Carbon dioxide immobilized enzyme adsorption material as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of enzyme engineering, and provides a carbon dioxide immobilized enzyme adsorption material and a preparation method and application thereof, and the adsorption material belongs to a nanoscale compound and comprises the following components in parts by weight: 5-300 parts of calcium oxide and 1-30 parts of a molecular sieve; the nanoscale compound is used for immobilizing enzyme preparations including a carbonic anhydrase preparation, cellulase, lipase, lysozyme and glucose oxidase. The carbon dioxide immobilized enzyme adsorption material is used for adsorption and in-situ utilization of carbon dioxide in flue gas, selective absorption and immobilization of carbon dioxide under the conditions of normal temperature and normal pressure are achieved, reaction energy consumption is reduced, and low-cost carbon dioxide adsorption and utilization are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of enzyme engineering, and particularly relates to a carbon dioxide fixation enzyme adsorption material and a preparation method and application thereof. Background Art

[0002] In-Situ Carbon Capture and Utilization (ICCU) is an innovative carbon dioxide capture and utilization technology that can complete the two reaction processes of carbon capture and carbon utilization in the same catalyst. ICCU technology eliminates the economic cost of CO2 compression and transportation in traditional carbon dioxide capture and storage (CCU), thereby improving the energy efficiency and technical economy of the entire process. The ultra-high energy consumption CO2 desorption step in traditional CCU technology can be replaced by catalytic reaction product desorption in ICCU, thereby reducing the energy consumption of adsorption site regeneration. ICCU technology has broad application prospects in many fields. ICCU technology can be applied to CO2 capture in flue gas such as power plants, transportation, and industrial waste gas, and catalytically convert it into valuable fuel or production raw materials. ICCU can effectively reduce CO2 emissions in flue gas, while realizing the recycling of resources, and can also be applied to CO2 capture at extremely low concentrations in the air. ICCU technology has huge advantages in energy saving and consumption reduction in theory, but its technical maturity remains a challenge. ICCU technology requires more complex catalysts and reaction conditions, which increases its research and development costs and difficulty. The high cost of ICCU technology limits its promotion and application. In ICCU technology, achieving efficient and selective CO2 capture and conversion is the key. However, due to the high chemical stability of CO2, its conversion process often requires high energy input and specific catalysts. This may lead to low reaction efficiency or the production of by-products, affecting the purity and quality of the product. In addition to CO2, flue gas also contains other pollutants (such as NO x 、SO x , particulate matter, etc.), these pollutants may adversely affect the performance of the catalyst and reduce the reaction efficiency and selectivity.

[0003] Therefore, how to reduce costs and reaction energy consumption while achieving efficient fixation of carbon dioxide and effective carbon utilization is a problem that needs to be solved. Summary of the invention

[0004] In view of the problems of carbon dioxide fixation and recycling in the prior art, the purpose of the present invention is to provide a carbon dioxide fixation enzyme adsorption material and a preparation method and application thereof. The adsorption material described in the present application is used to treat carbon dioxide in flue gas, which can achieve efficient adsorption of carbon dioxide and in-situ fixation at room temperature, reduce the pressure and temperature requirements of the adsorbent filling device during the adsorption process, and reduce energy consumption.

[0005] It is used for the fixation and utilization of carbon dioxide in flue gas or the environment, which can effectively reduce carbon dioxide emissions and realize carbon cycle, avoid high energy consumption experimental conditions in this process, and realize low-cost and low-energy consumption carbon cycle. The adsorption performance and effect of existing adsorbents on carbon dioxide are affected by temperature and pressure conditions. In the process of carbon dioxide capture, higher temperature and pressure conditions are required, resulting in higher energy consumption. Chemical adsorbents such as amine-based solvents perform well in selective absorption, but the regeneration energy consumption is also high. Therefore, the inventors have conducted research on this and found that the fixed enzyme technology can realize the formation of an efficient carbon dioxide adsorption layer on the microporous surface of nano-scale media, and the alkaline reaction conditions are constructed by mixing calcium oxide and molecular sieves to promote the adsorption and in-situ utilization of carbon dioxide on the adsorption surface, increase the adsorption efficiency, and reduce energy consumption. At the same time, the adsorbent can be regenerated under weak alkaline conditions, which is a new material for efficient and energy-saving carbon dioxide fixation and reuse. Carbon dioxide in the gas is selectively adsorbed by carbonic anhydrase fixed on the surface of the adsorbent, and carbon dioxide is efficiently catalyzed to be fixed as carbonic acid. The formed carbonic acid further reacts with the alkaline components in the adsorbent material, represented by calcium oxide, to generate calcium carbonate. In view of this, the inventors provide the following scheme of the present invention.

[0006] The objective of the present invention is achieved through the following technical solutions:

[0007] The first aspect of the present invention provides a carbon dioxide fixation enzyme adsorption material, which is a nanoscale composite and includes the following components in parts by weight:

[0008] Calcium oxide 5~300

[0009] Molecular sieve 1~30;

[0010] The nanoscale complex is used for immobilizing enzyme preparations including carbonic anhydrase preparations, formate dehydrogenase and carboxylase.

[0011] Furthermore, the molecular sieves include 5A, 4A and 3A molecular sieves.

[0012] The second aspect of the present invention provides a method for preparing the carbon dioxide fixation enzyme adsorption material according to the first aspect, comprising the following steps:

[0013] Step 1, preparing an adsorption matrix: mixing calcium oxide and molecular sieve according to the weight parts as described in claim 1, grinding them in a ball mill, first grinding the coarse particles, grinding the raw materials into a crude product with a particle size of no more than 500 nm, and after sieving, further finely grinding the crude product until the particle size distribution reaches 100 to 50 nm;

[0014] Step 2, enzyme preparation: dissolving the enzyme preparation in a solvent to prepare an enzyme solution with a concentration of 1 to 10 mg / mL;

[0015] Step 3, enzyme fixation: the adsorption matrix prepared in step 1 and the enzyme solution prepared in step 2 are added to an incubation tube at a ratio of 10 to 5:1 of adsorption matrix mass: enzyme solution volume (mg: mL), and incubated at a temperature of 30 to 50° C. with shaking;

[0016] Step 4, washing the adsorbent material: resuspending the incubated adsorbent material with a solvent, centrifuging, and eluting until the ultraviolet absorption value of the eluent at 280 nm is less than 0.2;

[0017] Step 5, freeze-drying and storage: freeze-drying the fixed enzyme adsorption material in the presence of a freeze-drying protective agent to prepare a finished adsorption material.

[0018] Furthermore, in step 2 and step 4, the solvent is one of PBS, phosphate buffer, TAE or TrisHCl buffer.

[0019] Furthermore, in step 5, the lyoprotectant is one of sugars, fatty acids, amino acids, polyols or thiol reagents.

[0020] Furthermore, in step 5, the amount of the lyophilization protectant added is 1% to 3% of the mass of the enzyme preparation.

[0021] Furthermore, in step 5, the freeze-drying treatment conditions are: vacuum degree 0 to 10 Pa, temperature -20°C to -30°C, and freeze-drying time 12h to 24h.

[0022] The third aspect of the present invention provides a method for treating flue gas using the carbon dioxide fixing enzyme adsorption material of the first aspect, comprising the following steps:

[0023] The flue gas to be treated enters the adsorption device from the air intake duct through the first gas online detection device, and the adsorption device is filled with the carbon dioxide fixation enzyme adsorption material described in the first aspect;

[0024] In the adsorption device, carbon dioxide in the flue gas to be treated is selectively adsorbed, captured and utilized in situ by the adsorption material;

[0025] The treated flue gas is discharged to the outside through the second gas online detection device and the gas outlet pipe.

[0026] Furthermore, the adsorption device is connected to a temperature control device so that the temperature of the adsorption material in the adsorption device is maintained at 30°C to 50°C.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. In the prior art, the fixation of carbon dioxide in flue gas often requires high energy consumption conditions such as high temperature and high pressure, which is costly and inefficient. The carbon dioxide fixation enzyme adsorption material described in the present application uses calcium oxide and molecular sieve nanocomposite as the main matrix. The carbonic anhydrase fixed by the adsorption matrix can achieve specific adsorption and efficient catalysis of carbon dioxide at room temperature, thereby improving the selectivity of the CO2(g)+H2O→H2CO3 reaction and the purity of the product. At the same time, the alkaline component (calcium oxide) in the matrix can realize the in-situ conversion and utilization of the fixed carbon dioxide.

[0029] 2. The carbon dioxide fixation enzyme adsorption material described in this application is used for the adsorption and in-situ utilization of carbon dioxide in flue gas and the environment, which can effectively reduce the release of carbon dioxide, improve the adsorption efficiency, reduce energy consumption, and achieve the fixation and utilization of carbon dioxide;

[0030] 3. The carbon dioxide fixation enzyme adsorption material described in the present application has good adsorption stability during use. The adsorption material can be regenerated using a low-concentration sodium hydroxide solution, has low regeneration energy consumption and high regeneration efficiency, and can reduce energy consumption costs. The single metal oxide used as a carbon dioxide absorbent in the prior art, such as magnesium oxide, sodium oxide, calcium oxide, etc., is usually carried out at a high temperature of more than 300°C for carbon dioxide adsorption, and a reversible chemical reaction occurs between carbon dioxide and metal compounds, while the desorption process requires calcination to more than 300°C. Although traditional molecular sieves have high adsorption capacity and selectivity, and low regeneration temperature, they have poor stability. The present invention uses enzyme engineering technology to fix the selective carbon dioxide adsorption catalyst carbonic anhydride enzyme on the surface of the adsorbent, while reducing the reaction temperature, improving the reaction selectivity and efficiency, reducing regeneration energy consumption, and fixing carbon at low cost. Coal-fired flue gas is used as the gas source, and has been desulfurized and dusted, with a carbon dioxide concentration of 6% to 10%. The carbon dioxide and moisture content in the flue gas are measured by an online device and then enter the capture system. The adsorption device is filled with a certain height of carbon dioxide adsorbent. Regeneration method: put the adsorbent into low concentration sodium hydroxide solution for regeneration, and dry it at low temperature for repeated use. The CO2 adsorption capacity can reach 0.72mmol / g at room temperature and 0.80mmol / g at 60℃. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0032] Figure 1 It is a structural schematic diagram of the carbon dioxide adsorption and fixation experimental device described in the embodiment;

[0033] Figure 2 is the pore size distribution diagram of the nanomatrix of Example 1;

[0034] Figure 3 This is an electron microscope image of the carbon dioxide fixation enzyme adsorption material described in Example 1;

[0035] Figure 4 This is an electron microscope image of the carbon dioxide fixation enzyme adsorption material described in Example 2;

[0036] Figure 5 This is an electron microscope image of the carbon dioxide fixation enzyme adsorption material described in Example 3;

[0037] Figure 6 This is a graph showing the comparison of the carbon dioxide fixation enzyme adsorption material and activated carbon adsorption results in Example 4;

[0038] Figure 7 This is a comparison diagram of the carbon dioxide fixation enzyme adsorption material and the organic amine adsorbent in Example 5;

[0039] Figure 8 It is a schematic diagram of dynamic adsorption of different adsorbents in Example 6 (a, b, c correspond to the adsorption materials in Examples 1 to 3, respectively). DETAILED DESCRIPTION

[0040] The examples are provided to better illustrate the present invention, but the present invention is not limited to the examples. Therefore, those skilled in the art may make non-essential improvements and adjustments to the implementation scheme according to the above invention content, which still fall within the protection scope of the present invention.

[0041] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0042] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention in detail, and are not used to limit the present invention.

[0043] Some of the raw materials involved in the following examples are shown in Table 1.

[0044] Table 1

[0045]

[0046] Experimental instruments are shown in Table 2.

[0047] Table 2

[0048]

[0049] Example 1

[0050] This embodiment provides a carbon dioxide fixation enzyme adsorption material, and the preparation method comprises the following steps:

[0051] Calcium oxide and 5A molecular sieve are mixed in a ratio of 5:1 and ground in a ball mill. The raw materials are ground into coarse particles first, and the raw materials are ground into a crude product with a particle size of no more than 500 nm. The raw materials are sieved and the crude product is further finely ground until the particle size distribution reaches 70 nm to obtain an adsorption matrix. The pore size distribution of the adsorption matrix is ​​as follows: Figure 2 shown.

[0052] The carbonic anhydrase preparation is dissolved in PBS solvent to prepare an enzyme solution with a concentration of 3 mg / mL; the adsorption matrix and the enzyme solution are added to the incubation tube at a ratio of 10:1 of the mass of the adsorption matrix: the volume of the enzyme solution (mg:mL), and the incubation is performed with shaking at a temperature of 37°C. The adsorption material obtained after the incubation is resuspended and centrifuged with a PBS blank solution, and eluted until the ultraviolet absorption value of the eluate at 280nm is less than 0.2. The fixed enzyme adsorption material is freeze-dried and stored in a freeze-drying protective agent, usually 8%-10% (mass to volume) of trehalose and mannitol as a freeze-drying protective agent. Freeze-drying is performed under the presence of conditions to prepare a finished carbon dioxide fixation enzyme adsorption material.

[0053] The structure of the prepared adsorption material was observed using an electron microscope. Figure 3 shown.

[0054] Example 2

[0055] This embodiment provides a carbon dioxide fixation enzyme adsorption material, and the preparation method comprises the following steps:

[0056] Calcium oxide and 3A molecular sieve are mixed in a ratio of 7:3 and ground in a ball mill. The raw materials are ground into coarse particles first, and the raw materials are ground into a crude product with a particle size of no more than 500 nm. The crude product is sieved and further finely ground until the particle size distribution reaches 50 nm to obtain an adsorption matrix.

[0057] Dissolve the carbonic anhydrase preparation in TAE solvent to prepare an enzyme solution with a concentration of 1 mg / mL; add the adsorption matrix and enzyme solution to the incubation tube at a ratio of 5:1 of adsorption matrix mass: enzyme solution volume (mg:mL), incubate with shaking, and incubate at 37°C. Resuspend the adsorption material obtained after the incubation with TAE blank solution, centrifuge, and elute until the ultraviolet absorption value of the eluate at 280nm is less than 0.2. For freeze-dried storage, the fixed enzyme adsorption material is freeze-dried in the presence of a freeze-dried protective agent, usually 8%-10% (mass to volume) of trehalose and mannitol as a freeze-dried protective agent, to prepare a finished carbon dioxide fixation enzyme adsorption material. Use an electron microscope to observe the structure of the prepared adsorption material product, such as Figure 4 shown.

[0058] Example 3

[0059] This embodiment provides a carbon dioxide fixation enzyme adsorption material, and the preparation method comprises the following steps:

[0060] Calcium oxide and 4A molecular sieve are mixed in a ratio of 6:4 and ground in a ball mill. The raw materials are ground into coarse particles first, and the raw materials are ground into a crude product with a particle size of no more than 500 nm. The crude product is sieved and further finely ground until the particle size distribution reaches 80 nm to obtain an adsorption matrix.

[0061] Dissolve the carbonic anhydrase preparation in TAE solvent to prepare an enzyme solution with a concentration of 5 mg / mL; add the adsorption matrix and enzyme solution to the incubation tube at a ratio of 8:1 of adsorption matrix mass: enzyme solution volume (mg:mL), incubate with shaking, and incubate at 37°C. Resuspend and centrifuge the adsorption material obtained after the incubation with TAE blank solution, and elute until the ultraviolet absorption value of the eluate at 280nm is less than 0.2. For freeze-dried storage, the fixed enzyme adsorption material is freeze-dried in the presence of a freeze-dried protective agent, usually 8%-10% (mass to volume) of trehalose and mannitol, to prepare a finished carbon dioxide fixation enzyme adsorption material. Use an electron microscope to observe the structure of the prepared adsorption material, such as Figure 5 shown.

[0062] Example 4 - Laboratory Determination of the Adsorption Capacity of Carbon Dioxide Fixation Enzyme Adsorption Materials

[0063] This example is to test the carbon fixation effect of the carbon dioxide fixation enzyme adsorption material prepared in Example 1. Figure 1 The reactor shown uses simulated flue gas of 12% carbon dioxide and 88% air. The test is carried out at room temperature and normal pressure. The control adsorption material is 5A molecular sieve.

[0064] The method for flue gas treatment comprises the following steps:

[0065] The introduced simulated flue gas enters the adsorption device 2 from the air intake pipe through the first gas online detection device 1, and the adsorption device is filled with the carbon dioxide fixation enzyme adsorption material or molecular sieve described in Example 1;

[0066] When the adsorption device 2 contains the adsorption material described in Example 1, the carbon dioxide in the simulated flue gas is selectively adsorbed, captured and utilized in situ by the adsorption material;

[0067] The treated simulated flue gas is discharged to the outside through the second gas online detection device 3 and the gas outlet pipe.

[0068] According to the set conditions, the carbon dioxide and the adsorbent sample undergo an adsorption reaction for 20 minutes. The adsorbent and the carbon dioxide gas undergo static adsorption at a fixed temperature and pressure. Figure 6 As shown, from the analysis of adsorption capacity, the carbon dioxide fixing enzyme adsorption material exceeds the adsorption capacity of the molecular sieve by more than 50%, which indicates that the carbon dioxide fixing enzyme adsorption material described in Example 1 can effectively adsorb carbon dioxide.

[0069] Example 5 - Laboratory Determination of the Adsorption Capacity of Carbon Dioxide Fixation Enzyme Adsorption Materials

[0070] This example is to test the carbon fixation effect of the carbon dioxide fixation enzyme adsorption material prepared in Example 2. Figure 1 The reactor shown uses simulated flue gas of 15% carbon dioxide and 85% N2. The test is carried out at room temperature and pressure. The control adsorption material is an organic amine adsorbent. The method of flue gas treatment is shown in Example 4. The carbon dioxide fixation enzyme adsorption material and the organic amine adsorbent are respectively loaded into the adsorption device, and the simulated flue gas is passed through. According to the set conditions, the carbon dioxide and the sample are subjected to adsorption reaction, and the reaction time is 20 minutes. The adsorption material and the carbon dioxide gas undergo static adsorption at a fixed temperature and pressure. Figure 7 As shown, from the analysis of adsorption capacity, the carbon dioxide fixing enzyme adsorption material exceeds the adsorption capacity of the molecular sieve by more than 30%, which indicates that the carbon dioxide fixing enzyme adsorption material described in Example 2 can effectively adsorb carbon dioxide.

[0071] Example 6 - Laboratory Determination of the Relationship between the Adsorption Capacity and Temperature of Carbon Dioxide Fixation Enzyme Adsorption Materials

[0072] This example is to detect the relationship between the adsorption capacity and temperature of the fixed enzyme adsorption materials described in Examples 1 to 3. The different carbon dioxide fixed enzyme adsorption materials are prepared, and a normal pressure temperature variable device is selected. A simulated flue gas of 15% carbon dioxide and 85% N2 is used to detect the change in the adsorption capacity of the adsorbent with temperature. Please refer to Example 4 for the flue gas treatment device and method. The carbon dioxide fixed enzyme adsorption materials are respectively loaded into the adsorption device, and the simulated flue gas is introduced. According to the set conditions, the carbon dioxide and the sample are subjected to an adsorption reaction, and the reaction time is 30 minutes. Dynamic adsorption occurs between the adsorbent and the carbon dioxide gas. Figure 8 As shown, from the analysis of adsorption capacity, the adsorption capacity of the carbon dioxide fixing enzyme adsorption material is temperature-dependent, which indicates that the carbon dioxide fixing enzyme adsorption material described in Examples 1 to 3 can effectively adsorb carbon dioxide, and its adsorption capacity can be further adjusted by the reaction temperature.

[0073] Finally, it should be noted that the above is only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred arrangement scheme, a person skilled in the art should understand that the technical solution of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention.

Claims

1. A carbon dioxide fixation enzyme adsorption material, characterized in that: The adsorption material is a nano-scale composite material, comprising the following components in parts by weight: Calcium oxide 5~300 Molecular sieve 1~30; The nanoscale complex is used for immobilizing enzyme preparations including carbonic anhydrase preparations, formate dehydrogenase and carboxylase.

2. The carbon dioxide fixation enzyme adsorption material according to claim 1, characterized in that: The molecular sieves include 5A, 4A and 3A molecular sieves.

3. A method for preparing the carbon dioxide fixation enzyme adsorption material as claimed in claim 1 or 2, characterized in that: The preparation method comprises the following steps: Step 1, preparing an adsorption matrix: mixing calcium oxide and molecular sieve according to the weight parts as described in claim 1, grinding them in a ball mill, first grinding the coarse particles, grinding the raw materials into a crude product with a particle size of no more than 500 nm, and after sieving, further finely grinding the crude product until the particle size distribution reaches 100 to 50 nm; Step 2, enzyme preparation: dissolving the enzyme preparation in a solvent to prepare an enzyme solution with a concentration of 1 to 10 mg / mL; Step 3, enzyme fixation: the adsorption matrix prepared in step 1 and the enzyme solution prepared in step 2 are added to an incubation tube at a ratio of 10 to 5:1 of the mass of the adsorption matrix to the volume of the enzyme solution, and incubated at 30 to 50° C. with shaking; Step 4, washing the adsorbent material: resuspending the incubated adsorbent material with a solvent, centrifuging, and eluting until the ultraviolet absorption value of the eluent at 280 nm is less than 0.2; Step 5, freeze-drying and storage: freeze-drying the fixed enzyme adsorption material in the presence of a freeze-drying protective agent to prepare a finished adsorption material.

4. The preparation method according to claim 3, characterized in that: In step 2 and step 4, the solvent is one of PBS, phosphate buffer, TAE or TrisHCl buffer.

5. The preparation method according to claim 3, characterized in that: In step 5, the lyoprotectant is one of sugars, fatty acids, amino acids, polyols or thiol reagents.

6. The preparation method according to claim 3 or 5, characterized in that: In step 5, the amount of the lyophilization protectant added is 1% to 3% of the mass of the enzyme preparation.

7. The preparation method according to claim 3, characterized in that: In step 5, the freeze-drying treatment conditions are: vacuum degree 0 to 10 Pa, temperature -20°C to -30°C, and freeze-drying time 12h to 24h.

8. A method for treating flue gas using the carbon dioxide fixing enzyme adsorption material as claimed in claim 1 or 2, characterized in that: The method comprises the following steps: The flue gas to be treated enters the adsorption device (2) from the air intake duct through the first gas online detection device (1), wherein the adsorption device is filled with the carbon dioxide fixation enzyme adsorption material according to claim 1 or 2; In the adsorption device, carbon dioxide in the flue gas to be treated is selectively adsorbed, captured and utilized in situ by the adsorption material; The treated flue gas is discharged to the outside through the second gas online detection device (3) and the gas outlet pipe.

9. The method according to claim 8, characterized in that The adsorption device (2) is connected to a temperature control device (4) so ​​that the temperature of the adsorption material in the adsorption device is maintained at 30° C. to 50° C.

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