Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

Processes for purifying acetic acid by distilling a process stream in a column in which acetic anhydride is formed in the lower portion of the column. The product stream withdrawn from the column comprises acetic acid, water at a concentration of no more than 0.2 wt. %, and acetic anhydride at a concentration of no more than 600 wppm. The process further comprises hydrating the acetic anhydride in the product stream to form a purified acetic acid product comprising acetic anhydride at a concentration of no more than 50 wppm.

The present disclosure is: a free polyunsaturated fatty acid-containing composition, which comprises at least one free polyunsaturated fatty acid having 20 or more carbon atoms, the content being at least 80.0% of the fatty acids in the composition, and satisfies at least one selected from a group consisting of conditions (1) and (2): (1) the content of conjugated unsaturated fatty acid is 1.0% or less of the fatty acids in the composition, and (2) the Gardner color is less than 3+; and a manufacturing method for the free polyunsaturated fatty acid-containing composition comprising the preparation of a raw material composition containing at least one polyunsaturated fatty acid having 20 or more carbon atoms, and hydrolysis of a reaction solution containing the prepared raw material composition, a lower alcohol, water and an alkali catalyst at a temperature of 10 C. or lower.

The present disclosure is: a free polyunsaturated fatty acid-containing composition, which comprises at least one free polyunsaturated fatty acid having 20 or more carbon atoms, the content being at least 80.0% of the fatty acids in the composition, and satisfies at least one selected from a group consisting of conditions (1) and (2): (1) the content of conjugated unsaturated fatty acid is 1.0% or less of the fatty acids in the composition, and (2) the Gardner color is less than 3+; and a manufacturing method for the free polyunsaturated fatty acid-containing composition comprising the preparation of a raw material composition containing at least one polyunsaturated fatty acid having 20 or more carbon atoms, and hydrolysis of a reaction solution containing the prepared raw material composition, a lower alcohol, water and an alkali catalyst at a temperature of 10 C. or lower.

The invention is directed to a process for the ring-opening of a cycloadduct obtainable from a reaction of a furanic compound and a diene, said process comprising contacting the cycloadduct with an acidic mixture comprising sulfuric acid and an activating agent to obtain a ring-opened product. The present invention is particularly directed a continuous process.

The invention is directed to a process for the ring-opening of a cycloadduct obtainable from a reaction of a furanic compound and a diene, said process comprising contacting the cycloadduct with an acidic mixture comprising sulfuric acid and an activating agent to obtain a ring-opened product. The present invention is particularly directed a continuous process.

The invention is directed to a process for the ring-opening of a cycloadduct obtainable from a reaction of a furanic compound and a diene, said process comprising contacting the cycloadduct with an acidic mixture comprising sulfuric acid and an activating agent to obtain a ring-opened product. The present invention is particularly directed a continuous process.

The present disclosure is: a free polyunsaturated fatty acid-containing composition, which comprises at least one free polyunsaturated fatty acid having 20 or more carbon atoms, the content being at least 80.0% of the fatty acids in the composition, and satisfies at least one selected from a group consisting of conditions (1) and (2): (1) the content of conjugated unsaturated fatty acid is 1.0% or less of the fatty acids in the composition, and (2) the Gardner color is less than 3+; and a manufacturing method for the free polyunsaturated fatty acid-containing composition comprising the preparation of a raw material composition containing at least one polyunsaturated fatty acid having 20 or more carbon atoms, and hydrolysis of a reaction solution containing the prepared raw material composition, a lower alcohol, water and an alkali catalyst at a temperature of 10? C. or lower.