Catalytic alkylation process

摘要

A continuous process for alkylating an alkylatable hydrocarbon in the presence of a acid-type catalyst. The reaction product is separated in a first separation zone into an alkylate product phase, located in the upper portion and a catalyst phase located in the lower portion. The catalyst phase is separated into a first portion and second portion, the first portion is cooled and recycled for use in the alkylation reaction zone, and the second portion is passed into a second separation zone, wherein the second portion catalyst phase is further separated into a hot rerun catalyst stream and an acid soluble oil stream. The rerun catalyst stream is passed into the alkylate product phase of the first separation zone. In order to prevent excessive pressure in the first separation zone as a result of the hot rerun catalyst stream, two liquid hydrocarbon drawoffs from the first separation zone are employed. The hotter upper drawoff of the first separation zone is charged as feed to a depropanizer and stripper zone and the cooler lower drawoff of the first separation zone is charged as reflux feed to an isostripper zone. The pressure in the upper portion of the first separation zone is determined. As the determined pressure increases, the flow rate of the cooler lower drawoff is decreased and the flow rate of the hotter upper drawoff is increased such that an increased amount of hot hydrocarbon is shifted to the isostripper zone so as to lower the heat in the first separation zone.