The present invention provides an integrated process for preparing 2,3,3, 3-tetrafluoropropene (1234yf), the process comprising: (a) vapour phase catalytic fluorination of a first composition comprising 3,3,3-trifluoro-2-chloro-prop-1-ene (CF3CCNCH2, 1233xf) with hydrogen fluoride (HF) in a fluorination reactor to produce a fluorination product stream comprising 1,1,2,2-pentafluoropropane (245cb), HF and HCI; (b) vapour phase catalytic dehydrofluorination composition comprising 245cb in a dehydrofluorination reactor to produce a dehydrofluorination product stream comprising 1234yf and HF; wherein the fluorination product stream and the dehydrofluorination product stream are combined and subjected to (c) purification to produce a composition comprising 245cb and a 1234yf product stream.

A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

A method including contacting a chromium-based catalyst with a reducing agent in a solvent to lower an oxidation state of at least some chromium in the chromium-based catalyst to give a reduced chromium-based catalyst, drying the reduced chromium-based catalyst at a temperature, and adjusting the temperature to affect the flow index response of the reduced chromium-based catalyst.

Disclosed is a catalytic test paper prepared by compositing metal particle-embedded bacterial cellulose with plant fibers, and a preparation method therefor. Hydroxyl groups of bacterial cellulose are bonded with a nitrogen-containing or phosphorus-containing organic small molecule compound. By means of a chelation between a nitrogen or phosphorus atom with a metal, transition metal ions are adsorbed to a nanoporous surface of bacterial cellulose, and the transition metal ions are reduced in situ to obtain bacterial cellulose embedded with metal nanoparticles. The bacterial cellulose is composited with the plant fiber, and the catalytic test paper is prepared by a papermaking method. The catalytic test paper has the advantages of convenient use and recovery, high reusability, simple design, low manufacturing cost, higher catalytic efficiency, a green degradable support material, etc.

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.

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 process for direct synthesis of light olefins uses syngas as the feed raw material. This catalytic conversion process is conducted in a fixed bed or a moving bed using a composite catalyst containing components A and B (A+B). The active ingredient of catalyst A is metal oxide; and catalyst B is an oxide supported zeolite. A carrier is one or more of Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2, MgO and Ga.sub.2O.sub.3 having hierarchical pores; the zeolite is one or more of CHA and AEI structures. The loading of the zeolite is 4%-45% wt. A weight ratio of the active ingredients in the catalyst A and the catalyst B is within a range of 0.1-20, and preferably 0.3-5. The total selectivity of the light olefins comprising ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane byproduct is less than 15%.

A process for direct synthesis of light olefins uses syngas as the feed raw material. This catalytic conversion process is conducted in a fixed bed or a moving bed using a composite catalyst containing components A and B (A+B). The active ingredient of catalyst A is metal oxide; and catalyst B is an oxide supported zeolite. A carrier is one or more of Al.sub.2O.sub.3, SiO.sub.2, TiO.sub.2, ZrO.sub.2, CeO.sub.2, MgO and Ga.sub.2O.sub.3 having hierarchical pores; the zeolite is one or more of CHA and AEI structures. The loading of the zeolite is 4%-45% wt. A weight ratio of the active ingredients in the catalyst A and the catalyst B is within a range of 0.1-20, and preferably 0.3-5. The total selectivity of the light olefins comprising ethylene, propylene and butylene can reach 50-90%, while the selectivity of a methane byproduct is less than 15%.

A method for the dehydrogenation of lower alkanes is disclosed. The method employs a chromium-alumina dehydrogenation catalyst with high chromium content supported on eta-alumina. The catalyst contains greater than 25 percent by weight chromium in the form of chromium (III) oxide, and exhibits extended stability over traditional alkane dehydrogenation catalysts.

A method for the dehydrogenation of lower alkanes is disclosed. The method employs a chromium-alumina dehydrogenation catalyst with high chromium content supported on eta-alumina. The catalyst contains greater than 25 percent by weight chromium in the form of chromium (III) oxide, and exhibits extended stability over traditional alkane dehydrogenation catalysts.