Alkylation of toluene by ethylene in the presence of catalysts based on pentasil-type zeolites

Alkylation of toluene by ethylene in the presence of catalysts based on pentasil-type zeolites

ABSTRACTS OF PAPERS PUBLISHED IN NEFTEKHIMIYA Voi. 27, No. 6 NEW TRENDS IN THE PRODUCTION OF LOWER OLEFINS S. N o w a k , H. Giirtschel, J. L a m z s ...

121KB Sizes 0 Downloads 27 Views

ABSTRACTS OF PAPERS PUBLISHED IN NEFTEKHIMIYA Voi. 27, No. 6 NEW TRENDS IN THE PRODUCTION OF LOWER OLEFINS S. N o w a k , H. Giirtschel, J. L a m z s c h arm K. A n d e r s , N e f t e k h i m i y a 27, No. 6, 736-749, 1987. DESPITE a number of unresolved problems, concerning above all an increase in the efficiency of the catalyst and the availability of technology for implementation of the combined process of conversion of methanol and transformation of hydrocarbons, the proposed process is a promising means of simultaneous production of lower olefins, aromatic hydrocarbons, and components of motor fuel. The main advantages of combined conversion of methanol and hydrocarbons into lower olefins, known as the GEMEKS process (from the German "Gekoppelte Methanol-Kohlenwasserstoff-Spaltung"), over other well-known processes are that it is thermally neutral and single-stage. It must be pointed out that the GEMEKS process is carried out with high degrees of both methanol and hydrocarbon transformation; it is noted for high product output and low feedstock consumption. The high temperature in the reaction zone (600°-700°C) makes it possible to achieve more efficient utilization of heat than is possible in the Mobil Oil process. STEREOCHEMISTRY AND RELATIVE THERMODYNAMIC STABILITY OF PERHYDROCHRYSENE EPIMERS N. S. Vorob'eva, T. 1. Peldlk, Z. K. Z e m s k o v a a n d A. A. Pctrov, N e f t e k h i m i y a 27, No. 6, 750-754, 1987. THE equilibrium of perhydrochrysene epimers at 573°K was determined. It was found that the trans, anti, trans, anti, trans-isomer is the most stable, lts concentration in the equilibrium isomerizate reaches 61 ~. The remaining 39 ~ belongs to four epimers having a single cis-connection of rings. The mass spectra and x3C and XH NMR spectra of some epimeric perhydrochrysenes were determined. POSSIBLE WAYS OF CONVERTING n-BUTANE ON MORDENITES N. N. Krupirta, A. Z. Dorogochinsldi arm A. L. Prosk-urnin, Neftekhimiya 27, No. 6, 755-760, 1987. IN the case of reactions of conversion of n-butane, the high reactivity of decationized and dealuminized forms of mordenite even in the absence of metals of the platinum group at low temperatures (below 300°C), is demonstrated. Such reactivity is due to the presence of "strong" and "superstrong" acid centres on their surface. The indicated ceutres govern the main routes of carbonium ion conversion: isomerization, cracking, disproportionation, alkylation (and autoalkylation), redistribution of hydrogen, and coking. ALKYLATION OF TOLUENE BY ETHYLENE IN THE PRESENCE OF CATALYSTS BASED ON PENTASIL-TYPE ZEOLITES Ya. [. Isakov, Kh. M. Minachev, T. A. Isakova, G. L. B i t m a n a n d S. P. Chernyldl, N e f t e k h i m i y a 27, No. 6, 766-775, 1987. 306

Abstracts

307

SYNTHETIC zeolites H-Pentasil, H-Ultrasil, H-TsVK, H-TsVM, dealuminized H-TsVM, and Mo" +Na-TsVM, including zcolites simultaneously containing cations of several transition and/or non-transition metals, are active catalysts for the alkylation of toluene by ethylene under atmospheric pressure. Their properties can be controlled by varying the nature, charge, and size of the Mo n+ cations, the degree of exchange of Na + in the initial aluminosilicate by H + or M "+, the SiO2/A1203 zatio in the skeleton, and the conditions of use. On the basis of TsVM Pentasils, it is possible to prepare catalytic systems possessing increased selectivity in relation to the formation ofp-ethyltoluene (with a p-isomer content in the target product of up to 91-96~o). FEATURES OF THE OXIDATION OF ETHANE-ETHYLENE MIXTURES E. A . A r a k e l y a n , S. D. A r s e n t ' e v a n d A. A . M a n t a s h y a n , N e f t e k h i m i y a 27, N o . 6, 776-779, 1987. IN the oxidation of ethane-ethylene mixtures, when the ethane content of the mixture is increased there is an increase in the induction period of oxidation. The introduction of ethane additives enables the selectivity of oxidation of ethylene to ethylene oxide to be increased. EPOXIDATION OF OCTENE~I BY HYDROGEN PEROXIDE IN THE PRESENCE OF AN HOMOGENEOUS CATALYST CONTAINING MOLYBDENUM AND TUNGSTEN T. M. Petrertkova, M. V. N i k i p a n c h u k a n d B. I. C h e r n y a k , N e f t e k h i m i y a 27, N o . 6, 780-786, 1987. IT WASestablished that the order of the reaction of epoxidation of octene-1 by hydrogen peroxide in the presence of an homogeneous catalyst containing molybdenum and tungsten is 1 with respect to the olefin and catalyst, and zero with respect to the hydrogen peroxide. The rate of accumulation of the target product (1,2-epoxyoct~Lne) depends on the initial concentration of the olefin. The water present in the reaction mass inhibits the epoxidation process, forming a low-activity complex with the catalyst; the equilibrium constant of complex formation at a temperature of 366°K ([RH]o=3"2, [H202]o=0'2 mole/l, volume of catalyst solution 4 ml) was (8.5 _+0.8) 1./mole. MECHANISM OF FORMATION OF p.METHYLBENZYLBROMIDE DURING OXIDATION OF p-XYLENE IN CONDITIONS OF METAL BROlVlIDE CATALYSIS M. N. F e d o r i s h c h e v a , N . G. A r i k o a n d N. I. Mitskevich, N e f t e k h i m i y a 27, N o . 6, 787-790, 1987. IT WAS shown that transition of a bromide ion into a covalently bound form (p-methylbenzylbromide) occurs at the initial stage'of oxidation of p-xylene and proceeds in parallel with the formation of p-toluyl aldehyde. p-Methylbenzylbromide is an intermediate compound, transformation of which leads to the formation of some bromide ions. HYDROXYLATION OF BENZENE BY HYDROGEN PEROXIDE IN HOMOGENEOUS AND HETEROPHASE SYSTEMS E. A. K a r a k h a n o v , S. Yu. N a r i n , T. Yu. F i l i p p o v a , Ye. A . I v a n o v a , S. M. V o l k o v a n d A. G. D c d o v , N e f t e k h i m i y a 27, N o . 6, 791-795, 1987.