Abstract: Provided is a method capable of manufacturing 1,3-butylene glycol having a high potassium permanganate test value. A method for manufacturing 1,3-butylene glycol, which is a method for obtaining purified 1,3-butylene glycol from a crude reaction liquid containing 1,3-butylene glycol, the method including: a dehydration step of removing water by distillation; a high boiling substance removal step of removing a high boiling point component by distillation; and a product distillation step of obtaining purified 1,3-butylene glycol, wherein in the product distillation step, a product column is used in which a liquid feed having a 1,3-butylene glycol concentration of 97% or higher, an acetaldehyde content of 500 ppm or lower, and a crotonaldehyde content of 200 ppm or lower is distilled under a condition of a reflux ratio of higher than 0.1, and a liquid concentrated with acetaldehyde and crotonaldehyde is distilled off from above a feed plate, and 1,3-butylene glycol is extracted from below the feed plate.

Abstract: A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead.

Abstract: A process for separating or removing permanganate reducing compounds (PRC's) from a first mixture containing at least one PRC, methyl iodide, and water comprises the steps of: feeding the first mixture to a feed port of a distillation column, and distilling and separating the first mixture into an upper stream and a lower stream, wherein the distillation of the first mixture forms a second mixture at an upper position than the feed port, and the process further comprises the steps of: withdrawing the second mixture as the upper stream, and withdrawing the lower stream from a lower position than the feed port.

Abstract: A process for producing acetic acid comprises a process comprising: (1) carbonylating methanol; (2) separating the reaction mixture into a volatile phase and a less-volatile phase; (3) distilling the volatile phase to forma first overhead rich in a lower boiling component, and an acetic acid stream rich in acetic acid; and at least one step group selected from the group consisting of the following sections (4), (9), and (15): (4) a section for separating impurities from the acetic acid stream to give purified acetic acid, (9) a section for separating the first overhead into a stream rich in acetaldehyde and a stream rich in methyl iodide, and (15) a section for absorption-treating an off-gas from the process with an absorption solvent and forming a carbon monoxide-rich stream and an acetic acid-rich stream.

Abstract: A process for producing acetic acid while efficiently separating permanganate reducing compounds (PRC's) and methyl iodide is provided. PRC's are separated or removed from a mixed composition (3A) containing PRC's and methyl iodide by distilling the mixed composition in a distillation step (5) to form an overhead stream (5A), a side-cut stream (5B), and a lower stream (5C). In a distillation column of the distillation step (5), an extractant (e.g., water) extracting PRC's preferentially to methyl iodide is added to a concentration zone in which PRC's and methyl iodide are concentrated, and an extraction mixture falling from the concentration zone is withdrawn as the side-cut stream (5B).

Abstract: A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead.

Abstract: A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead.

Abstract: It is intended to provide a method capable of suppressing distillation apparatus corrosion as a method for producing acetic acid, comprising the step of distilling a crude acetic acid solution containing acetic acid and an impurity having a higher boiling point than that of acetic acid to purify the acetic acid. The method for producing acetic acid of the present invention comprises the step described above, wherein the distillation of the crude acetic acid solution is performed under a condition involving a distillation column bottom temperature of not more than 165° C. An acetic acid concentration in the crude acetic acid solution to be subjected to the distillation is preferably not less than 90 mass %. Examples of the impurity having a higher boiling point than that of acetic acid include acetate salts, acetic anhydride, and propionic acid. A column bottom pressure of the distillation column is preferably less than 0.255 MPaG.

Abstract: A process for producing acetic acid comprises a process comprising: (1) carbonylating methanol; (2) separating the reaction mixture into a volatile phase and a less-volatile phase; (3) distilling the volatile phase to forma first overhead rich in a lower boiling component, and an acetic acid stream rich in acetic acid; and at least one step group selected from the group consisting of the following sections (4), (9), and (15): (4) a section for separating impurities from the acetic acid stream to give purified acetic acid, (9) a section for separating the first overhead into a stream rich in acetaldehyde and a stream rich in methyl iodide, and (15) a section for absorption-treating an off-gas from the process with an absorption solvent and forming a carbon monoxide-rich stream and an acetic acid-rich stream.

Abstract: A process for separating or removing permanganate reducing compounds (PRC's) from a first mixture containing at least one PRC, methyl iodide, and water comprises the steps of: feeding the first mixture to a feed port of a distillation column, and distilling and separating the first mixture into an upper stream and a lower stream, wherein the distillation of the first mixture forms a second mixture at an upper position than the feed port, and the process further comprises the steps of: withdrawing the second mixture as the upper stream, and withdrawing the lower stream from a lower position than the feed port.

Abstract: A process for separating or removing permanganate reducing compounds (PRC's) from a first mixture containing at least one PRC, methyl iodide, and water comprises the steps of: feeding the first mixture to a feed port of a distillation column, and distilling and separating the first mixture into an upper stream and a lower stream, wherein the distillation of the first mixture forms a second mixture at an upper position than the feed port, and the process further comprises the steps of: withdrawing the second mixture as the upper stream, and withdrawing the lower stream from a lower position than the feed port.

Abstract: A process for producing acetic acid comprises a process comprising: (1) carbonylating methanol; (2) separating the reaction mixture into a volatile phase and a less-volatile phase; (3) distilling the volatile phase to form a first overhead rich in a lower boiling component, and an acetic acid stream rich in acetic acid; and at least one step group selected from the group consisting of the following sections (4), (9), and (15): (4) a section for separating impurities from the acetic acid stream to give purified acetic acid, (9) a section for separating the first overhead into a stream rich in acetaldehyde and a stream rich in methyl iodide, and (15) a section for absorption-treating an off-gas from the process with an absorption solvent and forming a carbon monoxide-rich stream and an acetic acid-rich stream.

Abstract: A method produces acetic acid and includes a reaction step, a first purification step, a second purification step, and a third purification step. In the reaction step, a material mixture including methanol, carbon monoxide, a catalyst, and an iodide is subjected to a methanol carbonylation reaction in a reactor (1) to form acetic acid. In the first purification step, a crude acetic acid stream including acetic acid formed in the reaction step is subjected to distillation in a distillation column (3) to give a first acetic acid stream enriched with acetic acid. In the second purification step, the first acetic acid stream is subjected to distillation in a distillation column (5) to give a second acetic acid stream further enriched with acetic acid. In the third purification step, an acetic acid stream is subjected to purification in an additional purification unit (e.g.

Abstract: A process for producing acetic acid comprises a process comprising: (1) carbonylating methanol; (2) separating the reaction mixture into a volatile phase and a less-volatile phase; (3) distilling the volatile phase to form a first overhead rich in a lower boiling component, and an acetic acid stream rich in acetic acid; and at least one step group selected from the group consisting of the following sections (4), (9), and (15): (4) a section for separating impurities from the acetic acid stream to give purified acetic acid, (9) a section for separating the first overhead into a stream rich in acetaldehyde and a stream rich in methyl iodide, and (15) a section for absorption-treating an off-gas from the process with an absorption solvent and forming a carbon monoxide-rich stream and an acetic acid-rich stream.

Abstract: A process for stably and safely producing acetic acid without increasing an internal pressure of a distillation column is provided. The process comprises (1) a carbonylation reaction step for allowing methanol to react with carbon monoxide; (2) a flash step for separating the reaction mixture into a volatile phase and a less-volatile phase; (3) a first distillation step for separating the volatile phase into a first overhead and a crude acetic acid stream rich in acetic acid; and (4) a separation step for separating at least acetaldehyde from the first overhead.

Abstract: It is intended to provide a method capable of suppressing distillation apparatus corrosion as a method for producing acetic acid, comprising the step of distilling a crude acetic acid solution containing acetic acid and an impurity having a higher boiling point than that of acetic acid to purify the acetic acid. The method for producing acetic acid of the present invention comprises the step described above, wherein the distillation of the crude acetic acid solution is performed under a condition involving a distillation column bottom temperature of not more than 165° C. An acetic acid concentration in the crude acetic acid solution to be subjected to the distillation is preferably not less than 90 mass %. Examples of the impurity having a higher boiling point than that of acetic acid include acetates, acetic anhydride, and propionic acid. A column bottom pressure of the distillation column is preferably less than 0.255 MPaG.

Abstract: A process for producing acetic acid while efficiently separating permanganate reducing compounds (PRC's) and methyl iodide is provided. PRC's are separated or removed from a mixed composition (3A) containing PRC's and methyl iodide by distilling the mixed composition in a distillation step (5) to form an overhead stream (5A), a side-cut stream (5B), and a lower stream (5C). In a distillation column of the distillation step (5), an extractant (e.g., water) extracting PRC's preferentially to methyl iodide is added to a concentration zone in which PRC's and methyl iodide are concentrated, and an extraction mixture falling from the concentration zone is withdrawn as the side-cut stream (5B).

Abstract: A process for separating or removing permanganate reducing compounds (PRC's) from a first mixture containing at least one PRC, methyl iodide, and water comprises the steps of: feeding the first mixture to a feed port of a distillation column, and distilling and separating the first mixture into an upper stream and a lower stream, wherein the distillation of the first mixture forms a second mixture at an upper position than the feed port, and the process further comprises the steps of: withdrawing the second mixture as the upper stream, and withdrawing the lower stream from a lower position than the feed port.

Abstract: A method produces acetic acid and includes a reaction step, a first purification step, a second purification step, and a third purification step. In the reaction step, a material mixture including methanol, carbon monoxide, a catalyst, and an iodide is subjected to a methanol carbonylation reaction in a reactor (1) to form acetic acid. In the first purification step, a crude acetic acid stream including acetic acid formed in the reaction step is subjected to distillation in a distillation column (3) to give a first acetic acid stream enriched with acetic acid. In the second purification step, the first acetic acid stream is subjected to distillation in a distillation column (5) to give a second acetic acid stream further enriched with acetic acid. In the third purification step, an acetic acid stream is subjected to purification in an additional purification unit (e.g.

Abstract: Provided is a method for producing high-purity acetaldehyde from acetic acid inexpensively and industrially efficiently. The present invention relates to a method for producing acetaldehyde via acetic acid hydrogenation. The method hydrogenates acetic acid to give a reaction fluid. The reaction fluid is charged into an absorber. From the reaction fluid, condensed components are absorbed with an absorbing liquid, and non-condensable gases are dissolved in the absorbing liquid. A bottom liquid of the absorber is decompressed (reduced in pressure) to strip the dissolved non-condensable gases from the absorbing liquid. The residual liquid after the non-condensable gas stripping is recycled to the absorber.