Abstract: A method is disclosed for determining the acid concentration in acid-water-hydrocarbon (acid-soluble oil) solutions using near-infrared spectrophotometry. The use of a multivariate analysis such as Partial Least Squares algorithm enables one to predict simultaneously the concentrations of water and acid-soluble oil in the process acids from the near-infrared spectra. Although the preferred embodiment is directed to sulfuric and hydrofluoric acids used for alkylation, the method is also applicable to processes using other organic or inorganic acids containing hydrogen bound to either carbon, oxygen or nitrogen. Advantages are elimination of acid waste, hazardous acid handling, and better alkylate product quality.

Abstract: Poisoning of a cracking catalyst by contaminant metals such as nickel, vanadium and iron during fluid catalytic cracking of hydrocarbon charge stock containing the contaminant metals is suppressed by depositing minor amounts of a bismuth-containing passivating agent on the catalyst, desirably, a weight ratio of bismuth to nickel equivalents (nickel+0.2 vanadium+0.1 iron) of about 0.01:1 to about 1:1. The passivating agent can also comprise mixtures of compounds of bismuth and antimony, bismuth and tin.