1748results about "Carboxylic preparation by oxidation" patented technology

Disclosed is a process that relates to the recovery of a metal catalyst from an oxidizer purge stream produced in the synthesis of carboxylic acid, typically terephthalic acid. The process involves the addition of a wash solution to a high temperature molten dispersion to recover the metal catalyst and then subjecting an aqueous mixture or purified aqueous mixture so formed to a single stage extraction to remove organic impurities to produce an extract stream and a raffinate stream comprising the metal catalyst.

A process for performing a chemical reaction between a plurality of chemical reactants in the presence of a catalyst, with at least a first reactant in a liquid phase and at least a second reactant in a gas phase, the first and second reactants mixing at least by interdiffusion. The process comprises supplying the reactants to a passage defined by a first surface and a second surface and optionally moving at least one of the first surface and second surface relative to each other. The reactants their mixture or reaction products form respective boundary layers against the first and second surfaces and the radial spacing between the first surface and second surface is equal to or less than the back-to-back radial thicknesses of the boundary layers.

A method and apparatus for purifying crude terephthalic acid from a liquid dispersion thereof also containing impurities selected from unreacted starting materials, solvents, products of side reactions and/or other undesired materials is provided. The method comprises the steps of filtering the dispersion to form a crude terephthalic acid filter cake, dissolving the filter cake in a selective crystallization solvent at an elevated temperature to form a solution, crystallizing purified terephthalic acid from the solution in the crystallization solvent by reducing the pressure and temperature of the solution, and separating the crystallized purified terephthalic acid from the solution. According to the invention, the selective crystallization solvent is non-aqueous, non-corrosive and essentially non-reactive with terephthalic acid. Preferably, the selective crystallization solvent is N-methyl pyrrolidone. The method and apparatus produces purified terephthalic acid having a purity desired for use in forming polyester resin and other products at an economically attractive rate and at operating conditions of reduced severity which require a lower capital investment and simplified processing.

Oxidative dehydrogenation of paraffins to olefins provides a lower energy route to produce olefins. Oxidative dehydrogenation processes may be integrated with a number of processes in a chemical plant such as polymerization processes, manufacture of glycols, and carboxylic acids and esters. Additionally, oxidative dehydrogenation processes can be integrated with the back end separation process of a conventional steam cracker to increase capacity at reduced cost.

Disclosed is a process to produce a purified carboxylic acid slurry. The process comprises removing impurities from a crystallized product in a solid liquid displacement zone to form the purified carboxylic acid slurry. The process produces purified carboxylic acid slurry having good color and low impurity levels without the use of purification steps like hydrogenation or an impurity removal process.

Simple, economical preparative processes for the provision of pure hydroxyl functional materials that are derived by converting the alkene groups of the unsaturated molecules found in vegetable oils, into hydroxyl groups.

An environmentally beneficial method of producing methanol from varied sources of carbon dioxide including flue gases of fossil fuel burning powerplants, industrial exhaust gases or the atmosphere itself. Converting carbon dioxide by electrochemical reduction produces formic acid acid and some formaldehyde and methanol mixtures. The formic acid can be used as source of carbon as well as hydrogen to produce methanol, dimethyl ether and other products.

The present invention is directed to a method for preparing renewable and relatively high purity p-xylene from biomass. For example, biomass treated to provide a fermentation feedstock is fermented with a microorganism capable of producing a C₄ alcohol such as isobutanol, then sequentially dehydrating the isobutanol in the presence of a dehydration catalyst to provide a C₄ alkene such as isobutylene, dimerizing the C₄ alkene to a form one or more C₈ alkenes such as 2,4,4-trimethylpentenes or 2,5-dimethylhexene, then dehydrocyclizing the C₈ alkenes in the presence of a dehydrocyclization catalyst to selectively form renewable p-xylene in high overall yield. The p-xylene can then be oxidized to form terephthalic acid or terephthalate esters.

The invention provides a method of producing a graphene material from a starting graphitic material. In an embodiment, the method comprises: (a) dispersing the starting graphitic material in a liquid medium to form a graphite suspension; and (b) introducing the graphite suspension into a hydrodynamic cavitation reactor that generates and collapses cavitation or bubbles in the liquid medium to exfoliate and separate graphene planes from the starting graphitic material for producing the graphene material. The process is fast (minutes as opposed to hours or days of conventional processes), environmentally benign, and highly scalable. The reactor can concurrently perform the functions of graphene production, chemical functionalization, dispersion, and mixing with a polymer to make a composite.

A process for oxidation with oxygen of at least one aromatic hydrocarbon having oxidizable, substituents that maximizes the utilization of oxygen without reduction in the quality of the carboxylic acid products produced by means of a stagewise countercurrent oxidation system is disclosed.

Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly efficient reaction at relatively low temperatures. When the oxidized compound is para-xylene and the product from the oxidation reaction is crude terephthalic acid (CTA), such CTA product can be purified and separated by more economical techniques than could be employed if the CTA were formed by a conventional high-temperature oxidation process.

Disclosed is an optimized process and apparatus for more efficiently and economically carrying out the liquid-phase oxidation of an oxidizable compound. Such liquid-phase oxidation is carried out in a bubble column reactor that provides for a highly efficient reaction at relatively low temperatures. When the oxidized compound is para-xylene and the product from the oxidation reaction is crude terephthalic acid (CTA), such CTA product can be purified and separated by more economical techniques than could be employed if the CTA were formed by a conventional high-temperature oxidation process.

There is disclosed a production process for a catalyst which process makes it possible to efficiently carry out the supporting of a catalytic component onto a carrier and to obtain the catalyst excellent in quality and performance. This production process is a production process for the catalyst including a particulate lump carrier and a catalytic component supported thereon; with the production process comprising the step of carrying out simultaneous revolution and rocking of a treatment container 20 as charged with the carrier and a catalyst precursor including the catalytic component, thereby supporting the catalytic component onto the carrier.

This invention relates to the field of heterogeneous catalysis, and more particularly to catalysts including carbon supports having compositions which comprise one or more transition metals in combination with nitrogen and/or carbon formed on or over the surface of the carbon support. The present invention also relates to catalyst combinations comprising catalysts including carbon supports having compositions which comprise one or more transition metals in combination with nitrogen and/or carbon formed on or over the surface of a carbon support and a secondary catalyst or, co-catalyst, including a secondary transition metal. The invention further relates to the field of catalytic oxidation reactions, including the preparation of secondary amines by the catalytic oxidation of tertiary amines.

Reactor membranes for used in oxidation reactions of hydrocarbons involving oxygen comprising a selective oxidation catalyst on a mixed conducting, oxide ion selective ceramic membrane of the composition (Sr1-xCax)1-yAyMn1-zBzO3-delta, whereA is Ba, Pb, Na, K, Y, an element of the lanthanide group or a combination thereof,B is Mg, Al, Ga, In, Sn, an element of the 3d or 4d period or a combination thereof,x is from 0.2 to 0.8,y is from 0 to 0.4,z is from 0 to 0.6, anddelta is a number, dependent on x, y and z, that renders the composition charge neutral.