The present invention aims to provide an efficient method for obtaining a desired isomer of HFO-1132 from a composition comprising trans-1,2-difluoroethylene (HFO-1132(E)) and cis-1,2-difluoroethylene (HFO-1132(Z)). The present invention provides, as a means for solving the problem, a method for producing HFO-1132(E) and/or HFO-1132(Z), comprising steps (1) to (3): (1) supplying a composition comprising HFO-1132(E) and/or HFO-1132(Z) to a reactor filled with a catalyst to perform an isomerization reaction between the HFO-1132(E) and the HFO-1132(Z); (2) separating the reaction product obtained in step (1) into a first stream comprising the HFO-1132(E) as a main component, and a second stream comprising the HFO-1132(Z) as a main component; and (3) recycling the first stream or the second stream obtained in step (2) to the reactor, to subject the first stream or the second stream to the isomerization reaction.

A dehydrochlorination process is disclosed. The process involves contacting R.sub.fCHClCH.sub.2Cl with a chromium oxyfluoride catalyst in a reaction zone to produce a product mixture comprising R.sub.fCCl═CH.sub.2, wherein R.sub.f is a perfluorinated alkyl group.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

The invention relates to a method for preparation of diesters from anhydrides of carboxylic acids.

The invention relates to a method for preparation of diesters from anhydrides of carboxylic acids.

The present application relates to a hydrogenation catalyst, a process for producing the same and application thereof in the hydrotreatment of feedstock oil. The process comprises at least the following steps: (1) contacting a first active metal component and a first organic complexing agent with a carrier to obtain a composite carrier; (2) calcining the composite carrier to obtain a calcined composite carrier having a total carbon content of 1% by weight or less; and (3) contacting a second organic complexing agent with the calcined composite carrier to obtain the hydrogenation catalyst. The hydrogenation catalyst has both excellent hydrodesulfurization activity and hydrodenitrogenation activity, and exhibits a significantly prolonged service life.

The present application relates to a hydrogenation catalyst, a process for producing the same and application thereof in the hydrotreatment of feedstock oil. The process comprises at least the following steps: (1) contacting a first active metal component and a first organic complexing agent with a carrier to obtain a composite carrier; (2) calcining the composite carrier to obtain a calcined composite carrier having a total carbon content of 1% by weight or less; and (3) contacting a second organic complexing agent with the calcined composite carrier to obtain the hydrogenation catalyst. The hydrogenation catalyst has both excellent hydrodesulfurization activity and hydrodenitrogenation activity, and exhibits a significantly prolonged service life.

Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m.sup.2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

A dehydrochlorination process is disclosed. The process involves contacting R.sub.fCHClCH.sub.2Cl with a chromium oxyfluoride catalyst in a reaction zone to produce a product mixture comprising R.sub.fCCl═CH.sub.2, wherein R.sub.f is a perfluorinated alkyl group.

The present disclosure provides a method for conversion of a mixture of high-boiling fluorinated components comprising 1,1,3,3-tetrachloro-1-fluoropropane (HCFC-241fa), 1,3,3-trichloro-1, 1-difluoropropane (HCFC-242fa), 1,1,3-trichloro-1,3-difluoropropane (HCFC-242fb), 3,3-dichloro-1,1,1-trifluoropropane (HCFC-243fa), 1,3-dichloro-1,1,3-trifluoropropane (HCFC-243fb), 3-chloro-1,1,1,3-tetrafluoropropane (HCFC-244fa), their isomers, and combinations thereof, to 1-chloro-3,3,3-trifluoropropene (HCFO-1233zd). Heavy impurities, such as oligomers and other high boiling impurities, that are present may be purged during the process to prevent yield loss and reduction of catalyst efficacy.