摘要:
A method for measuring local fluid flow rates in a vessel, e.g., a packed bed two-phase flow catalytic reactor, is disclosed which comprises:(a) arranging a plurality of heated thermocouple probes in the vessel at predetermined locations in the path of the fluid flow therethrough;(b) obtaining a first set of temperature readings with the probe heaters off to provide the local reactor temperature;(c) obtaining a second set of temperature readings with the probe heaters on to provide the skin temperature of the heater well;(d) using the difference between readings (b) and (c) to calculate the fluid flow rates.
摘要:
A process for thermally and catalytically upgrading a heavy feed in a single riser reactor FCC unit is disclosed. A heavy feed is added to a blast zone in the base of the riser, and sufficient hot regenerated FCC catalyst is added to induce both thermal and catalytic cracking of the heavy feed. A reactive quench material, which cools the material discharged from the blast zone is added to a quench zone downstream of the blast zone, to reduce temperature at least in part by undergoing endothermic reactions in the riser. Quench liquids can be distillable FCC feeds such as gas oil, slack wax, or alcohols or ethers. The quench material is added in an amount equal to 100 to 1000 wt % of the non-distillable material in the heavy feed. A preferred catalyst, with a high zeolite content, is used which retains activity in the quench despite initial contact with the heavy feed, which tends to overwhelm conventional FCC catalysts.
摘要:
Conversion of benzene to heavier aromatics by contact with alkyl polynucleararomatics, preferably FCC heavy cycle oil, in the presence of an alkylation/transalkylation catalyst is disclosed. Efficient conversion of relatively dilute benzene in reformate is possible. Use of alkyl polynucleararomatics as a source of alkyl groups, with reduced use of monocyclic alkyl aromatics, permits robust reaction conditions to be used without a net formation of benzene by dealkylation. The process preferably uses a solid zeolite based acidic catalyst disposed in a fixed, moving or fluid bed reactor. Preferred catalysts comprise MCM-22 or ZSM-5.
摘要:
The operating performance of a tubular reactor system designed for the exothermic conversion of methanol to light olefins is improved by cofeeding small quantities of light olefins with the methanol feed, whereby a more controllable operation is achieved. Catalyst activity and cycle length also improves significantly. The light olefins can be produced in situ during conversion.
摘要:
A process for reducing the benzene content of a reformate stream in a conventional catalytic cracking reactor wherein a heavy hydrocarbon feed is cracked to lighter products by contact with a supply of hot regenerated cracking catalyst is disclosed. The reformate can be mixed with the heavy feed to the cracking reactor, but preferably reformate contacts hot regenerated cracking catalyst before the heavy feed is added. Benzene content is reduced by alkylation with reactive fragments created in the cracking reactor, or by transalkylation with alkyl aromatics. Benzene removal can be enhanced by adding a light reactive gas such as ethylene to the cracking reactor, by adding heavier aromatics, such as a light cycle oil, or both. The reaction is preferably conducted in an FCC riser reactor, but may be conducted in a moving bed cracking reactor.
摘要:
A catalytic cracking process especially useful for the catalytic cracking of high metals content feeds including resids in which the feed is cracked in the presence of a catalyst additive comprising an alkaline earth metal oxide and an alkaline earth metal spinel, preferably a magnesium aluminate spinel which acts as a trap for vanadium as well as an agent for reducing the content of sulfur oxides in the regenerator flue gas. The additive is used in the form of a separate additive from the cracking catalyst particles in order to keep the vanadium away from the cracking catalyst and so preserve the activity of the catalyst; in addition, use of separate additive particles permits the makeup rate for the additive to be varied relative to that of the cracking catalyst in order to deal with variations in the metals and sulfur content of the cracking feed. The additive may be separated from the cracking catalyst by physical classification so that it can be separately withdrawn from the unit for better control of the catalyst/additive ratio. The additive may be injected into the unit separate from the cracking catalyst so that it contacts the feed first to effect a preliminary demetallation.
摘要:
An improved process and apparatus are disclosed for fluidized bed catalyst regeneration in a cross-flow type regenerator. A baffled coked catalyst inlet located within the dense bed of catalyst disperses and distributes coked catalyst flow in a direction generally normal to the direction of flow in the catalyst inlet. The baffle significantly reduces the stagnant regions in the bed.
摘要:
Catalyst stripping in the fluid catalytic cracking process is improved by cooling the spent catalyst to quench catalytic condensation reactions, then stripping the cooled catalyst in a primary stripper, followed by heating and a stage of hot stripping. Quenched stripping reduces coke make by reducing conversion of light olefins, made during the FCC process, into coke.
摘要:
Operational flexibility of a fluid catalytic cracking process is improved by indirectly cooling catalyst in an endothermic catalyst cooler. Catalyst withdrawn from the FCC unit is cooled by driving an endothermic chemical reaction, which may be either thermal or catalytic. Dehydrogenation of, e.g., light aliphatics, produced by the cracking reactor in the endothermic cooler allows the FCC unit to adapt to heavier feeds. A preferred endothermic cooler, comprising a base heat exchanger section, transport riser, and solids collection and recycle vessel is disclosed.
摘要:
An process and apparatus are disclosed for fluidized bed catalyst regeneration in a cross-flow type regenerator. A baffled coked catalyst inlet located within the dense bed of catalyst disperses and distributes coked catalyst flow in a direction generally normal to the direction of flow in the catalyst inlet. The baffle significantly reduces the stagnant regions in the bed.