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Русская версия статьи/Russian version of the article

Kolesnichenko N. V., Khajiev S.N.

Order of the Red Banner of Labor A. V. Topchiev Institute of petrochemical synthesis of the Russian Academy of Sciences, Moscow, Russia Leninsky avenue, 29, Moscow, 119991, e-mail: nvk@ips.ac.ru

    Low molecular weight olefins are now created mainly as a result of pyrolisis of the gaso­line and gasoil fractions of oil. Inevitable reduction of oil stock, as well as the increasing demand for these valuable products of petroleum chemistry make scpecilaists concen­trate their attention on the methods of procressing natural gas to produce low molecular weight olefins. The aim of developing the process of production of ethylene and propylene from natural gas and, on this base, construction of enterpises for production of low molec­ular weight olefins in Russia, which has one-third of all world reserves of natural gas is very importnat at the moment. The most developed method of production of molecular weight olefins from natural gas is the one that involves preliminary conversion of natural gas into syngas (СО/Н₂), which is fairly popular and widely used in the chemical industry.

     The report contains comparative characteristics of the technological process of pro­duction of low molecular weight olefins from syngas through methanol and/or DME, devel­oped by the leading companies and by Institute of petrochemical synthesis of the Russian Academy of Sciences. Thus, the process of olefins synthesis from СО and Н2 through methanol, being developed by the American company Mobil Oil Corporation, is ready for commercial use and now it is actively introduced into the production sector. This method is more efficient than the traditional industrial method (pyrolisis of light oil fractions): due to a lower temperature, used at the stage of olefins synthesis and higher selectivity con­cerning ethylene and propylene. The process of the companies UOP and Norsk Hydro is focused at the production of ethylene and propylene (and it should be mentioned, in equal proportions); by-products of this process, including butens, are supposed to be sued as a fuel for a heat power plant. Institute of petrochemical synthesis of the Russian Academy of Sciences has developed technological process of producing olefins from syngas, not through methanol, but through dimethyl ether (DME), obtained from the syngas during one stage. Direct production of DME from the syngas is more profitable in terms of capital investment and ecological safety, comparing with the production of methanol. The advan­tage of this method is the reduction of the heat effect at the stage of olefins synthesis from DME. The new catalyst affords the synthesis of low molecular weight olefins from pure DME with the same high level of output as in case of commercial «methanol» processes (in the processes of firms UOP (Norsk Hydro and Lurgi), while the temperature is much lower and the catalyst is more stable.

Нехаева Л.А.¹, Максимов А.Л.¹, Решетников Д.М.¹, Боюнков А.И.², Виноградова М.Е.²

¹ Учреждение Российской академии наук Ордена Трудового Красного Знамени Институт нефтехимического синтеза им. А.В. Топчиева РАН, Москва, Россия

² Редкинский опытный завод, пос. Редкино Тверской обл., Россия

Английская версия статьи/English version of the article

      Выдающимся событием в химии полиолефинов было открытие высокоэффек­тивных гомогенных катализаторов, состоящих из производных цирконоценов и ме-тилалюмоксана (МАО) [1-4]. Использование металлоценов с различным лигандным окружением позволяет получать новые типы полимеров с технически важными свойствами. За прошедшие три десятилетия появилось множество публикаций, по­священных каталитическим свойствам систем этого типа в полимеризационных и олигомеризационных процессах, механизму их действия, при этом круг каталити­ческих систем был существенно расширен как за счет других переходных металлов и других их соединений, так и за счет привлечения гомологов МАО [5]. Нами пока­зано, что при использовании алкилалюмоксанов можно проводить стереоспецифическую полимеризацию не только олефинов и стирола, но и сопряженных диенов с высокой активностью. Результаты экспериментов по полимеризации бутадиена и изопрена, проведенных с помощью каталитических систем на основе соединений Со, Д V, Nd с различным лигандным окружением в сочетании с алкилалюмоксанами, показали, что помимо стерических затруднений и донорно-акцепторного вза­имодействия, возникающих вследствие лигандного окружения вокруг переходного металла, на стереоспецифичность каталитической системы также влияют природа металла и алюмоксана. Каталитические системы на основе соединений Со и МАО позволяют получать цис-1,4-ПБ с содержанием цис-звеньев более 95%. Замена МАО на изобутилалюмоксан приводит к получению синдиотактического кристалли­ческого 1,2-ПБ. Использованные метил-, этил- и изобутилалюмоксаны были полу­чены на пилотной установке АО «Технороз», изучены их свойства и структура. Оп­тимальные условия получения алкилалюмоксанов в лаборатории и 15 л реакторе с мешалкой были заложены в основу регламента на проектирование установки на Редкинском опытном заводе. Процесс проводится по непрерывной схеме в Т-об­разном реакторе (500л).

Nekhaeva L.A.¹, Maksimov A.L.¹, Reshetnikov D.M.¹, Boyunkov A.I.², Vinogradova M.E.²

Establishment of the Russian Academy of Sciences of the Order of the Red Banner of Labor AV A.V. Topchieva Institute of Petrochemical Synthesis, Russian Academy of Sciences, Moscow, Russia ²Redkinsky Pilot Plant, Redkino, Tver Region., Russia

Русская версия статьи/Russian version of the article

     The outstanding event in the chemistry of poly-olefins was the discovery of highly homogeneous catalysts consisting of derivatives of zirconcenes and methylaluminoxane (MAO) [1-4]. The use of metallocenes with different ligand environment allows obtain new types of polymers with technically important properties. Over the past three decades, a host of publications on the catalytic properties of systems of this type of polymerization and oligomerization processes, their mechanism of action, and the range of catalytic sys­tems has been greatly expanded both at the expense of other transition metals and other compounds, as well as through the involvement of homologues of MAO [5]. We have shown that using alkyl-alumoxanes the stereospecific polymerization of not only olefins and styrene can be carried out, but also of conjugated dienes with high activity. Results of experiments on the polymerization of butadiene and isoprene, conducted by Catalyst systems, based on compounds of Co, Ti, V, Nd with different ligands in combination with alkyl-alumoxanes, showed that in addition to steric hindrance and donor-acceptor inter­action, arising due to ligand environment around the transition metal, the nature of the metal and aluminoxane also affect the stereospecificity of the catalytic system. Catalytic systems, based on compounds Co and MAO, allow obtain cis-1 ,4-PB with the content of cis-units more than 95%. Replacement of MAO in isobutylalyumoxane results in crystalline syndiotactic 1,2-PB. Used methyl-, ethyl-and isobutylalumoxane were obtained on a pilot plant Tehnoroz, their properties and structure were study. Optimal conditions for obtaining alkyl-alumoxanes in the laboratory and reactor of 15 l with a stirrer were laid in the basis of regulations on the design of installation on Redkino pilot plant. The process is carried out in the unbroken pattern of T-shaped reactor (500l).

Английская версия статьи/English version of the article

Гидрокарбометоксилирование циклогексена представляет практический инте­рес как реакция, лежащая в основе получения важного промежуточного продукта в синтезе лекарственных препаратов — метилциклогексанкарбоксилата [1]. В этой связи исследование активности используемых для этой цели катализаторов представляет актуальную задачу. В контексте этой задачи при 378 К изучено влияние концентрации катализаторов Pd(PPh₃)₂Cl₂, PdCl₂ и (CH₃COO)₂Pd, промотированных свободным трифенилфосфином и п-толуолсульфокислотой (TsOH), на скорость ги-дрокарбометоксилирования циклогексена при постоянстве концентраций осталь­ных участников реакции.

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 Русская версия статьи/Russian version of the article

    Hydrocarboalcoksilation of cyclohexene is of practical interest as the reaction, present­ing the basis of the receipt of an important intermediate product in the synthesis of phar­maceuticals — methylcyclohexanecarboksilat [1]. In this regard, the research of the activi­ty of the catalysts, used for this purpose, is the actual problem. In the context of this prob­lem and in strictly comparable conditions, we studied the activity of palladium catalysts Pd(PPh₃)₂Cl₂, PdCl₂ and (CH₃COO)₂Pd, promoted by means of free triphenylphosphine and p-toluenesulfonic acid (TsOH), in the reaction of hydrocarbomethoksilation of cyclo-hexene at constant concentrations of precursors.

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