Abstract:
Very desirable temperature control in the ammoxidation of propylene or isobutylene in a fixed-bed, tubular reactor is obtained by using an oxidation catalyst having two physical forms. The first catalyst which initially contacts the reactants is an essentially inert support having a strongly adhering coat of a catalytic material, and the second catalyst that contacts the reactants after contact with the first catalyst consists essentially of the catalytic material.
Abstract:
Catalysts containing phosphorus, vanadium and molybdenum have been found to be especially effective for the oxidation of methacrolein with molecular oxygen to obtain methacrylic acid. The catalysts may be optionally promoted with Bi, As, B, Ce, Cr, Ag, Fe, W, Pb, Mn, Tl, Te, Ni, Nb, B, Sn and/or Cu.
Abstract:
PREPARATION OF METHACRYLIC ACID FROM METHACROLEIN Methacrylic acid or acrylic acid are produced by the oxidation of methacrolein or acrolein, respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, bismuth, copper, oxygen, a halogen selected from the group consisting of chlorine, bromine or iodine, and optionally, at least one element selected from the group consisting of Fe, Cr, Ni, Mn, Sb, Te, Rh, and Pd.
Abstract:
PREPARATION OF MALEIC ANHYDRIDE FROM FOUR-CARBON HYDROCARBONS Maleic anhydride is produced by the oxidation of n-butane, n-butenes, 1,3-butadiene with molecular oxygen in the vapor phase in the presence of catalysts containing molybdenum, phosphorus, oxygen and the following components delineated in Groups I to IV: (I) bismuth, copper and a halogen selected from the group consisting of chlorine, bromine or iodine; or (II) arsenic and at least one element selected from the group consisting of Sn, rare earth metal, Zr, Rh, Mn, Re, Ru, Cu, Pb, Zn, Ti, Cr, Nb, Al, Ga and alkaline earth metal; or (III) at least one element selected from the group consisting of As, Rb, Pd, Cd, Cs, Tl and In; or (IV) rubidium, and at least one element selected from the group consisting of Sn, rare earth element, Ni, Zr, Ba, Fe, Rh, Mn, Re, Ru, Co and Cu.
Abstract:
Catalysts containing the oxides of molybdenum and phosphorus promoted with rubidium and at least one element selected from the group consisting of As, Cd, In, Sn, Tl, K, Ca, V, U, Ce, W, Ni, Zr, Ba, Fe, Rh, Mn, Re, Ru, Co, and Cu have been found to be especially desirable in the vapor phase oxidation of acrolein and methacrolein with molecular oxygen to yield acrylic acid and methacrylic acid respectively. The reaction of methacrolein gives an especially pure product in high yields and selectivities of methacrylic acid.
Abstract:
PROCESS FOR THE PREPARATION OF UNSATURATED ACIDS FROM UNSATURATED ALDEHYDES Methacrylic acid or acrylic acid are produced by the oxidation of methacrolein or acrolein respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum, phosphorus, and promoted with chromium or at least one element selected from the group consisting of thallium, rubidium, cesium, potassium, titanium and arsenic, or a mixture thereof, wherein at least part of the molybdenum employed in the preparation of the catalyst is supplied in the form of molybdenum trioxide. The oxidation of methacrolein in the presence of a catalyst wherein all the molybdenum employed in the preparation of the catalyst has been supplied by molybdenum trioxide gives especially desirable high yields and selectivities to methacrylic acid.