An apparatus for forming a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon is described. The apparatus comprises: a dielectric barrier discharge, DBD, device arranged to generate a plasma; and a passageway having an inlet for the carbon dioxide and the C1 to C4 hydrocarbon and an outlet for the oxygenates. In one example the passageway includes therein a catalyst. The passageway extends, at least in part, through the DBD device wherein, in use, the carbon dioxide in reacted with the C1 to C4 hydrocarbon in the generated plasma, thereby forming the oxygenates from at least some of the carbon dioxide and the C1 to C4 hydrocarbon. The DBD device comprises a conducting liquid as a ground electrode. A method and a use are also described.

An apparatus for forming a C1 to C5 oxygenate from carbon dioxide and a C1 to C4 hydrocarbon is described. The apparatus comprises: a dielectric barrier discharge, DBD, device arranged to generate a plasma; and a passageway having an inlet for the carbon dioxide and the C1 to C4 hydrocarbon and an outlet for the oxygenates. In one example the passageway includes therein a catalyst. The passageway extends, at least in part, through the DBD device wherein, in use, the carbon dioxide in reacted with the C1 to C4 hydrocarbon in the generated plasma, thereby forming the oxygenates from at least some of the carbon dioxide and the C1 to C4 hydrocarbon. The DBD device comprises a conducting liquid as a ground electrode. A method and a use are also described.

A catalyst may suppress pressure loss and coaking and produce a target substance in high yield when a gas-phase catalytic oxidation reaction of a material substance is conducted using the catalyst to produce the target substance. A ring-shaped catalyst may have a straight body part and a hollow body part, which is used when a gas-phase catalytic oxidation reaction of a material substance is conducted to produce a target substance, wherein a length of the straight body part is shorter than a length of the hollow body part and at least at one end part, a region from an end part of the straight body part to an end part of the hollow body part is concavely curved.

A strengthening oxidation system of the external micro-interfacial unit for producing PTA with PX is provided, including: a reactor, a circulating heat exchange device and a micro-interfacial unit. The reactor includes an outer casing and an inner cylinder disposed concentrically inside the outer casing. The circulating heat exchange device is disposed at an exterior of the reactor, and is connected with the outer casing and the inner cylinder respectively, for regulating reaction temperatures of the first reaction zone, the second reaction zone and the third reaction zone inside the reactor in a reaction process of producing PTA with PX. the micro-interfacial unit is connected between the reactor and the circulating heat exchange device, and connected with an external feed pipe of the reactor, for crushing a gas phase material into micro bubbles with a diameter greater than or equal to 1 μm and less than 1 mm and for mixing the micro bubbles with a liquid phase material to form an emulsion at the exterior of the reactor before a reaction material enters each of the reaction zones inside the reactor.

A strengthening oxidation system of the external micro-interfacial unit for producing PTA with PX is provided, including: a reactor, a circulating heat exchange device and a micro-interfacial unit. The reactor includes an outer casing and an inner cylinder disposed concentrically inside the outer casing. The circulating heat exchange device is disposed at an exterior of the reactor, and is connected with the outer casing and the inner cylinder respectively, for regulating reaction temperatures of the first reaction zone, the second reaction zone and the third reaction zone inside the reactor in a reaction process of producing PTA with PX. the micro-interfacial unit is connected between the reactor and the circulating heat exchange device, and connected with an external feed pipe of the reactor, for crushing a gas phase material into micro bubbles with a diameter greater than or equal to 1 μm and less than 1 mm and for mixing the micro bubbles with a liquid phase material to form an emulsion at the exterior of the reactor before a reaction material enters each of the reaction zones inside the reactor.

The present invention provides a method for producing an oxide catalyst containing antimony, comprising a step (A) of obtaining the oxide catalyst using antimony particles containing a diantimony trioxide as a source of the antimony, wherein an abundance of a pentavalent antimony in a surface layer of the antimony particle to be measured in XPS analysis is less than 70 atom %, and the antimony particle has an average particle size of 1.2 μm or less.

The present invention provides a method for producing an oxide catalyst containing antimony, comprising a step (A) of obtaining the oxide catalyst using antimony particles containing a diantimony trioxide as a source of the antimony, wherein an abundance of a pentavalent antimony in a surface layer of the antimony particle to be measured in XPS analysis is less than 70 atom %, and the antimony particle has an average particle size of 1.2 μm or less.

The present invention provides a method for producing an oxide catalyst containing antimony, comprising a step (A) of obtaining the oxide catalyst using antimony particles containing a diantimony trioxide as a source of the antimony, wherein an abundance of a pentavalent antimony in a surface layer of the antimony particle to be measured in XPS analysis is less than 70 atom %, and the antimony particle has an average particle size of 1.2 μm or less.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.

A method of production of malic acid includes treating a first intermediate product to form a second intermediate product. The treating includes substantially removing impurities from the first intermediate product to obtain a treated intermediate product by gas stripping the crude maleic anhydride, or subjecting a mixture of one or more of the crude maleic acid, the crude fumaric acid, and the vent gas scrubber solution obtained from a phthalic anhydride production process or a maleic anhydride production process to crystallization, passing an aqueous solution of the treated intermediate product through a carbon column to substantially remove retained impurities to form the second intermediate product, obtaining a feed that includes the second intermediate product, and causing the feed to undergo hydration reaction in a tubular reactor or a continuous stirred tank reactor to produce malic acid.