Alkylation of isobutane with C4 olefins. 2. Production and characterization of conjunct polymers

Abstract

Conjunct polymers, which are byproducts formed during the alkylation of isobutane with C3-C5 olefins, dilute the acid catalyst used so that it eventually loses effectiveness. For alkylations involving both n-butenes and sulfuric acid, decomposition of sec-butyl sulfates produces conjunct polymers, liquid hydrocarbons rich in heavy isoparaffins and olefins, sulfur dioxide, and water. During alkylation the polymers are present as conjunct polymer sulfates that contain sulfone, sulfonic acid, or sulfonic acid ester groups. NMR and IR spectroscopies were used to elucidate the structure of the conjunct

Liquid-Phase Isobutane/Butene-Alkylation Using Promoted Lewis-Acidic IL-Catalysts

“…-synthesis. Another reason for the unwanted shift of the product composition towards C 10? can be found in the high reactivity of isobutene, which is produced during deactivation of the catalysts and which is very prone to polymerization [1,38].…”

Ionic liquid-catalyzed alkylation of isobutane with 2-butene

“…13. For a fair comparison, the reaction with sulfuric acid was performed under optimum conditions, delineated in the literature [1,[34][35][36] such as sulfuric acid of 95% purity and at 18 • C. At temperatures above (25 • C), oligomerization of olefin becomes significant and the activity decreases with temperature. It can be seen that both catalysts showed comparable catalytic behavior under optimum reaction conditions.…”

“…These materials have been described to have empirical compositions of about (C 1.0 H 1.75 ) n , where n averages from about 10 to 30 [34]. These highly unsaturated cyclic hydrocarbons relatively rapidly deactivate the acid catalyst [35].…”

Alkylation of isobutane and butene using chloroaluminate imidazolium ionic liquid as catalyst: Effect of organosulfur compound additive

“…Therefore, it is conclusive that low temperatures are favorable for the alkylation of isobutane/2-butene catalyzed by the BMIC-2AlCl 3 /thioalcohol ionic liquid. This characteristic is similar to the alkylation catalyzed by sulfuric acid [31,32] or aluminium chloride [24].…”