摘要:
The present invention relates to a catalyst system for oxidation of o-xylene and/or naphthalene to phthalic anhydride (PA) comprising at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active material of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt.%. The present invention further relates to a process for gas phase oxidation in which a gas stream comprising at least one hydrocarbon and molecular oxygen is passed through a catalyst system which comprises at least four catalyst zones arranged in succession in the reaction tube and filled with catalysts of different chemical composition wherein the active materials of the catalysts comprise vanadium and titanium dioxide and the active material of the catalyst in the last catalyst zone towards the reactor outlet has an antimony content (calculated as antimony trioxide) between 0.7 to 3.0 wt.%.
摘要:
Die vorliegende Erfindung betrifft einen Mehrlagenkatalysator zur Herstellung von Phthalsäureanhydrid, der mehrere im Reaktionsrohr hintereinander angeordnete Katalysatorlagen aufweist, wobei die einzelnen Katalysatorlagen in Strömungsrichtung abnehmende Alkalimetallgehalte aufweisen. Ferner betrifft die vorliegende Erfindung ein Verfahren zur Oxidation von Naphthalin oder o-Xylol/Naphthalin-Mischungen an einem solchen Mehrlagenkatalysator sowie die Verwendung solcher Mehrlagenkatalysatoren zur Oxidation von Naphthalin oder o-Xylol/Naphthalin-Mischungen zu Phthalsaureanhydrid.
摘要:
The invention generally relates to a method for purifying a mixture of crude aromatic acids comprising at least one benzene carboxylic acid and at least one napthalene carboxylic acid. The purification method of the present invention provides a purified aromatic acid mixture useful in the manufacture of ultraviolet light resistance polyesters.
摘要:
A composition containing isomeric mixtures of arylaldehydes prepared from a mixed alkyl aromatic feedstock. A composition containing isomeric mixtures of dimethylbenzaldehydes prepared from a mixed xylene feedstock using a Gatterman-Koch type reaction. A composition of isomeric mixtures of tolualdehydes prepared from a toluene feedstock using a Gatterman-Koch type reaction.
摘要:
The invention relates to a method for oxidizing o-xylol with oxygen, preferably mixed with an inert gas, especially air, while adding a catalyst, in order to produce a mixture of oxidation products of the o-xylol. The selectivity of the reaction can be increased by adding an aldehyde to the o-xylol.
摘要:
Alkyl aromatic compounds are converted to alkyl aromatic aldehydes by a carbonylation reaction. The carbonylation catalyst can be a high boiling point carbonylation catalyst which allows for the separation of the aldehyde product by selective volatilization. Alternatively, the carbonylation catalyst can be selected from perfluoroalkyl sulfonic acids having 2 to 18 carbon atoms, perfluoroether sulfonic acids having 2 to 18 carbon atoms, BF3.(ROH)x wherein R represents CH3 or H and X is a number within the range of from 0.2 to 2, GaBr3, GaCl3, TaF5, NbF5, and NbBr5, with the proviso that when the catalyst is TaF5, NbF5, or NbBr5, then the reaction takes place in the absence of added HF. Preferably, all of the carbonylation reactions take place in the absence of added HF. The alkyl aromatic aldehydes can be oxidized to form an aromatic acid. A mixed xylene feed stock can be converted to a mixture of diemthylbenzaldehydes and then oxidized to form trimellitic acid without the need to separate the xylene or dimethylbenzaldehyde isomers.
摘要:
The invention relates to a method for producing shell catalysts for the catalytic vapor-phase oxidation of aromatic carboxylic acids and/or carboxylic acid anhydrides comprised of a supporting core and of catalytically active metal oxides which are deposited in a shell-shaped manner on said supporting core. The inventive catalysts are obtained by spraying an aqueous active mass suspension, said suspension containing the active metal oxides, at higher temperatures onto the hot supporting material which has a temperature ranging from 50 to 450 DEG C. The aqueous active mass suspension contains 1 to 10 wt. %, with regard to the solid content of the active mass suspension, of a binding agent comprised of A) a polymerizate obtained by radical polymerization, containing 5 to 100 wt. % of monomers (a) in the form of ethylenically unsaturated acid anhydrides or ethylenically unsaturated dicarboxylic acids whose carboxyl groups can form an anhydride and containing 0 to 95 wt. % monoethylenically unsaturated monomers (b) with the provision that the monomers (a) and (b) comprise, on average, a maximum of 6 carbon atoms which are not functionalized with groups containing oxygen, and of B) an alkanolamine having at least 2 OH groups, a maximum of 2 nitrogen atoms and a maximum of 8 C-atoms, whereby the weight ratio A:B ranges from 1:0.05 to 1:1.
摘要:
A process for separating a compound from a mixture of different compounds is disclosed for compounds comprising at least two negatively charged groups connected by a linker group. The process comprises treating the mixture with a material comprising layers containing at least two different types of cation disposed in an ordered arrangement within each layer, such as layers of formula LiAl2(OH)6 , in order to separate the compound from the mixture by selective intercalation of the compound into the material.
摘要:
Die vorliegende Erfindung betrifft ein Verfahren zur Gewinnung von aromatischen Dicarbonsäuren aus einem Abstrom einer basischen Depolymerisation von Polykondensaten enthaltend Metallcarboxylate der zu gewinnenden aromatischen Dicarbonsäure, bei dem diesem Abstrom eine mineralische oder organische Säure zugesetzt wird, deren pKs-Wert größer oder gleich derjenigen der dem Polykondensat zugrundeliegenden aromatischen Dicarbonsäure ist.