Alkylation Unit Monitoring

Alkylation reactions occur in the liquid phase under controlled conditions, using hydrofluoric acid (HF) or sulfuric acid (H₂SO₄) as a catalyst. Maintaining a low temperature—typically around 70°F for H₂SO₄ and 100°F for HF—is critical for selective reactions and achieving optimal product quality. High pressures are applied to keep the hydrocarbons and acid in liquid form, while a high isobutane-to-olefin ratio ensures maximum conversion efficiency.

The reaction mixture flows through a series of steps:

1. Reaction Phase: The hydrocarbons react in the presence of the acid catalyst under controlled temperature and pressure.
2. Acid Recovery: The acid is separated in an acid settler, recovered, and reused in the reactor.
3. Fractionation: The reaction products are fractionated to separate gaseous LPG, propane, and n-butane, with alkylate as the primary product.

Careful control of operating variables, including acid strength, reaction temperature, and mixing efficiency, is essential for high selectivity and conversion rates. The exothermic nature of alkylation reactions also necessitates precise temperature management to avoid runaway reactions and ensure product consistency.