A unique crystalline transition metal molybdotungstate 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.

The present invention relates to a catalyst for preparing acrolein and acrylic acid, and a preparation method thereof. The catalyst according to the present invention can be uniformly packed in a reactor and the collapse of the catalyst can be minimized because it has excellent mechanical properties, and it can be stably used for a long period of time.

The present invention relates to a catalyst for preparing acrolein and acrylic acid, and a preparation method thereof. The catalyst according to the present invention can be uniformly packed in a reactor and the collapse of the catalyst can be minimized because it has excellent mechanical properties, and it can be stably used for a long period of time.

A method for producing at least one oxidation product selected from the group consisting of acrolein and acrylic acid is provided. This method can alleviate concerns about deterioration of a gas-phase oxidation catalyst and reaction runaway in a restart period after a shutdown, and can allow the reaction to proceed in a stable state. Using a fixed-bed reactor filled with a gas-phase oxidation catalyst, at least one source gas selected from the group consisting of propylene and acrolein is subjected to a gas-phase contact oxidation reaction while a heating medium is caused to contact with or circulate through the fixed-bed reactor and thereby to heat the fixed-bed reactor. The temperature of the heating medium when the load is maximum in the restart period after the shutdown is controlled to be lower than the temperature of the heating medium when the load is maximum in an initial start-up period.

A method for producing at least one oxidation product selected from the group consisting of acrolein and acrylic acid is provided. This method can alleviate concerns about deterioration of a gas-phase oxidation catalyst and reaction runaway in a restart period after a shutdown, and can allow the reaction to proceed in a stable state. Using a fixed-bed reactor filled with a gas-phase oxidation catalyst, at least one source gas selected from the group consisting of propylene and acrolein is subjected to a gas-phase contact oxidation reaction while a heating medium is caused to contact with or circulate through the fixed-bed reactor and thereby to heat the fixed-bed reactor. The temperature of the heating medium when the load is maximum in the restart period after the shutdown is controlled to be lower than the temperature of the heating medium when the load is maximum in an initial start-up period.

A highly active quaternary 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 quaternary 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 catalyst comprising a carrier and a metals component impregnated in the carrier, the carrier comprising alumina; and the metals component comprising a first metals fraction and a second metals fraction, the first metals fraction comprising at least one metal selected from chromium, molybdenum, or tungsten, and the second metals fraction comprising at least two metals selected from cobalt, rhodium, iridium, nickel, palladium, or platinum, wherein the catalyst has a first pore volume of 0.28 to 0.45 mL/g for pores having a pore diameter of 12 nm to less than 16 nm, and a second pore volume of 0.15 to 0.28 mL/g for pores of 2.0 nm to less than 12.0 nm.

A catalyst comprising a carrier and a metals component impregnated in the carrier, the carrier comprising alumina; and the metals component comprising a first metals fraction and a second metals fraction, the first metals fraction comprising at least one metal selected from chromium, molybdenum, or tungsten, and the second metals fraction comprising at least two metals selected from cobalt, rhodium, iridium, nickel, palladium, or platinum, wherein the catalyst has a first pore volume of 0.28 to 0.45 mL/g for pores having a pore diameter of 12 nm to less than 16 nm, and a second pore volume of 0.15 to 0.28 mL/g for pores of 2.0 nm to less than 12.0 nm.

The present invention provides a method for increasing the UV transmittance of ethylene glycol. The method uses an ethylene glycol solution and hydrogen as raw materials, and uses an alloy catalyst comprising nickel, one or more rare-earth elements, tin, and aluminum, the contents thereof in parts by weight being 10-90, 1-5, 1-60, and 5-9, respectively. The method of the present invention uses an inexpensive, stable-in-aqueous-phase, carrier-free alloy as a catalyst, and continuously adds hydrogen to reduce unsaturated impurities in ethylene glycol. In application of the method of the present invention in continuous industrial-scale production, the use of this type of alloy catalyst could be especially significant for the achievement of long-term system stability and control of production costs.