Alkylation of 3-Methylthiophene with 2-Methyl-2-butene over a Zeolitic Catalyst

Abstract

Sulfur removal remains a challenging task for refiners. To attain high desulfurization levels for gasoline, new processes were recently patented. One of them proposed to separate sulfur compounds by distillation after being weighed down by alkylation with olefins present in the feed. In this study, the transformation mechanism of the alkylation of 3-methylthiophene with 2-methyl-2-butene was studied in a batch reactor over zeolitic catalysts at 358 K. The first step of this study was devoted to the hydrodynamic of the reactor, to ensure that the reaction proceeds under chemical control. A detailed mechanistic study, including competitive catalytic experiments, then is reported.

The performance of benzenesulfonic acid catalyst on the alkylation of thiophenic sulfur

“…Especially the temperature rise from 90 to 95°C, the conversion of diene was improved from 29 to 44 %. Because the polymerization of the diene is an endothermic reaction [15] and the reaction rate of the polymerization can be improved by an increase of reaction temperature. By comparison with results of Ke et al, the conversion of diene was from 62 to 96 % over a series of compound systems of Brunsted acidic ionic liquid with sulfuric acid under 30°C and the conversion of diene was only 20 % over benzenesulfonic acid under 85°C.…”

Alkylation of Thiophenic Compounds with Olefins and its Kinetics over MCM-41 Supported Phosphoric Acid in FCC Gasoline

“…[10][11][12][13], supported phosphoric acids [14,15], and supported heterogeneous acids [16,17]. However, most of the studies were carried out in a simulated gasoline system and the catalytic performances in real gasoline were not investigated.…”

“…Previous work generated some controversies regarding the intrinsic kinetics studies for the alkylation mechanism of 3MT and 2-methyl-2-butene (2M2B) over a USY zeolite [10] and SPA [15]. The alkylation of 3MT with 2M2B followed a Langmuir-Hinselwood (LH) model over the USY zeolite, but an Eley-Rideal (ER) model over the SPA.…”

“…4, the corresponding content of olefins and aromatics decreased perceptibly with increasing temperature, especially the concentrations of higher carbon (C 6 , C 7 ) olefins and aromatics. Because the oligomerization of olefins was endothermic, it happened easily at higher temperature [10]. Previous studies [12,21] had proved that the increase of temperature was profitable to the aromatics alkylation.…”

Transformation of thiophenic compounds over acidic zeolites

“…Thus, these compounds could be eliminated by distillation and concentrated in the heavier fractions of the gasoline streams. British Petroleum developed this process under the name olefinic alkylation of thiophenic compounds (OATS 1 ) [12] and fundamental studies on the subject were reported recently [13]. In this context, disproportionation and transalkylation reactions, which are both acid catalyzed reactions, are also of interest since they can lead to the increase of the molecular weight of part of the sulfur compounds without consumption of olefins.…”