Alkylation of Isobutane with Butylenes on Catalysts with Various NaX Zeolites in the CaLaHX Form
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NIC SYNTHESIS AND INDUSTRIAL ORGANIC CHEMISTRY
Alkylation of Isobutane with Butylenes on Catalysts with Various NaX Zeolites in the CaLaHХ Form I. M. Gerzelieva,*, V. A. Temnikovaa, M. N. Baskhanovaa, and A. L. Maksimova a Topchiev
Institute of Petrochemical Synthesis, Russian Academy of Sciences, Leninskii pr. 29, Moscow, 119991 Russia *e-mail: [email protected] Received June 16, 2020; revised August 28, 2020; accepted September 4, 2020
Abstract—Various zeolites for preparing an active heterogeneous catalyst for the commercial alkylate production process were studied. NaX zeolites produced by Russian catalyst plants (powdered, granulated without binders, and formed with binders) were used in the experiments. The zeolites were converted to the active form by successive ion exchange with aqueous solutions of calcium, lanthanum, and ammonium salts at 140°С in a rotating autoclave. Isobutane alkylation with butylenes was performed on a flow-through laboratory installation in a fixed-catalyst-bed reactor. Comparative analysis of the physicochemical (crystal structure, acidity, mechanical strength) and catalytic (conversion of butylenes, alkylate yield, selectivity) properties of the synthesized catalysts in the CaLaHX form was performed. With respect to the set of the properties, the sample based on the NaXch catalyst and formed with a binder (clay) is the best catalyst. It exhibits good strength, high acidity, and high activity (conversion of butylenes 100 wt % , alkylate yields based on butylenes in the feed 99 wt % , selectivity with respect to trimethylpentanes 77.1 wt % ). Keywords: ion exchange, NaX zeolite, heterogeneous catalylst, alkylation of isobutane with butylenes, highoctane component DOI: 10.1134/S107042722010134
Alkylation of isoparaffins with olefins is aimed at preparing a high-octane component, alkyl gasoline (alkylate), which mainly consists of a mixture of isoalkanes and meets the most stringent modern quality requirements of the Euro-5 standard to gasolines of new generations [1]. The research octane number of alkylate is no less than 96. Alkyl gasoline contains no aromatic hydrocarbon and virtually no sulfur; it has low saturated vapor pressure and hence is less prone to evaporation in the course of storage and transportation. Technologies of isobutane alkylation with olefins using sulfuric and hydrofluoric acids as catalysts are used in industry, compete with each other, and are being steadily improved. These catalysts are highly toxic and corrosion-active; they are hazardous in handling and transportation. Therefore, passing to heterogeneous catalysts free of such drawbacks is a topical problem. Zeolites, in particular, those of faujasite type (X, Y), having unique microporous structure, show promise for this purpose [2–8]. Zeolite-based catalysts can compete
in the performance and cost with traditional catalysts for isobutane alkylation with olefins, which makes their commercial use attractive [3]. In Russia, there are several catalyst plants producing faujasite-type zeolites in the sodium form;
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