Effluent refrigeration

Two licensors now offer sulfuric acid alkylation units. The one with the higher market share is Stratco, with its Effluent Refrigerated Sulfuric Acid Alkylation... 

Graves, D.C. (2004) STRATCO Effluent refrigerated H2S04 alkylation process, in Handbook of Petroleum Refining... 

Important aviation and motor alkylate gasoline processes are the jet-type sulfuric acid process, the Kellogg sulfuric acid autoref rigeration process, the UOP hydrofluoric acid process, and the Stratford effluent refrigeration process. Petrochemical alkylation includes various processes using as catalysts solid phosphoric acid, aluminum chloride, hydrofluoric acid, boron trifluoride, and phenol and ether complexes of boron trifluoride (1). 

Figure 1. Stratco effluent-refrigeration alkylation unit...

Many alkylation units use auto refrigeration to cool their reactors. Effluent refrigeration commonly used on Stratco units also falls within this classification. To maximize isobutane purity in the refrigerant recycle stream, circulating refrigerant is depropanized. 

Figure 6.10.7 shows the flow-sheet of an effluent refrigeration alkylation unit. After passing the reaction zone, the emulsion is sent to a settler for phase separation. The acid is then recirculated and the pressure of the hydrocarbon phase is lowered to flash vaporize a portion of the stream and reduce the liquid temperature to about... 

Figure 6.10.6 Schematic view of the reactor applied in the Effluent Refrigerator Process (HC = hydrocarbon). Adapted from DuPont, 2010.

Figure 6.10.7 Flow sheet of an alkylation unit using the effluent refrigeration technique.

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