Patent ID: 8877964
Filing Date: 2014-11-04
Classification: B01J,C07C

Abstract:
1. A method for producing acrylic acid through vapor-phase contact oxidation of acrolein, wherein a reactor tube is divided into at least two catalyst layers, and catalysts having a higher activity are charged in the reactor tube sequentially toward an outlet port side from a material source gas inlet port side for a reaction therein to give acrylic acid, and wherein the catalyst activity-controlling method is a method comprising: a step of mixing a molybdenum-containing compound, a vanadium-containing compound, a copper-containing compound and an antimony-containing compound with water, then drying and calcining a resulting mixture, in which a catalytically-active element composition is kept constant but material source compounds are made to vary to give composite metal oxides having a different activity, said composite metal oxides having the formula: wherein Mo, V, W, Cu, Sb and O each indicate molybdenum, vanadium, tungsten, copper, antimony and oxygen, respectively; X represents at least one element selected from the group consisting of an alkali metal and thallium; Y represents at least one element selected from the group consisting of magnesium, calcium, strontium, barium and zinc; Z represents at least one element selected from the group consisting of niobium, cerium, tin, chromium, manganese, iron, cobalt, samarium, germanium, titanium and arsenic; a, b, c, d, e, f, g and h each indicate the atomic ratio of the elements; relative to the molybdenum element 12, 0<a≦10, 0≦b≦10, 0<c≦6, 0<d≦10, 0≦e≦0.5, 0≦f≦1, 0≦g<6; and h indicates the number of the oxygen atoms necessary to satisfy the atomic valences of the constitutive elements, wherein the antimony-containing compound is varied and is a combination of antimony trioxide and antimony acetate.