Catalysis and petrochemistry

Development of oxidation heterogeneous catalysis in Institute for Sorption and Problems of Endoecology NAS of Ukraine

Valeriy O. Zazhigalov — Thu, 07 Sep 2023 11:37:58 +0000

In this publication the results of heterogeneous catalytic processes of different nature compounds oxidation in productive and ecological catalysis obtained in Institute for Sorption and Problems of Endoecology NAS of Ukraine during last 30-years are summarized. The problems of effective catalysts synthesis for these reactions and development of nontraditional preparation methods to catalysts technology are considered. The results obtained in investigation of saturated hydrocarbons (methane, ethane, propane, butane, pentane) partial oxidation in valuable products (formaldehyde, ethylene, propylene, maleic and phthalic anhydrides) are presented. The mechanisms of paraffins hydrocarbons transformation are presented. New approaches to effective catalysts preparation, which based on alternative methods (mechanochemistry, sonochemistry, barothernal synthesis, ionic implantation) using, for these processes are shown and the comparison of results obtained on synthesis catalysts with known literature data was realized. It was established that in most cases the catalysts prepared by us are more effective in different processes that known analogous catalysts.

New schemes of maleic anhydride production in excess of n-butane in reaction mixture and phthalic anhydride from n-pentane with two catalysts in catalytuic bed were proposed.

The process of ethanol oxidation to acetaldehyde was studied and very effective catalysts for this process realization were proposed.

The synthesis of the catalysts for environment protection (total oxidation of H₂S, CO and CO in hydrogen excess) is considered and it was shown that the developed catalysts don’t give in activity foreign analogues. The results obtained at catalysts preparation for photocatalytic degradation of different organic compounds, including herbicides and medical substances, in water medium are presented. The positive effects of the catalysts synthesis by nontradional methods (mechanochemistry and sonochemistry) for effective photocatalysts preparation are shown. The new perspective directions of catalytic oxidation processes and methods of the catalysts preparations are presented.

Researches on heterogeneous acid-base catalysis in Institute for sorption and problems of endoecology of the National Academy of Sciences of Ukraine

Volodymyr V. Brei — Thu, 07 Sep 2023 11:39:33 +0000

In chronological order, the reaseach results of Department of heterogeneous acid-base catalysis at Institute for sorption and endoecology problems in 2003-2023 are described. It relates to the synthesis, study and application of solid superacids WO₃/ZrO₂, WO₃/ZrO₂-SiO₂, ZrO₂-SiO₂-Al₂O₃, ZrO₂-SiO₂-SnO₂, as catalysts, in vacuum gas oil cracking, alkylation of isobutane with isobutanol, acylation toluene, oligomerization of tetrohydrofuran, acylation of methyl tert-butyl ether and other. Some study deals with a search of the correlations between of acid site strength of a catalyst and its activity, in particular, in dehydration reaction of C₂-C₄ alcohols, and the correlations between ability of primary and secondary alcohols to dehydrogenation and oxidation and their chemical shifts δ (R¹⁷OH) and δ (R¹³СОH ). For the first time, the values of Hammett's acidity function have been measured at elevated (up to 200 °C) temperatures for solid acids. In particular, for H-Y faujasite, H₀ reaches superacidic value H₀ at 160 °С.

Since 2010, the main focus has been on the catalytic conversion of renewable raw materials, mainly bioalcohols (ethanol, glycerol) and C₆ carbohydrates, into important products of organic synthesis (ethyl acetate, 1,1 diethoxyethane, n-butanol, propylene glycol, alkyl lactates, lactide, glycolide). In cooperation with “Techinservice Manufacturing Group”, new processes for obtaining ethyl acetate, 1,1 diethoxyethane, n-butanol from bioethanol and racemic lactide from glycerol were developed. Also, new technologies for obtaining propylene oxide from propylene and hydrogen peroxide (НРPОа-process), vapor phase hydrogenation of the pyrolysis C_4-5fraction, and direct high-temperature chlorination of ethylene to vinyl chloride have been developed for Kalush “Karpatnaftochim” plant. The HHPOa installation (2000 t/y) has been started at “Karpatnaftochim” in 2020.

Vapour phase Guerbet condensation of ethanol to 1-butanol on CsX zeolite

Lyubov K. Patrylak, Olexandra P. Pertko, Karina V. Valihura, Yulia G. Voloshyna — Thu, 07 Sep 2023 11:41:31 +0000

Nowadays, the conversion of ethanol into valuable chemical products is getting wider application.One of such promising processes is Guerbet condensation of alcohols, which permits the obtaining of 1-butanol from renewable raw materials that are alternatives to petroleum ones.Oxide systems combining acid and basic sites in their composition are promising catalysts for such a transformation.In this study, the efficiency of the magnesium-aluminum oxide and zirconium-oxide catalysts was compared to the activity of the cesium form of X-type zeolite produced by hydrothermal ion exchange in the condensation of ethanol to 1-butanol. The integrity of the zeolite structure was confirmed by using the XRD and XRF analysis, as well as by the IR spectroscopy.The depth of exchange of native sodium for cesium was 82%. It was also found that cesium cations are localized only in ion-exchange positions of faujasite, in places SIII (supercages) and SI` (sodalite cages). CsX zeolite acid to basic sites ratio was found tobe close to optimal for this reaction. Cesium-containing zeolite at 300 °C showsethanol 35-55 % conversion and 20-25 % selectivity for 1-butanol, which is higher than the same characteristics for zirconium samples, but slightly inferior to magnesium-aluminum oxide catalysts. The obtained results indicate the promising use of zeolites of a similar nature in the process of condensation of ethanol to 1-butanol.

Influence of mechanochemical treatment of a mixture of two oxides based on TiO2 on the physico-chemical and photocatalytic properties of the obtained composites in the degradation of metronidazole

Olena V. Kiziun, Olena V. Sachuk, Valeriy O. Zazhigalov, Liudmyla Yo. Kotynska — Thu, 07 Sep 2023 11:45:48 +0000

The effect of mechanochemical treatment of oxide composites based on TiO₂ (TiO₂/ZnO, TiO₂/ZrO₂, TiO₂/MgO, TiO₂/SnO₂, TiO₂/Nb₂O₅ with a molar ratio of 1:1) on their physical and chemical properties was investigated. It is shown that this treatment leads to a change in the crystal structure of the initial oxides without the formation of new phases, a significant grinding of particles, which is sometimes accompanied by amorphization of both or one of the oxides. As a result of mechanochemical treatment, the specific surface of the composites increases, except for the TiO₂/Nb₂O₅ sample for which grinding is accompanied by agglomeration, which leads to a some decrease in the specific surface. It was established that as a result of the treatment, the morphology of the surface of the compositions changes, and in some cases the elements are redistributed in the near-surface layer. A significant decrease in the size of oxide particles leads to the formation of zones of dense contact between oxides in the composite. The photocatalytic properties of the original compositions and samples after their mechanochemical treatment in the reaction of degradation of metronidazole under ultraviolet radiation were established. It is shown that the photoreaction rate constant and the degree of metronidazole degradation do not depend on the band gap width, which is explained by the greater influence of local activation on the photoprocess than the collective properties of the solid body. It was established that a mixture of titanium oxide with another oxide leads to the formation of an effective catalyst for the photodegradation of metronidazole with a transformation degree of 95-98 % (after 5 hours of reaction), which is 4-7 % higher than that of the original titanium oxide.

The influence of mechanochemical and microwave modification on the properties of SnO2 as photocatalyst

Mariia M. Samsonenko, Svitlana V. Khalameida — Thu, 07 Sep 2023 11:53:18 +0000

Samples of precipitated SnO₂ were modified by means of mechanochemical and microwave treatment. Physicochemical properties of all samples were investigated using DTA, XRD, FTIR spectroscopy, nitrogen adsorption-desorption and UV-Vis spectroscopy. Photocatalytic activity was evaluated using the degradation of rhodamine B and safranin T under Vis-irradiation. It was found that the initial precipitated and modified samples correspond to the composition of tin oxyhydroxide - SnO(OH)х. It has been established that as a result of mechanochemical and microwave treatment of tin oxyhydroxide in the wet gel stage, it is possible to obtain photocatalytically active materials with a uniform mesoporous structure and high specific surface values and a band gap of about 3.5-3.6 eV. A peculiarity of the mechanochemical treatment of xerogels in water is the formation of a meso-macroporous structure. Relationship between physicochemical and photocatalytic properties of prepared samples has been discussed. The dependence of the efficiency of photocatalytic degradation of dyes on changes in the porous structure, the presence of defects on the surface of the catalyst, and its electronic characteristics was established.

Vapor-phase oxidation of propylene glycol-methanol mixture to methyl lactate on CeO2/Al2O3 catalyst

Mykhailo E. Sharanda, Artur M. Mylin, Oleksii Yu. Zinchenko, Volodymyr V. Brei — Thu, 07 Sep 2023 11:55:59 +0000

The vapor-phase oxidation of mixtures of propylene glycol with methanol and ethanol to methyl and ethyl lactate, respectively, on supported CeO₂/Al₂O₃ catalyst at 210-250⁰С was investigated. Air oxygen and a flow reactor with a fixed catalyst bed were used. A 20% solution of propylene glycol in alcohol was supplied to the reactor inlet. Oxidation of propylene glycol in the presence of methanol occurs according to the overall reaction CH₃CHOHCH₂OH +O₂+ СН₃OH = CH₃CHOHCOOСН₃ +2H₂O. First, hydroxyacetone is formed, which is further oxidized to pyruvic aldehyde, which adds alcohol to form a hemiacetal. Next, this hemiacetal is rearranged according to Cannizzaro into methyl lactate. At 220⁰C and catalyst load < 2 mmol PG/g_cat/h, the selectivity for methyl lactate reached 70 wt.% at 100% propylene glycol conversion. In the presence of ethanol, the formation of a significant amount of acetaldehyde and its aldol condensation products, as well as the formation of diethoxyethane, was observed. Therefore, the selectivity for ethyl lactate at 100% propylene glycol conversion did not exceed 45%.

Development of new resource-efficient approaches to the solution of the problem of purification of naphtha local wastewater

Oleksandr P. Khokhotva, Olena I. Ivanenko , Oksana M. Tereshchenko — Thu, 07 Sep 2023 11:57:55 +0000

The article noted that the pollution of surface water bodies by oil products as part of wastewater in Ukraine in 2020 reached 246.6 tons. For aquatic organisms, oil and oil products are highly toxic substances and belong to the group of nerve poisons. Most of the wastewater generated today in industry is subject to purification from petroleum products before discharge into the environment, however, existing purification technologies do not fully meet modern requirements. Electrochemical cleaning methods have a number of significant advantages over reagent methods: the salt content in water does not increase, which plays an important role in the organization of circulating water supply systems; less sediment is formed; the technological scheme of cleaning is simplified; there is no need to organize a reagent farm; small production areas are required for the placement of electrochemical treatment plants. The operation of electric cleaning plants is simple due to their high manufacturability and the possibility of automation.

As a result of research, the optimal conditions for electroflotation water purification from oil products have been determined. The dependence of the degree of purification on the material of the anode, the pH of the initial solution and the current density was studied. It was established that the best effect is achieved in the pH range of 5-7 at current densities of 0.25-0.3 A/dm². In the presence of sulfates, cleaning proceeds better than in the presence of chlorides, since Cl^– ions intensify the point breakdown of the anode material. Among the studied materials, 08кп steel can be recommended as an anode. The nature of the electrochemical dissolution of 08kp steel depending on its preliminary treatment and the effect of such treatment on the degree of purification of water from petroleum products was studied. It is shown that when adding sulfanol НП-3 with flocculant ВПК-402 to oil-containing water, a water-insoluble complex is formed, which contributes to a more complete purification of water from oil and oil products.

Obtaining high-quality antifriction grease based on modified fatty acid raw materials

Oleksii O. Papeikin, Irina O. Venger, Larysa Yu. Bodachivska — Thu, 07 Sep 2023 12:00:44 +0000

Currently, the highest quality greases are made on the basis of 12-hydroxystearic acid soaps. But over 80 % of the world’s raw material source of this fatty acid - castor oil - is concentrated in South Asia. This prompts grease manufacturers to search for alternative raw materials for the production of greases with high thixotropic properties. The paper demonstrates the possibility of using phosphatide concentrates as components of high-temperature greases. Active groups in their composition– -OH, -NH₂, -CONH, -COOH, -PO(OH)₂ provide improved protective and tribochemical properties to lubricating compositions, but the existing double bonds impair their antioxidant resistance. Therefore, a technology for chemical modification of phosphatide concentrate by hydroxylation of unsaturated bonds with subsequent saponification and insitu complexation of the lubricating composition has been developed. The physico-chemical properties of the developed complex calcium grease were studied and a comparative analysis of their quality indicators with greases based on 12-hydroxystearic, stearic acids and unmodified phosphatide concentrate was carried out. The synthesized grease is characterized by high mechanical, colloidal stability and high-temperature properties, its upper temperature limit of application, which is established by the method of derivatographic analysis, reaches 180-200 °С. In addition, this thixotropic system is resistant to oxidation, does not cause corrosion of non-ferrous metals and is able to work in contact with water. Phosphorus-containing residues improve the lubricating properties of the synthesized composition without the addition of tribological modifiers and surpass the functional additives contained in the commercial grease Uniol-2. The conducted tests prove the promising application of hydroxylated phosphatide concentrates as components of high-temperature dispersed phases of soap compositions.

Fabrication of proton exchange membrane for non-humidified fuel cells based on polyimide Matrimid® and hydrophobic protic ionic liquid

Thu, 07 Sep 2023 12:02:15 +0000

New proton exchange membrane based on polyimide Matrimid^® (PI) and hydrophobic protic ionic liquid, 1-methylimidazolium bis(trifluoromethylsulfonyl)imide (MIM-TFSI), has been prepared by casting from methylene chloride/dimethylformamide solution. Infrared analysis revealed physicochemical interactions between 1-methylimidazolium cations and imide groups of PI. The results of mechanical testing indicate significantly reduced tensile strength of PI/MIM-TFSI composite membrane compared to neat polymer. Moreover, the dynamical mechanical analysis results revealed sharp drop in storage modulus (E´) of the polymer film above 60 °C.

To improve the elastic properties of the membrane, PI was successively cross-linked with polyetheramine Jeffamine^® D-2000 (10 mol. %) in methylene chloride/dimethylformamide solution, as well as in solid film at 100 °C. This approach allowed to prepare PI/Jeffamine/MIM-TFSI (70 wt. %) composite film which has an acceptable E' value of 210 MPa at 140 °C. According to thermal gravimetric analysis data, PI/Jeffamine/MIM-TFSI composite has a thermal degradation point (i.e. 5 % weight loss) of 286 °C. The ionic conductivity of PI/Jeffamine/MIM-TFSI composite membrane is around 10^–⁴ S/cm at room temperature and reaches the minimal level of 10^–³ S/cm, required for fuel cell applications, above 100 °C. Overall, the results of this study indicate that the cross-linking of polyimide Matrimid with flexible polyetheramine Jeffamine is an efficient approach for preparing dense composite membrane with high content of the protic ionic liquid. Such polymer-electrolyte membrane has the reasonable combination of good stiffness, thermal stability, and ionic conductivity and therefore is a promising candidate for use in fuel cells operating at elevated temperatures in water-free conditions.

To the 70th birthday of Professor Svitlana .M. Orlyk

Fri, 22 Sep 2023 15:05:07 +0000

To the 70th birthday of Professor Svitlana .M. Orlyk

To the 60th birthday of Professor Peter E. Strizhak

Fri, 22 Sep 2023 15:06:03 +0000

To the 60th birthday of Professor Peter E. Strizhak

To the 70th birthday of Professor Volodymyr V. Brei

Fri, 22 Sep 2023 15:07:22 +0000

To the 70th birthday of Professor Volodymyr V. Brei

In memory of Professor Michael M. Bratychak

Fri, 22 Sep 2023 15:08:09 +0000

In memory of Professor Michael M. Bratychak

In memory of Professor Kazymyr I. Patrylak (dedicated to 85th anniversary of birth)

Lyubov K. Patrylak, Anzhela V. Yakovenko — Fri, 22 Sep 2023 15:08:46 +0000

In memory of Professor Kazymyr I. Patrylak (dedicated to 85th anniversary of birth)