Ryoichi Yoshida

Chemical structure changes in Condor shale oil and catalytic activities during catalytic hydrotreatment

Abstract Chemical structure changes in Condor shale oil during catalytic hydrotreatment were studied based on elemental analysis. 1 H-NMR analysis, TLC/FID and GCD. Catalytic activities of red-mud/sulfur and Niue5f8Mo catalysts were discussed as to the hydrogenation and hydrogenolysis of structure units in addition to the removal of heteroatoms.

Growth of ZnO needle crystals by vapor phase reaction method

Abstract ZnO needle crystals were grown by the oxidation of zinc vapor produced by the reduction of ZnO powder with carbon powder at an elevated temperature. The typical crystals were colorless and transparent with maximum size of 0.1 mm diameter and 200 mm length.

Vapor phase growth of Zn2SnO4 needle crystals

Abstract Needle crystals of Zn2SnO4 were grown in a comparatively short time from the vapor phase in a porcelain crucible using a starting mixture of ZnO powder and tin powder. The effect of the mixing ratio of the starting material (ZnO and Sn) and that of temperature on crystal growth were discussed. The properties of the needle crystals grown were also described.

Catalytic activities of metal oxides containing iron for hydrocracking coal model compounds and Taiheiyo coal

Abstract Twenty-five catalysts of metal oxides principally containing iron were prepared and examined in hydrocracking of coal model compounds: diphenyl ether, diphenylmethane and benzyl phenyl ether. Highly active catalysts were Fe 2 O 3 -I and -II and FE 2 O 3 ue5f8TiO 2 for diphenyl ether, Fe 2 O 3 -I and -II and Fe 2 O 3 ue5f8SiO 2 for diphenylmethane, and sulfated Fe 2 O 3 -I, -II and -III and Fe 2 O 3 ue5f8TiO 2 together with WO 3 /ZrO 2 for benzyl phenyl ether. The best method for preparation of iron oxide was precipitation of the hydroxide from the nitrate with ammonia followed by calcination. The catalysts were tested for the liquefaction of Taiheiyo coal using a high-pressure d.t.a. apparatus; sulfated Fe 2 O 3 ue5f8TiO 2 was most effective, and the order of activity was similar to that for benzyl phenyl ether. From the results of hydrocracking of model compounds and liquefaction of Taiheiyo coal, both Cue5f8C and Cue5f8O bond cleavages are discussed on the basis of acid property and hydorgenation ability of the catalysts.

Clean Coal Technologies in Japan

Coal provided 16.1% (116.3 million tons) of the energy for Japan in FY 1992. According to the long-term energy supply and demand outlook in Japan, prepared and revised in June 1994 by the Advisory Committee for Energy, it is estimated that coal will provide 16.4% (130 million tons) of the energy in 2000 and 15.4% (134 million tons) in 2010, and that coal demand will increase. Japan imports one-third of the amount of international coal trade and depends heavily on overseas coals. In FY 1993, Japan imported 112 million tons of overseas coals and depended on foreign countries for about 94% of coal used. Coal provides about 30% of the energy for the world. Owing to the stable supply of coal and its economic efficiency for the middle and long term, technologies for coal utilization such as clean coal conversion, including liquefaction, gasification, etc., and efficient combustion processes are being developed in Japan as the chief substitute for petroleum to reduce the excessive dependence on petroleum. Clean coal technologies being developed in Japan will spread widely throughout the world and are expected to create sustainable growth while solving energy and environmental issues.

Mechanism of high-pressure hydrogenolysis of Hokkaido coals (Japan) 3. Chemical structure changes in coal asphaltenes during hydrogenolysis

Abstract Asphaltenes produced by hydrogenolysis of coal were further hydrogenated in a batch autoclave at 400°C and 22 MPa hydrogen pressure. Red-mud was used as a catalyst and sulfur as promoter. The hydrogen content of the residual asphaltene increases and the fraction of aromatic carbon and the fraction of protons bound to aromatic carbons decrease as the reaction proceeds, indicating that hydrogenation of aromatic rings occurs. Aromatic ring systems of more than 2 rings are relatively easily hydrogenated to 2 rings. However, 2 ring systems are not easily hydrogenated. The heteroatoms-to-carbon ratios are similar for both the oil and the residual asphaltene, but less than that of the original asphaltene. The main differences in the chemical structure between the oil and the residual asphaltene are the hydrogen-to-carbon ratio, the fraction of aromatic carbon, the molecular weights and the average degrees of crosslinking. The residual asphaltene is composed of trimers and/or oligomers of unit structures of two or more condensed aromatic rings bound together by crosslinks. The size and composition of the condensed ring systems varies about the average properties measured in these experiments. Cleavage of the crosslinks by hydrogenation and heteroatom removal produces oil, composed for the most part of monomers of unit structures of two condensed aromatic rings. Coals of different rank show similar behavior although the magnitude of the changes depends on rank.

Chemical structure changes in Cold Lake oil-sand bitumen and catalytic activities during catalytic hydrotreatment

Abstract Chemical structure changes in Cold Lake oil-sand bitumen and catalytic activities of red-mud/sulfur and Niue5f8Mo catalysts during catalytic hydrotreatment are discussed. Particular attention is given to hydrogenation and hydrogenolysis of structural units, and to the removal of heteroatoms. Niue5f8Mo catalyst at 450°C reaction temperature gives high conversion of oil-sand bitumen to lower boiling fractions improving H C ratio and extensive removal of heteroatoms. According to the deposition of metals on the spent catalysts, red-mud/sulfur catalyst is effective for bitumen demetallization, removing V and Ni metals.

Comparison of the chemical structure of coal hydrogenation products, athabasca tar sand bitumen and Green River shale oil

Abstract Coal hydrogenation products, Athabasca tar sand bitumen, and Green River shale oil produced by retorting were analyzed by the Brown—Ladner method and the Takeya et al. method on the basis of elemental analysis and 1 H-NMR data, by 13 C-NMR spectroscopy and by FT-IR spectroscopy. Structural characteristics were compared. The results show that the chemical structure of oils from Green River shale oil and Athabasca tar sand bitumen, and the oils produced in the initial stage of hydrogenation of Taiheiyo coal and Clear Creek, Utah, coal is characterized as monomers consisting of units of one aromatic ring substituted highly with C 3–6 aliphatic chains and heteroatom-containing functional groups. The chemical structure of asphaltenes from Green River shale oil and Athabasca tar sand bitumen is characterized by oligomers consisting of units of 1–2 aromatic rings substituted highly with C 3–5 aliphatic chains and heteroatom-containing functional groups. The chemical structure of asphaltenes from coal hydrogenation is characterized by dimers and/or trimers of unit structures of 2 to 5 condensed aromatic rings, substituted moderately with C 2–5 aliphatic chains and heteroatom-containing functional groups. The close agreement between fa ( 1 H-NMR) and fa ( 13 C-NMR) for Green River shale oil derivatives and Athabasca tar sand derivatives indicates that the assumption of 2 for the atomic H/C ratio of aliphatic structures is reasonable. For coal hydrogenation products, a value of 1.6–1.7 for the H/C ratio of aliphatic structures would be more reasonable.

Colombian coal liquefaction and its coprocessing with Venezuelan crude oil

Titiribi coal from Colombia shows an excellent reactivity to liquefaction and coprocessing. Anthracene oil was excellent as a vehicle oil to facilitate the liquefaction reaction during the initial stage at 400°C. In the case of coprocessing with Morichal crude oil and red-mud/sulfur catalyst, the maximum conversion of Titiribi coal was ca. 79 wt% daf at 400°C and ca. 93 wt% daf at 450°C. The hydrogen consumption in the presence of Morichal crude oil is lower than that in the presence of anthracene oil. It is considered to be the effect of hydrogen sulfide and the hydrogen donor ability of Morichal crude oil.

Separation of iron catalyst from coal liquefaction crude oil with high gradient magnetic separator

Publisher Summary This chapter summarizes the effects of the magnetic field and feed rates of coal liquefaction crude oil on a separation selectivity for a recovery of synthetic pyrite catalysts. A magnetic separation of iron catalyst is carried out for a coal liquefaction crude oil by using a high gradient magnetic separator (HGMS). The iron catalyst is aerated as a chemical form of pyrrhotite, and iron contents in benzene insoluble (BI) of magnetic separated substance is concentrated 1.5 times, even though the mean particle size is small. Concentrations of iron and sulfursulfursulfur in magnetic separated substances is increased as increase in the magnetic field and decreased in the feed rate of coal liquefaction crude oil. The mineral matter relating coal ash is decreased. Carbonaceous matter is also included in magnetic separated substances, and it may come from adherent heavy hydrocarbon fractions of crude oil. The performance of a magnetic separation procedure can be improved at higher temperature condition.