摘要:
This invention relates to purification and/or recovery of ethanol from a crude ethanol product obtained from the hydrogenation of acetic acid. Separation and purification processes of a crude ethanol mixture are employed to allow recovery of ethanol and remove impurities. In particular, the process involves one or more sidestreams to regulate C3+ alcohols concentration in the recovered ethanol.
摘要:
A process for producing ethanol is disclosed, comprising the steps of hydrogenating acetic acid in a reactor in the presence of a catalyst to form a crude ethanol product, separating at least a portion of the crude ethanol product in a column into a first distillate comprising ethanol and a first residue comprising acetic acid and water, wherein a substantial portion of the water in the crude ethanol product that is fed to the column is removed in the first residue, and separating a portion of the ethanol mixture stream to the second distillation column to yield an ethanol product sidedraw, second residue comprising water and a second distillate comprising ethyl acetate. The water content of the ethanol product sidedraw may be further reduced to yield a stream having reduced water content.
摘要:
Recovery of an alcohol such as ethanol from a crude alcohol product, preferably obtained from the hydrogenation of acetic acid using a low energy process. The crude ethanol product is separated in a column to produce a distillate stream comprising ethyl acetate and a residue stream comprising ethanol, acetic acid, and water. The ethanol product is recovered in a second column as an ethanol side stream.
摘要:
To reduce acetal concentrations when separating ethanol from a crude product in one or more distillation column, at least one of the columns has a stripping section that comprises at least 40 stages to favor hydrolysis of the acetal. The crude product may comprise ethanol, acetaldehyde, water and one or more acetals, such as diethyl acetal. The acetal concentration may be reduced thus reducing the need to separate acetal from the crude product.
摘要:
A process for operating a distillation column to separate an ethanol mixture comprising ethanol and acetic acid where the recovered ethanol comprises less than 700 wppm acetic acid. The operating conditions for the column may vary depending on the fed composition. In particular the process provides energy efficient recovery of ethanol with low concentration acetic acid.
摘要:
To reduce acetal concentrations when separating ethanol from a crude product in one or more distillation column, at least one of the columns is operated at a higher pressure to increase the equilibrium constant that favors hydrolysis of the acetal. The crude product may comprise ethanol, acetaldehyde, water and one or more acetals, such as diethyl acetal. The acetal concentration may be reduced thus reducing the need to separate acetal from the crude product.
摘要:
A process for operating a distillation column to separate an ethanol mixture comprising ethanol and acetic acid where the recovered ethanol comprises less than 700 wppm acetic acid. The operating conditions for the column may vary depending on the fed composition. In particular the process provides energy efficient recovery of ethanol with low concentration acetic acid.
摘要:
To reduce acetal and/or ester concentrations when separating ethanol from a crude product in one or more distillation column, at least one of the columns is operated at a higher pressure to increase the equilibrium constant that favors hydrolysis of the acetal. The crude product may comprise ethanol, acetaldehyde, water, ethyl acetate and one or more acetals, such as diethyl acetal. The acetal and/or ester concentration may be reduced thus reducing the need to separate acetal and/or ester from the crude product.
摘要:
In one embodiment, the invention is to a process for purifying a crude ethanol product. The process comprises the step of hydrogenating acetic acid in a first reaction zone in the presence of a first catalyst to form the crude ethanol product comprising ethanol, acetaldehyde, acetic acid, water, and acetal. The process further comprises the step of separating at least a portion of the crude ethanol product into a refined ethanol stream and a by-product stream. The refined ethanol stream comprises ethanol and acetaldehyde; and the by-product stream comprises acetic acid and a substantial portion of the water from the crude ethanol product. The process further comprises the step of hydrolyzing in a second reaction zone at least a portion of the acetal.
摘要:
In one embodiment, the invention is to a process for purifying a crude ethanol product. The process comprises the step of hydrogenating acetic acid in a first reaction zone in the presence of a first catalyst to form the crude ethanol product comprising ethanol, acetaldehyde, acetic acid, water, and acetal. The process further comprises the step of separating at least a portion of the crude ethanol product into a refined ethanol stream and a by-product stream. The refined ethanol stream comprises ethanol and acetaldehyde; and the by-product stream comprises acetic acid and a substantial portion of the water from the crude ethanol product. The process further comprises the step of hydrolyzing in a second reaction zone at least a portion of the acetal.