A carbon dioxide utilization process and its application

Abstract

The present invention relates to the field of carbon dioxide utilization, specifically to B01D53 / 62, and more specifically to a carbon dioxide utilization process and its application. The carbon dioxide utilization process comprises: solidifying solid waste after pretreatment and molding under the action of gas containing carbon dioxide. The carbon dioxide utilization process obtains the best curing humidity by adjusting the volume fraction of water vapor under a certain curing environment temperature and pressure, thereby promoting the progress of the curing reaction and greatly reducing the carbon dioxide fixation cost.

Description

Technical Field

[0001] The present invention relates to the field of carbon dioxide utilization, in particular to B01D53 / 62, and more particularly to a carbon dioxide utilization process and application thereof. Background Art

[0002] At present, the impact of high carbon emissions on the ecological environment is becoming increasingly prominent, and the global climate is constantly warming, threatening the human living environment. Carbon dioxide can be stored after being captured, purified and compressed in industrial flue gas. For example, crude oil extraction is a widely used storage technology, but this technology can only use high-concentration carbon dioxide, which is costly. In recent years, the comprehensive recycling of resources while fixing carbon dioxide can solve the problem of high carbon dioxide emissions while realizing the utilization of solid waste. The principle is that the calcium and magnesium active compounds in industrial waste react with carbon dioxide to form carbonate minerals, which realizes the utilization of carbon dioxide and converts industrial waste into construction products with economic value. At present, there are many studies on the mineralization of solid waste. Some studies use mineralization technology to maintain construction waste powder prefabricated parts to generate building products. For example, Chinese patent CN202110778996 crushes the raw material to 20-100 μm, and then goes through a series of subsequent processes such as adding carbon dioxide-containing gas and absorption liquid, homogenizing, and molding. This process has high requirements for process operation, requiring both crushing operation and homogenization treatment, and additional absorption liquid needs to be added to increase the reaction rate of carbon dioxide. The entire process is cumbersome. Summary of the invention

[0003] In view of some problems existing in the prior art, the first aspect of the present invention provides a carbon dioxide utilization process, comprising: pre-treating and molding solid waste, and then solidifying it under the action of a gas containing carbon dioxide.

[0004] Preferably, the curing temperature is 45-120°C, for example 45°C, 60°C, 80°C, 100°C, 120°C.

[0005] Preferably, the curing pressure is 0.1-2.2 MPa, for example, 0.1 MPa, 0.2 MPa, 0.5 MPa, 1.1 MPa, 2.2 MPa.

[0006] Preferably, the curing time is 1-4 hours, preferably 2 hours.

[0007] In one embodiment, the gas containing carbon dioxide contains water vapor, and the volume content of the water vapor is 8-11%.

[0008] Preferably, the volume content of carbon dioxide in the carbon dioxide-containing gas is 8-95%, for example 8%, 10%, 20%, 25%, 30%, 40%, 50%, 55%, 60%, 70%, 80%, 82%, 84%, 86%, 88%, 90%, 92%, 94%, 95% and the like.

[0009] In one embodiment, the volume fraction w of water vapor satisfies w≥1 / P·10^(7.96681-1668.21 / (T+228))·133.28947.

[0010] P is the curing pressure and T is the curing temperature.

[0011] In one embodiment, the volume content of carbon dioxide in the carbon dioxide-containing gas is 13.9%, the curing temperature is 100-120° C., the curing pressure is 1.1-2.2 MPa, and the volume content of water vapor is 10-11%.

[0012] Preferably, the volume content of carbon dioxide in the carbon dioxide-containing gas is 13.9%, the curing temperature is 100° C., the curing pressure is 1.1 MPa, and the volume content of water vapor is 10-11%.

[0013] Preferably, the volume content of carbon dioxide in the carbon dioxide-containing gas is 13.9%, the curing temperature is 120° C., the curing pressure is 2.2 MPa, and the volume content of water vapor is 10-11%.

[0014] In one embodiment, the volume content of carbon dioxide in the carbon dioxide-containing gas is 80-81%, the curing temperature is 80-100° C., the curing pressure is 0.5-1.1 MPa, and the volume content of water vapor is 9-11%.

[0015] Preferably, the volume content of carbon dioxide in the carbon dioxide-containing gas is 80-81%, the curing temperature is 80° C., the curing pressure is 0.5 MPa, and the volume content of water vapor is 9-11%.

[0016] Preferably, the volume content of carbon dioxide in the carbon dioxide-containing gas is 80-81%, the curing temperature is 100° C., the curing pressure is 1.1 MPa, and the volume content of water vapor is 9-11%.

[0017] The curing reaction temperature, pressure, and the carbon dioxide and water vapor content in the carbon dioxide-containing gas are closely related to the reaction rate, utilization rate, and quality of the cured product. When the volume content of carbon dioxide in the carbon dioxide-containing gas is 13.9%, the curing temperature is 100-120°C, the curing pressure is 1.1-2.2MPa, and the volume content of water vapor is 10-11%, or the volume content of carbon dioxide in the carbon dioxide-containing gas is 80-81%, the curing temperature is 80-100°C, the curing pressure is 0.5-1.1MPa, and the volume content of water vapor is 9-11%, the curing product can achieve the highest absorption rate of carbon dioxide while ensuring a good reaction rate, and the compressive strength of the cured product is also good. This is because under this condition, as the reaction proceeds, the reaction environment can maintain a balance with the internal environment of the solid waste, avoiding the escape of components in the solid waste molding, and allowing carbon dioxide to continue to act on the inside of the molding to be converted into carbonate or bicarbonate, and the effect is long-lasting.

[0018] In addition, the applicant unexpectedly discovered in the experiment that when the volume content of carbon dioxide in the carbon dioxide-containing gas is higher than 80%, when the volume content of water vapor exceeds a certain amount, the utilization rate of carbon dioxide and the compressive strength of the cured product are reduced, which is contrary to the general rule in the prior art, increasing the difficulty of controlling the curing reaction. Based on the experimental results, the applicant analyzed and found that when w≥1 / P·10^(7.96681-1668.21 / (T+228))·133.28947, especially when the volume fraction of water vapor is equal to or close to 1 / P·10^(7.96681-1668.21 / (T+228))·133.28947, the carbon dioxide absorption rate and compressive strength can reach a higher level.

[0019] In one embodiment, the solid waste contains calcium, magnesium and silicon components, and the sum of calcium, magnesium and silicon compounds exceeds 40 wt %.

[0020] The molding process in this application can be conventionally selected by those skilled in the art.

[0021] In one embodiment, the method for pre-treating solid waste includes: mixing solid waste and water to obtain a pre-treated product, which is then kept for use after 20-28 hours.

[0022] Preferably, the solid content of the pretreated material is 88-95wt%, exemplified by 88wt%, 89wt%, 90wt%, 91wt%, 92wt%, 93wt%, 94wt%, 95wt%; more preferably, it is 91wt%.

[0023] Preferably, the obtained pretreated material is ready for use after 24 hours.

[0024] The second aspect of the present invention provides an application of a material obtained by the carbon dioxide utilization process in the preparation of industrial materials.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] (1) The present invention adjusts the contents of carbon dioxide and water vapor in the carbon dioxide-containing gas, and analyzes and confirms the relationship between the water vapor content and the curing temperature and curing pressure, so that the curing reaction is easy to control and operate. The water vapor content in the carbon dioxide-containing gas can be adjusted according to different curing conditions, so that a higher reaction rate and carbon dioxide utilization rate can be achieved during the curing reaction, and the compressive strength of the cured product can be increased.

[0027] (2) The solid waste pretreatment method in the present application facilitates subsequent molding, so that a better molded body can be obtained under better pressure;

[0028] (3) The solid content of the pre-treated material in the present application is 88-95 wt %. After subsequent molding, during the curing process, it can coordinate with the gas containing carbon dioxide, thus avoiding the removal of water molecules to a certain extent;

[0029] (4) In this application, the pretreated material is left for 20-28 hours to be used, which promotes the uniformity of moisture in the solid waste;

[0030] (5) The carbon dioxide utilization process in the present application controls the water vapor content in the curing environment to keep the green body in the optimal environmental humidity, and efficiently fixes the carbon dioxide in the solid waste, thereby achieving direct utilization of carbon dioxide mineralization without adding additional carbon capture processes, greatly saving the cost of carbon dioxide fixation. The total carbon emissions of the building bricks prepared by the process are more than 50% lower than those of traditional silicate cement products.

[0031] (6) The present invention controls the volume fraction of water vapor to place the curing reaction in an optimal humidity environment, thereby ensuring that the moisture in the green body is retained in the structural pores. Carbon dioxide can exist in the green body structure in the form of carbonate or bicarbonate, making it easier to react with calcium and magnesium compounds in the green body, further enhancing the mineralization degree of solid waste to carbon dioxide, and generating mineralized products such as calcium carbonate with stable performance;

[0032] (7) The present invention proposes a method for determining the optimal moisture content of the curing environment. When the temperature and pressure of the curing environment are determined, the optimal range of the moisture content of the environment can be obtained. If the water vapor content in the environment is low, water vapor can be supplemented by additional water vapor, thereby accelerating the curing reaction and efficiently fixing carbon dioxide in solid waste. This method saves the cost of carbon dioxide fixation, effectively reduces the difficulty of industrial promotion, and provides a practical and effective carbon emission reduction path for current enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 1 of the present invention;

[0034] Figure 2 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 2 of the present invention;

[0035] Figure 3 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 3 of the present invention;

[0036] Figure 4 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 4 of the present invention;

[0037] Figure 5 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 5 of the present invention;

[0038] Figure 6 This is a graph showing the change in carbon dioxide absorption rate and compressive strength of Example 6 of the present invention. DETAILED DESCRIPTION

[0039] The present invention is described below by specific implementation methods, but is not limited to the specific embodiments given below.

[0040] In the embodiment, the molded product is formed into a size of 20 mm×20 mm×20 mm at a pressure of 40 MPa.

[0041] Example

[0042] Example 1

[0043] A carbon dioxide utilization process, in which steelmaking waste is pretreated and formed, and then solidified under the action of waste gas.

[0044] The pretreatment process is to mix steelmaking waste with a certain amount of water to form a 91wt% pretreatment product, which is ready for use after 24 hours.

[0045] The calcium silicate in steelmaking waste is amorphous, and its composition by weight percentage is 55.3% CaO, 29.4% SiO2, 4.8% Al2O3, 2.5% MgO, 2.6% P2O5, 2.0% K2O, 1.5% SO3, 0.8% Fe2O3, 0.4% TiO2, 0.3% Na2O, 0.2% SrO, and 0.2% MnO.

[0046] Among them, the curing temperature is 60°C and the curing pressure is 0.2MPa.

[0047] Among them, the volume fraction of carbon dioxide in the exhaust gas is 13.9%, the volume fraction of oxygen is 3.81%, the volume fractions of water vapor are 8%, 9%, 10%, and 11% respectively, and the rest is nitrogen.

[0048] After testing, the results are shown in Table 1 and Figure 1 , where the carbon dioxide absorption rate is the percentage of the mass of carbon dioxide absorbed by solid waste to the mass of mineralized products, where the content of carbon dioxide absorbed by solid waste is obtained by testing the TG / DTG curve of mineralized products, and the content of carbon dioxide absorbed by solid waste is the weight reduction at 550-850℃; the mass of mineralized products is the mass of mineralized products at 105℃; the compressive strength is measured in accordance with GBT4111-2013 "Test Methods for Concrete Blocks and Bricks". .

[0049] Table 1

[0050]

[0051] Example 2

[0052] A carbon dioxide utilization process is the same as Example 1, except that the curing temperature is 100° C. and the curing pressure is 1.1 MPa.

[0053] After testing, the results are shown in Table 2 and Figure 2 .

[0054] Table 2

[0055]

[0056] Example 3

[0057] A carbon dioxide utilization process is the same as Example 1, except that the curing temperature is 120° C. and the curing pressure is 2.2 MPa.

[0058] After testing, the results are shown in Table 3 and Figure 3 .

[0059] Table 3

[0060]

[0061]

[0062] From Table 1-3 and Figure 1-3 It can be seen that under the same curing temperature and curing pressure, the volume ratio of water vapor in the exhaust gas has a positive effect on the carbon dioxide absorption rate, and the growth rate of the carbon dioxide absorption rate gradually slows down with the increase of water vapor content, and the absorption rate gradually increases.

[0063] Example 4

[0064] A carbon dioxide utilization process is specifically the same as Example 1, except that the curing temperature is 45°C and the curing pressure is 0.1MPa; the waste gas is replaced by carbon captured gas (85vol% carbon dioxide, 7.21vol% nitrogen, 5mol% water vapor, 2.79vol% oxygen), and the carbon captured gas is added with water vapor content so that the water vapor content reaches 8vol%, 9vol%, 10vol%, and 11vol%, respectively.

[0065] After testing, the results are shown in Table 4 and Figure 4 .

[0066] Table 4

[0067]

[0068] Example 5

[0069] A carbon dioxide utilization process is the same as Example 4, except that the curing temperature is 80° C. and the curing pressure is 0.5 MPa.

[0070] After testing, the results are shown in Table 5 and Figure 5 .

[0071] Table 5

[0072]

[0073]

[0074] Example 6

[0075] A carbon dioxide utilization process is specifically the same as Example 4, except that the curing temperature is 100° C. and the curing pressure is 1.1 MPa.

[0076] After testing, the results are shown in Table 6 and Figure 6 .

[0077] Table 6

[0078]

[0079] From Table 4-6 and Figure 4-6 It can be seen that under the same curing temperature and curing pressure, the water vapor volume ratio has a positive effect on the carbon dioxide absorption rate, and the growth rate of the carbon dioxide absorption rate gradually slows down with the increase of water vapor content, and the absorption rate gradually increases. When it reaches the optimal value, the carbon dioxide absorption rate decreases instead.

[0080] After analysis, the applicant found that when w≥1 / P·10^(7.96681-1668.21 / (T+228))·133.28947, where w is the volume fraction of water vapor, P is the curing pressure, and T is the curing temperature, especially when the volume fraction of water vapor is equal to or close to 1 / P·10^(7.96681-1668.21 / (T+228))·133.28947, the carbon dioxide absorption rate and compressive strength can reach a higher level.

Claims

1. A process for utilizing carbon dioxide, characterized in that: include: After pretreatment and molding, the solid waste is solidified under the action of a gas containing carbon dioxide at a temperature of 45-120°C and a pressure of 0.1-2.2MPa; The carbon dioxide-containing gas contains water vapor, and the volume fraction w of the water vapor satisfies w≥1 / P·10^(7.96681-1668.21 / (T+228))·133.28947, wherein P is the curing pressure and T is the curing temperature.

2. The carbon dioxide utilization process according to claim 1, characterized in that: The carbon dioxide-containing gas contains water vapor with a volume content of 8-11%.

3. The carbon dioxide utilization process according to claim 2, characterized in that: The volume content of carbon dioxide in the carbon dioxide-containing gas is 8-95%.

4. The carbon dioxide utilization process according to claim 1, characterized in that: The volume content of carbon dioxide in the carbon dioxide-containing gas is 13.9%, the curing temperature is 100-120° C., the curing pressure is 1.1-2.2 MPa, and the volume content of water vapor is 10-11%.

5. The carbon dioxide utilization process according to claim 1, characterized in that: The volume content of carbon dioxide in the carbon dioxide-containing gas is 80-81%, the curing temperature is 80-100° C., the curing pressure is 0.5-1.1 MPa, and the volume content of water vapor is 9-11%.

6. The carbon dioxide utilization process according to claim 4 or 5, characterized in that: The curing time is 1-4h.

7. The carbon dioxide utilization process according to claim 6, characterized in that: The method for pre-treating solid waste includes: mixing solid waste with water to obtain pre-treated material, which is kept ready for use after 20-28 hours.

8. The carbon dioxide utilization process according to claim 7, characterized in that: The solid content of the pretreated material is 88-95 wt%.

9. Use of a material obtained by the carbon dioxide utilization process according to any one of claims 1 to 8 in the preparation of industrial materials.

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