Method for producing acrylic acid

A process for producing acrylic acid, comprising the steps of:

• a) vaporizing a raw material comprising an aqueous glycerol solution to generate a first gas, wherein said aqueous glycerol solution has a water content of not more than 50% by weight;
• b) applying a dehydration reaction to glycerol in a gas phase that includes said first gas;
• then
• c) applying a gas phase oxidation reaction to a gaseous reaction product formed by the dehydration reaction to obtain said acrylic acid;
• and
• d) wherein the dehydration reaction and the gas phase oxidation reaction are conducted in a tandem-type reactor.

A process for producing acrylic acid, comprising the steps of:

• a) vaporizing a raw material comprising an aqueous glycerol solution to generate a first gas, wherein said aqueous glycerol solution has a water content of not more than 50% by weight;
• b) applying a dehydration reaction to glycerol in a gas phase that includes said first gas;
• then
• c) applying a gas phase oxidation reaction to a gaseous reaction product formed by the dehydration reaction to obtain said acrylic acid;
• and
• d) wherein the dehydration reaction and the gas phase oxidation reaction are conducted in a single-type reactor comprising one reaction tube, where said one reaction tube is filled with a catalyst for the gas phase oxidation on the reaction gas outlet side and with a catalyst for the dehydration reaction of glycerol on the reaction gas inlet side, thus conducting in said one reaction tube the dehydration reaction followed by the gas phase oxidation reaction.

A petroleum independent process for producing acrylic acid, comprising the steps of:

• a) obtaining glycerol from one of i) hydrolysis of oils-and-fats, ii) waste fluids in soap production, and iii) a by-product in production of a bio-diesel fuel as a renewable fuel;
• b) vaporizing a raw material comprising an aqueous glycerol solution having said glycerol to generate a first gas, wherein said aqueous glycerol solution has a water content of not more than 50% by weight;
• c) adding an inert gas to the first gas to obtain a resultant mixed gas, wherein the inert gas is selected from the group consisting of nitrogen gas, carbon dioxide gas and rare gas, and controlling a concentration of said inert gas in said resultant mixed gas to a concentration of not less than 50% by volume;
• d) applying a dehydration reaction to glycerol in a gas phase that includes said resultant mixed gas, wherein the gas phase in which said dehydration reaction is conducted comprises glycerol, water vapor and oxygen, and wherein the amount of the water vapor relative to the glycerol in the mixed gas is not larger than 1.2 times by mol;
• then
• e) applying a gas phase oxidation reaction to a gaseous reaction product formed by the dehydration reaction to obtain said acrylic acid;
• and
• f) wherein the dehydration reaction and the gas phase oxidation reaction are conducted in a tandem-type reactor.

A petroleum independent process for producing acrylic acid, comprising the steps of:

• a) obtaining glycerol from one of i) hydrolysis of oils-and-fats, ii) waste fluids in soap production, and iii) a by-product in production of a bio-diesel fuel as a renewable fuel;
• b) vaporizing a raw material comprising an aqueous glycerol solution having said glycerol to generate a first gas, wherein said aqueous glycerol solution has a water content of not more than 50% by weight;
• c) adding an inert gas to the first gas to obtain a resultant mixed gas, wherein the inert gas is selected from the group consisting of nitrogen gas, carbon dioxide gas and rare gas, and controlling a concentration of said inert gas in said resultant mixed gas to a concentration of not less than 50% by volume;
• d) applying a dehydration reaction to glycerol in a gas phase that includes said resultant mixed gas, wherein the gas phase in which said dehydration reaction is conducted comprises glycerol, water vapor and oxygen, and wherein the amount of the water vapor relative to the glycerol in the mixed gas is not larger than 1.2 times by mol;
• then
• e) applying a gas phase oxidation reaction to a gaseous reaction product formed by the dehydration reaction to obtain said acrylic acid;
• and
• f) wherein the dehydration reaction and the gas phase oxidation reaction are conducted in a single-type reactor comprising one reaction tube, where said one reaction tube is filled with a catalyst for the gas phase oxidation on the reaction gas outlet side and with a catalyst for the dehydration reaction of glycerol on the reaction gas inlet side, thus conducting in said one reaction tube the dehydration reaction followed by the gas phase oxidation reaction.