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The catalytic transformation of petroleum-derived asphaltene with Co loaded smectite and CoMo loaded alumina based catalysts was studied in the range from 40 to 420°C using proton magnetic resonance thermal analysis (PMRTA). Residual hydrogen as a qualitative measure of the hydrogen remaining in the sample and second moment (M2T16), which is sensitive to molecular mobility, were obtained as a function of temperature. Both residual hydrogen and M2T16 of the asphaltene were dependent on the properties of the coexisting catalyst. Metal oxides in the Co porous saponite and CoMo alumina based catalysts, which are active for the transformation of asphaltene, were probably reduced to the metals and became ferromagnetic at about 350°C, because the M2T40 values of the char derived from the asphaltene with the active catalysts after cooling to room temperature were over 250kHz2, compared to typical values of 150kHz2 for chars without ferromagnetic material. Hydrodesulfurization and hydrocracking with the catalysts were correlated with the values of M2T16 at 400°C. Moderate interaction of the metal oxide with the support material resulted in an intermediate reduction state with high HDS acctivity. The PMRTA method with 1H as a probe of the state of hydrocarbons such as asphaltene provides useful information about the catalyst activity and is helpful for the design and preparation of the catalyst.

レーザー脱離イオン化質量分析 (LDI-MS) 法による石油系重質油アスファルテンの分子量分布測定を行った。試料調製濃度と照射レーザー出力の条件検討により分子量分布を反映していると思える質量スペクトルが得られた。このスペクトルは異なる油種についてもほぼ同じ結果が示された。アラビアンヘビー (AH-VR) アスファルテンでは, 質量スペクトルから求めた重量および数平均分子量は, 蒸気圧平衡法やゲルパーミエーションクロマトグラフィー (GPC) 法で得られたものよりも小さかった。また, AH-VRアスファルテンを溶剤分画法やGPC法により分画し, 詳細な解析を試みた。照射レーザー出力の強い条件下では周期的な質量ピークが観察され, その質量差からアスファルテンが同族タイプに属する芳香族縮合環構造を有していると推定した。スマトラライト (SL-VR) アスファルテンについても同様の周期性が認められたが, グループ解析結果では両者は異なっており, 骨格構造がAH-VRとは異なることが示唆され, アスファルテン芳香族骨格構造の解析が可能であることを示した。

As a part of our fundamental studies on the acid function of catalysts for hydrocracking, alumina-pillared montmorillonite catalysts were prepared and characterized by means of temperature-programmed desorption with NH 3 from sulfided catalysts (TPD-S) and temperature-programmed reduction of sulfided catalysts (TPR-S). The TPD-S and TPR-S characteristics of catalysts thus obtained have been compared with the activities of cumene cracking in a pulse-type micro reactor. Commercial hydrocracking catalysts were also characterized with similar methods and the performance of cumene cracking was tested. TPD, TPR profiles and cumene cracking activity changed after sulfiding of alumina-pillared montmorillonite. Both the chemical property changes by the heat treatment and the sulfur species adsorbed on the surface allow us to alter its acid property and cumene cracking activity as well.

Catalysts of cobalt oxide loaded on smectic clays having high surface areas were prepared. Smectic clays used were montmorillonite, saponite, porous saponite, hectorite and stevensite. The catalysts were tested for hydrodesulfurization (HDS) activity with thiophene in a pulse flow reactor at different temperatures. Co–porous saponite catalyst prepared by an ion-exchange method in the series including CoMo–Al 2 O 3 shows the highest thiophene HDS activity so far studied. The catalytic properties of the selected catalysts were characterized by temperature-programed-reduction (TPR) and -sulfiding (TPS) together with electron spin resonance (ESR). The HDS performance with thiophene is closely dependent upon the reduction temperature of cobalt oxide obtained by TPR for Co–smectite catalysts. The TPS measurements indicate that small particles of cobalt oxide are highly dispersed in the smectic layer by means of ion-exchange method. It is suggested that the properties such as sensitivity toward H 2 S and catalyst color of cobalt oxide on Co–porous saponite by ion-exchange method are different from those of Co–porous saponite by impregnation method. Reactivity of loaded cobalt oxide with H 2 S is strongly dependent upon the sulfiding paths.

Hydrocracking reactions of diphenylmethane and tetralin were carried out over three kinds of zeolites with or without NiW sulfide to discuss the roles of catalytic bifunctionality in two types of hydrocracking reactions. It was found that strong acid sites were not needed for the hydrocracking of diphenylmethane, while the conversion of tetralin required relatively strong acid sites. Ultra-stable Y zeolite with strong acidity exhibited high hydrocracking activity for both reactions. In contrast, mordenite catalysts did not show high activity for either hydrocracking, though isomerization of tetralin and excess hydrocracking to gaseous products proceeded. The superior performances of ultra-stable Y zeolite in the tetralin hydrocracking were suggested to be related to the hydrogen transfer ability. In most cases, the loading of NiW sulfide enhanced catalytic activity. In the diphenylmethane hydrocracking, the role of NiW sulfide was found to supply active hydrogen to the hydrocracking active sites on zeolite and to prevent polymerization of benzyl cations. In the tetralin hydrocracking, the dehydrogenated products from tetralin were re-hydrogenated over NiW sulfide.

The catalytic functionality and structural properties of three kinds of unsupported molybdenum sulfide catalysts were investigated by model test reactions and BET, TEM, XPS and XRD analyses. The results indicated that highly bent multi-layered MoS2 structures were more catalytically active, while a well crystallized MoS2 structure was more favorable for direct S-extrusion during the reactions of dibenzothiophene. It was proposed that the curvature of MoS2 basal planes was catalytically active, though they were less active for hydrodesulfurization than the edge planes.

CoMo-Al2O3 catalyst was characterized with a combination technique of temperature-programmed sulfiding (TPS) and electron spin resonance (ESR). The behavior of the MoO3 loaded over the surface of Al2O3 obtained from TPS has been compared with that of Mo5+ observed with ESR at isothermal and elevated temperatures. The Mo6+ in the MoO3 supported is easily reduced with H2S+H2 under very mild conditions and transformed into Mo5+ as an intermediate. This Mo5+ peak drastically decreased around 200°C with H2S desorption, and H2 consumption appeared simultaneously in the TPS profile. These results suggest that the Mo5+ species observed with ESR associates with sulfur from H2S.

The thermal transformations in petroleum derived asphaltene in a temperature range from 40 to 420°C was studied using proton magnetic resonance thermal analysis (PMRTA). Stacked plot of 1 H-NMR signals and residual hydrogen suggest the gradual structural transition of asphaltene from largely rigid material to one having a high degree of molecular mobility at 300°C. From the results of solid echo curve fitting analysis, an increasing Weibull time constant and decreasing power may be taken as gradual shifting of rigid structure to a more mobile one. No clear abrupt changes are observed relating to liquid phase transition and the formation of coke precursor from asphaltene in the temperature range up to 420°C. The second moment, M 2Γ (V T ), is sensitive to molecular dynamics and also to concentration and distribution of protons and unpaired electrons in the molecular lattice. The value of M2T16 provides an appropriate measure to study the extent to which molecular lattice of asphaltene was mobilized by thermal destabilization. The asphaltene has extremely high fluidity compared with those derived from coals at 400°C. From PMRTA of reheated samples, first heat treatment up to 450°C have resulted in irreversible thermal transformations.

This paper reports the development of novel hydrocracking catalysts supported on high-surface area saponite clay and pillared with either cobalt or nickel oxide. The catalysts were prepared by aging the Co or Ni nitrate solution, followed by addition of saponite, washing, drying and calcination. The catalysts were evaluated for HDS, HDN and hydrocracking activities in a batch autoclave reactor using vacuum gas oil as feedstock. The results show that the HDS, HDN and cracking activities of the novel catalysts are comparable to that of a conventional NiW/SiO2-Al2O3 catalyst. The Co catalyst gave better HDS activity while the Ni catalyst showed higher HDN and cracking activity. Calcination before metal loading does not seem to effect the overall performance of the Co catalysts. It should be noted these activities are achieved despite the use only one metal as the active ingredient. The results of this study clearly indicate that the saponite clay based catalysts are a potential alternative to the conventional hydrocracking catalysts.

The maximum activity of MoS2 dispersed catalysts in the reaction of resid-containing feedstocks were examined. The results suggested that MoS2 catalysts could not yield sufficient conversion of residue at low temperatures even if the catalyst particles were atomically dispersed. To overcome this limitation, two methods were proposed. One was the addition of a promoter element to M0S2 catalysts. The other was the use of bifunctional catalysts with solid acidity.

The activity of carbon-supported catalysts was investigated for a slurry phase system. In this paper, some active carbons were used as carbon-supports. We prepared NiMo/active carbon and Fe/active carbon catalysts. These catalysts were used for hydrogenation of heavy oil at 693K. At the same time, we examined 1-methylnaphthalene (1-MN) hydrogenation activity and methylcyclohexane (MCH) dehydrogenation activity for our catalysts and supports. We discussed the correlation of asphaltene conversion with 1-MN and MCH reactivity. There was little correlation between them. It is found that active carbons contributed to decrease the coke formation.

The activation volume of viscous flow in mixtures of paraffinic and naphthenic base oils of high and low viscosities, and in those of liquid fatty acids, their esters, and fatty oils have been determined experimentally. The results are used to test the applicability of the semiempirical formula which can estimate the activation volume from the molecular structure of the substance involved. Limitations in its applicability are also discussed.

The flow activation quantities were experimentally determined at 25.0°C with mineral lubricating oils blended with various concentrations of VI-improver. While polylauryl-methacrylate increases activation volume substantially and decreases activation entropy considerably, it does not affect activation enthalpy. Polyisobutylene changes the quantities only slightly. Molecular interpretation of these observations has been attempted.

Activation enthalpy, entropy, and volume of viscous flow were determined experimentally with 16 mineral lubricating oils and 4 blends. The relations between these quantities were examined and it was found that the relation between activation enthalpy and volume and that between the enthalpy and entropy were approximately linear. The later relation seems similar to the so-called compensation effect in chemical reactions. The activation enthalpy of the blends was shown to be additive when expressed in volume fraction.