Provided is a method of separating and refining 1-butene with a high purity and a high yield from a raffinate-2 stream, and recovering the refined 1-butene while maximizing an energy saving rate by using a high efficiency distillation column installed with a separation wall.

A dividing wall column or a pair of conventional columns can be used to separate an unstabilized naphtha stream to produce an aromatics-free light naphtha stream as a feed for a catalytic cracking unit for olefins production.

A dividing wall column is used in an alkylation process flow scheme to fractionate an alkylate reactor effluent to produce an iso-butane-rich stream as a recycle feed for the alkylation reactor while also separating iso-butane, normal butane and alkylate as separate product streams depending on the reactor effluent composition. In an optional embodiment, the scheme may contain propane.

A process for preparing an aromatic polyamine mixture including 4,4′-methylenedi(phenylamine) and higher homologues of MDA is provided. The process includes steps of (i) reaction of aniline with formaldehyde by means of an acid catalyst to form a crude product mixture (I), (ii) neutralization of the crude product mixture (I) and removal of the salts formed; (iii) isolation of aniline; (iv) distillation of the resulting crude product mixture so as to separate off (iv-1) a mixture (II) of MDA isomers (II-1) containing from 8 to 20% by weight of 4,4′-methylenedi(phenylamine) and not more than 0.3% by weight of secondary components (II-2) and (iv-2) a low boiler mixture of at least 55% by weight of secondary components (II-2) and MDA isomers (II-1); and (v) recirculation of the mixture (II).

A process including (a) directing a hydrocarbon mixture to contact a material catalytically active in hydrocracking under hydrocracking conditions, (b) providing a first hydrocracked product, (c) directing an amount of the first hydrocracked product and an amount of a converted hydrocracked product to a product separation step separating it into one or more products and a recycle oil having a higher boiling point than the products, (d) directing the recycle oil to contact a second material catalytically active in hydrocracking under hydrocracking conditions providing a second hydrocracked product, (e) directing at least an amount of the second hydrocracked product as feed to a second separation step, separating the second hydrocracked product in at least two fractions, a converted hydrocracked product and an unconverted oil an unconverted oil having a higher average boiling point than the recycle oil, (f) withdrawing at least an amount of the unconverted oil as purge.

The present invention relates to a toluene diisocyanate purification method enabling acquisition of a product having a small amount of dimers in a final product by means of using a reactive dividing wall column during toluene diisocyanate preparation. More particularly, according to the present invention, in order to obtain a product having a small amount of dimers in accordance with a reversible reaction of a monomer and a dimer, a purification procedure is designed by means of applying the temperature, pressure, time of stay and the like of a reactive dividing wall column as appropriate particular conditions, a reboiler having short time of stay and high heat transfer rate is used, and thus a dimerization reaction is inhibited and the purity and yield of the product are enhanced. Therefore, high-purity toluene diisocyanate can be purified and obtained.

The invention relates to a method (100, 200) of obtaining one or more olefins, in which, using an oxidative coupling of methane (10), a gas mixture comprising hydrogen, methane, carbon monoxide and higher-boiling hydrocarbons than methane is formed and is subjected to a low-temperature separation (1-5), characterized in that the low-temperature separation (1-5) is conducted using a rectification column (2) having a first separation region (21), a second separation region (22) arranged above the first separation region (21), and a condenser-evaporator (23), wherein the gas mixture is cooled, fed at least partly as first separation feed into the first separation region (21) and subjected to a first rectification in the first separation region (21) to form a first tops gas and a first bottoms liquid, wherein, using a first proportion of the first tops gas in the condenser-evaporator (23), a condensate which is recycled to the first separation region and, using a second proportion of the tops gas, a second separation feed which is fed into the second separation region (22) are formed, and wherein the second separation feed is subjected to a second rectification in the second separation region to form a second tops gas and a second bottoms liquid.

The present invention relates to a process for producing high-purity para-xylene, comprising a single step of separation by adsorption in an SMB, with a subsequent step of separation by distillation in a first three-fraction distillation column producing at least two raffinates and optionally of two isomerization steps, making it possible to improve the overall para-xylene yield of the aromatic loop and to minimize the economic impact.

Systems and methods are provided for separating a feedstock into a plurality of separation products using dividing wall column technology that includes a plurality of dividing walls. Including a plurality of dividing walls in the column can provide reduced energy consumption and reduced equipment footprint for production of a plurality of high purity distillation products. The systems and methods can allow for separation of a large number of products from a feed while having a reduced or minimized number of liquid splits and/or vapor splits.

An annular divided wall column for the cryogenic rectification of air or constituents of air is provided. The annular divided wall column includes a first annular column wall and a second annular column wall disposed within the first annular column wall to define an annulus column region and an interior core column region. The present annular divided wall column further includes structured packing elements disposed within at least the annulus column region as well as a ring-shaped cantilevered collector; and a ring-shaped distributor disposed in the annulus column region above or below the plurality of structured packing elements. The thermal expansion and contraction of the second annular column wall in a radial direction and in an axial direction is independent of the thermal expansion and contraction of the first annular column wall in the radial and axial directions.