A process for the production of 2,3,3,3-tetrafluoropropene including the stages: i) in a first reactor, bringing a stream A including 2-chloro-3,3,3-trifluoropropene into contact with hydrofluoric acid in the gas phase in the presence of a catalyst in order to produce a stream B including 2,3,3,3-tetrafluoropropene, HCl, HF and unreacted 2-chloro-3,3,3-trifluoropropene; and ii) in a second reactor, bringing hydrofluoric acid into contact, in the gas phase in the presence or not of a catalyst, with a stream including at least one chlorinated compound selected from the group of 1,1,1,2,3-pentachloropropane, 2,3-dichloro-1,1,1-trifluoropropane, 2,3,3,3-tetrachloropropene and 1,1,2,3-tetrachloropropene, in order to produce a stream C including 2-chloro-3,3,3-trifluoropropene, wherein the stream B obtained in stage i) feeds the second reactor used for stage ii); and wherein the electrical conductivity of the stream A provided in stage i) is less than 15 mS/cm.

Provided is a method for directly preparing dimethyl ether by synthesis gas, the method comprises: the synthesis gas is passed through a reaction zone carrying a catalyst, and reacted under the reaction conditions sufficient to convert at least a portion of the raw materials to obtain the reaction effluent comprising dimethyl ether; and the dimethyl ether is separated from the reaction effluent, wherein the catalyst is zinc aluminum spinel oxide. In the present invention, only one zinc aluminum spinel oxide catalyst is used, which can make the synthesis gas to highly selectively form dimethyl ether, the catalyst has good stability and can be regenerated. The method of the present invention realizes the production of dimethyl ether in one step by the synthesis gas, and reduces the large energy consumption problem caused by step-by-step production.

The present disclosure provides a method for producing fluoroolefin represented by formula (1): CX.sup.1X.sup.2=CX.sup.3X.sup.4, wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 are the same or different, and represent a hydrogen atom or a fluorine atom, with high selectivity. Specifically, the present disclosure is a method for producing a fluoroolefin represented by formula (1) described above, the method comprising a dehydrofluorination step of bringing a fluorocarbon represented by formula (2): CX.sup.1X.sup.2FCX.sup.3X.sup.4H, wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 are as defined above, into contact with a metal catalyst to perform dehydrofluorination, the dehydrofluorination step being performed in the gas phase in the presence of water, the concentration of the water being less than 500 ppm relative to the fluorocarbon represented by formula (2).

The present disclosure provides a method for producing fluoroolefin represented by formula (1): CX.sup.1X.sup.2=CX.sup.3X.sup.4, wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 are the same or different, and represent a hydrogen atom or a fluorine atom, with high selectivity. Specifically, the present disclosure is a method for producing a fluoroolefin represented by formula (1) described above, the method comprising a dehydrofluorination step of bringing a fluorocarbon represented by formula (2): CX.sup.1X.sup.2FCX.sup.3X.sup.4H, wherein X.sup.1, X.sup.2, X.sup.3, and X.sup.4 are as defined above, into contact with a metal catalyst to perform dehydrofluorination, the dehydrofluorination step being performed in the gas phase in the presence of water, the concentration of the water being less than 500 ppm relative to the fluorocarbon represented by formula (2).

Direct conversion of syngas produces liquid fuels and light olefins. The catalytic reaction is conducted on a fixed bed or a moving bed. The catalyst comprises A and B components. The component A is composed of active metal oxides, and the active ingredients of the component B are zeolites with a MEL structure. The distance between the geometric centers of catalyst A and catalyst B particles is 2 nm-10 mm; a weight ratio of the catalyst A to the catalyst B is 0.1-20. The pressure of the syngas is 0.1-10 MPa; reaction temperature is 300-600° C.; and space velocity is 300-10000 h.sup.−1. The reaction mainly produces gasoline with high octane number, and co-generates light olefins. Meanwhile, the selectivity for a methane byproduct is low (less than 10%).

Direct conversion of syngas produces liquid fuels and light olefins. The catalytic reaction is conducted on a fixed bed or a moving bed. The catalyst comprises A and B components. The component A is composed of active metal oxides, and the active ingredients of the component B are zeolites with a MEL structure. The distance between the geometric centers of catalyst A and catalyst B particles is 2 nm-10 mm; a weight ratio of the catalyst A to the catalyst B is 0.1-20. The pressure of the syngas is 0.1-10 MPa; reaction temperature is 300-600° C.; and space velocity is 300-10000 h.sup.−1. The reaction mainly produces gasoline with high octane number, and co-generates light olefins. Meanwhile, the selectivity for a methane byproduct is low (less than 10%).

Provided is a method for producing p-xylene, comprising: a provision step of providing a C4 fraction comprising at least isobutene as a product formed by fluidized catalytic cracking of a heavy oil fraction; a dimerization step of bringing a first raw material comprising the isobutene into contact with a dimerization catalyst to produce a C8 component comprising a dimer of isobutene; and a cyclization step of bringing a second raw material comprising the C8 component with a dehydrogenation catalyst to produce p-xylene through a cyclization/dehydrogenation reaction of the C8 component.

Provided is a method for producing p-xylene, comprising: a provision step of providing a C4 fraction comprising at least isobutene as a product formed by fluidized catalytic cracking of a heavy oil fraction; a dimerization step of bringing a first raw material comprising the isobutene into contact with a dimerization catalyst to produce a C8 component comprising a dimer of isobutene; and a cyclization step of bringing a second raw material comprising the C8 component with a dehydrogenation catalyst to produce p-xylene through a cyclization/dehydrogenation reaction of the C8 component.

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%.