Catalyst and process for preparing acrolein and/or acrylic acid by dehydration reaction of glycerin

Abstract

A catalyst composition comprising at least an heteropolyacid deposited on a porous titania carrier. A catalyst composition comprising at least an heteropolyacid in which protons in the heteropolyacid may be partially exchanged by at least one cation selected from elements belonging to Group 1 to Group 16 of the Periodic Table of Elements that have been deposited on a porous titania carrier. A method for preparing the catalyst composition, comprising impregnating a titania carrier with a solution of at least one metal selected from elements belonging to the Group 1 to Group 16 of the Periodic Table of Elements or onium, drying and firing the resulting solid mixture, secondly impregnating the resulting solid mixture with a solution of heteropolyacid, drying, and firing the resulting solid mixture. A process for preparing acrolein and acrylic acid by dehydration of glycerin, carried out in the presence of the catalyst.

1 . A catalyst composition comprising at least an heteropolyacid in which protons in the heteropolyacid may be partially exchanged by at least one cation selected from elements belonging to Group 1 to Group 16 of the Periodic Table of Elements that have been deposited on a porous titania carrier. 
     
     
         2 . The catalyst composition of  claim 1 , in which said porous titania carrier is covered at least partially by a compound represented by the formula (I):
   H a A b [X 1 Y c Z d O e   ].n H 2 O  (I)
   
       in which
 H is hydrogen, 
 A is more than one cation selected from elements belonging to Group 1 to Group 16 of the Periodic Table of Elements except hydrogen, 
 X is P or Si, 
 Y is more than one element selected from the group comprising W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Tl, Sn and Pb, 
 Z is more than one element selected from the group comprising W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Tl, Sn and Pb, 
 a, b, c, d and n satisfying following ranges:
 0≦a<9 
 0≦b≦9, preferably 0<b≦9 
 0<c≦12 and 
 0≦d<12 
 n≧0 
 
 
       and e is a number determined by the oxidation of the elements. 
     
     
         3 . The catalyst composition of  claim 1 , in which said titania carrier comprises rutile or anatase or amorphous titanium oxide. 
     
     
         4 . The catalyst composition of  claim 3 , in which said titania carrier comprises at least 80% anatase. 
     
     
         5 . The catalyst composition of  claim 1 , in which said cation is at least one alkali metal cation. 
     
     
         6 . The catalyst composition of  claim 5 , in which said alkali metal is cesium. 
     
     
         7 . The catalyst composition of  claim 2 , in which said compound contains at least one element selected from the group comprising W, Mo and V. 
     
     
         8 . A method for preparing a catalyst composition, comprising impregnating a titania carrier with a solution of at least one metal selected from elements belonging to the Group 1 to Group 16 of the Periodic Table of Elements or onium, drying and firing the resulting solid mixture, secondly impregnating the resulting solid mixture with a solution of heteropolyacid, drying, and firing the resulting solid mixture. 
     
     
         9 . A method for preparing a catalyst composition, comprising impregnating a titania carrier with a solution of heteropolyacid, drying and firing the resulting solid mixture, optionally secondly impregnating the resulting impregnated carrier with a solution of at least one metal selected from elements belonging to the Group 1 to Group 16 of the Periodic Table of Elements or onium, drying, and firing the resulting solid mixture. 
     
     
         10 . A method for preparing a catalyst composition prepared by more than one cycle of impregnation and firing, in which each impregnation is effected with a solution of an element of the group 1 to belonging to the Group 1 to Group 16 of the Periodic Table of Elements or onium or with a solution containing more than one element selected from the group comprising P, Si, W, Mo, Ti, Zr, V, Nb, Ta, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, In, Tl, Sn, Pb, and in which at least one impregnation is made with an acid precursor. 
     
     
         11 . The method for preparing a catalyst composition of  claim 8 , in which one impregnation is made with a phosphotungstic acid or phosphotungstate solution. 
     
     
         12 . The method for preparing a catalyst composition of  claim 8 , in which one impregnation is made with a silicotungstic acid or silicotungstate solution. 
     
     
         13 . The method for preparing a catalyst composition of  claim 8 , in which one impregnation is made with a cesium salt solution. 
     
     
         14 . The method for preparing a catalyst composition of  claim 8 , in which the impregnation is performed by techniques of pore volume impregnation or excess solution impregnation. 
     
     
         15 . The method for preparing a catalyst composition of  claim 8 , in which the firing (calcination) is carried out under an atmosphere of air, inert gas or a mixture of oxygen and inert gas, or under a reduced gas. 
     
     
         16 . The method for preparing a catalyst composition of  claim 8 , in which firing (calcination) is effected at a temperature of 150 to 900° C. for 0.5 to 10 hours. 
     
     
         17 . A process for preparing acrolein by dehydration of glycerin, carried out in the presence of a catalyst according to  claim 1 . 
     
     
         18 . The process of  claim 17  in which dehydration of glycerin is effected in the presence of molecular oxygen. 
     
     
         19 . The process of  claim 17  in which dehydration of glycerin is effected in the presence of a gas containing propylene. 
     
     
         20 . The process of  claim 17  carried out in a reactor of the plate heat exchanger type or in a fixed bed reactor or in a fluidized bed type reactor or in a circulating fluidized bed or in a moving bed. 
     
     
         21 . The process of  claim 17 , in which the resulting acrolein is further oxidized to produce acrylic acid. 
     
     
         22 . The process of  claim 17 , followed by second step of ammoxidation of acrolein to acrylonitrile. 
     
     
         23 . The process of  claim 17 , having an intermediate step of partial condensation of water and heavy by-products issuing from the dehydration step. 
     
     
         24 . A catalyst composition comprising at least an heteropolyacid deposited on a porous titania carrier. 
     
     
         25 . The catalyst of  claim 24  for preparing acrolein or acrylic acid by dehydration of glycerin. 
     
     
         26 . Use of the catalyst of  claim 25  in a preparation of acrolein or acrylic acid by dehydration of glycerin.