RECOVERY AND RECYCLE OF HF-AMINE COMPLEX IN HF ALKYLATION

An HF-amine complex such as HF-pyridine is recovered and recycled from a by- product containing stream [10] in an alkylation process using the complex as the catalyst system by (a) selectively removing a portion of the HF from the by-product stream [10] to produce an HF-depleted stream [22] containing an HF to complexing agent mole ratio of 3 :1 to 5:1, (b) separating the resulting HF-depleted stream [22] into a hydrocarbon phase [2 6] enriched in ASO and an acid phase [28] depleted in ASO and containing a substantial portion of the complex, and (c) recycling the acid phase [28] to the hydrocarbon alkylation step.