Abstract: The present invention relates to a liquid dispensing device which is placed inside a distillation column and can precisely control the supply ratio of a liquid to continuously supply the liquid. The liquid dispensing device is placed inside a distillation column, thereby reducing the total installation space.

Abstract: The present invention is capable of precisely controlling a supply ratio of liquid and continuously supplying liquid at a constant rate by using partition plates for controlling the amount of liquid distribution.

Abstract: Provided is a method of separating off reaction product water and recovering a carboxylic acid used as a solvent in a reactor from a reactor discharge during oxidation of an aromatic compound, and more particularly, a method of separating off reaction product water and recovering a carboxylic acid used as a solvent in a reactor from a reactor discharge during oxidation of an aromatic compound, wherein during the oxidation of the aromatic compound, the reactor discharge is led into two or more dehydration towers having different operating pressures such that a condenser of one dehydration tower operates as a reboiler of another dehydration tower, thereby remarkably reducing energy consumption.

Abstract: The present invention relates to a liquid dispensing device which is placed inside a distillation column and can precisely control the supply ratio of a liquid to continuously supply the liquid. The liquid dispensing device is placed inside a distillation column, thereby reducing the total installation space.

Abstract: Provided is a method of separating off reaction product water and recovering a carboxylic acid used as a solvent in a reactor from a reactor discharge during oxidation of an aromatic compound, and more particularly, a method of separating off reaction product water and recovering a carboxylic acid used as a solvent in a reactor from a reactor discharge during oxidation of an aromatic compound, wherein during the oxidation of the aromatic compound, the reactor discharge is led into two or more dehydration towers having different operating pressures such that a condenser of one dehydration tower operates as a reboiler of another dehydration tower, thereby remarkably reducing energy consumption.

Abstract: A method of reducing or eliminating inflow of water to a dehydration tower using steam for separating water from a carboxylic acid from a reactor outlet gas produced in a reactor during oxidation of an aromatic compound in a carboxylic acid solvent to produce an aromatic acid, for example, oxidation of p-xylene in acetic acid solvent to produce terepthalic acid. The aromatic compound is introduced at the top of an absorption tower and collects ascending carboxylic acid solvent, introduced in the reactor outlet gas at the bottom of the absorption tower, for reintroduction into the reactor eliminating the need to remove and recover the solvent. The absorption tower, condensers and an organic-water separator remove the water in the reactor outlet gas as waste water, and the amount of water inflow to the dehydration tower is reduced or eliminated, as is the amount of steam required for separation.

Abstract: The present invention relates to a method of reducing water from the reactor outlet gas in the oxidation process of an aromatic compound, for example, in the preparation of terephthalic acid by oxidation of xylene in an acetic acid solvent. As water is removed from the reactor outlet gas at the first absorption tower, the amount of water inflow to the dehydration tower is reduced and, thus, the amount of steam required to separate water and acetic acid at the dehydration tower is reduced and the load of the dehydration tower can be decreased. Further, by carefully controlling the flow amount of the reactor outlet gas to the first absorption tower, the operation of the dehydration tower may be made unnecessary.

Abstract: The present invention relates to a recovering method of acetic acid using an apparatus comprising a dehydration tower, a condenser and a separation tank. As p-xylene is used as an azeotropic agent to form an azeotrope with water, which is discharged from the top of the dehydration tower, and the remaining p-xylene is discharged from the bottom of the dehydration tower along with acetic acid, the acetic acid containing the p-xylene azeotropic agent can be recycled directly to a reactor for producing terephthalic acid without further separation process and without regard to the content of the p-xylene azeotropic agent which is recovered along with acetic acid.