Durability and regeneration of catalysts of the iron family in hydrogenation of low-temperature tar

Energy Technology Data Exchange (ETDEWEB)

Funasaka, W; Yokogawa, C; Hayashi, K; Kawamura, T; Fujita, H; Suga, S

1949-01-01

The low-temperature tar consisting of neutral and acidic oils has been reduced under atmospheric pressure between 400/sup 0/ and 500/sup 0/ by using catalysts prepared from Fe-Cr-kieselguhr, yellow ocher, and other material. When the reduction was performed at 480/sup 0/ with the yellow ocher from Niwasaka, Fukushima Prefacture, Japan, the low-temperature tar was easily converted to neutral and light oils and the catalysts could be regenerated by repeated baking and reduction. It is concluded that the commercialization of this reduction process is possible by using a cycle (each takes 20 minutes) composed of catalytic reaction, baking, and reduction of the catalysts.

Inert carriers for column extraction chromatography

International Nuclear Information System (INIS)

Katykhin, G.S.

1978-01-01

Inert carriers used in column extraction chromatography are reviewed. Such carriers are devided into two large groups: hydrophilic carriers which possess high surface energy and are well wetted only with strongly polar liquids (kieselguhrs, silica gels, glasses, cellulose, Al 2 O 3 ) and water-repellent carriers which possess low surface energy and are well wetted with various organic solvents (polyethylene, polytetrafluorethylene polytrifluorochlorethylene). Properties of various carriers are presented: structure, chemical and radiation stability, adsorption properties, extracting agent capacity. The effect of structure and sizes of particles on the efficiency of chromatography columns is considered. Ways of immovable phase deposition on the carrier and the latter's regeneration. Peculiarities of column packing for preparative and continuous chromatography are discussed

Distilling shale

Energy Technology Data Exchange (ETDEWEB)

Kern, L

1922-07-21

In the distillation of shale and similar materials the shale is ground and briquetted and the briquettes are placed in a retort so that air passages are left between them, after which they are uniformly and slowly heated to at least 700/sup 0/C, the air passages facilitating the escape of the oil vapors, and the slow heating preventing fusion of the flux forming constituents. After the bitumen has been driven off, air is passed into the retort and heating continued to about 1050/sup 0/C, the result being a porous product suitable for insulating purposes or as a substitute for kieselguhr. The ground shale may be mixed prior to distillation with peat, sawdust, or the like, and with substances which yield acids, such as chlorides, more particularly magnesium chloride, the acids acting on the bitumen.

Gas-phase hydrogenation of benzene on supported nickel catalyst

Energy Technology Data Exchange (ETDEWEB)

Franco, H.A.; Phillips, M.J.

1980-06-01

The reaction of 22.66-280 Pa benzene with 72.39-122.79 Pa hydrogen on kieselguhr-supported nickel at 392.2/sup 0/-468.2/sup 0/K yielded only cyclohexane and was independent of 5.33-40 Pa cyclohexane added to the feed of the differential flow reactor. Best fit for the kinetic data was obtained with a rate equation developed by van Meerten and Coenen which assumed that all hydrogen addition steps have the same rate constant and are slow. An observed rate maximum at 458/sup 0/K may be the result of an increasing rate constant and decreasing cyclohexyl surface coverage as the temperature increases. Temperature-programed hydrogen desorption showed a series of desorption peaks at 358/sup 0/-600/sup 0/K, including one at 453/sup 0/K, which may be due to the hydrogen involved in the surface reaction.

Studies for the yttrium determination by activation analysis, in the presence of lanthanides. Application of the substoichiometric technique

International Nuclear Information System (INIS)

Silva, D.I.T. da.

1978-01-01

Some methods using extraction chromatography for the separation of yttrium from the lanthanide elements were applied. The separation of yttrium was studied, using di-(2 ethylhexyl) orthophosphoric acid as stationary phase, Kieselguhr as support and HNO 3 of concentration between 4,5 and 5,0 N as the mobile phase. In these conditions, about 50% of pure yttrium was obtained. The substoichiometric technique was applied to the determination of yttrium. The elements was partially complexed and the Y 3 + ions were separated from the complex (EDTA-Y) - by means of a cationic resin. The sensitivity, precision and accuracy which can be expected in the analytical results were studied. The possibility of the analysis of a sample containing 1 part per million of yttrium with an error just above 8% was demonstrated. It was also shown that, admitting an error of 10%, it is possible to determine 60 parts per billion of yttrium [pt

Design of a stationary-basket (microreactor)

Energy Technology Data Exchange (ETDEWEB)

Timidei, A; Raisa, L

1977-05-01

A continuous-flow stirred-tank microreactor (295 cc capacity) for kinetic studies in gas-solid heterogeneous catalysis has been designed to obtain an apparatus characterized by perfect mixing, absence of resistance to mass and heat transfer, and pressure tightness, and which would not require sophisticated machine-shop work. This reactor is suitable for operation at up to 300/sup 0/C and 20 atm, and has clear advantages over the spinning-basket or rotating reactor in studies of catalysts of low mechanical strength. Tests with nitrogen or ethane as tracer and helium as carrier gas, run with a thermal conductivity detector, gave a ''decadence'' curve with a -0.97 slope at all mixing speeds, compared with a -1.0 slope for perfect mixing. Thermal gradients between fluid and pellet were minimal for three different pellet positions within the annular bed, at 92/sup 0/C. In benzene hydrogenation over a nickel/kieselguhr catalyst, measurement of reaction rates as a function of mixing speeds showed that good results in kinetic studies were obtainable at 1500 rpm and above. Diagrams and graphs.

A Novel Methodology for the Synthesis of Acyloxy Castor Polyol Esters: Low Pour Point Lubricant Base Stocks.

Science.gov (United States)

Kamalakar, Kotte; Mahesh, Goli; Prasad, Rachapudi B N; Karuna, Mallampalli S L

2015-01-01

Castor oil, a non-edible oil containing hydroxyl fatty acid, ricinoleic acid (89.3 %) was chemically modified employing a two step procedure. The first step involved acylation (C(2)-C(6) alkanoic anhydrides) of -OH functionality employing a green catalyst, Kieselguhr-G and solvent free medium. The catalyst after reaction was filtered and reused several times without loss in activity. The second step is esterification of acylated castor fatty acids with branched mono alcohol, 2-ethylhexanol and polyols namely neopentyl glycol (NPG), trimethylolpropane (TMP) and pentaerythritol (PE) to obtain 16 novel base stocks. The base stocks when evaluated for different lubricant properties have shown very low pour points (-30 to -45°C) and broad viscosity ranges 20.27 cSt to 370.73 cSt, higher viscosity indices (144-171), good thermal and oxidative stabilities, and high weld load capacities suitable for multi-range industrial applications such as hydraulic fluids, metal working fluids, gear oil, forging and aviation applications. The study revealed that acylated branched mono- and polyol esters rich in monounsaturation is desirable for developing low pour point base stocks.

The Laboratory for Laser Energetics’ Hydrogen Isotope Separation System

Energy Technology Data Exchange (ETDEWEB)

Shmayda, W.T., E-mail: wshm@lle.rochester.edu; Wittman, M.D.; Earley, R.F.; Reid, J.L.; Redden, N.P.

2016-11-01

The University of Rochester’s Laboratory for Laser Energetics has commissioned a hydrogen Isotope Separation System (ISS). The ISS uses two columns—palladium on kieselguhr and molecular sieve—that act in a complementary manner to separate the hydrogen species by mass. The 4-sL per day throughput system is compact and has no moving parts. The columns and the attendant gas storage and handling subsystems are housed in a 0.8 -m{sup 3} glovebox. The glovebox uses a helium cover gas that is continuously processed to extract oxygen and water vapor that permeates through the glovebox gloves and any tritium that is released while attaching or detaching vessels to add feedstock to or drawing product from the system. The isotopic separation process is automated and does not require manual intervention. A total of 315 TBq of tritium was extracted from 23.6 sL of hydrogen with tritium purities reaching 99.5%. Deuterium was the sole residual component in the processed gas. Raffinate contained 0.2 TBq of activity was captured for reprocessing. The total emission from the system to the environment was 0.4 GBq over three weeks.

Study on the method for determination of the nuclear fuel elements burnout by the quantitative analysis of 148Nd

International Nuclear Information System (INIS)

Enoshita, Margarida

1978-01-01

The scope of present work to study the precision and accuracy of a method for separation and determination of the.stable isotope 148 Nd. The extraction chromatography and ion exchange techniques were used for the separation of fission products and uranium. Kieselguhr and di(2-ethyl-hexyl)phosphoric acid were used as inert support and stationary phase, respectively, in the steps of the separation procedure where the extraction chromatography technique was applied, and anionic resin mixed with Pb0 2 was used for the ion exchange operation. The behaviour of each element in the separation procedure was verified by means of radioactive tracers, namely, 147 Nd, 141 Ce and 137 Cs. Use was made of the thermal neutron activation analysis in order to determine the 148 Nd percentage recovered after the separation procedure was run. On the other hand, the radioactive isotope 147 Nd was used to find chemical yield achieved for the separation procedure. Student's t test applied to verify the accuracy of the method used whose acceptability was verified by using the criterion recommended by McFarren and also taking into account the suggestion proposed by Eckschlager. The precision of the method was verified by means of the standard deviation of the several determinations. (author)

Magnetic diatomite(Kieselguhr)/Fe2O3/TiO2 composite as an efficient photo-Fenton system for dye degradation

Science.gov (United States)

Barbosa, Isaltino A.; Zanatta, Lucas D.; Espimpolo, Daniela M.; da Silva, Douglas L.; Nascimento, Leandro F.; Zanardi, Fabrício B.; de Sousa Filho, Paulo C.; Serra, Osvaldo A.; Iamamoto, Yassuko

2017-10-01

We explored the potential use of diatomite/Fe2O3/TiO2 composites as catalysts for heterogeneous photo-Fenton degradation of methylene blue under neutral pH. Such system consists in magnetic solids synthesized by co-precipitation with Fe2+/Fe3+ in the presence of diatomite, followed by impregnation of TiO2. The results showed that the optimal amount of the catalyst was 2.0 g L-1, since aggregation phenomena become significant above this concentration, which decreases the photodegradation activity. The catalyst is highly efficient in the degradation of methylene blue and shows an easy recovery by an external magnetic field. This allows for an effective catalyst reuse without significant loss of activity in catalytic cycles, which is a highly interesting prospect for recyclable dye degradation systems.

Thermodynamic parameters and sorption of U(VI) on ACSD

International Nuclear Information System (INIS)

Donat, R.; Cilgi, G.K.; Cetisli, H.; Aytas, S.

2009-01-01

This paper discusses the sorption properties for U(VI) by alginate coated CaSO 4 x 2H 2 O sepiolite and calcined diatomite earth (Kieselguhr) (ACSD). The removal of U(VI) from aqueous solution by sorption onto ACSF in a single component system with various contact times, pH, temperatures, and initial concentrations of U(VI) was investigated. The sorption patterns of uranium on the composite adsorbent followed the Langmuir, Freundlich and Dubinin-Radushkhevic (D-R) isotherms. The Freundlich, Langmuir, and D-R models have been applied and the data correlated well with Freundlich model and that the sorption was physical in nature (sorption energy, E a = 17.05 kJ/mol). The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnK 0 vs. 1/T plots. Thermodynamic parameters (ΔH ads = 31.83 kJ/mol, ΔS ads = 167 J/mol x K, ΔGdeg ads (293.15 K) = -17.94 kJ/mol) showed the endothermic heat of sorption and the feasibility of the process. The thermodynamics of U(VI) ion/ACSD system indicates the spontaneous and endothermic nature of the process. It was noted that an increase in temperature resulted in a higher uranium loading per unit weight of the adsorbent. (author)

Reducing pesticide level in wine by selective filtration

Directory of Open Access Journals (Sweden)

Lempereur Valérie

2014-01-01

Full Text Available Wine Pesticide residues, even when below grape regulatory limit, are a concern for consumers and have an impact on the export potential of wine in certain markets. A consortium of European SMEs (www.adfimax.com has developed a product that reduces the level of mycotoxins and pesticides in wine while keeping all other wine parameter identical. The product is derived from renewable vegetable fiber. The production process includes both activation and micronisation. The usage recommendation is to substitute only the pre-coat, typically perlite, by the product at 1 or 1.5 kg⋅m−2 without changing the other layer (body feed typically kieselguhr. This paper describes the results of numerous industrial trials that were performed in France, Luxemburg, Germany and Spain. The impact of the product on the wine oenological characteristics was evaluated for different wine (white, red and rosé in different countries and for different grape variety (including Cabernet sauvignon, Merlot and Gamay. Results showed a reduction of the test wine pesticide level of 50% to 60% for all pesticides compared to the blank. Level of pesticide analyzed in the cake where extremely high at a level of a 1,000 times greater than the filtered wine showing the ability of the product to selectively capture the pesticides molecules.

Determination of minor-and trace elements in magnesite samples, by activation analysis

International Nuclear Information System (INIS)

Sepulveda Munita, C.J.A.

1979-01-01

A method employing activation analysis with thermal neutron was developed for the determination of minor and trace elements in magnesite samples from the states of Ceara and Bahia (Brazil). Ten samples were analyzed. A qualitative analysis of the samples indicated the presence of Mn, Fe, Sc, Ca, Cu, Co and some of the lanthanides. The experimental part includes a non-destructive analysis of manganese and analysis with chemical separation of the other elements, individually or in groups, after sample dissolution, The dissolutions were made with concentrated HCl and the further separations were carried out in 8 N HCl medium. Iron was separated by means of an extraction of HFeCl 4 with isopropyl ether. Scandium and calcium were determined by retention of scandium with di-(2-ehylhexyl) phosphoric acid (HDEHP). The activities of 46 Sc and 47 Sc (a 47 Ca descendant) were employed for the analysis of scandium and calcium in the sample. In the effluent of the kieselguhr column copper and cobalt were determined, after retention in an anionic resin of the CuCl - 3 and CoCl - 3 complexes. Finally, in the effluent of the resin, the lanthanide group was separated by oxalate precipitation. In the gamma-ray spectrum of this precipitate the elements europium, cerium, samarium and lanthanum were determined. A detailed study of the possible interferences in the neutron activation analysis of the elements analysed was also made. The precision and accuracy of the results obtained and the sensitivity of the method are discussed. (Author) [pt

Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

International Nuclear Information System (INIS)

Clark, E.A.

1992-01-01

Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (AHL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns

Trace Analysis of Boron in Nuclear Graphite by Means of Gas Chromatography; Analyse de traces de bore dans le graphite nucleaire au moyen de la chromatographie gazeuse; Analiz metodom gazovoj khromatografii sledov bora v yadernom grafite; Analisis de vestigios de boro en el grafito nuclear por cromatografia de gases

Energy Technology Data Exchange (ETDEWEB)

Zado, F. [Rudjer Boskovlc Institute, Zagreb, Yugoslavia (Croatia)

1963-11-15

No literature is available about the application of gas chromatography in trace analysis of boron in graphite. The following methods of transformation of boron into its volatile compounds are discussed: (a) Ignition of graphite in a stream of oxygen and subsequent transformation of boron oxide into volatile methyl borate which is then analysed on a Dilkens Aerograph H Model 96 gas chromatograph with silicone column and hydrogen as carrier (concentration method). (b) Extraction of boron from the graphite by means of sodium fluoride at 2800{sup o}C with simultaneous chlorination and trapping of boron trichloride, which is then analysed (direct method). A home-made gas chromatograph with a thermal conductivity detector and nitrogen as a carrier was used. The column was made of glass with a 20% (wt./wt.) fluorocarbon oil on kieselguhr. Special precautions were taken on account of the sensitivity of boron trichloride to moisture. (author) [French] Rien n'a ete publie sur l'application de la chromatographie gazeuse a l'analyse de traces de bore dans le graphite. L'auteur examine les methodes suivantes de transformation du bore en composes volatils: a) Brulage du graphite dans un courant d'oxygene, puis transformation de l'oxyde de bore en borate de methyle volatil, que l'on analyse ensuite a l'aide d'un appareil a chromatographie gazeuse Dilkens Aerograph H, Modele 96, utilisant une colonne de silicium et de rhydrogene comme entrafheur (methode de concentration). b) Extraction du bore contenu dans le graphite par chauffage avec du fluorure de sodium a 2800{sup o}C, avec chloruration simultanee et captage du trichlorure de bore qui est ensuite analyse (methode directe). On s' est servi d'un appareil a chromatographie gazeuse construit sur place, dote d'un detecteur a conductibilite thermique et utilisant l'azote comme entrafheur. La colonne etait faite de verre contenant 20% en poids de fluorocarbure huileux sur du kieselguhr. Des precautions particulieres ont ete prises

Reactions of Hot Tritium Atoms with Amino Acids; Reactions entre Atomes Chauds de Tritium et Acides Amines; Reaktsii goryachikh atomov tritiya s aminokislotami; Reacciones de Atomos de Tritio Calientes con Aminoacidos

Energy Technology Data Exchange (ETDEWEB)

Simonov, E. F.; Nesmejanov, An. N. [Moskovskij Gosudarstvennyj Universitet, Moskva, SSSR (Russian Federation)

1965-04-15

In the existing literature there is a lack of systematic data on the interaction of tritium recoil atoms with amino acids, yet such data, in conjunction with results already obtained for organic acids and amines, could help in determining the mechanism of hot reactions in relation to the structure of compounds (chain length, functional substitutes). A study was made of the yields from the reaction of hot tritium atoms: (1) with amino acids having lengthened chains, and (2) with amino acids having a carbon chain of constant length, but with various functional substitutes. For this purpose mixtures of lithium carbonate and the acids under study were irradiated for 15 min with a slow neutron flux of 0.87 x 10{sup 13} cm{sup 2}/s. Analysis was carried out on a gas chromatography unit with interchangeable columns (molecular sieves, and liquid petrolatum on kieselguhr) and with paper chromatography. Although the data obtained for the radiation survival capacity of amino acids as a function of carbon chain length were at variance with a basic tenet of radiation chemistry according to which the conservation of molecules increases in proportion to the length of their chains, the data can be explained in terms of an intramolecular transfer of energy along the carbon chain from the collision site of the hot atom to the hydroxyl group, and subsequent ''de-excitation''; on the other hand, although the energy, of tritium recoil atoms is greater than that of the chemical bond, the latter nevertheless exerts an influence on the radiation conservation of molecules with a carbon chain of constant length but with various substitutes. (author) [French] Les etudes publiees jusqu'a present ne contiennent guere de renseignements systematiques sur les interactions entre atomes de tritium de recul et acides amines. Pourtant, ces donnees, completees par celles dont on dispose sur les acides organiques et les amines, pourraient aider a definir le mecanisme des reactions chaudes en fonction