Anhydrous, amorphous and porous magnesium carbonates and methods of production thereof
An X-ray amorphous magnesium carbonate is disclosed that is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of at least 0.018 cm 3 /g, and a specific surface areas of at least 60 m 2 /g. The X-ray amorphous magnesium carbonate is produced by reacting an inorganic magnesium compound with alcohol in a CO 2 atmosphere. The X-ray amorphous magnesium carbonate can be a powder or a pellet and acts as a desiccant in, for example, production of food, chemicals or pharmaceuticals.
1. A magnesium carbonate, wherein the magnesium carbonate is X-ray amorphous, and wherein the magnesium carbonate is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of at least 0.018 cm 3 /g.
2. The magnesium carbonate of claim 1 , wherein the magnesium carbonate is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of at least 0.8 cm 3 /g.
3. The magnesium carbonate of claim 1 , wherein the magnesium carbonate is characterized by a BET specific surface area obtained from N 2 sorption isotherms of between 60 m 2 /g and 1500 m 2 /g.
4. The magnesium carbonate of claim 3 , wherein the cumulative pore volume of pores with a diameter smaller than 10 nm is between 0.018 cm 3 /g and 3.0 cm 3 /g.
5. The magnesium carbonate of claim 4 , wherein the cumulative pore volume of pores with a diameter smaller than 10 nm is between 0.018 cm 3 /g and 1.5 cm 3 /g.
6. The magnesium carbonate of claim 3 , wherein the magnesium carbonate is characterized by a BET specific surface area obtained from N 2 sorption isotherms of between 240 m 2 /g and 1500 m 2 /g.
7. The magnesium carbonate of claim 1 , wherein the magnesium carbonate is characterized by adsorbing more than 0.3 mmol water/g material at an RH of 3% at room temperature.
8. The magnesium carbonate of claim 7 , wherein the magnesium carbonate is characterized by adsorbing more than 14 mmol water/g material at an RH of 90% at room temperature.
9. A desiccant comprising the magnesium carbonate as in claim 1 .
10. A powder or a pellet or a film comprising the magnesium carbonate as in claim 1 .
11. An additive to a food, a chemical, a cosmetic or a pharmaceutical comprising the magnesium carbonate as in claim 1 .
12. An excipient in a cosmetic or a pharmaceutical comprising the magnesium carbonate as in claim 1 .
13. A method of controlling moisture content in a volume of a material, comprising exposing the volume to the magnesium carbonate as in claim 1 .
14. A method to produce magnesium carbonate, the method comprising:
reacting MgO with alcohol in a CO 2 atmosphere,
wherein the pressure is above atmospheric pressure,
wherein the temperature is between 40° C. to a boiling temperature of the alcohol,
wherein the produced magnesium carbonate is X-ray amorphous, and
wherein the produced magnesium carbonate is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of between 0.018 cm 3 /g and 3.0 cm 3 /g.
15. The method of claim 14 , wherein the pressure is 1 to 3 bar above atmospheric pressure.
16. The method of claim 14 , wherein the magnesium carbonate is characterized by a BET specific surface area obtained from N 2 sorption isotherms of between 60 m 2 /g and 1500 m 2 /g.
17. A method to produce magnesium carbonate, the method comprising the steps of:
mixing MgO and an alcohol-containing liquid in a reactor, to form at least one Mg-based intermediary that can interact with CO 2 ;
forming a carbonated intermediate product by reacting the at least one Mg-based intermediary with CO 2 , wherein the carbonated intermediate is a liquid or a gel; and
transforming the liquid or gel carbonated intermediate product into magnesium carbonate by drying,
wherein the magnesium carbonate is X-ray amorphous, and
wherein the magnesium carbonate is characterized by a cumulative pore volume of pores with a diameter smaller than 10 nm of at least 0.018 cm 3 /g,
wherein the CO 2 that reacts with the at least one Mg-based intermediary is at a pressure of 1 to 12 bar above atmospheric pressure,
wherein mixing is performed at a temperature between 40° C. and a boiling temperature of the alcohol-containing liquid, and
wherein drying is performed at a temperature below 350° C.
18. The method of claim 17 , wherein forming the carbonated intermediate product is performed at a temperature below 50° C.
19. The method of claim 17 , wherein the pressure is less than 5 bar above atmospheric pressure.
20. The method of claim 17 , wherein drying is performed at a temperature between 60° C. and 300° C.
21. The method of claim 17 , wherein the cumulative pore volume of pores with a diameter smaller than 10 nm is between 0.018 cm 3 /g and 3.0 cm 3 /g, and
wherein the magnesium carbonate is characterized by a BET specific surface area obtained from N 2 sorption isotherms of between 60 m 2 /g and 1500 m 2 /g.