Liquid-Phase Etherification/Dimerization of Isobutene over Sulfonic Acid Resins

Abstract

Simultaneous isobutene etherification/dimerization reactions have been studied in the liquid phase using macroporous sulfonic acid resins. It has been found that, in the presence of methanol, oligomerization to species heavier than dimers may be greatly reduced with respect to data reported in the literature for isobutene dimerization. Products of the described synthesis are MTBE and a mixture of branched C 8 hydrocarbons having excellent properties for gasoline blending. These two products may be obtained in a wide range of relative ratios. The influence of methanol (i.e., methanol/isobutene molar ratio), feedstock type, and reactor design on product composition and byproducts formation is discussed.

Palladium Supported on an Acidic Resin: A Unique Bifunctional Catalyst for the Continuous Catalytic Hydrogenation of Organic Compounds in Supercritical Carbon Dioxide

“…Addition of 0.5% Pt to 0.5% Pd/Amberlyst-15 caused a negative effect (entry 3 vs. 7). The by-products formed over the metal-loaded Amberlyst 15 were the dimerization product 3, which was formed by the action of Brçnsted acid sites on Amberlyst 15, [8] and its hydrogenated product, bicyclohexyl 4.…”

About the Acidity-Catalytic Activity Relationship in Ionic Liquids: Application to the Selective Isobutene Dimerization

“…As catalytic acidic reaction, we have chosen to examine the dimerization of isobutene. From an industrial point of view, this reaction is of interest to produce isooctenes that can further be hydrogenated into isooctanes, an ideal octane booster additives for the reformulated gasoline pool [20,21] as well as a possible alternative for MTBE [22]. From a scientific point of view, the challenge is then to fine tune the acidity level of the catalyst to optimize the isooctenes selectivity while maintaining good isobutene conversion.…”

Effect of Butadiene in Catalytic Trimerization of Isobutene Using Commercial C4Feeds

“…It has been reported that codimerization reactions between isobutene and n-butenes are slower than isobutene dimerization 10 in the etherification/dimerization of isobutene. Even though the codimerization is slow reaction, the codimers are obtained noticeably probably because of low activity of codimers for trimerization or high concentration of n-butenes suitable for codimerization.…”

“…Despite the importance of the utilization of isobutene, the trimerization has not received so much attention so far in comparison with the dimerization of olefins. [5][6][7][8][9][10] Several solid acid catalysts such as sulfated titania, 1,11,12 cation exchange resins (CERs), 2,13 heteropoly acid, 14 zirconia 15 and zeolites 16,17 have been suggested for the trimerization. Recently, we have reported the isobutene trimerization over solid acid catalysts such as zeolites beta (BEA) 16 and ferrierite (FER) 17 and cationexchange resins (Amberlyst-35 and Amberlyst-15).…”