The present disclosure relates to a process for stabilizing an antimony ammoxidation catalyst in an ammoxidation process. The process may comprise providing an antimony ammoxidation catalyst to a reactor; reacting propylene with ammonia and oxygen in the fluidized bed reactor in the presence of the antimony ammoxidation catalyst to form a crude acrylonitrile product; and adding an effective amount of an antimony-containing compound to the antimony ammoxidation catalyst to maintain catalyst conversion and selectivity; wherein the antimony-containing compound has a melting point less than 375° C. The present disclosure also relates to catalyst compositions and additional processes using the antimony ammoxidation catalyst stabilized by an antimony-containing compound.

Described herein are methods, systems, and compositions for providing catalysts for tail gas clean up in sulfur recovery operations. Aspects involve obtaining catalyst that was used in a first process, which is not a tailgas treating process and then using the so-obtained catalyst in a tailgas treating process. For example, the catalyst may originally be a hydroprocessing catalyst. A beneficial aspect of the described methods and systems is that the re-use of spent hydroprocessing catalyst reduces hazardous waste generation by operators from spent catalyst disposal. Ultimately, this helps reduce the environmental impact of the catalyst life cycle. The described methods and systems also provide an economically attractive source of high-performance catalyst for tailgas treatment, which benefits the spent catalyst generator, the catalyst provider, and the catalyst consumer.

The invention relates to a process for treatment of a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, comprising contacting a gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein said gas stream comprises 0 to 25 vol. % of an alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.

The invention relates to a process for treatment of a mixed metal oxide catalyst containing molybdenum, vanadium, niobium and optionally tellurium, comprising contacting a gas stream comprising methane, an inert gas or oxygen or any combination of two or more of these with the catalyst, wherein said gas stream comprises 0 to 25 vol. % of an alkane containing 2 to 6 carbon atoms and/or alkene containing 2 to 6 carbon atoms.

The present invention discloses a process for recovery and regeneration of rare earth metals or salts thereof used as catalyst and which is conveniently integrated within the overall flow sheets of manufacturing dialkyl carbonates. Alkyl carbamate, alcohol and a rare earth metal salt as catalyst selected from the lanthanide series are added in a reactor to afford dialkyl carbonate. The rare earth metal catalyst is selected from samarium, cerium, lanthanum, neodymium, ytterbium, europium and gadolinium. Ammonia is added to a portion of the reaction mixture to precipitate the catalyst and the separated deactivated catalyst is dissolved in acid to afford regenerated catalyst, e.g., in triflic acid in the case of samarium triflate catalyst.

The present invention discloses a process for recovery and regeneration of rare earth metals or salts thereof used as catalyst and which is conveniently integrated within the overall flow sheets of manufacturing dialkyl carbonates. Alkyl carbamate, alcohol and a rare earth metal salt as catalyst selected from the lanthanide series are added in a reactor to afford dialkyl carbonate. The rare earth metal catalyst is selected from samarium, cerium, lanthanum, neodymium, ytterbium, europium and gadolinium. Ammonia is added to a portion of the reaction mixture to precipitate the catalyst and the separated deactivated catalyst is dissolved in acid to afford regenerated catalyst, e.g., in triflic acid in the case of samarium triflate catalyst.

An alumina exhibiting a structure with a porosity such that the volume of the pores having a diameter of between 70 and 2000 Å is between 0.15 and 0.50 ml/g, and comprising at least one alkali metal (M), such that the content by weight of alkali metal, expressed as M.sub.2O, is between 400 and 1500 ppm, with respect to the total weight of the alumina, and a process for the transformation of a feedstock comprising at least one alcohol into an olefinic effluent, said process comprising a stage of dehydration of said alcohol in the presence of the alumina according to the present invention, having an acidity and a structure with a porosity which are optimal.

Described herein are methods and devices that allow the generation of [F-18]triflyl fluoride and other [F-18] sulfonyl fluorides (such as [F-18]tosyl fluoride) in a manner that is suitable for radiosynthesis of F-18 labeled radiopharmaceuticals using currently available synthesis modules.

Described herein are methods and devices that allow the generation of [F-18]triflyl fluoride and other [F-18] sulfonyl fluorides (such as [F-18]tosyl fluoride) in a manner that is suitable for radiosynthesis of F-18 labeled radiopharmaceuticals using currently available synthesis modules.

Provided are: a cleaning agent for a denitration catalyst; and a denitration catalyst regeneration method and a denitration catalyst regeneration system which make it possible to efficiently remove matter adhering to a surface of a catalyst and to greatly restore catalytic performance. The regeneration method includes: a prewashing step (S12) of washing a denitration catalyst with water; a liquid agent cleaning step (S14) of immersing the denitration catalyst washed with water in a liquid agent containing an inorganic acid and a fluorine compound; a step of recovering the denitration catalyst from the liquid agent; and a finish washing step (S16) of washing the denitration catalyst recovered from the liquid agent with a finish cleaning liquid which is water or sulfamic acid-containing water.