A device configured to be interposed between a lower layer and an upper layer of particles arranged inside a cylindrical shell, thereby limiting or preventing the migration of particles between the layers.

Known catalyst systems for the catalytic combustion of ammonia to form nitrogen oxides consist of a plurality of single- or multilayer catalyst gauzes warp-knitted, weft-knitted or woven from platinum-based noble metal wire, which, when arranged one behind the other in a fresh gas flow direction, form a front group of gauze layers and at least one downstream group of gauze layers arranged after the front group. To provide from this starting point a catalyst system for use in a medium-pressure plant for ammonia oxidation, with which a high service life and a high yield of the main product NO can be achieved, it is proposed that the front group comprises a gauze layer or a plurality of gauze layers made of a first, rhodium-rich noble metal wire, wherein the gauze layer or one of the gauze layers made of the rhodium-rich noble metal wire is a front gauze layer facing the fresh gas, and that the downstream group comprises gauze layers made of a second, rhodium-poor noble metal wire, wherein the rhodium content in the rhodium-rich noble metal wire is at least 7 wt. % and no more than 9 wt. % and is at least 1 percentage point higher than the rhodium content in the rhodium-poor noble metal wire

An upflow reactor (1), comprising a housing (20), a catalyst bed layer (30) and a pressing device (10). The housing (20) is internally provided with a reaction chamber (210), a reaction material inlet (220) and a reaction material outlet (230) which are in communication with the reaction chamber (210) are provided on the housing (20); the catalyst bed layer (30) is provided within the reaction chamber (210), the pressing device (10) is provided within the reaction chamber (210) and located above the catalyst bed layer (30), and at least a part of the pressing device (10) is provided to be movable up and down, so that the at least a part of the pressing device (10) can be pressed against the catalyst bed layer (30).

An aspect of the present disclosure relates to a process for preparing a composite hydroalkylation catalyst including: (a) effecting impregnation of a hydrogenation metal on an inorganic oxide to form a metal impregnated inorganic oxide; (b) effecting calcination of the metal impregnated inorganic oxide to obtain a calcined metal impregnated inorganic oxide; (c) preparing a composite mixture comprising a molecular sieve, the calcined metal impregnated inorganic oxide and a binder; (d) preparing an extruded catalyst; and (e) effecting calcination of the extruded catalyst to obtain the composite hydroalkylation catalyst. The composite hydroalkylation catalyst prepared using this process affords dramatic improvement in conversion of mononuclear aromatic hydrocarbon and the yield of the hydroalkyled mononuclear aromatic hydrocarbon (e.g. CHB).

Process vessels can contain one or more entry zones containing stability-improving materials. The entry zones address bed movement and filtration problems. The stability-improving material can be positioned above a treating zone or above a processing bed within the vessel. Entry Zones are intended to improve the stability of downstream operations.

A multi-phase combination reaction system has at least one fixed bed hydrogenation reactor. The fixed bed hydrogenation reactor has, arranged from top to bottom, a first hydrogenation reaction area, a gas-liquid separation area, a second hydrogenation reaction area and a third hydrogenation reaction area. The gas-liquid separation area is provided with a raw oil inlet. A hydrogen inlet is provided between the second hydrogenation reaction area and the third hydrogenation reaction area. The system is capable of simultaneously obtaining two fractions in one hydrogenation reactor.

A catalyst bed contains one or more segments of monolithic catalyst, wherein the monolithic catalyst includes a mono-lithic honeycomb structure and a layer of catalyst coating the honeycomb structure; the honeycomb structure contains a plurality of channels aligned side by side; and each channel includes an inlet positioned at a first terminus of the channel, an outlet positioned at a second terminus of the channel, and openings positioned along the channel in the direction of fluid flow through the channel for transverse fluid flow in and/or out of the channel.

A method for facilitating the distribution of the flow of one or more streams within a bed vessel is provided. Disposed within the bed vessel are internal materials and structures including multiple operating zones. One type of operating zone can be a processing zone composed of one or more beds of solid processing material. Another type of operating zone can be a treating zone. Treating zones can facilitate the distribution of the one or more streams fed to processing zones. The distribution can facilitate contact between the feed streams and the processing materials contained in the processing zones.

The present invention relates to a process for producing 2,3,3,3-tetrafluoropropene, comprising the steps: i) providing a stream A comprising at least one starting compound selected from the group consisting of 2-chloro-3,3,3-trifluoropropene and 2,3-dichloro-1,1,1-trifluoropropane; and ii) in an adiabatic reactor comprising a fixed bed composed of an inlet and an outlet, bringing said stream A into contact, in the presence or absence of a catalyst, with HF in order to produce a stream B comprising 2,3,3,3-tetrafluoropropene, characterized in that the temperature at the inlet of the fixed bed of said adiabatic reactor is between 300° C. and 400° C. and the longitudinal temperature difference between the inlet of the fixed bed and the outlet of the fixed bed of said reactor is less than 20° C.

Incorporating into a fixed bed reactor for an exothermal reaction having a catalyst supported on a support having a thermal conductivity typically less than 30 W/mk within the reaction temperature control limits heat dissipative particles having a thermal conductivity of at least 50 W/mk less than 30 W/mk within the reaction temperature control limits helps control the temperature of the reactor bed.