METHOD FOR TRAPPING AND STORING CO2

Abstract

Method for trapping and storing CO.sub.2 by mechanochemical route including: a) dissolving an amine or amino acid to obtain a concentrated solution whose concentration of amine function is at least 3M; b) bringing the solution into contact with a CO.sub.2-containing gas; c)1. bringing into contact under stirring the solution with an oxide, hydroxide, silicate, aluminate, phosphate, chloride or sulfate of alkaline earth metal or a material containing an oxide, silicate, aluminate, phosphate, chloride or sulfate of alkaline earth metal, the energy implemented for stirring being at least 2.5 W per gram; or 2. bringing into contact under grinding the precipitate with an oxide, hydroxide, silicate, aluminate, phosphate, chloride or sulfate of alkaline earth metal or a material containing an oxide, silicate, aluminate, phosphate, chloride or sulfate of alkaline earth metal, the energy implemented for grinding being at least 2.5 W per gram; and d) washing the obtained solid.

Claims

1. A method for trapping and storing CO.sub.2 by mechanochemical route comprising the following steps: a) dissolving an amine or an amino acid in order to obtain a concentrated solution whose concentration of amine function is at least 3M; b) bringing the solution thus obtained into contact with a CO.sub.2-containing gas; c) 1. bringing into contact, while stirring, the concentrated solution obtained in step b) with an oxide, a hydroxide, a silicate, an aluminate, a phosphate, a chloride or a sulfate of alkaline earth metal or a material containing an oxide, a silicate, an aluminate, a phosphate, a chloride or a sulfate of alkaline earth metal, the energy implemented for stirring being at least 2.5 W per gram of the stirred sample; or 2. bringing into contact under grinding the precipitate obtained in step b) with an oxide, a hydroxide, a silicate, an aluminate, a phosphate, a chloride or a sulfate of alkaline earth metal or a material containing an oxide, a silicate, an aluminate, a phosphate, a chloride or a sulfate of an alkaline earth metal, the energy implemented for grinding being at least 2.5 W per gram of the ground sample; and d) washing the obtained solid.

2. The method according to claim 1, wherein the concentration of amine function of the concentrated solution obtained in step a) is at least 5M.

3. The method according to claim 1, wherein the energy implemented for stirring or grinding during step c) is at least 5 W per gram of sample.

4. The method according to claim 1, wherein the energy implemented for stirring or grinding during step c) is at most 500 W per gram of sample.

5. The method according to claim 1, wherein step c.2) is preceded by a step of filtering and washing the precipitate obtained in step b).

6. The method according to claim 1, wherein the amine is chosen as being ethylenediamine (EDA), diethylenetriamine (DETA), monoethanolamine (MEA), diethanolamine (DEA), N-methyldiethanolamine (MDEA), 2-amino-2methylpropanol (AMP), piperazine or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

7. The method according to claim 1, wherein the amino acid is chosen as being a proteinogenic amino acid.

8. The method according to claim 7, wherein the amino acid is chosen as being L-arginine (L-Arg), L-asparagine (L-Asn), L-aspartate (L-Asp), L-cysteine (L-Cys), glycine (Gly), histidine (His) or L-lysine (L-Lys), as well as their alkaline salts.

9. The method according to claim 8, wherein the amino acid is chosen as being L-lysine (L-Lys).

10. The method according to claim 1, wherein the organic solution is a water/alcohol mixture in a water:alcohol ratio comprised between 1:10 and 10:1.

11. The method according to claim 1, wherein the CO.sub.2-containing gas is a combustion or industrial exhaust gas.

12. The method according to claim 11, wherein the CO.sub.2-containing gas is an exhaust gas from a cement plant.

13. The method according to claim 1, wherein the precipitate obtained at the end of step c) is brought into contact with an alkaline earth metal oxide or silicate or a material containing an alkaline earth metal oxide or silicate.

14. The method according to claim 13, wherein the alkaline earth metal oxide is chosen as being CaO or MgO.

15. The method according to claim 13, wherein the alkaline earth metal silicate is chosen as being CaSiO.sub.3 or MgSiO.sub.3.

16. The method according to claim 13, wherein the alkaline earth metal hydroxide is chosen as being Ca(OH).sub.2 or Mg(OH).sub.2.

Description

EXAMPLE 1METHOD FOR TRAPPING AND STORING CO.SUB.2 .ACCORDING TO THE INVENTION

1.1Trapping CO.SUB.2

a/ Method

Amino Acid

[0091] 1 g of amino acid and one equivalent of KOH are dissolved in 6 ml of a distilled water/methanol mixture in a water:methanol ratio of 1:5.

[0092] CO.sub.2 is introduced into the solution thus formed at 200 mg/min for 1 hour. The formation of a white precipitate is observed.

[0093] At the end of the reaction, the precipitate is filtered on a frit, washed cold with a mixture of water/methanol (ratio 1:5) and dried under vacuum for 12 hours.

[0094] The injected quantity of CO.sub.2 is monitored by gravimetry and the total load of trapped CO.sub.2 is confirmed by quantitative 13C NMR analysis.

[0095] The amino acids used in this method are lysine, glycine and cysteine.

Industrial Amine

[0096] A concentrated 5M solution of diethylenetriamine (DETA) is prepared from commercial DETA and distilled water in a graduated flask.

[0097] The solution is charged with a CO.sub.2 flow of 200 mg/min using a flow meter.

[0098] The injected quantity of CO.sub.2 is monitored by gravimetry and the total load of trapped CO.sub.2 is confirmed by quantitative 13C NMR analysis.

b/ Results

TABLE-US-00001 TABLE 1 Amount of CO.sub.2 trapped by the amino acid or amine Amount of CO.sub.2 trapped by the amino Amino acid/Amine acid/amine GlyK 0.61 LysK 0.77 CysK 0.61 DETA 0.45

[0099] In this table, the amount of CO.sub.2 trapped by the amino acid/amine corresponds to the ratio of moles of CO.sub.2/moles of nitrogen.

1.2Storing CO.SUB.2

a/ Method

i) Dry Grinding

[0100] 0.3 g of solid -amino acid-CO.sub.2 obtained in example 1.1 is introduced into a 20 ml tungsten carbide (WC) mechanochemistry reactor with 60 5 mm diameter balls.

[0101] The alkaline earth metal oxide is introduced in stoichiometric quantity relative to the CO.sub.2.

[0102] Grinding is performed at 500 rpm for 30 minutes.

[0103] The resulting solids are collected using 5 ml of distilled water, centrifuged and washed 3 times.

[0104] The liquid and solid phases are separated and dried via a freeze dryer.

ii) Liquid Assisted Grinding (LAGAmino Acid

[0105] 0.3 g of solid -amino acid-CO.sub.2 obtained in example 1.1 is introduced into a 20 ml tungsten carbide (WC) mechanochemistry reactor with 60 5 mm diameter balls.

[0106] The alkaline earth metal oxide is introduced in stoichiometric quantity relative to the CO.sub.2.

[0107] A defined amount of water is added into the reactor with a liquid:solid ratio comprised between 0.1 and 2 L/mg.

[0108] Grinding is performed at 500 rpm for 30 minutes.

[0109] The resulting solids are collected using 5 ml of distilled water, centrifuged and washed 3 times.

[0110] The liquid and solid phases are separated and dried via a freeze dryer.

iii) Liquid Assisted Grinding (LAG)Amine

[0111] 1 ml of the DETA-CO.sub.2 solution obtained according to example 1.1 is introduced into a 20 ml tungsten carbide (WC) mechanochemistry reactor with 60 5 mm diameter balls.

[0112] The alkaline earth metal oxide is introduced in stoichiometric quantity relative to the CO.sub.2.

[0113] Grinding is performed at 500 rpm for 30 minutes.

[0114] The resulting solids are collected using 5 ml of distilled water, centrifuged and washed 3 times.

[0115] The liquid and solid phases are separated and dried via a freeze dryer.

b/ Results

Regeneration Rate of the Amino Acid/Amine

[0116] The regeneration rate of the amino acid or amine is determined by elementary analysis of the quantity of nitrogen N in the solid according to the following procedure, which corresponds to: (number of introduced moles-number of retained moles)/number of introduced moles100.

[0117] The solid phase is analyzed by CHNS in order to obtain the mass percentage of the various present elements. The percentage can be converted into moles of each element according to the following equations:

[00001]$\begin{array}{cc}\%N/100=gN\mathrm{in}1g\mathrm{of}\mathrm{solid}\mathrm{sample}& \left(1\right)\end{array}$$\begin{array}{cc}\mathrm{Eq}.\left(1\right)& \\ x\mathrm{exact}\mathrm{mass}\mathrm{of}\mathrm{the}\mathrm{sample}=gN\mathrm{in}\mathrm{the}\mathrm{sample}\mathrm{studied}& \left(2\right)\end{array}$$\begin{array}{cc}\mathrm{Eq}.\left(2\right)& \\ /14.008\left(\mathrm{atomic}\mathrm{mass}\mathrm{of}\mathrm{nitrogen}\right)=\mathrm{moles}\mathrm{of}N& \left(3\right)\end{array}$

[0118] After obtaining the number of moles of N in the sample, the number of moles of amino acid/amine is obtained by dividing the number of moles of nitrogen by the number of nitrogens present on the amine (e.g. 3 for DETA and 2 for lysine):

[00002]$\begin{array}{cc}\mathrm{Moles}\mathrm{of}N\left(3\right)/\mathrm{\#nitrogens}\mathrm{present}\mathrm{on}\mathrm{the}\mathrm{amino}\mathrm{acid}/\mathrm{amine}=\mathrm{moles}\mathrm{of}\mathrm{amino}\mathrm{acid}/\mathrm{amine}& \left(4\right)\end{array}$

[0119] From the number of moles of amine in the solid sample, the amino acid/amine regeneration rate (RR) can be calculated according to the following equation:

[00003]$\begin{array}{cc}\mathrm{TR}\left(\%\right)=\left(\mathrm{Moles}\mathrm{of}\mathrm{initial}\mathrm{amino}\mathrm{acid}/\mathrm{amine}-\mathrm{moles}\mathrm{of}\mathrm{amino}\mathrm{acid}/\mathrm{amine}\mathrm{in}\mathrm{the}\mathrm{sample}\right)/\mathrm{moles}\mathrm{of}\mathrm{initial}\mathrm{amino}\mathrm{acid}/\mathrm{amine}& \left(5\right)\end{array}$

Carbonation Rate of the Alkaline Earth Metal Oxide

[0120] The carbonation rate of the alkaline earth metal oxide (ratio of moles of CO.sub.2 fixed in the solid phase per mole of alkaline earth metal oxide) is determined: [0121] by volumetric titration of the CO.sub.2 expelled during the acid digestion of the solid obtained (dosage of the so-called inorganic carbonate) on a Chittick apparatus with a 3 ml burette: an aliquot of dry solid of approximately 10 mg is titrated with 1 ml of 1M H.sub.2SO.sub.4 acid. The calibration of the apparatus is done beforehand with NaHCO.sub.3titrated with 1M H.sub.2SO.sub.4, thus obtaining a calibration curve of y=13.225 with R.sub.2=0.9943; [0122] and by elementary analysis of the carbon content (called total) after deduction of the possible contribution of the trapped amine: the nitrogen content of the solid makes it possible to go back to the quantity of amine and therefore of carbon coming from the amine in the solid. Subtracted from the quantity of total carbon in the solid, we deduce the quantity of carbon coming from the fixed CO.sub.2

[0123] These two measurements are confirmed by q13C NMR on the liquid phases to confirm the amount of amine: an aliquot of the liquid phase is analyzed by NMR in the presence of an internal reference to allow quantification of the amine in solution.

[0124] The carbonation rate is calculated following the same principle as for calculating the regeneration rate of the amine/amino acid.

[0125] Equations (1), (2) and (3) above are adapted by dividing by the atomic mass of carbon.

[0126] The number of moles of CO.sub.2 in the solid phase is calculated by subtracting the number of moles of amino acid/amine from the number of moles of carbon:

[00004]$\begin{array}{cc}\mathrm{Moles}\mathrm{of}\mathrm{CO}2=\mathrm{moles}\mathrm{of}C-\left(\mathrm{moles}\mathrm{of}\mathrm{amino}\mathrm{acid}/\mathrm{amine}x\mathrm{\#C}\mathrm{in}\mathrm{amino}\mathrm{acid}/\mathrm{amine}\right)& \left(6\right)\end{array}$

[0127] In equation 6 the number of moles of amine were calculated by eq. (4) and the #C varies according to the amino acid/amine (e.g. 4 for DETA and 6 for lysine).

[0128] The carbonation rate (CR) is then calculated as:

[00005]$\begin{array}{cc}\mathrm{TC}\left(\%\right)=\mathrm{moles}\mathrm{of}{\mathrm{CO}}_2/\mathrm{moles}\mathrm{of}\mathrm{initial}{\mathrm{CO}}_2& \left(7\right)\end{array}$

Dry Grinding (Neat Grinding) with Amino Acid

TABLE-US-00002 TABLE 2 Carbonation rate of the metal oxide and regeneration rate of the amino acid - Dry route Carbonation rate Amino Alkaline earth of the alkaline Regeneration rate acid metal oxide earth metal oxide of the amino acid GlyK CaO 45% 95% LysK CaO 82% 95% CysK CaO 52% 100% GlyK MgO 8.9% 99% LysK MgO 21% 98% CysK MgO 16% 100%
LAG Grinding with Amino Acid

TABLE-US-00003 TABLE 3 Carbonation rate of the metal oxide and regeneration rate of the amino acid - LAG route Carbonation Alkaline Distilled water rate of the Regeneration Amino earth metal (l/mg of total alkaline earth rate of the acid oxide solid) metal oxide amino acid LysK(s) MgO 0.5 41% 92% MgO 1.0 37% 87% MgO 2.0 31% 94%
LAG Grinding with Amine

TABLE-US-00004 TABLE 4 Carbonation rate of the Metal oxide and regeneration rate of the amine - LAG route Carbonation Distilled water rate of the Regeneration Alkaline earth (l/mg of metal alkaline earth rate of the Amine metal oxide oxide) metal oxide Amine DETA CaO 2.56 51% 93% DETA MgO 3.89 17% 94%

1.3Conclusion

[0129] The obtained experimental results confirm that the method according to the present invention makes it possible to carry out the step of carbonating the alkaline earth metal oxide by dry route or in the presence of very small quantities of water, which significantly limits the quantities of water required in comparison with the methods conventionally implemented.

[0130] Furthermore, the reaction kinetics, the carbonation rate of the alkaline earth metal oxide and the regeneration rate of the amino acid or amine used are significantly higher than for conventionally used method (see for example Liu et al., Single-step, low temperature and integrated CO.sub.2 capture and conversion using sodium glycinate to produce calcium carbonate, Fuel (2020), Ed. 275, 117887, or Liu et al., Integrated CO.sub.2 Capture and Removal via Carbon Mineralization with Inherent Regeneration of Aqueous Solvents, Energy & Fuels (2021), 35 (9), 8051-8068)).