The present disclosure relates to a corrosion resistant duplex stainless steel (ferritic austenitic alloy), which is suitable for use in a plant for the production of urea and uses thereof. The disclosure also relates to objects made of the duplex stainless steel. Furthermore, the present disclosure relates to a method for the production of urea and to a plant for the production of urea having one or more parts made from the duplex stainless steel, and to a method of modifying an existing plant for the production of urea.

The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.5, a stage B of fractionation by distillation in a 2-cut distillation column of the fractions A21 and A22 resulting from stage A, in which said fractions are introduced separately at distinct injection points, and makes it possible to obtain a fraction B2 containing ethylbenzene, ortho-xylene and meta-xylene, and a fraction B42 devoid of aromatic compounds having 8 carbon atoms and containing desorbent.

The present invention describes a process for obtaining para-xylene from a feedstock containing xylenes, ethylbenzene and C9+ hydrocarbons, said process comprising a single stage A of separation in a simulated moving bed carried out with a zeolite as adsorbent and a desorbent and making it possible to obtain at least three fractions, a fraction A1 comprising a mixture of para-xylene and of desorbent and two fractions A21, A22 comprising ethylbenzene (EB), ortho-xylene (OX) and meta-xylene (MX) and desorbent, said stage is carried out at a temperature between 20° C. and 250° C., under a pressure between the bubble pressure of the xylenes at the operating temperature and 2.0 MPa, and with a ratio by volume of the desorbent to the feedstock in the unit for separation 2 in a simulated moving bed is between 0.4 and 2.5, a stage B of fractionation by distillation in a 2-cut distillation column of the fractions A21 and A22 resulting from stage A, in which said fractions are introduced separately at distinct injection points, and makes it possible to obtain a fraction B2 containing ethylbenzene, ortho-xylene and meta-xylene, and a fraction B42 devoid of aromatic compounds having 8 carbon atoms and containing desorbent.

Devices, systems, and methods for forming furan based surfactants by reactive distillation are disclosed herein. Various embodiments can provide a consolidated reaction process that uses reactive distillation to synthesize oleo-furan surfactant molecules and intermediates by combining reaction and separation steps into a single reaction unit or a number of connected reaction units. The single reaction unit or a number of connected reaction units can include a catalyst bed and act to separate reaction side products at opposing ends of the unit or units.

Devices, systems, and methods for forming furan based surfactants by reactive distillation are disclosed herein. Various embodiments can provide a consolidated reaction process that uses reactive distillation to synthesize oleo-furan surfactant molecules and intermediates by combining reaction and separation steps into a single reaction unit or a number of connected reaction units. The single reaction unit or a number of connected reaction units can include a catalyst bed and act to separate reaction side products at opposing ends of the unit or units.

A process and system for the production of at least one xylene isomer is provided. The process includes passing a first stream to one side of a split shell fractionation column and a second stream to the other side of the column. The first stream has a higher ratio of methyl to C2+ alkyl-substituted C9 aromatic compounds than the second stream. A bottoms stream from the one side is separated and passed as feed to a transalkylation zone.

A process and system for the production of at least one xylene isomer is provided. The process includes passing a first stream to one side of a split shell fractionation column and a second stream to the other side of the column. The first stream has a higher ratio of methyl to C2+ alkyl-substituted C9 aromatic compounds than the second stream. A bottoms stream from the one side is separated and passed as feed to a transalkylation zone.

The present application relates to a distillation device, and according to the distillation device of the present application, in first and second compounds being capable of forming an azeotrope, by introducing the second compound having a relatively high boiling point into a supply port located below the first compound having a relatively low boiling point, the first compound can be previously separated from the top of a first distillation column and the content of the first compound in the flow discharged from the bottom of the first distillation column can be minimized, and thus, as a moving route of the first compound is minimized, the second compound can be separated in high purity.

The present application relates to a distillation device, and according to the distillation device of the present application, in first and second compounds being capable of forming an azeotrope, by introducing the second compound having a relatively high boiling point into a supply port located below the first compound having a relatively low boiling point, the first compound can be previously separated from the top of a first distillation column and the content of the first compound in the flow discharged from the bottom of the first distillation column can be minimized, and thus, as a moving route of the first compound is minimized, the second compound can be separated in high purity.

The methods apparatuses described herein involve recovering of glycol from an aqueous phase to form a stream of recovered glycol and a glycol recovery system. The aqueous phase is fed to the top of a lower theoretical stage in a distillation column. An overhead vapor stream is drawn from the distillation column overhead of an upper theoretical stage, and a bottom stream comprising a stream of regenerated glycol is drawn from the distillation column via a bottom outlet configured below the lower theoretical stage. The stream of recovered glycol comprises the regenerated glycol. In addition, a first middle theoretical stage is situated within the distillation column gravitationally above the lower theoretical stage and below the upper theoretical stage. A side stream of liquid water is drawn from the bottom of the upper theoretical stage in the distillation column.