Nanosized ZSM-5 zeolites were synthesized by an in situ seed-induced hydrothermal method, and samples modified with an Fe promoter were prepared by the traditional wet impregnation-thermal decomposition and dielectric barrier discharge plasma (DBD) methods, respectively. The physico-chemical properties of the catalysts were studied by XRD, SEM, TEM, BET, XPS, H-2-TPR, NH3-TPD and Py-IR techniques. The catalytic performance was eValuated by the methanol-to-olefin (MTO) reaction. The results showed that the acidity of the catalysts, the dispersity of the Fe promoter and the interaction degree with the ZSM-5 zeolite are closely related to product selectivity in the MTO reaction. Compared with the Fe-NZ5 sample prepared by the traditional impregnation-calcination method, the FeD-NZ5 samples prepared by the DBD method exhibited the higher selectivity of C-2-C-4 light olefins and the lower coke deposition during long-term eValuation (100 h), which can be attributed to the weaker acid strength, more uniform Fe promoter dispersion and strong interaction with the ZSM-5 zeolite. The developed Fe-modified catalysts have high potential for application in the MTO reaction.

The conversion of ethanol and fusel oils to a С3–С12 alkane–aromatic fraction with high activity and selectivity in the presence of the Pd–Zn/TsVM pilot catalyst has been demonstrated. It has been shown that the ethanol conversion to alkanes and aromatic hydrocarbons in the presence of this catalyst proceeds by various routes to give ethylene and diethyl ether as intermediate products providing a 90–95% yield on the converted ethanol carbon basis for the target С3–С12 fraction containing up to 40% of branched alkanes.

The effect of the method of introduction of zinc cations and the zinc content in a nanocrystalline zeolite of the ZSM-5 type on the physicochemical and catalytic properties of the material in DME conversion to a mixture of liquid synthetic hydrocarbons has been studied. Zinc is introduced into the catalysts both during the zeolite synthesis and the ion exchange (Zn n Al m NZ5 and ZnNZ5, respectively). The use of nanocrystalline Zn n Al m NZ5 zeolites provides the formation of a mixture of liquid hydrocarbons with a high selectivity of no less than 90%; the liquid hydrocarbons contain more than 70% of isoparaffins and a small amount of aromatic compounds. An increase in the zinc loading of the Zn n Al m NZ5 zeolite from 0.9 to ~3% leads to an increase in the methanol content in the aqueous phase of the liquid product, an increase in the selectivity for liquid hydrocarbons, and a slight increase in the concentration of aromatic and unsaturated hydrocarbons in the mixture. In the presence of the ZnNZ5/Al 2 O 3 catalyst with Zn introduced by ion exchange, the methanol content in the aqueous phase and the aromatics content in the liquid hydrocarbon mixture are significantly higher. The Zn n Al m NZ5 nanozeolites are characterized by a more developed external surface, a higher concentration of mesopores, and higher acidity.

The development of single-stage synthesis of dimethyl ether (DME) from synthesis gas makes it possible to obtain hydrocarbons directly from DME. The effect of the nature and concentration of components of the vapor–gas mixture that arrives at the stage of DME conversion to liquid hydrocarbons on activity and selectivity of a zinc–palladium zeolite catalyst has been examined. It has been found that and increase in DME concentration to more than 20 vol % in the reaction stream leads to lowering both DME conversion and gasoline selectivity and increasing the yield of byproducts. The presence of components such as H2, CO, H2O in the vapor–gas mixture ensures high stability of the catalytic system. Switching from the flow-through to the recycle operation mode increases the catalyst selectivity for gasoline, decreases the formation of durene, and reduces catalyst coking.

Comparative data obtained by studying the synthesis of С5+ hydrocarbons from dimethyl ether (DME) on catalysts using MFI zeolites available from different manufacturers are presented. It has been shown that MFI zeolite samples substantially differ in their acidic properties and structural, morphological, and textural characteristics. The catalysts based on different MFI zeolites also noticeable differ in the yield and chemical composition of С5+ hydrocarbons. By switching from the stand-alone operation of a DME conversion reactor to the joint operation of two reactors for synthesis of oxygenates (DME and/or methanol) from synthesis gas and synthesis of hydrocarbons from oxygenates connected by a single circuit, high selectivity for hydrocarbons of the gasoline fraction is achieved with the catalyst based on the MFI zeolite, for which the bands characteristic of Н3О+ acid sites are observed in diffuse reflectance IR spectra.

Технология производства на цеолитах бензиновых фракций (синтетических углеводородов) из синтез-газа (СИ-газа) через стадию получения оксигенатов, разработанная ИНХС РАН, отличается от применяемой в классическом MTG-процессе компании “ExxonMobil” тем, что стадии получения оксигенатов и БФ интегрированы в один контур. В новой технологии в составе синтетических углеводородов в зависимости от отношения Н2 в СИ-газе содержится от 6 до 27 мас. % ароматических углеводородов (бензол и дурол 2 мас. %). При использовании СИ-газа с Н2 3.5 в парогазовой смеси, поступающей на стадию получения бензиновых фракций, наблюдается повышенное содержание метанола (МеОН) и при исчерпывающей конверсии диметилового эфира (ДМЭ) отмечена неполная конверсия МеОН. С целью повышения степени вовлечения МеОН в процесс синтеза бензиновых фракций изучено влияние различных параметров на конверсию МеОН и ДМЭ. Показано, что изменение состава свежего СИ-газа оказывает более заметное влияние на конверсию МеОН, чем на конверсию ДМЭ в синтетические углеводороды и усиливается с увеличением массовой скорости подачи МеОН. Если в составе парогазовой смеси, поступающей из реактора получения оксигенатов на стадию получения бензиновых фракций, присутствует более 50 мас. % МеОН, то для повышения селективности по бензиновым фракциям синтез необходимо проводить при меньших значениях массовой скорости подачи оксигенатов, чем в случае, когда парогазовая смесь содержит только ДМЭ.

The technology for the manufacturing of gasoline fractions (synthetic hydrocarbons) from synthesis gas (syngas) on zeolites through the oxygenate production step as developed at the Topchiev Institute of Petrochemical Synthesis, differs from the classical MTG process of ExxonMobil in that the oxygenate and gasoline production steps are integrated in one circuit. In the new technology, the synthetic hydrocarbons contain 6 to 27 wt % aromatic hydrocarbons (benzene and durene ≤2 wt %) depending on the H2/CO ratio in syngas. When syngas with H2/CO ≤ 3.5 in the vapor-gas mixture arriving at the gasoline production stage is used, an increased methanol (MeOH) content is observed and the MeOH conversion is incomplete with the exhaustive conversion of dimethyl ether (DME). To increase the involvement of MeOH in the synthesis of the gasoline fraction, the influence of various parameters on the conversion of MeOH and DME has been studied. It has been shown that a change in the composition of fresh syngas has a more significant effect notably on the MeOH, rather than the DME conversion into synthetic hydrocarbons and is enhanced with an increase in the MeOH weight hourly space velocity (WHSV). If the vapor-gas mixture arriving from the oxygenate production reactor at the step of production of the gasoline fraction contains more than 50 wt % MeOH, in order to improve the selectivity for the gasoline fraction, the synthesis should be conducted at a lower WHSV of oxygenates than in the case when the vapor-gas mixture contains DME alone.

The effect of the manner and conditions of introducing lanthanum cations into NH4-ZSM-5 zeolite on the properties of catalysts for the conversion of dimethyl ether into the mixtures of gasoline hydrocarbons is studied. The physicochemical properties of synthesized catalysts are studied by means of temperature-programmed ammonia desorption, the adsorption of benzene, atomic absorption spectroscopy, differential scanning calorimetry, and thermogravimetry. It is shown that the degree to which lanthanum cations are replaced by ammonium cations both depends on the conditions of ion exchange in the zeolite and affects its acidity spectrum and the selectivity of the formation of paraffin hydrocarbons with isostructure. It is concluded that an increase in the amount of introduced lanthanum leads to an increase in the content of iso-paraffins from 69 to 76 wt % and a decrease in the content of aromatic hydrocarbons from 10.5 to 5.5 wt % and that of durene from 1.5 to 0.2 wt % in the products.

Изучено влияние способа и условий введения катионов лантана в NH4 ZSM-5 на свойства катализаторов превращения диметилового эфира в смесь углеводородов бензинового ряда. Методами температурно-программированной десорбции аммиака, адсорбции бензола, атомно-абсорбционной спектроскопии, дифференциальной сканирующей калориметрии и термогравиметрии изучены физико-химические свойства синтезированных катализаторов. Показано, что степень замещения катионов аммония катионами лантана зависит от условий проведения ионного обмена в цеолите и влияет на спектр его кислотности и селективность образования парафиновых углеводородов изо-строения. Так сделан вывод, что увеличение количества вводимого лантана приводит к повышению содержания изо-парафинов от 69 до 76 мас. % и уменьшению содержания ароматических углеводородов от 10.5 до 5.5 мас. %, в том числе дурола от 1.5 до 0.2 мас. %, в составе продуктов реакции.

Results on the conversion of rape oil into the alkane-aromatic fraction in the presence of a prototype of a MFI-based industrial catalyst (Si/Al = 30) promoted with 0.6 wt % Pd and 1 wt % Zn are presented. It has been shown that an increase in the process temperature from 360 to 420°C leads to a significant increase in the yield of aromatic compounds, and an increase in the substrate space velocity leads to a three-fold increase in the yield of C4–C6 alkanes of primarily the iso-branched structure. The genesis of active Pd and Zn clusters is discussed on the basis of X-ray data.

Представлены результаты по конверсии рапсового масла в алкан-ароматическую фракцию в присутствии опытно-промышленного катализатора на основе цеолита ЦВМ (Si/Al = 30), модифицированного 0.6 мас. % Pd и 1 мас. % Zn. Показано, что увеличение температуры процесса от 360 до 420°С приводит к значительному увеличению выхода ароматических соединений, а увеличение объемной скорости подачи субстрата приводит к трехкратному увеличению выхода алканов С4 С6, преимущественно изо-строения. С использованием рентгеновских методов структурного анализа обсуждается генезис активных кластеров Pd и Zn.

Zeolite H-TsVM has been loaded with palladium by different methods. The properties of the resulting catalysts in gasoline synthesis from syngas via dimethyl ether depend on the way in which palladium was introduced. The catalysts have been characterized by ammonia temperature-programmed desorption (TPD), temperature-programmed reaction with hydrogen, and X-ray photoelectron spectroscopy. According to ammonia TPD data, use of a palladium ammine complex instead of palladium chloride reduces the concentration of strong acid sites and raises the concentration of medium-strength acid sites, thereby reducing the yield of C1–C4 hydrocarbons and increasing the yield of gasoline hydrocarbons. At T = 340°C, P = 100 atm, and GHSV = 2000 h−1, the dimethyl ether conversion is 98–99%, the gasoline selectivity is >60%, the isoparaffin content of the product is ∼61%, and the arene content is not higher than 29%.

Изучено влияние способа введения соли палладия в Н-ЦВМ на свойства катализаторов синтеза бензина из синтез-газа (через диметиловый эфир). Методами температурно-программированной десорбции аммиака, температурно-программированной реакции водорода, рентгеновской фотоэлектронной спектроскопии изучены физико-химические свойства катализаторов. Методом температурно-программированной десорбции аммиака показано, что использование аммонийной соли палладия приводит к снижению концентрации сильных кислотных центров и увеличению концентрации кислотных центров средней силы, что обуславливает уменьшение выхода углеводородов С1 С4 и увеличение выхода углеводородов бензиновой фракции. При T = 340°С, P = 100 атм, V = 2000 ч-1 конверсия диметилового эфира составила 98–99%, причем селективность по бензину была выше 60%, с содержанием изо-парафинов около 61% и ароматических углеводородов в продуктах не выше 29%.