Alkylene oxides production using molten nitrate salt catalysts

A process for producing an alkylene oxide or mixture of alkylene oxides by a reaction which comprises reacting an olefin having from 3 to 6 carbon atoms per molecule, or mixture thereof, with an oxygen-containing gas, said olefin and said oxygen-containing gas being gaseous reactants, by contacting said gaseous reactants with a bath, stream, spray or mist of at least one molten nitrate salt catalyst, in the absence of a co-catalyst, said catalyst being present in an amount sufficient to absorb any heat generated during said reaction while maintaining an essentially constant reaction temperature, said reaction being conducted at a reaction temperature of between about 135.degree. C. and about 600.degree. C. and a reaction pressure of between about 1 and about 40 atmospheres.