Catalytic system for the production of olefins

Abstract

Catalytic system for partial oxidation reactions of hydrocarbons characterized in that it contains: one or more metals belonging to the 1 st , 2 nd , and 3 rd transition series; one or more elements of group IIIA, IVA or VA, wherein at least one of said metals or said elements is in the form of a nitride.

1 ) A catalytic system for catalytic partial oxidation reactions of hydrocarbons containing: 
 one or more metals belonging to the 1 st , 2 nd  and 3 rd  transition series    one or more elements of group IIIA, IVA or Va characterized in that at least one of said metals or said elements is in the form of a nitride.    
     
     
         2 ) The catalytic system according to  claim 1 , wherein the metal belonging to the 1 st , 2 nd  and 3 rd  transition series is deposited on the nitride or oxy-nitride.  
     
     
         3 ) The catalytic system according to  claim 2 , wherein the metal belonging to the 1 st , 2 nd  and 3 rd  transition series deposited on the nitride or oxy-nitride is in a quantity ranging from 0.05 to 15% by weight.  
     
     
         4 ) The catalytic system according to  claim 1 , wherein the element of group IIIA, IVA or VA is deposited on the nitride or oxy-nitride.  
     
     
         5 ) The catalytic system according to  claim 4 , wherein the element of group IIIA, IVA or VA deposited on the nitride or oxy-nitride is in a quantity ranging from 0.05 to 15% by weight.  
     
     
         6 ) The catalytic system according to  claim 1 , wherein the metal belonging to the 1 st , 2 nd  and 3 rd  transition series is selected from Pt, Cr, V, Mo, Cu, W, Ru, Zn, Ag, Au, Rh, Mn, Fe, Co and Ni.  
     
     
         7 ) The catalytic system according to  claim 1 , wherein the element of group IIIA, IVA or VA is selected from Sn, Ga, Pb, Sb, Bi and Si.  
     
     
         8 ) The catalytic system according to claims  3  and  5 , wherein there are two or three metals deposited on the nitride or oxy-nitride.  
     
     
         9 ) The catalytic system according to  claim 8 , wherein the two metals deposited are selected from the combinations Pt—Sn, Pt—Ga and Pt—Cu.  
     
     
         10 ) The catalytic system according to  claim 8 , wherein the three metals deposited are selected from the combinations Pt—Sn—Cr, Pt—Sn—Ga and Pt—Sn—Bi and Pt—Sn—Sb.  
     
     
         11 ) A process for the production of olefins from gaseous paraffinic hydrocarbons, having from two to 6 carbon atoms, comprising a partial oxidation of said hydrocarbons with a gas containing molecular oxygen in the presence of a catalytic system according to at least one of  claims 1  to  10 .  
     
     
         12 ) The process according to  claim 11 , wherein the partial oxidation is effected at a temperature ranging from 450 to 1000° C., at a pressure ranging from 1 to 15 Atm and a space velocity ranging from 5000 to 800000 h −1 .  
     
     
         13 ) The process according to  claim 11 , wherein the partial oxidation is carried out using reactors in which the gas inlet zone and catalytic zone either have a tubular shape or a sand-glass shape or a truncated-conical shape.  
     
     
         14 ) The process according to  claim 13 , wherein a stream of oxygen, air or enriched air and a fuel not having the function of directly producing olefins is sent into the gas inlet zone and a gaseous stream of paraffinic hydrocarbons is sent into the catalytic zone.  
     
     
         15 ) The process according to  claim 13 , wherein in the tubular-shaped or sand-glass shaped or truncated-conical shaped reactor, the catalyst fillings are differentiated so as to have two or three catalytic beds in series.  
     
     
         16 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt deposited on nitrides or oxy-nitrides and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         17 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt and Cu deposited on nitrides or oxy-nitrides and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         18 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt and Ni deposited on nitrides or oxy-nitrides and the catalytic bed downstream consists of Pt, Sn and Cr deposited on nitrides or oxy-nitrides.  
     
     
         19 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt deposited on nitrides or oxy-nitrides, the intermediate catalytic bed consists of Pt and Sn deposited on nitrides or oxy-nitrides, and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         20 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt and Cu deposited on nitrides or oxy-nitrides, the intermediate catalytic bed consists of Pt, Sn and Bi deposited on nitrides or oxy-nitrides, and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         21 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt deposited on nitrides or oxy-nitrides, the intermediate catalytic bed consists of Pt and Sn deposited on nitrides or oxy-nitrides, and the catalytic bed downstream consists of Pt, Sn and Sb deposited on nitrides or oxy-nitrides.  
     
     
         22 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt and Cu deposited on nitrides or oxy-nitrides, the intermediate catalytic bed consists of Pt, Sn and Cr deposited on nitrides or oxy-nitrides, and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         23 ) The process according to  claim 15 , wherein the catalytic bed upstream consists of Pt and Sn deposited on nitrides or oxy-nitrides, the intermediate catalytic bed consists of Pt and Sn deposited on nitrides or oxy-nitrides, and the catalytic bed downstream consists of Pt, Sn and Ga deposited on nitrides or oxy-nitrides.  
     
     
         24 ) A process for the production of olefins from gaseous paraffinic hydrocarbons, having from two to 6 carbon atoms, comprising a partial oxidation of said hydrocarbons with a gas containing molecular oxygen in the presence of a catalytic system effected at a temperature ranging from 450 to 1000° C., at a pressure ranging from 1 to 15 Atm and at a space velocity ranging from 5000 to 800000 h −1 , using reactors in which the gas inlet zone and catalytic zone either have a tubular shape or a sand-glass shape or a truncated-conical shape, characterized in that a stream of oxygen, air or enriched air and a fuel not having the function of directly producing olefins is sent into the gas inlet zone and a gaseous stream of paraffinic hydrocarbons is sent into the catalytic zone.  
     
     
         25 ) The process according to  claim 14  or  24 , wherein the fuel not having the function of directly producing olefins is selected from natural gas, synthesis gas, hydrogen or a mixture of hydrogen and CO.