Abstract: A method of preparing acrolein from glycerol or glycerine is disclosed. The method includes dehydrating glycerol or glycerine in the presence of a catalyst consisting of at least (a) a mixed oxide of zirconium and at least one metal, said metal being selected from niobium, tantalum and vanadium, or (b) a zirconium oxide and at least one metal oxide, the metal being selected from niobium, tantalum and vanadium, or (c) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, or (d) a titanium oxide and a mixed oxide of zirconium and at least one metal, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon.

Abstract: The disclosure concerns a method for preparing acrolein from glycerol, according to which a dehydration of the glycerol is carried out in the presence of a catalyst MWOA, wherein MWO represents a mixture of simple oxides and/or mixed oxides of tungsten and at least one metal M selected among zirconium, silicon, titanium, aluminium and yttrium, and A represents one or several Lewis base(s), one said Lewis base being of the formula B(R1)p(R2)q(R3)r, wherein B is an element selected among C, S, P, O, N and halides, R1, R2 and R3 represent, independently of each other, H, a C1-C6 alkyl group, O, OH or OR wherein R represents a C1-C6 alkyl group, and the sum of p, q and r varies from 0 to 4.

Abstract: The disclosure concerns a method for preparing acrolein from glycerol, according to which a dehydration of the glycerol is carried out in the presence of a catalyst MWOA, wherein MWO represents a mixture of simple oxides and/or mixed oxides of tungsten and at least one metal M selected among zirconium, silicon, titanium, aluminium and yttrium, and A represents one or several Lewis base(s), one said Lewis base being of the formula B(R1)p(R2)q(R3)r, wherein B is an element selected among C, S, P, O, N and halides, R1, R2 and R3 represent, independently of each other, H, a C1-C6 alkyl group, O, OH or OR wherein R represents a C1-C6 alkyl group, and the sum of p, q and r varies from 0 to 4.

Abstract: The invention concerns a method for preparing acrolein from glycerol or glycerine, wherein dehydration of the glycerol or glycerine is achieved in the presence of a catalyst based on zirconium oxide and which active phase consists in at least a) a silicon oxide, a zirconium oxide and at least one metal M oxide, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and titanium, b) a titanium oxide, a zirconium oxide and at least one metal M oxide, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and silicon. This method can be used for making 3-(methylthio)propionic aldehyde MMP, 2-hydroxy-4-methylthiobutyronitrile HMTBN, methionine and its analogs.

Abstract: A method of preparing acrolein from glycerol or glycerine is disclosed. The method includes dehydrating glycerol or glycerine in the presence of a catalyst consisting of at least (a) a mixed oxide of zirconium and at least one metal, said metal being selected from niobium, tantalum and vanadium, or (b) a zirconium oxide and at least one metal oxide, the metal being selected from niobium, tantalum and vanadium, or (c) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, or (d) a titanium oxide and a mixed oxide of zirconium and at least one metal, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon.

Abstract: The invention concerns a method for preparing acrolein from glycerol or glycerine, wherein dehydration of the glycerol or glycerine is achieved in the presence of a catalyst based on zirconium oxide and which active phase consists in at least a) a silicon oxide, a zirconium oxide and at least one metal M oxide, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and titanium, b) a titanium oxide, a zirconium oxide and at least one metal M oxide, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and silicon. This method can be used for making 3-(methylthio)propionic aldehyde MMP, 2-hydroxy-4-,methylthiobutyronitrile HMTBN, methionine and its analogs.

Abstract: The invention relates to a method for preparing acrolein from glycerol or glycerine, comprising dehydrating glycerol or glycerine in the presence of a catalyst consisting of at least a) a mixed oxide of zirconium and at least one metal, said metal being selected from niobium, tantalum and vanadium, b) a zirconium oxide and at least one metal oxide, the metal being selected from niobium, tantalum and vanadium, c) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, d) a silicon oxide and a mixed oxide of zirconium and at least one metal, the metal being selected from tungsten, cerium, manganese, niobium, tantalum, vanadium and titanium, e) a titanium oxide and a mixed oxide of zirconium and at least one metal, said metal being selected from tungsten, cerium, manganese, niobium, tantalum, titanium, vanadium and silicon, f) a titanium oxide and a mixed oxide or zirconium and at least on

Abstract: The invention concerns solids comprising a single tungsten oxide layer on a zirconia support and/or titanium dioxide support, characterized in that the tungsten exhibits tetrahedral co-ordination, before and after calcining. The invention also concerns the method for preparing the solids, and their uses as acid catalysis reactions catalyst.

Abstract: The invention concerns solids comprising a single tungsten oxide layer on a zirconia support and/or titanium dioxide support, characterized in that the tungsten exhibits tetrahedral co-ordination, before and after calcining. The invention also concerns the method for preparing the solids, and their uses as acid catalysis reactions catalyst.