An apparatus for separating a feed stream into product streams. The apparatus includes an upper section, a middle section, and a lower section. The middle section has a dividing wall separating it into two portions. A liquid barrier blocks the flow of liquid from the upper section into the middle section and allows vapor to flow from the middle section to the upper section. A vapor and liquid barrier blocks both the flow of both vapor from the lower section to the middle section and the flow of liquid from the middle section to the lower section. Vapor conduits allow vapor to flow from the lower section to each of the middle portions in varying amounts. Also processes for separating a feed stream.

An apparatus and process doubles the number of trays in a single fractionation column. A dividing wall is used to isolate a first side from a second side and fractionation on trays on each side is independent of the other. A transition vapor stream is ducted from a top of a first side to the bottom of the second side, and a transition liquid stream is ducted from a bottom of the second side to the top of the first side.

The method for industrially producing a cyclic alkylene carbonate comprises: a first distillation and separation step of continuously introducing a crude cyclic alkylene carbonate into a low-boiling separation column A, and continuously withdrawing a column top component (At) through the column top and a column bottom component (Ab) containing a cyclic alkylene carbonate through the column bottom in the low-boiling separation column A; and a second distillation and separation step of continuously introducing the column bottom component (Ab) obtained in the first step into a cyclic alkylene carbonate purification column B having a side outlet, and continuously withdrawing three components of a column top component (Bt) through the column top, a side cut component (Bs) through the side outlet, and a column bottom component (Bb) through the column bottom in the purification column B, wherein the side cut component (Bs) is a cyclic alkylene carbonate with electronic grade specifications.

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.

A method for purifying acrylonitrile involving a purification step of distilling an acrylonitrile solution containing acrylonitrile, hydrogen cyanide, and water, wherein the purification step involves a first step of separating a side stream withdrawn from a first position of a distillation column into an organic layer and an aqueous layer, and then returning the organic layer to a second position of the distillation column, the second position being positioned below the first position and a second step of supplying water from a third position of the distillation column, the third position being positioned below the second position and above a lowermost stage of the distillation column is a novel method in which stabilization of product quality and reduction in load on the acrylonitrile production process can be achieved by stabilizing a hydrocyanic acid-removing dehydration column in the process for producing acrylonitrile.

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.

A method for purifying acrylonitrile involving a purification step of distilling an acrylonitrile solution containing acrylonitrile, hydrogen cyanide, and water, wherein the purification step involves a first step of separating a side stream withdrawn from a first position of a distillation column into an organic layer and an aqueous layer, and then returning the organic layer to a second position of the distillation column, the second position being positioned below the first position and a second step of supplying water from a third position of the distillation column, the third position being positioned below the second position and above a lowermost stage of the distillation column is a novel method in which stabilization of product quality and reduction in load on the acrylonitrile production process can be achieved by stabilizing a hydrocyanic acid-removing dehydration column in the process for producing acrylonitrile.

An apparatus is disclosed for maintaining constant fluid pressure and equalized fluid flow among a plurality of downcomer lines through which liquid from a tower is directed. A substantially annular fluid distribution belt is disposed at the circumference of the tower. The fluid distribution belt collects liquid from the tower. At least two outlets direct liquid from the fluid distribution belt out of the tower and into a corresponding number of downcomer lines disposed external to the tower.

By using the distillation device of the present application, energy loss occurring in a purification process of a solution including a waste stripper and a stripped photoresist resin used in a stripping process of a photoresist can be minimized and the installation cost of the distillation device can be reduced compared to the case in which dual distillation columns are used, thereby increasing the economic feasibility of a process.

The present disclosure includes a column (1) having a cylindrical, vertical column body (2) forming a column cavity (3), and a mass transfer tray (4) disposed in the column cavity (3) and forming a collecting area (5). The column (1) is characterized by a circulation device (9) having at least one drain orifice (10) formed in the column body (2) above the collecting area (5), a circulation line (11) in fluid connection with the drain orifice (10) and at least one recycling orifice (14; 14-1 to 14-3) which is in fluid connection with the circulation line (11) and is formed in the column body (2) above the collecting area (5). Also disclosed herein is a thermal separating process in which a gas ascends within a column (1) of the present disclosure, and a liquid descends within the column (1), said gas and/or liquid containing (meth)acrylic monomers.