Abstract:
Maleic anhydride is produced by passing a C.sub.4 to C.sub.12 hydrocarbon stream together with molecular oxygen over a fixed bed containing a vanadium molybdate catalyst promoted with a novel cobalt niobate having the formulaCoNb.sub.a O.sub.xwherein a is a number from about 1.0 to about 4.0 and x is a number from about 3.5 to about 11.0. The catalyst is prepared by calcining a slurry containing cobalt oxide and niobium oxide, or their precursors, in at a temperature range from about 400.degree. to about 1200.degree. C. for about 1 to about 40 hours to obtain a cobalt niobate, which is then slurried with a mixture of oxides of vanadium and molybdenum, or their precursors, dried, and then calcined at a temperature from about 300.degree. to about 650.degree. C. for about 0.5 to about 24 hours. A support cam can be used for the catalyst.
Abstract:
The hydrogen fluoride catalyzed alkylation of isoparaffins such as isobutane with monoolefins such as propylene is promoted utilizing small amounts of trifluoromethanesulfonic acid or fluorosulfonic acid.
Abstract:
Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of added sulfur.
Abstract:
A catalytic reforming process is disclosed using a catalyst containing a Group VIII metal, low amounts of bismuth, and a zeolite L. The catalyst is a non-acidic, monofunctional reforming catalyst. Preferably, the catalyst contains one or more halogens. Preferably, the feed includes C.sub.8 hydrocarbons. The addition of small amounts of bismuth increase or substantially maintain catalyst stability. Unexpectedly low dealkylation rates are achieved using the catalyst while reforming to produce aromatics, especially to produce xylenes such as paraxylene.
Abstract:
Carburization and metal-dusting while hydrodealkylating a hydrodealkylatable hydrocarbon are reduced even in the substantial absence of sulfur.
Abstract:
A high temperature treatment process is disclosed for increasing conversion and reducing the fouling rate of reforming catalysts. The process comprises reducing the catalyst in a reducing gas atmosphere at a temperature below 1025.degree. F. and then treating the reduced catalyst at a temperature of from 1025.degree. F. to 1275.degree. F. in an inert gas atmosphere.
Abstract:
Color change devices which are capable of undergoing a color change on bending. The devices comprise a flexible substrate having a color generating metal (e.g. a valve metal such as Ta or Nb) at at least one surface and an intimately contacting optically thin anodic film covering the color generating metal and generating a visible color by light interference and absorption effects. The thin anodic film is produced by anodizing the color generating metal in the presence of an adhesion-reducing agent (e.g. a fluoride) for weakening the normally tenacious bond between the anodic film and the metal. Devices of this kind capable of being activated by bending, as well as by separation of the constituent layers, are produced by carrying out the anodization step in the presence of a particular concentration of the adhesion reducing agent from a narrow range (e.g. 40-350 ppm of fluoride). The devices can be used as tamper evident labels and the like which show evidence of removal of the labels from articles to which they are originally attached as an indication of tampering.