PROCESS FOR PRODUCING NANOSTRUCTURED MATERIAL, PRODUCT AND USE

Abstract

The present invention describes a process for producing nanostructured material, produced from polymer waste doped with alkaline metals and/or alkaline earth metals, which is capable of capturing and storing CO.sub.2. The process for obtaining the material uses waste generated by the polymer industry and is therefore environmentally sustainable. The product produced, that is, the nanostructured material, shows high CO.sub.2 absorption capacity, being able to absorb up to 80% by weight in mass in CO2. In addition, the product produced shows low density, an important characteristic for application in vehicles. Therefore, the product obtained can be used for capturing and storing CO.sub.2 emitted by different emission sources, mainly mobile sources such as vehicles, but can also be used in industries such as the mining industry, oil industry, inter alia, in addition to the automotive industry.

Claims

1-9. (canceled)

10. A process of making a nanostructured material, comprising the following steps: (a) preparing a solution by solubilizing a metal hydroxide with a purity of 95 to 99.99% in acetyl acetone with a purity of 97 to 99%, in a ratio of 0.5 to 5 parts of metal hydroxide to 1 part of acetyl acetone; (b) stirring the solution prepared in step (a) for 15 to 20 minutes; (c) transferring the solution obtained in step (b) to an oven at a temperature of from 90° C. to 120° C. for a period of 18 to 36 hours, until a compound remains with mass constant forming the metal acetylacetonate (X(acac)n); (d) transferring the compound obtained in step (c) to a polystyrene dissolved in organic solvent; (e) transferring the compound obtained in step (d) to a reactor and pressurizing the reactor to an inert atmosphere from 5 to 15 bar; (f) heating the reactor at a rate of 5° C. to 10° C. min.sup.−1 to a temperature of 500° C. to 600° C. and maintaining at that temperature for a period of 3 to 8 hours; (g) cooling the reactor to a temperature of 20° C. to 30° C.

11. The process of claim 10, wherein the metal hydroxide in step (a) is selected from the group comprising alkali and/or alkaline earth metals.

12. The process of claim 10, wherein the metal acetylacetonate (X(acac)n) in step (c) is selected from the group comprising calcium, magnesium, sodium and beryllium acetylacetonate, where X is Ca, Mg, Na or Be, respectively, and n is 1 or 2.

13. The process of claim 10, wherein the organic solvent in step (d) is ethyl acetate or acetone.

14. The process of claim 10, wherein the inert atmosphere in step (e) comprises nitrogen or argon.

15. A nanostructured material produced according to the process of claim 10, wherein the nanostructured material comprises a mesoporous support and alkali and/or alkaline earth metals.

16. The nanostructured material of claim 15, wherein the mesoporous support is impregnated with magnesium, sodium or beryllium salts, or soluble and calcined calcium.

17. The nanostructured material of claim 15, wherein the mesoporous support is based on polymeric residues or carbonaceous material obtained from a carbon source.

18. The nanostructured material of claim 17, wherein the carbon source is selected from the group consisting of alcohols, sugars, cellulose, aliphatic and aromatic hydrocarbons, wherein the mesoporous support is impregnated or doped with calcium, magnesium, sodium, or beryllium.

19. A use of the nanostructured material produced according to the process of claim 10, characterized by absorption of CO.sub.2 at temperatures of 100 to 600° C.

20. The process of making a nanostructured material of claim 10, wherein the ratio of the metal hydroxide to acetyl acetone in step (a) is 1:1.

21. The process of making a nanostructured material of claim 10, wherein the oven temperature in step (c) is 105° C.

22. The process of making a nanostructured material of claim 10, wherein, in step (d), the compound obtained in step (c) is transferred to a polystyrene dissolved in organic solvent in the proportion of 1 g of the compound obtained in step (c) in 20 mL of organic solvent.

23. The process of making a nanostructured material of claim 10, wherein the reactor in step (f) is heated to a temperature of 530° C.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0019] FIG. 1 depicts exemplary the material produced and the percentage of CO.sub.2 captured by some produced samples.

[0020] FIG. 2 depicts the profile of mass loss of some of the materials developed. The thermal analysis of magnesium acetylacetonate (A) and sodium acetylacetonate (B) shows that the profile of mass loss is different from the materials CarbMgNa 3:6 (C) and CarbMgNa (Be10) (D) materials.

[0021] FIG. 3 depicts images of Scanned Electron Microscopy (MEV) of the products obtained. The structure of some materials CarbMgNa 3:2-0.2 (A). CarbMgNa 3:6-0.6 (B). showing small spheres, using 1,000-fold magnification, and the sample prepared with beryllium (CarbMgNa3:6:0.6 (Be10)) (C) showing the presence of needles using 10,000-fold magnification. FIG. (D) also of the CarbMgNa3:6:0.6 (Be10) sample, was magnified 20,000 times and shows the same profile.

[0022] FIG. 4 shows some Raman Spectroscopy data. The spectra obtained in the graphs (A) and (B) showed the presence of a band near 1,570 cm.sup.−1, typical of more organized carbon and a band at 1,350 cm.sup.−1, which suggests the presence of more defective amorphous carbon structures.

[0023] FIG. 5 shows the X-Ray Diffractograms of the sample of CarbMgNa3:6:0.6. This structure is mainly comprised of MgO, Mg(OH).sub.2 and Na.sub.2O.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present invention describes the process of obtaining nanostructured material, produced from a polymeric residue doped with alkali and alkaline earth metals, that is capable of capturing and storing CO.sub.2. The process of obtaining the material utilizes residues generated by the polymer industry, being environmentally sustainable. The product obtained, that is, the nanostructured material, has low density and high CO.sub.2 absorption capacity, and can absorb up to 80% of the mass weight of CO.sub.2.

[0025] The proposed process for obtaining nanostructured material comprises the following steps of:

[0026] a. solubilizing the metal hydroxide with purity between 95 and 99.99% in acetyl acetone with purity between 97 and 99%, in the ratio of 0.5 to 5 parts of metal hydroxide to a part of acetyl acetone being preferably in the 1:1 ratio;

[0027] b. stirring for 15 to 20 minutes;

[0028] c. transferring the solution obtained in step b to an oven at a temperature of from 90° C. to 120° C., preferably 105° C. for a period of 18 to 36 hours, until the material remains with the mass constant forming the metal acetylacetonate (X(acac)n);

[0029] d. transferring the compound obtained in step c) to polystyrene dissolved in organic solvent, preferably in the ratio of 1 g of the compound obtained in step “c” in 20 mL of the organic solvent;

[0030] e. transferring the compound obtained in step “d” into a reactor and pressurizing in an inert atmosphere between 5 and 15 bar;

[0031] f. heating the reactor with a heating rate of 5° C. to 10° C./min.sup.−1 to a temperature in the range of 500° C. to 600° C., preferably 530° C.; and maintaining at that temperature for a period of 3 to 8 hours;

[0032] g. cooling the system to a temperature of 20° C. to 30° C.

[0033] In step “a”, the metal hydroxide is selected from the group comprising the alkali and/or alkaline earth metals.

[0034] In step “c”, the metal acetylacetonate (X(acac)n) is selected from the group comprising calcium, magnesium, sodium and beryllium acetylacetonate, wherein X is Ca, Mg, Na or Be, respectively, and n is 1 or 2.

[0035] In step “d”, the organic solvent used to dissolve the polystyrene is preferably ethyl acetate or acetone.

[0036] In step “e”, the inert atmosphere is characterized by containing preferably nitrogen or argon.

[0037] The nanostructured material of present invention comprises a mesoporous material and alkali and/or alkaline earth metals.

[0038] The mesoporous support may be impregnated with soluble and calcined calcium magnesium, sodium or beryllium salts.

[0039] The support may be based on carbon (activated or not) can be obtained from any source of carbon (alcohols, sugars, cellulose, aliphatic and aromatic hydrocarbons), impregnated or doped with calcium, magnesium, sodium or beryllium.

[0040] The mesoporous support can be impregnated or doped with alkali and/or alkaline earth metals.

[0041] The nanostructured material comprising mesoporous material and alkali and/or alkaline earth metals can be used for absorption of CO.sub.2 at temperatures between 100 and 600° C.

[0042] The present invention may be better understood by the following examples, not limiting the technology.

EXAMPLE 1

Obtaining the Carbon-Based Nanostructured Material and Alkali and/or Alkaline Earth Metals

[0043] Ca, Mg, Na and/or Be doped hybrid materials were prepared from co-pyrolysis of the complexes of magnesium, sodium or beryllium (X(acac)n acetylacetonate, where X can he Ca, Mg, Na and Be and n =1 or 2) with a carbon source, where a polystyrene residue (PS) at 530° C. for 5 hours at 10 bar of inert atmosphere (N.sub.2 Or Ar) was used. For such, the PS and the Ca, Mg, Na, and/or Be acetylacetonate (acac) complexes were mixed and dissolved in an organic solvent, such as acetone or ethyl acetate, (not limiting, as the type of solvent used to dissolve polystyrene does not interfere with the process) and then poured into a stainless steel reactor where the mixture was then pyrolyzed. The obtained material can be used directly in the absorption of CO.sub.2 or shaped into monoliths using an extruder, or with a commercial binder, for example, 10% by weight carboxymethyl cellulose.

[0044] The Ca, Mg, Na and/or Be doped hybrid materials prepared from co-pyrolysis of the complexes of magnesium, sodium or beryllium acetylacetonate with a carbon source, a polystyrene residue (PS) can be obtained using different atomic or molar ratios of the four basic components in the co-pyrolysis as shown in Table 1

TABLE-US-00001 TABLE 1 Different mass or molar ratios used in co-pyrolysis Component OS Ca(acac).sub.2 Mg(acac).sub.2 Na(acac) Be(acac).sup.2 Percentage 5%-40% 30%-80% 30%-80% 3%-10% 5%-30% (m/m)

[0045] The carbon source may also be replaced by any carbon-containing, polymeric or not such as, for example, thermoplastics, bitumen, petroleum refining residues, among others.

[0046] The metal complex used as a source of Ca, Mg, Na and Be can also be with different ligands since they are soluble in organic solvents or partially soluble solvents. FIG. 1 shows a schematic of preparing the materials with some data of the amount of CO.sub.2 captured. The advantage of these samples is at the temperature used to capture CO.sub.2 that is close to 100° C. while the samples containing only calcium need temperatures greater than 500° C. to store CO.sub.2.

EXAMPLE 2

CO.SUB.2 .Capture Assays and Characterization of the Materials Obtained

[0047] For CO.sub.2 capture assays, the obtained materials were transferred to a reaction system comprised of a glass reactor and held under heating (at 130° C. preferably, this temperature can be varied from 100 to 150° C.). The reactor was connected to the gas inlet. The reaction proceeded for 12 hours (which can vary from 3-15 hours) under CO.sub.2 flow at 50 mL min.sup.−1 (and can vary from 30 to 80 mL min.sup.−1). At the end of the reaction the material was dried in an oven at 80° C. (which can be 60-100° C.) and analyzed.

[0048] The assays show that the Cub Mg3:6 and Carb Mg3:1,2 material captures less than 5% CO.sub.2. However, the addition of sodium causes this percentage to be close to 20% as the data shown in Table 2.

[0049] Physical-chemical characterizations indicate that the material is composed of approximately 60% carbon according to thermal analysis data noted in FIG. 2. The thermal analysis of magnesium Acac (A) and sodium Acac (B) shows that the profile of mass loss is different from materials (CarbMgNa 3:6-0.6 (C) and Carb MgNa (Be10) (D)). This indicates that carbonaceous structures are not equal and that an interaction between the polystyrene and the acac(M) occurred thus leading to the formation of carbonaceous structures doped with the metals. According to the profile of mass loss it is possible to say that there is about 42% magnesium and sodium oxide in the CarbMgNa3:6-0.6 (C) sample and about 45% magnesium, sodium, and berylium oxide in the CarbMgNa3:6:0.6 (Be10) (D) sample.

[0050] Scanning Electron Microscopy (MEV) assays were performed, as shown in FIG. 3, which show a surface composed of irregular particles comprised mainly of needles and spheres. The structure of CarbMgNa 3:2-0,2 (A) and CarbMgNa 3:6-0.6 (B) show small spheres, which are more organized in sample (A), probably due to the lesser amount of metal present in the carbonaceous structure. In the sample prepared with beryllium (CarbMgNa3:6:0.6 (Be10)) (C) and (D) it is possible to observe the presence of needles that are likely due to the presence of this metal in the structure.

[0051] Raman Spectroscopy (FIG. 4) assays were conducted to characterize the nature of the carbon present in the samples. The spectra obtained showed the presence of a band near 1,570 cm.sup.−1 (G band related to the carbon-carbon bond of sp.sup.3 type) typical of more organized carbon and a band of 1.350 cm.sup.−1 (D band typical for sp2 carbon-carbon), which suggests the presence of more defective amorphous carbon structures. The degree of organization of the structures was related to the intensity of those bands. The IG/ID ratio (G-Band Intensity/D-Band Intensity) was 1.08 for the CarbMgNa 3:6-0.6 (A) and 1.15 for CarbMgNa3:6:0.6 (Be10) (B). This indicates that the structures are similar in relation to the degree of organization and that the presence of the beryllium does not interfere with this property.

[0052] X-ray diffraction analyses of sample CarbMgNa3:6:0.6, shown in FIG. 5 were performed. This structure is mainly comprised of MgO (JCDPS-75-447). Mg(OH).sub.2 (JCDPS-44-1482) and Na.sub.2O (JCDPS-77-2148).

TABLE-US-00002 TABLE 2 Amount of CO.sub.2 captured by some materials. Material CO.sub.2 captured (%) Carb Mg 3:6 3.5 Carb Mg 3:1.2 2.6 Carb MgNa 3:4-0.4 17 Carb MgNa 3:6-0.6 21 Carb MgNa (Be10) 17 Carb MgNa (Be20) 13