The present invention belongs to the field of petrochemical industry, and discloses a method for selective hydrogenation of butadiene extraction tail gas and a selective hydrogenation apparatus thereof. The method for selective hydrogenation of butadiene extraction tail gas comprises: (1) an alkyne-containing tail gas from a butadiene extraction unit is fed into a raw material tank, optionally impurities entrained in the alkyne-containing tail gas are removed before being fed into the raw material tank; (2) a C4 raw material in the raw material tank is pressurized by a feed pump to a pressure required for reaction, then merged with a circulated C4 stream from a first-stage reactor outlet buffer tank and fed into a first-stage mixer, wherein it is mixed with hydrogen gas, and fed into the first-stage reactor to undergo a first-stage hydrogenation reaction, and a first-stage reaction stream obtained by the reaction is fed into the first-stage reactor outlet buffer tank; the hydrogen gas required for the reaction in the first-stage reactor is fed through a first feeding mode or a second feeding mode: the first feeding mode comprises: all the hydrogen gas required for the reaction is fed through the first-stage reactor outlet buffer tank, and then fed into the first-stage reactor through a first route at an outlet of the first-stage reactor outlet buffer tank; the second feeding mode comprises: a part of the hydrogen gas required for the reaction is fed through the first-stage reactor outlet buffer tank, and then fed into the first-stage reactor through the first route at an outlet of the first-stage reactor outlet buffer tank; and the other part of the hydrogen gas is fed through the first-stage mixer, and then fed into the first-stage reactor; (3) there is no gas-phase discharge from the first-stage reactor outlet buffer tank, and a liquid-phase product is divided into at least two streams, the first stream is returned to the first-stage reactor as the circulated C4 stream, and the second stream is used as a feed to a stabilization tower or subjected to further hydrotreatment prior to being fed into the stabilization tower; (4) a C4 hydrogenation product is recovered after separation in the stabilization tower.

A method for selective hydrogenation of a C2 steam cracking fraction comprising acetylene, in the presence of a catalyst comprising an active phase based on at least one group VIII metal and a support provided in the form of a ceramic or metal monolith, characterized in that said support comprises a number of channels per unit length, CPSI, of between 300 and 1200, and in that the active phase is provided in the form of a layer on the walls of said support, the thickness of said layer of active phase being between 30 m and 150 m.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575 C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

A cascade reactor scheme with acid and hydrocarbon flowing in reverse directions. The systems and processes for alkylation of olefins herein may include providing a first olefin to a first alkylation zone, and a second olefin to a second alkylation zone. Isoparaffin may be provided to the first alkylation zone. The isoparaffin and first olefin may be contacted with a partially spent sulfuric acid in the first alkylation zone to form a spent acid phase and a first hydrocarbon phase including alkylate and unreacted isoparaffin. The first hydrocarbon phase and second olefin may be contacted with a sulfuric acid feed in the second alkylation zone to form a second hydrocarbon phase, also including alkylate and unreacted isoparaffin, and the partially spent sulfuric acid that is fed to the first alkylation zone. Further, the second hydrocarbon phase may be separated, recovering an isoparaffin fraction and an alkylate product fraction.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575 C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

Systems and methods are provided for conveyor operation and maintenance that employ a smart shoe technology where one or more conveyor shoes incorporate features, such as an RFID tag, allowing selective wireless tracking and identification capability. A conveyor system comprises a shoe management system allowing interactions directly with a reader where interface between this application and the reader can be implemented via a socket interface. An open platform communications (OPC) wrapper can be created around the interface so that a Human Machine Interface (HMI) could interact directly with shoe management system

A method of producing olefins by catalytic cracking of hydrocarbons is disclosed. The method may include catalytic cracking hydrocarbons in a feed stream that includes the hydrocarbons and the dry gas diluent. The catalytic cracking may be carried out in a process using a train of fixed bed reactors while one or more other trains of fixed bed reactors are being regenerated or are on standby after being regenerated. When the train of fixed bed reactors being used needs regenerating, it is taken out of service and the one or more other trains of fixed bed reactors put in service to carry out the catalytic cracking process. Dry gas instead of steam may be used to reduce the partial pressure of hydrocarbons.

Crackers for hydrocarbon such as naphtha and C.sub.2-C.sub.4 paraffins contain a radiant section and a convection section. The exhaust gases leaving the radiant section pass through the convection. Generally fouling from the convection section was low relative to fouling (e.g., coke build up) in the radiant section. With improved metallurgy and operating conditions, the time between decokes of the radiant section has increased and now there is a need to reduce fouling from the convection section. This may be achieved by using stainless steel, and particularly high nickel, high chrome stainless steel in the passes in the convection section.

Selective recovery of C2 to C4 hydrocarbons is achieved through the use of a converging-diverging nozzle, or de Laval nozzle. The vapor stream comprising C2 to C4 hydrocarbons is fed into an inlet of a de Laval nozzle having a throat. The vapor stream may have an initial temperature of between 0 C. and 100 C., and an initial pressure of between 200 psig and 500 psig. In the de Laval nozzle, the vapor stream expands after passing through the throat of the de Laval nozzle, producing a vapor stream having reduced temperature and pressure. Then, C2 to C4 hydrocarbons condense from the reduced-temperature vapor stream as liquid droplets, which may be recovered. Fractionation of C2 to C4 hydrocarbons by means of a de Laval nozzle is possible; the technique allows selective recovery of a stream enriched in propene from a mixture of propane and propene.

This invention pertains to a method for purifying an olefinic feedstock that comprises olefins with 4 carbon atoms and impurities including isobutanal, ethanol, and acetone, where said method comprises a pretreatment that comprises a step for eliminating acetone and optionally a step for eliminating the water that is present in said olefinic feedstock, and a step for simultaneously eliminating isobutanal and ethanol by running the feedstock obtained from the pretreatment over at least one fixed bed having at least one adsorbent that comprises at least one porous refractory oxide-based material, optionally impregnated with one or more alkaline or alkaline-earth cations; where said step for simultaneously eliminating isobutanal and ethanol operates at a temperature of between 0 and 200 C., at a pressure of 0.1 to 10 MPa, and with an hourly volumetric flow rate (VVH) of the feedstock on the fixed bed of between 0.1 and 10 h.sup.1.