A process for producing magnesia can include contacting CO.sub.2-containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a CO.sub.2 by-product and magnesia; and recycling at least a portion of the CO.sub.2 by-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

A process for producing magnesia can include contacting CO2-containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a CO2 by-product and magnesia; and recycling at least a portion of the CO.sub.2 by-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

A process for producing magnesia can include contacting CO2-containing emissions with a magnesium-containing material to produce magnesium carbonate; subjecting the magnesium carbonate to calcination to produce a CO2 by-product and magnesia; and recycling at least a portion of the CO.sub.2 by-product for contacting the magnesium-containing material to produce the magnesium carbonate. The magnesium-containing material can include mining residues, such as phyllosilicate or chrysotile mining residue, and the magnesium carbonate produced can include precipitated nesquehonite that is subjected to calcination to produce the magnesia.

Disclosed are a method for manufacturing hydrogen microbubbles (A1) and a device (10) thereof. The device comprises air pressure assembly (1) and a water container (2), wherein the water container (2) is loaded with water (A). The air pressure assembly (1) can perform gas suction and pressurization and the gas enters a hydrogen oscillation generation unit (3). The hydrogen oscillation generation unit (3) is internally provided with a magnesium alloy-manufactured hydrogen oscillator (4), and the hydrogen oscillator (4) is reacted with water molecules contained in the gas to obtain magnesium oxide and hydrogen. Then, the chemically reacted gas is sprayed by the hydrogen oscillation generation unit (3) into the water (A) via a gas spray nozzle (5), forming hydrogen microbubbles (A1) containing hydrogen in the water (A).

Disclosed are a method for manufacturing hydrogen microbubbles (A1) and a device (10) thereof. The device comprises air pressure assembly (1) and a water container (2), wherein the water container (2) is loaded with water (A). The air pressure assembly (1) can perform gas suction and pressurization and the gas enters a hydrogen oscillation generation unit (3). The hydrogen oscillation generation unit (3) is internally provided with a magnesium alloy-manufactured hydrogen oscillator (4), and the hydrogen oscillator (4) is reacted with water molecules contained in the gas to obtain magnesium oxide and hydrogen. Then, the chemically reacted gas is sprayed by the hydrogen oscillation generation unit (3) into the water (A) via a gas spray nozzle (5), forming hydrogen microbubbles (A1) containing hydrogen in the water (A).

Provided is a method of preparing a metal oxide-silica composite aerogel and a metal oxide-silica composite aerogel having an excellent weight reduction property prepared by the method. The method comprises adding an acid catalyst to a first water glass solution to prepare an acidic water glass solution (step 1); adding a metal ion solution to the acidic water glass solution to prepare a precursor solution (step 2); and adding a second water glass solution to the precursor solution and performing a gelation reaction (step 3).

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.sup.3/g, and a specific surface areas of at least 60 m.sup.2/g. The X-ray amorphous magnesium carbonate is produced by reacting an inorganic magnesium compound with alcohol in a CO.sub.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.

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.sup.3/g, and a specific surface areas of at least 60 m.sup.2/g. The X-ray amorphous magnesium carbonate is produced by reacting an inorganic magnesium compound with alcohol in a CO.sub.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.

The present teachings are directed to inorganic oxide materials that include Al.sub.2O.sub.3, CeO.sub.2, and at least one of MgO and Pr.sub.6O.sub.11. The present teachings are also directed to catalysts having at least one noble metal supported on these inorganic oxide materials, as well as methods for treating exhaust gases from internal combustion engines using such catalysts.

The present teachings are directed to inorganic oxide materials that include Al.sub.2O.sub.3, CeO.sub.2, and at least one of MgO and Pr.sub.6O.sub.11. The present teachings are also directed to catalysts having at least one noble metal supported on these inorganic oxide materials, as well as methods for treating exhaust gases from internal combustion engines using such catalysts.