摘要:
Catalysts for the oxidation of hydrocarbons to acid anhydrides, for example maleic and phthalic anhydrides, are prepared from a vanadium/phosphorus mixed oxide precursor by conditioning it by contact with a strong acid of concentration at least 3 N and solvent extraction to remove unwanted phases. The treated precursor is converted to a catalytically active form by heating. Novel catalysts containing phase X are produced. The catalysts may contain rare earth metal promoters.
摘要:
Catalysts for the oxidation of hydrocarbons to acid anhydrides, for example maleic and phthalic anhydrides, are prepared from a vanadium/phosphorus mixed oxide precursor by conditioning it by contact with a strong acid of concentration at least 3N and solvent extraction to remove unwanted phases. The treated precursor is converted to a catalytically active form by heating. Novel catalysts containing phase X are produced. The catalysts may contain rare earth metal promoters.
摘要:
Hydrocarbons, particularly n-butane, are oxidized to acid anhydrides, especially maleic anhydride, by contacting them at concentrations above the flammable limit with oxygen in the presence of a vanadium/phosphorus mixed oxide catalyst having a surface area of at least 10 m.sup.2 /g. The oxygen concentration is greater than 13 molar percent and/or the concentration of inert gas is less than 70 molar percent.
摘要:
Maleic anhydride is produced by oxidizing a straight chain C.sub.4 hydrocarbon with oxygen in a stream comprising 25 to 60% by volume of the C.sub.4 hydrocarbon, 20 to 45% by volume of oxygen and optionally inert gases to produce a stream containing at least 21/2% by volume of maleic anhydride and condensing maleic anhydride substantially free from water from this stream.
摘要:
Hydrocarbons, particularly n-butane, are oxidized to acid anhydrides, especially maleic anhydride, by contacting them at concentrations above the flammable limit with oxygen in the presence of a vanadium/phosphorus mixed oxide catalyst having a surface area of at least 10 m.sup.2 /g. The concentration of inert gas is more than 70 molar percent and the oxygen concentration is greater than 13 molar percent.
摘要:
Catalysts for the oxidation of hydrocarbons to maleic anhydride comprise a phosphorus/vanadium mixed oxide promoted by tungsten antimony, niobium, and/or molybdenum, having a surface area of at least 10m.sup.2 /g.
摘要:
This invention relates to a 50% drug loaded compressed tablet formulation for efavirenz. Efavirenz is a non-nucleoside reverse trancriptase inhibitor being studied clinically for use in the treatment of HIV infections and AIDS.
摘要:
A delayed release pharmaceutical formulation comprising a core containing an active agent (e.g., a drug) and a delayed release compression coating comprising a natural or synthetic gum applied onto the surface of the core.
摘要:
A chronotherapeutic pharmaceutical formulation comprising a core containing an active agent (e.g., a drug) and a delayed release compression coating comprising a natural or synthetic gum applied onto the surface of the core.
摘要:
A chronotherapeutic pharmaceutical formulation comprising a core containing an active agent (e.g., a drug) and a delayed release compression coating comprising a natural or synthetic gum applied onto the surface of the core.