Process for isolating pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate from the corresponding crude alkyl acrylate by distillation, wherein the process is carried out in a dividing wall column (1) which has separation-active internals and vaporizer (7) and in which a dividing wall (8) is arranged in the longitudinal direction of the column to form an upper joint column region (9), a lower joint column region (14), an inflow section (10, 12) having a side feed point (2) and an offtake section (11, 13) having a side offtake point (3), the column has a number of theoretical plates in the range from 10 to 60, where the number of theoretical plates of the dividing wall column (1) relates to the sum of the theoretical plates in the joint upper column region (9), the joint lower column region (14) and the inflow section (10, 12), the side feed point (2) for the corresponding crude alkyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate, the side offtake point (3) for the pure 2-ethylhexyl acrylate or pure 2-propylheptyl acrylate is arranged at a theoretical plate in the region commencing at least two theoretical plates above the bottommost theoretical plate and ending at least two theoretical plates below the uppermost theoretical plate and the dividing wall (8) is arranged in the column in the region commencing at least one theoretical plate above the bottommost theoretical plate and ending at least one theoretical plate below the uppermost theoretical plate, where the ratio of amount of liquid at the upper end of the dividing wall (8) going to the enrichment section (10) and the stripping section (11) of the column is set in the range from 1:0.2 to 1:5.

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.

A process directed to acetic acid production comprising providing a feed stream comprising methyl iodide, water, acetic acid, methyl acetate, and at least one PRC to a distillation column comprising a distillation zone and a bottom sump zone and distilling the feed stream at a pressure and a temperature sufficient to produce an overhead stream comprising methyl iodide and at least one PRC, and a residuum stream flowing from the bottom sump zone comprising water and greater than or equal to about 0.11 weight percent HI is disclosed herein.

The present invention relates to a method for treating a pyrolysis gasoline C5.sup.+ containing monoolefinic, diolefinic and sulfur hydrocarbons, comprising at least, and in any order: a) a step of hydrotreating the pyrolysis gasoline or a hydrocarbon fraction C6.sup.+ originating from the pyrolysis gasoline, in the presence of hydrogen and at least one hydrotreatment catalyst at a temperature ranging between 220 and 380 C. so as to produce a hydrotreated effluent; b) a step of separating the pyrolysis gasoline or the hydrotreated effluent originating from step a) when said step is completed before step b), into a separation column for separating into a top hydrocarbon fraction C5.sup. and a bottom hydrocarbon fraction C6.sup.+, said separation column comprising a reboiling section including two heat exchangers, at least one of the two exchangers being configured to perform a heat exchange with a portion of the bottom fraction that is recycled in the column via the reboiling section. According to the invention, one of the two heat exchangers of the reboiling section is supplied with at least one portion of the hydrotreated effluent so as to supply part of the heat required to operate the reboiling section.

Systems and methods for producing a colorless triethanolamine product stream with a degree of purity of greater than or equal to 99% by weight from the triethanolamine distillation columns in a non-reactive distillation process. The desired triethanolamine product stream can be obtained by increasing the bottom stream flow rate at the diethanolamine column by 80 kilograms per hour, and reducing the triethanolamine product stream flow rate by 500 kilograms per hour. This process can result in a reduction of the temperature at the triethanolamine column by up to 23.5 degrees. The reduced temperature can result in a triethanolamine product stream with an APHA color of 0 to less than 50, for example, 0 to 40, for example, 0 to 30, for example 0 to 20, and for example, 0 to 10.

A CO.sub.2 recovery device includes: a CO.sub.2 absorption tower in which CO.sub.2 included in an exhaust gas is absorbed by a CO.sub.2 absorption liquid; and a CO.sub.2 absorption liquid regeneration tower that heats and regenerates the CO.sub.2 absorption liquid that has absorbed CO.sub.2. The CO.sub.2 absorption liquid regeneration tower includes: a main body part in which the CO.sub.2 absorption liquid is temporarily stored; a boot part provided downward from a tank end of the main body part, having a relatively smaller capacity than the main body part; a flowmeter provided to the boot part, and measuring the liquid surface level of the CO.sub.2 absorption liquid that changes between the main body part and the boot part; and a control device controlling the liquid surface level of the CO.sub.2 absorption liquid between the main body part and the boot part on the basis of the measurement result of the flowmeter.

A CO.sub.2 recovery device includes: a CO.sub.2 absorption tower in which CO.sub.2 included in an exhaust gas is absorbed by a CO.sub.2 absorption liquid; and a CO.sub.2 absorption liquid regeneration tower that heats and regenerates the CO.sub.2 absorption liquid that has absorbed CO.sub.2. The CO.sub.2 absorption liquid regeneration tower includes: a main body part in which the CO.sub.2 absorption liquid is temporarily stored; a boot part provided downward from a tank end of the main body part, having a relatively smaller capacity than the main body part; a flowmeter provided to the boot part, and measuring the liquid surface level of the CO.sub.2 absorption liquid that changes between the main body part and the boot part; and a control device controlling the liquid surface level of the CO.sub.2 absorption liquid between the main body part and the boot part on the basis of the measurement result of the flowmeter.

A distillation system operating below minimum flow. The distillation column is configured for separating a mixed feed into one or more fractional mixtures, producing an overhead product and a bottom product. A bottom return line is provided for returning at least a portion of the bottom product to supplement the mixed feed to the distillation column. A control valve is configured for controlling a flow rate in the bottom return line. A feed surge drum is configured for receiving a feed from the bottom return line and fresh feed, producing the mixed feed.

Processes and apparatuses for producing para-xylenes are provided. The processes comprises providing a reformate stream comprising aromatic hydrocarbons to a reformate splitter to provide a reformate bottoms stream and a reformate overhead stream. A portion of the reformate bottoms stream is passed to a para-xylene separation unit for separating para-xylene, wherein the portion of the reformate bottoms stream is passed to the para-xyelene separation unit without an intermediate step for removal of olefins.

A CO.sub.2 recovery device includes: a CO.sub.2 absorption tower in which CO.sub.2 included in an exhaust gas is absorbed by a CO.sub.2 absorption liquid; and a CO.sub.2 absorption liquid regeneration tower that heats and regenerates the CO.sub.2 absorption liquid that has absorbed CO.sub.2. The CO.sub.2 absorption liquid regeneration tower includes: a main body part in which the CO.sub.2 absorption liquid is temporarily stored; a boot part provided downward from a tank end of the main body part, having a relatively smaller capacity than the main body part; a flowmeter provided to the boot part, and measuring the liquid surface level of the CO.sub.2 absorption liquid that changes between the main body part and the boot part; and a control device controlling the liquid surface level of the CO.sub.2 absorption liquid between the main body part and the boot part on the basis of the measurement result of the flowmeter.