Selective removal of non-aromatic hydrocarbons from a xylene isomerization process for para-xylene production is accomplished using a membrane unit positioned within a xylene recovery loop. The membrane unit may include a one-stage or multi-stage (e.g., two-stage) membrane system and may be configured to separate a membrane unit product stream from a non-aromatics rich stream, which can be removed from the xylene recovery loop. The membrane unit may have a xylene permeance of about 60 gm/m2/hr/psi and a xylene to non-aromatic permeance ratio of about 15.

The invention relates to a process for the dehydrogenation of a feedstock comprising ethanol, using at least one multitubular reactor advantageously comprising a plurality of tubes comprising at least one dehydrogenation catalyst, and a calender, said feedstock being introduced into the tubes in gas form, at an inlet temperature of greater than or equal to 240° C., a pressure between 0.1 and 1.0 MPa, and a WWH between 2 and 15 h.sup.−1, wherein a heat-transfer fluid circulates in said calender at a flow rate such that the weight ratio of said heat-transfer fluid relative to said feedstock is greater than or equal to 1.0, and such that said heat-transfer fluid is introduced into said calender in gas form at an inlet temperature of greater than or equal to 260° C. and at an inlet pressure of greater than or equal to 0.10 MPa, and less than or equal to 1.10 MPa, and leaves the calender at least partly in liquid form.

A method for preparing a purified styrene composition with a styrene yield of at least 80%. The method comprises providing a crude composition containing styrene, and subjecting the crude composition to at least one crystallization step. The at least one crystallization step comprises at least one static crystallization stage and at least one dynamic crystallization stage.

The present invention describes a process to separate ethylene products from impurities such as nitrogen, hydrogen, ethane, propane and isobutane without the need for distillation processes.

In a propane dehydrogenation (PDH) process, the purpose of the deethanizer and chilling train systems is to separate the cracked gas into a methane-rich tail gas product, a C2, and a C3 process stream. By the use of staged cooling, process-to-process inter-change against propane feed to the reactor and use of high efficiency heat exchangers and distributed distillation techniques, refrigeration power requirements are reduced and a simple and reliable design is provided by the process described herein.

As part of an integrated oxidative alkane dehydrogenation and hydrogen generation process, carbon dioxide from Pressure Swing Adsorption (PSA) off gas stream of Hydrogen Generation Unit (HGU), and alkane from any known source are sent to oxidative dehydrogenation (ODH) unit for producing high value olefins, such as ethylene, propylene and butenes. Products formed from ODH reactor are separated and the stream comprising of hydrogen, carbon monoxide and methane are recycled to Shift reactor of HGU unit for enhanced production of hydrogen at PSA.

Provided are a method for preparing an oligomer and an apparatus for preparing an oligomer. The method for preparing an oligomer includes performing an oligomerization reaction by feeding a feed stream containing a monomer to a reactor; feeding a first discharge stream of the reactor to a first separation device, and feeding a second discharge stream of the reactor to a second separation device; feeding a lower discharge stream of the second separation device to a third separation device; feeding an upper discharge stream containing the monomer of the third separation device to a monomer dissolution device and dissolving the upper discharge stream in a solvent fed to the monomer dissolution device; and feeding a discharge stream of the monomer dissolution device to the reactor.

A process can treat a gaseous material mixture obtained by catalytic conversion of synthesis gas that contains at least alkenes, possibly alcohols and possibly alkanes, and also possibly nitrogen as inert gas and unconverted components of the synthesis gas, comprising hydrogen, carbon monoxide and/or carbon dioxide. After catalytic conversion of synthesis gas, separation of the product mixture obtained in this reaction into a gas phase and a liquid phase is performed by at least partial absorption of the alkenes, possibly of the alcohols and possibly of the alkanes, in a high boiling point hydrocarbon or hydrocarbon mixture as an absorption medium, separation as the gas phase of the gases not absorbed into the absorption medium, separating an aqueous phase from the organic phase of the absorption medium, preferably by decanting, and desorption of the alkenes, possibly of the alcohols and possibly of the alkanes, from the absorption medium.

The present invention relates to a method for the production of chromoplastid carotenoids that can be isolated from fruits. The procedure of the invention allows to selectively isolate, on the basis of the size (Size Exclusion Chromatography) and in pure form, the carotenoid in the form of regularly shaped and sized aggregates. The process includes the following steps: i) production, in suspension, of homogeneous fragments of the chromoplastidial membranes from the fruits; ii) solution isolation of the membrane components by solubilization with detergents; iii) selective and high-purity isolation of the carotenoid in the form of regular paracrystalline aggregates by a screening technique such as size exclusion chromatography (SEC—Size Exclusion Chromatography).

The invention relates to a formulation for the diluting and dispersing of oily residues for the recovery of crude oil in processes for producing petroleum, comprising surfactant elements, as well as the process for recovering crude oil using a method for diluting and dispersing the oily residues generated in the petroleum production process.