DEGRADATION AND ISOMERIZATION OF ISOPARAFFINS WHILE IN CONTACT WITH SULFURIC-ACID IN ALKYLATION UNITS - CHEMISTRY AND REACTION-KINETICS

When isoparaffins such as those produced during the alkylation of isob utane with C3-C5 olefins are contacted with H2SO4, both isomerization and degradation reactions occur. The degradation products consist of m ainly C4-C-12 isoparaffins and acid-soluble oils. Experimental runs we re made with the following hydrocarbons: 2,2,4-trimethylpentane, 2,3-d imethylpentane, two commercial alkylates, and mixtures of isobutane an d alkylates. Both alkylate quality and quantity decreased significantl y due primarily to the degradation reactions of both commercial alkyla tes and trimethylpentanes. Correlations were developed to predict the levels of degradation of alkylates by acids of different compositions. Methods to minimize these undesired reactions in commercial alkylatio n units are proposed.