 310ppm, or from 150ppm to 500ppm, based on the total weight of the composition.

In embodiments of the present disclosure, the chelating agent can also prevent CO from electrolyzing₂During which the electrodes are degraded while also ensuring stable operation of the electrochemical reaction.

Further, according to embodiments of the present disclosure, the composition may further include piperazine. Piperazine can accelerate CO₂Without sacrificing CO absorption rate₂The conversion selectivity of (1).

The piperazine content may be in the range of 1ppm to 10000ppm, such as 100ppm to 9900ppm, 300ppm to 9700ppm, 500ppm to 9700ppm, 700ppm to 9500ppm, 900ppm to 9300ppm, 1000ppm to 9000ppm, 2000ppm to 8000ppm, 3000ppm to 7000ppm, 4000ppm to 6000ppm, or any range defined by the values given above, such as 6000ppm to 10000ppm or 7000ppm to 9000ppm, based on the total weight of the composition.

Furthermore, compositions according to embodiments of the present disclosure may also include other non-aqueous organic solvents in addition to alcoholic solvents. For example, the composition may further include at least one of propylene carbonate, dimethyl ether, polyethylene glycol, acetonitrile, and dimethylformamide; however, embodiments of the present disclosure are not limited thereto.

In addition, the composition according to an embodiment of the present disclosure may further include an additive for increasing ionic conductivity. The additive may be an inorganic salt, for example, sodium chloride, potassium chloride, and the like.

Compositions according to embodiments of the present disclosure may be applied to CO emissions in various industries₂For example, industrial processes that generate heat or power from carbon-rich fuels such as coal or natural gas, or processes that use carbon-based reductants such as steel making or carbon feedstocks to produce other chemicals such as methane.

The following will describe in detail for capturing and electrolyzing CO according to an embodiment of the present disclosure with reference to fig. 1₂The method of (1).

The method comprises the following steps: to include CO₂Is contacted with a composition according to the above description (step S1), whereby the composition is capable of absorbing and capturing CO in the gas mixture₂To obtain a composition comprising CO₂And mixtures of such compositions; will comprise CO₂And the mixture of the composition is supplied as an electrolyte to the electrolytic device (step S2); and electrifying the anode and the cathode to electrolyze CO₂(step S3).

In step S1, the CO is included₂The gas mixture of (a) may refer to a waste gas stream (e.g., high)Furnace gas or flue gas, etc.); however, embodiments of the present disclosure are not limited thereto. Further, the composition in step S1 is the same as that described above, and thus the description thereof will be omitted.

In step S1, a composition according to embodiments of the present disclosure may first be placed in a gas absorption unit, and then the composition will include CO₂Is supplied to a gas absorption unit so as to include CO₂Is contacted with the composition to capture CO in the gas mixture₂And obtaining CO rich₂The fluid of (1).

For ease of understanding, the capture of CO by the MEA is shown in chemical equation (1) and chemical equation (2)₂The process of (1).

CO₂+MEA＝MEA⁺COO^- (1)

MEA⁺COO^-+B＝MEACOO^-+BH⁺ (2)

Wherein B is any basic species present in the composition, such as MEA or methanol, etc.

In step S2, the electrolysis device may be any suitable electrolysis device commonly used in the art. Specifically, the electrolysis device includes an anode, a cathode, and an ion-conducting membrane disposed between the anode and the cathode. The cathode may include at least one of silver, nickel, cobalt, zinc, palladium, tin, bismuth, mercury, lead, and copper; the anode may comprise one of graphite, a noble metal-based dimensionally stable anode, a foam electrode, and a non-noble metal electrode. In embodiments of the present disclosure, the noble metal-based dimensionally stable anode may be surface-loaded IrO, for example₂And RuO₂Titanium plates or porous titanium materials of noble metals; the non-noble metal electrode may be, for example, a porous nickel or titanium material supported with a transition metal such as nickel, iron, or cobalt.

In step S2, the CO-enriched product obtained in step S1 is subjected to₂The fluid is pumped into the electrolysis device as an electrolyte. Furthermore, if the electrolysis device has an additional compartment for gas transport and a porous cathode structure for gas diffusion,then CO will also be included₂The gas mixture is fed directly into the electrolysis device.

In step S3, the anode and the cathode are electrified under stirring of the electrolyte at a predetermined temperature (e.g., normal or low temperature), thereby electrolyzing CO₂. Specifically, CO can be electrolyzed under conditions where the cathode potential (V vs. RHE) is from-1.084 to-0.784₂。

In the embodiment of the present disclosure, CO can be introduced according to the type of the electrode₂Conversion to value-added chemicals, e.g. CO, CH₄Formic acid or other products, and the like. For example, metal-based electrodes such as silver, nickel, cobalt, zinc, or palladium, etc., help to convert CO₂Converting into CO; metal-based electrodes such as tin, bismuth, mercury or lead help to convert CO₂Conversion to formate or formic acid, etc.; the copper-based electrode helps to mix CO₂To hydrocarbons such as methane, ethylene, methanol, ethanol, and the like.

Furthermore, during electrolysis operation, the electrolyte becomes lean in CO₂Fluid, so that the electrolyte in the electrolysis unit can be recycled for reuse in capturing CO₂。

Further, CO achieved by the compositions of the embodiments of the present disclosure₂Emission capture and conversion offsets the traditional CO capture₂Cost (e.g., capture of per ton of CO using conventional means)₂>$ 60) cost more than 90%. For example, reducing the total carbon dioxide emissions from a steel mill by only 10%, the technology critical to this disclosure can save carbon dioxide emission control costs in excess of 24 billion dollars each year.

The invention for capturing and electrolyzing CO will be described below with reference to the examples and FIGS. 2 to 5₂The compositions and methods of (a) are described in detail.

1. Effect of different potentials on Faraday efficiency of converted CO

Example 1

Dissolving 30 wt% monoethanolamine (purity 99.5%) in 70 wt% methanol to obtain a composition; CO by using the composition₂Capture to obtain CO-rich₂A fluid having a pH of 8.5; will be rich in CO₂The fluid was supplied to an H-type three-electrode system electrolyzer and CO was measured at a potential of-1.184V₂Conversion to H₂And faradaic efficiency of CO products, the results of which are shown in figure 2. In the electrolytic cell, an anode chamber and a cathode chamber are separated by an ion conducting membrane, the cathode electrode is made of polycrystalline silver foil, the anode electrode is made of graphite, and the reference electrode is made of Ag | AgCl.

Examples 2 to 5

Except that CO is measured at the potential shown with reference to FIG. 2₂Conversion to H₂And the faradaic efficiency of CO products of example 2 (potential of-1.084V), example 3 (potential of-0.984V), example 4 (potential of-0.884V) and example 5 (potential of-0.784V) were examined in the same manner as in example 1, the results of which are shown in fig. 2.

As can be seen from fig. 2, the compositions of the present disclosure as electrolytes CO at different potentials₂The conversion efficiency of the catalyst is obviously improved, but the faradaic efficiency of CO is greatly influenced under different potentials, and the faradaic efficiency of CO products can reach up to 72 percent.

2. Effect of additives in the composition on Faraday efficiency of converted CO

Reference example 1

30 wt% MEA having a purity of greater than 99.5% was dissolved in 70 wt% methanol to obtain a composition. CO by using the composition₂Capture to obtain CO-rich₂A fluid; will be rich in CO₂Supplying the fluid to an electrolytic cell and measuring CO₂Conversion to H₂And faradaic efficiency of the CO product, the results of which are shown in table 1. The electrolytic bath is an H-shaped electrolytic bath, the cathode is silver foil, and the anode is a graphite electrode.

Reference example 2

Reference example 2 was prepared in the same manner as reference example 1, except that the corresponding components were added in the amounts given in table 1. The results are shown in Table 1.

Examples 6 and 7

Examples 6 and 7 were prepared in the same manner as in reference example 1, except that the respective components were added at the contents given in table 1. The results are shown in Table 1.

TABLE 1

Note: ep represents the maximum positive potential during the test, En represents the maximum negative potential during the test, RHE (reversible hydrogen electrode) represents the reference potential, FE represents the average value within the potential range, and DEA is diethanolamine.

As can be seen from reference example 1 and reference example 2, the purity of the MEA is required to be high from the viewpoint of fe (co). As can be seen from reference examples 2 and 6, the exemplary CO was added after EDTA addition₂The conversion efficiency is improved significantly, and the requirement for MEA purity can be reduced.

In addition, for a more intuitive review of the H converted at different potentials with reference to examples 1, 6 and 7₂And the faradaic efficiency of the CO product, as shown in fig. 3 and 4, showing H in a graphical manner₂And faradaic efficiency of CO products.

Referring to table 1, fig. 3, and fig. 4, reference example 2 of MEA having a purity of 98% shows fe (co) of about 38%, which is much lower than reference example 1 of MEA having a purity of 99.5%. However, example 6 of MEA with 98% purity showed a significant improvement with the addition of 150ppm EDTA, achieving about 60% FE (CO). Furthermore, after addition of piperazine, substantially no CO is lost₂The conversion selectivity can accelerate CO₂The absorption rate of (c).

2. Effect of additives in compositions on the purity of amino alcohols

Reference example 3 to reference example 10

Except that the corresponding components were added in the amounts as given in Table 2Furthermore, reference examples 3 to 10 were prepared in the same manner as reference example 1, and CO was electrolyzed according to the conditions of table 2₂. The results are shown in Table 2.

Example 8 to example 24

Examples 8 to 24 were prepared in the same manner as in reference example 1 except that the respective components were added in the amounts given in table 2, and CO was electrolyzed in the conditions of table 2₂. The results are shown in Table 2.

In addition, in order to more intuitively reflect the influence of EDTA on the purity of amino alcohol compounds, different amounts of EDTA are added on the basis of 30 wt% of MEA and 70 wt% of methanol, and then the Faraday efficiency of CO is examined under different potentials by using silver foil as a cathode and graphite as an anode.

TABLE 2

Referring to table 2 and fig. 5, by adding EDTA, high fe (CO) can be obtained even when MEA having low purity is used, and CO can be captured and electrolyzed by MEA having low purity₂。

In summary, the method for capturing and electrolyzing CO according to the present disclosure₂Can capture CO₂Can also be used as electrolyte for making CO₂Electrolysis and CO₂The conversion efficiency is obviously improved.

In addition, the compositions of the non-aqueous systems of the present disclosure can greatly improve the faradaic efficiency of CO.

Furthermore, the method according to the invention for capturing and electrolyzing CO₂Can reduceThe cost of controlling carbon dioxide emission is low.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims and their equivalents. The embodiments should be considered in descriptive sense only and not for purposes of limitation. Therefore, the scope of the invention is defined not by the detailed description of the invention but by the appended claims, and all differences within the scope will be construed as being included in the present invention.

Claims

1. For capturing and electrolyzing CO₂The composition comprises the following components in percentage by mass: 2-60 wt% of amino alcohol compound and 40-98 wt% of alcohol solvent,

2. The composition of claim 1, wherein the amino alcohol compound comprises at least one of an ethanolamine compound and an aminocyclitol compound.

3. The composition of claim 2, wherein the ethanolamines comprise at least one of monoethanolamine, diethanolamine, and triethanolamine;

the aminocycloalcohol compound comprises at least one of aminocyclopentanol, aminocyclohexanol and aminocycloheptanol.

4. The composition of claim 3, wherein the ethanolamine-based compound is monoethanolamine, and the monoethanolamine has a purity of 99.5 wt% to 98 wt%.

5. The composition of claim 1 or 3, wherein the alcoholic solvent comprises at least one of methanol, ethanol, propanol, and butanol.

6. The composition of claim 1, wherein the chelating agent comprises ethylenediaminetetraacetic acid.

7. The composition of claim 1, further comprising from 1ppm to 10000ppm piperazine based on the total weight of the composition.

8. For capturing and electrolyzing CO₂The method of (2), said method comprising the steps of:

to include CO₂With a composition according to any one of claims 1 to 7, to obtain a composition comprising CO₂And mixtures of said compositions;

will comprise CO₂And the composition is supplied as an electrolyte to an electrolysis device, wherein the electrolysis device comprises an anode, a cathode, and an ion-conducting membrane disposed between the anode and the cathode; and

electrifying the anode and cathode to electrolyze CO₂。

9. The method of claim 8, wherein the cathode comprises at least one of silver, nickel, cobalt, zinc, palladium, tin, bismuth, mercury, lead, and copper.

10. The method of claim 8, wherein the anode comprises one of graphite, a noble metal-based dimensionally stable anode, a foam electrode, and a non-noble metal electrode.

11. The method of claim 8, wherein the energizing step is performed with agitation of the electrolyte at a predetermined temperature.