Reactionary Ability Research Articles

Influence of the coal-derived synthesis gas composition on the thermal stability of ZnO sorbents in the desulfurization process

The priority direction of thermal energy on solid fuels is to increase efficiency and environmental safety, approaching zero emissions of harmful substances. To achieve these goals, they are currently creating new schemes for combined cycle gas turbine units with intra-cycle gasification (IGCC). To improve the efficiency of the IGCC cycle, hot dry desulfurization (HGC) technologies are being developed. HGC uses regenerable sorbents that allow the repeated adsorption of hydrogen sulfide from synthesis gas, among which the most acceptable thermodynamic and operational characteristics are based on ZnO sorbents. The article uses the method of thermogravimetric analysis (TGA) to investigate the development of target reaction capture hydrogen sulfide ZnO-containing sorbent and sorbent reactions with components of synthesis gas in the temperature range up to 1000°C. The sorbent calcined at 900°C shows thermal stability in an inert atmosphere over the entire temperature range studied. Uncalcined sorbents at temperatures of 200 and 600°C emit carbon dioxide in an amount of 1.5-4.5% by weight of the sorbent. At temperatures up to 550°C, the target reaction is basic, and side reactions practically do not develop. The maximum rate of absorption of hydrogen sulfide by the sorbent is observed at a temperature of 600°C. At 500-550°C reactions of a sorbent begin with H2 and CO, at 750-800°C – with carbon, at 850°C – with CH4. The intensity of effect of reagents is defined on degradation of a sorbent by reactionary ability of gases more than temperature.

SYNTHESIS, STRUCTURE AND THERMAL PROPERTIES OF RHENIUM CARBONYL CONTAINING HETEROBIMETALLIC DERIVATIVES OF VANADIUM (III)

This paper describes the data on synthesis of bis(cyclopentadienyl)vanadium(III) of pentacarbonyl rhenium bistetrahydrofuranate complex with the reaction between dicyclopentadienylvanadium (III) chloride and rhenium sodiumpentacarbonyl in tetrahydrofurane (THF). Formed in this case the target product was separated from reaction mixture by extracting with hot hexane. Their reactionary ability in relation to protonic and aprotonic acids Lewis had been inverstigated. It is revealed, that at interaction of the above mentioned complexes with HCl there is a splitting Re-V bond with formation (C5H5)2VCl and HRe(CO)5; (C5H5)2VCl and HRe(CO)4PPh3 respectively. At interaction with HgCl2 also occurs having break V-Re bond and it turn out (C5H5)2VCl and (OC)5ReHgCl; (C5H5)2VCl and PPh3(OC)4ReHgCl. The interection of these complexes with ligands of various dentate is investigated. A monodentate liqand-triphenil phosphine (PPh3) substitutes one of carbonyl-groups in Re(CO)5) – fragment. Bidentate ligand- acetylacetone (acac) easily push out from coordination sphere vanadium more donor ligand cyclopentadienyl. The composition and structure of the complexes were characterized by the data of NMR, IR, EPR-spectroscopy and thermal analysis.

KINETIC MODEL FOR FISCHER-TROPSCH SYNTHESIS OVER NANOPARTICLES IRON CATALYSTS WITH POLYMER MATRIX IN A SLURRY REACTOR

Influence of additives of synthetic polymers of various natures on reactionary ability of the nanostructured iron catalysts in the three-component Fe-paraffin-polymer system in Fischer-Tropsch (FTS) in the slurry reactor was studied. The polymers used: polyacrylonitrile (PAN), polyvinyl alcohol (PVA), polystyrene, cross-linked with divinylbenzene (PS-DVB), polyamide-6 (PA). The catalysts obtained by droplet thermolysis is influenced by, the nature of the stabilizing polymer. Besides the conversion of the synthesis gas depends on the contact time and is between 10 to 80%. The highest rate of FTS is observed in the Fe-paraffin-PAN. The conditions of synthesis in Fe-paraffin-polymer systems produced a wide range of saturated and unsaturated compounds. It is found that the nature of the stabilizing polymer also affects the olefin /paraffin ratio. Based on experimental data the analysis of kinetic models for the flow of CO is carried out, a kinetic and thermodynamic characteristics of the process was obtained. The relationship between the values of the activation energies and the nature of the stabilizer was established.

NATURAL POLYACETYLENE COMPOUNDS

In article the review of the initial stage of researches of natural polyacetylene compounds is resulted. The high reactionary ability leading to fast oxidation and degradation of these compounds, especially at influence of Uf-light, oxygen of air, pH and other factors, has caused the serious difficulties connected with an establishment of structure and studying of their physical and chemical properties. Therefore the greatest quantity of works of this stage is connected with studying of essential oils of plants from families Apiaceae, Araliaceae, Asteraceae, Campanulaceae, Olacaceae, Pittosporaceae and Santalaceae where have been found out, basically, diacetylene compounds. About development of physical and chemical methods of the analysis of possibility of similar researches have considerably extended. More than 2000 polyacetylenes are known today, from them more than 1100 are found out in plants fam. Asteraceae. Revolution in the field of molecular biology has allowed to study processes of biosynthesis of these compounds intensively.

Adsorption of Methane on the Pt/Al2O3 Catalyst. Studying of Reactionary Activity of the Adsorbed Methane Forms in Reaction of Joint Transformation with N Pentane

It is shown in the work that in the presence of the preadsorbed hydrogen forms on the catalyst 1%Pt/Al2O3 the maximum size of adsorption of methane at 823K makes 1,1 CH4/Pt of mol/mol. Existence on the surface of the preadsorbed oxygen leads to emergence in the reactionary environment 0,6mol. CO, and the total of the turned methane makes 1,3 CH4/Pt of mol/mol. On the catalyst surface (in lack of the preadsorbed forms of hydrogen and oxygen) the amount of the adsorbed methane decreases to 0,8 CH4/Pt mol/mol. Studying of reactionary ability of the adsorbed methane forms in reaction of joint transformation with N pentane shows quite high catalytic activity of alkanes in the formation of aromatic hydrocarbons.

METALCOMPLEXES OF TELLURIUM-CONTAINING AMINES AND AZOMETINES

In this article methods of synthesis and reactionary ability of metalcomplexes of tellurium-containing amines, azometines, of a problem of competitive coordination with use of the principle of "soft" and "rigid" acids and the bases (R. Pearson).

Influence of adjustment accuracy of dynamic dampers of fluctuations on seismic stability of bridges

The analysis of reactionary ability and fractional composition of large fillers for production of ferroconcrete cross ties is carried out in the article.

The Synthesis of Organophosphorus Compounds from Phosphine and Alcohols in the Presence of Quinones and Redox Polymers on their Basis

<p>This article presents the synthesis of phosphoric acid esters from phosphoric hydrogen РН3 and aliphatic alcohols. The process is based on the oxidation of phosphine by quinones and redox polymers on the basis of mono- and disubstituted quinoid derivatives of monoethanolamine vinyl ether. Molecular iodine is used as a catalyst. Two-, three-, four- and multicomp onent systems are studied in order to determine optimal conditions of the oxidation of phosphine quinones and repoxpolymers on their basis. The rate and selectivity of reaction were monitored by the absorption of РН<sub>3</sub>. As alcohols used aliphatic alcohols: BuOH, PrOH, EtOH, MeOH. Organophosphorus compounds were analyzed by a chromatographic method. It was established that alcohol solutions of individual components of reactionary system (quinones, redox ionites or iodine) are characterized by a low activity in relation to phosphine. Organophosphorus compounds are formed in insignificant quantities. In the mixed alcohol<br /> solution of benzoquinone takes place PH<sub>3</sub> oxidation forming trialkylphosphates. Conversion of phosphine constitutes 80-100%. Increasing the concentration of reagents of catalytic system has a positive effect on the process as a whole. Similar patterns were obtained when redox monomers and polymers on the base of quinones in the presence of iodine were used as oxidants. Esters of phosphoric acid – dialkylphosphites and esters of phosphorous acid – trialkylphosphates were identified as organophosphorus compounds. By selecting a redox agent in a zone of the catalysis it is possible to direct process in the desirable direction. The most activity in the oxidation of phosphine by iodine-alcohol solutions of quinoid monomers and polymers, is exhibited by 2-[N-(2-vinyloxy) ethyl]amino-NQ and polymer on their basis. Results of our experiments and literature data on oxidation-reduction processes with participation of iodine and quinones in organic solutions allowed to propose the separate oxidation-reduction mechanism of formation of organophosphorus compounds. In investigated multicomponent systems, the synergetic effect is manifested which is reached at the expense of distribution of oxidation-reduction functions among iodine, quinones and its derivatives. In this report, for the first time, it is established reactionary ability of quinones and redox ionites on their basis in an oxidizing alkoxylation of phosphine to valuable esters of acids of phosphorus. Reaction can be used for purification of exhaust and technological gases from phosphine and its utilization.</p>

Phosphorus-contained polycondensation type ion-exchange resins

This work describes synthesis and research of new polycondensation type phosphorus� contained ionexchange polymers by phosphorylation of polymers received through the interaction of furfural (accessible and cheap product of hydrolytic and cotton scraping industry of Uzbekistan) with benzyl bromide (chloride). Furfural and its derivatives possess high reactionary ability thanks to presence of carbonyl groups, and presence of a heterocyclic cycle gives to the received polymers high thermal and chemical stability. Polycondensation reaction kinetics of furfural and benzyl bromide, and phosphorylation reaction of the received benzyl bromidefurfural polymer were studied. Sorpt ion, kinetic and thermochemical properties of received ionexchange resins were stu died using physicochemical and chemical analyses to find out specific objects of practical application. Particularly, sorption and selective properties of received ionexchange resins to ions of such metals as copper, nickel, calcium, magnesium, and uranyl ion were studied. Received results support the application of the investigated ionexchange resins in processes of cl earing of industrial and waste waters of hydrometallurgical manufactures.

Conversion of biomass products to energy sources in the presence of nanocatalysts and membrane-catalyst systems

A particular role in the harmonious exploitation of raw materials is assigned to organic sources of fuels based on renewable biomass. The most promising feedstocks of major energy sources, such as hydrogen and organic components of motor fuels, include ethanol and other bioalcohols, i.e., the primary products of its conversion. In this work, we describe the results for new reactions of conversion of ethanol and a mixture of ethanol and glycerol, which are the major products of biomass, to the C3–C10 alkane-olefin fraction in the presence of nanoscale mono- and bimetal-containing active components supported on γ-Al2O3 (〈d〉 = 5–8 nm) and on the inner surface of microchannels of ceramic membranes (〈d〉 = 15–20 nm). Mono- and bimetallic alkoxide and acetate complexes are used as precursors. It is found that the selectivity for the ethanol conversion to aliphatic hydrocarbons, as well as the content of branched structures, heavily depends on the nuclearity and composition of metal-complex precursors supported on γ-Al2O3. It is found for the first time that glycerol exhibits high reactionary ability in the reaction of cross-condensation of the carbon skeleton of alcohols of different nature. In the presence of a Ta-Re-containing system, a mixture of ethanol and glycerol is converted to 60% of C4–C10+ olefins, which contain up to 50% of branched structures. It is shown that by varying the composition of Pd-Zn-containing active components, it is possible to targetedly convert ethanol to the olefin, alkane, or alkane-olefin fraction. Porous membrane-catalyst systems are designed to produce hydrogen and syngas from biomass products; the systems exhibit high activity in the carbon dioxide and steam reforming of ethanol, a mixture of ethanol and glycerol, and acetic acid. A scheme for the production of a wide range of valuable organic products based on bioalcohols containing no toxic impurities and independent of crude oil is described. According to this scheme, alkanes derived from ethanol and other bioalcohols are the major components of motor fuels; a large number of organic synthesis products can be derived from olefins, hydrogen, and carbon monoxide in the carbonylation/hydrocarbonylation processes.

Polyfunctional Photochromism of Spirocompounds

The review of own results in the field of the unusual properties (photoinduced nonlinear behavior, irradiation capacity, complex formation, refractive index, reactionary ability) for spirocompounds exhibiting photochromic transformations is presented. These polyfunctional properties of spirocompounds extend their capabilities for application in modem optical information technologies and molecular photonics.