The present application pertains to methods for making metal oxides and/or citric acid and/or capturing carbon dioxide. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth sulfite or bisulfite and an aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

The present application pertains to methods for making metal oxides and/or citric acid and/or capturing carbon dioxide. In one embodiment, the application pertains to a process for producing calcium oxide, magnesium oxide, or both from a material comprising calcium and magnesium. The process may include reacting a material comprising calcium carbonate and magnesium carbonate. Separating, concentrating, and calcining may lead to the production of oxides such as calcium oxide or magnesium oxide. In other embodiments the application pertains to methods for producing an alkaline-earth oxide and a carboxylic acid from an alkaline earth cation-carboxylic acid anion salt. Such processes may include, for example, reacting an alkaline-earth cation-carboxylic acid anion salt with aqueous sulfur dioxide to produce aqueous alkaline-earth sulfite or bisulfite and an aqueous carboxylic acid solution. Other useful steps may include desorbing, separating, and/or calcining.

A composition of zinc salts of carboxylic acids. The carboxylic acids of the zinc salts include 0.5 to 6.0 mass % of a component (A), 0.05 to 1.2 mass % of a component (B) and 88.0 to 98.0 mass % of a component (C) described below. A ratio [(A)/(B)] of a mass of the component (A) with respect to a mass of the component (B) is 99/1 to 75/25, where (A) is a straight chain and saturated carboxylic acid having a carbon number of 12 to 22; (B) is a strait chain and unsaturated carboxylic acid having one unsaturated bond and a carbon number of 18, said unsaturated bond comprising a trans-form double bond; and (C) is a straight-chain and unsaturated carboxylic acid having one unsaturated bond and a carbon number of 18, said unsaturated bond comprising a cis-form double bond.

A composition of zinc salts of carboxylic acids. The carboxylic acids of the zinc salts include 0.5 to 6.0 mass % of a component (A), 0.05 to 1.2 mass % of a component (B) and 88.0 to 98.0 mass % of a component (C) described below. A ratio [(A)/(B)] of a mass of the component (A) with respect to a mass of the component (B) is 99/1 to 75/25, where (A) is a straight chain and saturated carboxylic acid having a carbon number of 12 to 22; (B) is a strait chain and unsaturated carboxylic acid having one unsaturated bond and a carbon number of 18, said unsaturated bond comprising a trans-form double bond; and (C) is a straight-chain and unsaturated carboxylic acid having one unsaturated bond and a carbon number of 18, said unsaturated bond comprising a cis-form double bond.

Provided is a process for producing acrylic acid, wherein the process comprises a first step and a second step in which a first absorbent is added to a reaction product of a bio-material and cooled to separate a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA). The process is capable of producing high-purity acrylic acid at high yield, and acetaldehyde is produced as by-product along with the reaction product of the bio-material. The process includes separating the acetaldehyde produced as by-product into a high-purity product at high yield.

Provided is a process for producing acrylic acid, wherein the process comprises a first step and a second step in which a first absorbent is added to a reaction product of a bio-material and cooled to separate a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA). The process is capable of producing high-purity acrylic acid at high yield, and acetaldehyde is produced as by-product along with the reaction product of the bio-material. The process includes separating the acetaldehyde produced as by-product into a high-purity product at high yield.

Provided is a process for producing acrylic acid, wherein the process comprises a first step and a second step in which a first absorbent is added to a reaction product of a bio-material and cooled to separate a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA). The process is capable of producing high-purity acrylic acid at high yield, and acetaldehyde is produced as by-product along with the reaction product of the bio-material. The process includes separating the acetaldehyde produced as by-product into a high-purity product at high yield.

Provided is a process for producing acrylic acid, comprising (step 1) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by adding a first absorbent to a reaction product of a bio-raw material and cooling the result; (step 2) separating a first incompressible material and a second low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the first low-boiling-point material including acetaldehyde (ACHO) and cooling the result; (step 3) heating the second low-boiling-point material including acetaldehyde (ACHO); (step 4) separating the heated second low-boiling-point material including acetaldehyde (ACHO) to acetaldehyde (ACHO) and the second absorbent and (step 5) producing acrylic acid by purifying the first high-boiling-point material including acrylic acid (AA).

Provided is a process for producing acrylic acid, comprising (step 1) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by adding a first absorbent to a reaction product of a bio-raw material and cooling the result; (step 2) separating a first incompressible material and a second low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the first low-boiling-point material including acetaldehyde (ACHO) and cooling the result; (step 3) heating the second low-boiling-point material including acetaldehyde (ACHO); (step 4) separating the heated second low-boiling-point material including acetaldehyde (ACHO) to acetaldehyde (ACHO) and the second absorbent and (step 5) producing acrylic acid by purifying the first high-boiling-point material including acrylic acid (AA).

Provided is a process for producing acrylic acid, comprising (step 1) separating a first low-boiling-point material including acetaldehyde (ACHO) and a first high-boiling-point material including acrylic acid (AA) by adding a first absorbent to a reaction product of a bio-raw material and cooling the result; (step 2) separating a first incompressible material and a second low-boiling-point material including acetaldehyde (ACHO) by adding a second absorbent to the first low-boiling-point material including acetaldehyde (ACHO) and cooling the result; (step 3) heating the second low-boiling-point material including acetaldehyde (ACHO); (step 4) separating the heated second low-boiling-point material including acetaldehyde (ACHO) to acetaldehyde (ACHO) and the second absorbent and (step 5) producing acrylic acid by purifying the first high-boiling-point material including acrylic acid (AA).