摘要:
A fluid bed catalyst which has lost activity or fluidization quality through agglomeration, contamination, or a physical or chemical change on the surface of the catalyst is deagglomerated and/or its surface re-exposed, by contacting the fluidized catalyst with a high velocity gas sufficient to cause multiple collisions among the catalyst particles and thereby deagglomerating the particles and/or abrading the surface of the particles to expose fresh catalyst.
摘要:
The present invention relates to improvements of fluid bed catalysts. More particularly, the present invention relates to improvements of fluid bed oxidation catalysts useful in the preparation of maleic anhydride from C.sub.4 hydrocarbons, including n-butane. The present invention includes a process of contacting a fluid bed catalyst with a reactivating agent in a catalyst standpipe. The present invention also provides a catalyst containing the mixed oxides of vanadium and phosphorus, treated using the above process. The present invention further provides a process for producing maleic anhydride, utilizing the catalyst prepared using the above process. The present invention additionally provides for a reactor standpipe, utilized for regenerating catalyst according to the above process.
摘要:
Vanadium phosphorus mixed oxide containing catalysts are prepared by sequentially forming an alpha-VOPO.sub.4 catalyst precursor in aqueous media, and thereafter partially reducing a portion of the vanadium to a valence state of +4 in an organic liquid reducing media, in the absence of corrosive reducing agents. The catalysts exhibit excellent activity for the production of maleic anhydride from 4 carbon atom hydrocarbons such as n-butane.
摘要:
Unsaturated nitrile compounds, e.g., acrylonitrile, are used as microbiocides to inhibit undesired bacterial growth in injection water used in enhanced oil recovery methods. The biocides are efficacious for the control of sulfate reducing bacteria, including Desulfovibrio desulfuricans.
摘要:
The present invention provides a process for the preparation of oxidation catalysts containing mixed oxides of vanadium and phosphorus, which catalysts are particularly effective in the oxidation of n-butane, n-butenes, 1,3-butadiene or a mixture thereof with molecular oxygen or an oxygen-containing gas in the vapor phase to produce high yields of maleic anhydride with good selectivity. A vanadium compound is introduced into an olefinic oxygenated organic liquid medium, a phosphorus-containing compound is added to the medium, reduction of at least a portion of the vanadium to a +4 valence state is effected either prior to or subsequent to the addition of the phosphorus-containing compound, and the resulting vanadium-phosphorus oxide catalyst precursor is recovered, dried and calcined.
摘要:
The present invention provides improved oxidation catalysts containing mixed oxides of vanadium and phosphorus and the method for the preparation thereof, which catalysts are particularly effective in the oxidation of n-butane, n-butenes, 1,3-butadiene or a mixture thereof with molecular oxygen or an oxygen-containing gas in the vapor phase to produce excellent yields of maleic anhydride with very good selectivity. At least one vanadium compound, a substantial portion of which is in the pentavalent state, and at least one phosphorus-containing compound is added to an organic liquid medium capable of reducing at least a portion of the vanadium to a +4 valence state, to form a reaction mixture. Partial reduction of the vanadium is effected in the presence of the phosphorus-containing compound and a highly ordered and uniform mixed vanadium phosphorus oxide-containing catalyst precursor is formed.
摘要:
A process for the destruction of organic contaminants from wastewater streams and solid surfaces, including soil. The process comprises removing volatile organic compounds from the wastewater stream or surface by steam stripping and then contacting a stream comprising steam and the stripped organic compounds with a catalyst at an elevated temperature so as to convert the hydrocarbon portion of the organic compounds to a mixture of hydrogen and carbon dioxide.
摘要:
Vanadium phosphorus mixed oxide containing catalysts are prepared by sequentially forming an alpha-VOPO.sub.4 catalyst precursor in aqueous media, and thereafter partially reducing a portion of the vanadium to a valence state of +4 in an organic liquid reducing media, in the absence of corrosive reducing agents. The catalysts exhibit excellent activity for the production of maleic anhydride from 4 carbon atom hydrocarbons such as n-butane.
摘要:
Vanadium phosphorus mixed oxide containing catalysts are prepared in an organic liquid reaction medium with heating wherein at least 1.5 moles organic liquid are removed from the reaction medium such as by distillation for each mole of vanadium which is reduced or reacted during such reaction and/or reduction. The resulting catalysts are useful for the production of maleic anhydride from 4 carbon atom hydrocarbons.
摘要:
Catalysts comprising the combined oxides of vanadium and at least one element selected from the group consisting of boron, niobium, tantalum, antimony, tungsten and chromium have been found to be especially effective in the oxidation of n-butane, n-butenes and butadiene, or a mixture thereof with molecular oxygen in the vapor phase to yield maleic anhydride. The catalysts of the present invention may be further promoted with additional elements to enhance activity, stability and selectivity. The reaction with n-butane gives an especially pure product in good yield and selectivity.