A process for hydroprocessing a renewable feedstock involves introducing the renewable feedstock and hydrogen in a downward flow into a top portion of a fixed-bed reactor and distributing the downward flow to a top surface of a first catalyst bed in a manner such that the top surface is uniformly wetted across the reactor cross section. The feedstock then flows downwardly through the first catalyst bed, where it is reacted under hydroprocessing conditions sufficient to cause a reaction selected from the group consisting of hydrogenation, hydrodeoxygenation, hydrodenitrogenation, hydrodesulphurization, hydrodemetallization, hydrocracking, hydroisomerization, and combinations thereof. A hydrocarbon liquid separated from the reaction effluent is recycled to the renewable feedstock in a ratio of 0.4:1 to 1.8:1, based on the volume of the renewable feedstock.

The present subject matter relates an apparatus (120) for distributing polyphasic fluid mixture to a catalyst bed in a downflow reactor (100). The apparatus (120) comprises a distributor tray (140) comprising a plurality of distributor units (150). The distributor unit (150) comprises an inner tube (210), an outer tube (220) disposed outside and concentric to the inner tube (210), a cover (346), a cap plate (350), and a gas inlet (358). The inner tube comprises a first aperture (314) to allow liquid to enter the inner tube (210) and a solid insert (326). The solid insert (326) forms a narrow passage (330). The outer tube (220) comprises a slot (338) to allow liquid from the distributor tray (140) to enter an annular portion (342).

A combined reforming apparatus is provided. The combined reforming apparatus includes a body, a first catalyst tube disposed inside the body and reacting at a first temperature to reform hydrocarbons (C.sub.xH.sub.y) having two or more carbon atoms into methane (CH.sub.4), a second catalyst tube disposed inside the body, connected to the first catalyst tube, and reacting at a second temperature higher than the first temperature to reform methane (CH.sub.4) into synthesis gas comprising hydrogen (H.sub.2) and carbon monoxide (CO), and a combustion unit configured to supply heat to the first and second catalyst tubes.

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).

A method of revamping vertical converters having a bolt-on flanged pressure shell extension for housing an internal heat exchanger is performed by replacing an existing pressure shell extension with a larger pressure shell extension for housing a plurality of internal heat exchangers.

A system for separating first reactor effluent product by means of an intermediate separator, and sending the unconverted slurry material from the separator to further reactors. Such intermediate separation decreases the required size of downstream reactors.

An object of the present invention is to provide a method for producing an unsaturated carboxylic ester, wherein the risk of polymerization blockage is reduced and the required equipment cost and workload involved are kept low while maintaining a high conversion rate in an esterification reaction of unsaturated carboxylic acid. This object can be achieved by a method for producing an unsaturated carboxylic ester, which includes performing an esterification reaction using a reactor packed with a solid catalyst, wherein unsaturated carboxylic acid and alcohol are continuously fed to the reactor from an inlet thereof to form a fluid of the reaction solution in the reactor, and the vaporized organic solvent is continuously fed to the reactor from the inlet or a part near the inlet of the reactor.

A process for conducting an exothermic reaction in a vertical tubular reactor comprising; providing a reactor with two or more reaction zones each containing multiple tubes attached to common tube sheets at top and bottom, each zone separated by segmented baffles in the top head and the bottom head.

The present invention relates to a distributor and a down flow catalytic reactor comprising same, and according to one aspect of the present invention, provides a distributor comprising: an inside downcomer which has a first flow space; an outside downcomer which is disposed so as to surround at least some area of the inside downcomer, and has a second flow space partitioned from the first flow space of the inside downcomer; and a cap which has a plurality of slots and is mounted on the inside or the outside downcomer so as to enable a fluid that has passed through the slots to flow to at least one flow space among the first flow space and the second flow space.

This disclosure provides improved processes for converting aromatic hydrocarbons, such as benzene/toluene, alkylation, transalkylation, or isomerization. In an embodiment, a process comprises utilizing a passivated reactor to reduce deactivation of a molecular sieve catalyst. Additional measures such as the use of an auxiliary catalyst and/or an elevated reactor pressure may be used to further reduce deactivation of the molecular sieve catalyst.