The present invention relates to a process for hydroconversion of a heavy hydrocarbon feedstock in the presence of hydrogen, at least one supported solid catalyst and at least one dispersed solid catalyst obtained from at least one salt of a heteropolyanion combining molybdenum and at least one metal selected from cobalt and nickel in a Strandberg, Keggin, lacunary Keggin or substituted lacunary Keggin structure.

Provided is a hydrodesulfurization catalyst for hydrocarbon oil, the catalyst comprising: an inorganic oxide carrier comprising Si, Ti and Al; and at least one metal component, carried on the inorganic oxide carrier, being selected from the group consisting of group 6 elements, group 8 elements, group 9 elements and group 10 elements, wherein the content of Al in the inorganic oxide carrier is 50% by mass or higher in terms of Al.sub.2O.sub.3; the content of Si therein is 1.0 to 10% by mass in terms of SiO.sub.2; and the content of Ti therein is 12 to 28% by mass in terms of TiO.sub.2; and in the inorganic oxide carrier, the absorption edge wavelength of an absorption peak from Ti is 364 nm or shorter as measured by ultraviolet spectroscopy.

Provided is a hydrodesulfurization catalyst for hydrocarbon oil, the catalyst comprising: an inorganic oxide carrier comprising Si, Ti and Al; and at least one metal component, carried on the inorganic oxide carrier, being selected from the group consisting of group 6 elements, group 8 elements, group 9 elements and group 10 elements, wherein the content of Al in the inorganic oxide carrier is 50% by mass or higher in terms of Al.sub.2O.sub.3; the content of Si therein is 1.0 to 10% by mass in terms of SiO.sub.2; and the content of Ti therein is 12 to 28% by mass in terms of TiO.sub.2; and in the inorganic oxide carrier, the absorption edge wavelength of an absorption peak from Ti is 364 nm or shorter as measured by ultraviolet spectroscopy.

A simple, scalable, inexpensive, and reproducible method of selectively preparing the M1 phase of a MoVNbTe mixed oxide in a hydrothermal synthesis using tellurium dioxide is disclosed which can utilize inexpensive metal oxides as starting compounds.

A simple, scalable, inexpensive, and reproducible method of selectively preparing the M1 phase of a MoVNbTe mixed oxide in a hydrothermal synthesis using tellurium dioxide is disclosed which can utilize inexpensive metal oxides as starting compounds.

The present invention can provide a method for producing an aromatic nitrile in which a fixed-bed reactor including a plurality of reaction tubes is used to subject a gaseous mixture comprising an aromatic hydrocarbon, ammonia, and oxygen by contact catalytic reaction on a catalyst to thereby produce the corresponding aromatic nitrile, wherein the catalyst is composed of an oxide containing vanadium, chromium, and boron and one or more supports selected from among alumina, silica-alumina, zirconia, and titania. One of the reaction tubes is filled with the catalyst of one kind and examined as to where a hot spot lies therein. An inert substance is filled into that portion of each of the plurality of reaction tubes which corresponds at least to the hot spot, and the catalyst is filled into the remaining portions.

The present invention can provide a method for producing an aromatic nitrile in which a fixed-bed reactor including a plurality of reaction tubes is used to subject a gaseous mixture comprising an aromatic hydrocarbon, ammonia, and oxygen by contact catalytic reaction on a catalyst to thereby produce the corresponding aromatic nitrile, wherein the catalyst is composed of an oxide containing vanadium, chromium, and boron and one or more supports selected from among alumina, silica-alumina, zirconia, and titania. One of the reaction tubes is filled with the catalyst of one kind and examined as to where a hot spot lies therein. An inert substance is filled into that portion of each of the plurality of reaction tubes which corresponds at least to the hot spot, and the catalyst is filled into the remaining portions.

A highly active trimetallic mixed transition metal oxide material has been developed. The material may be sulfided to generate metal sulfides which are used as a catalyst in a conversion process such as hydroprocessing. The hydroprocessing may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

A highly active trimetallic mixed transition metal oxide material has been developed. The material may be sulfided to generate metal sulfides which are used as a catalyst in a conversion process such as hydroprocessing. The hydroprocessing may include hydrodenitrification, hydrodesulfurization, hydrodemetallation, hydrodesilication, hydrodearomatization, hydroisomerization, hydrotreating, hydrofining, and hydrocracking.

Provided is a method for decomposing a plastic composite with which it is possible to sufficiently decompose the matrix resins of the plastic composite in a short time even when the heating temperature of the plastic composite is low. In this method for decomposing a plastic composite, the plastic composite is brought into contact with an inorganic oxide catalyst having a band gap of 4 eV or less in a reactor, and the atmospheric temperature in the reactor is set at 380 to 530° C. in the presence of oxygen, and the surface temperature of the plastic composite is 480 to 650° C., which is at least 50° C. higher than the atmospheric temperature.