Process and Catalysts for the Production of Linear Alkanes

Abstract

The invention relates to a process for the production of linear alkanes, containing less than 6′ carbon atoms, from a mix comprising one or more hydrocarbons containing at least 6 carbon atoms. The process uses a catalytic composition comprising particular combinations of a Y-type zeolite, at least one element selected from Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of Group VIII and optionally one or more lanthanides.

1 . A process for the production of linear alkanes containing less than 6 carbon atoms comprising contacting a mixture comprising one or more hydrocarbons containing at least 6 carbon atoms, in presence of hydrogen, with a catalytic composition comprising: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of group VIII Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    with the exclusion of a catalytic composition comprising at least one lanthanide, at least one metal belonging to group VIII and a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B when the mixture treated is a mixture containing aromatic compounds.    
   
   
       2 . The process according to  claim 1 , wherein the mixture comprises one or more hydrocarbons containing at least 6 carbon atoms, selected from the group consisting essentially of aromatic compounds, open-chain alkanes, alkanes with cyclic structures, alkenes having one or more unsaturations with open chains and alkenes with cyclic structures having one or more unsaturations.  
   
   
       3 . The process according to  claim 2 , wherein the mixture comprises one or more hydrocarbons selected from the group consisting essentially of open-chain alkanes, alkanes with cyclic structures, open-chain alkenes having one or more unsaturations and alkenes with cyclic structures having one or more unsaturations.  
   
   
       4 . The process according to  claim 2 , wherein the mixture contains aromatic compounds is contacted with a catalytic composition comprising: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of group VIII,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    with the exclusion of a catalytic composition comprising at least one lanthanide, at least one metal belonging to group VIII and a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B.    
   
   
       5 . The process according to  claim 4 , wherein the mixtures containing aromatic compounds are contacted with catalytic compositions essentially consisting of: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of group VIII,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B.    
   
   
       6 . The process according to  claim 1 , wherein the catalytic composition comprises: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of group VIII, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    c) one or more lanthanides,    with the exclusion of a catalytic composition comprising at least one lanthanide, at least one metal belonging to group VIII and a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B when the mixture treated is a mixture containing aromatic compounds.    
   
   
       7 . The process according to  claim 6 , wherein mixtures containing aromatic compounds are contacted with catalytic compositions containing: 
 a) at least one element selected from the group consisting essentially of Mo, Cu, Ga, In, W, Ta, Zr, Ti,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    c) one or more lanthanides,    with the exclusion of a catalytic composition comprising at least one lanthanide, at least one metal belonging to group VIII and a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B.    
   
   
       8 . The process according to  claim 7 , wherein the catalytic composition essentially consists of: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    c) one or more lanthanides.    
   
   
       9 . The process according to  claim 1 , wherein the zeolite is Y-zeolite.  
   
   
       10 . The process according to  claim 1 , wherein the zeolite is partially in acidic form.  
   
   
       11 . The process according to  claim 9 , wherein the molar ratio SiO 2 /Al 2 O 3  in the zeolite ranges from 3 to 400.  
   
   
       12 . The process according to  claim 11 , wherein the molar ratio between silicon oxide and aluminum oxide is from 5 to 50.  
   
   
       13 . The process according to  claim 1 , wherein the Me is selected from the group consisting essentially of Pt, Pd, Ti, Zn, Mo, Cu, Ni, Zn/Mo, Cu/Zn, Pd/Ti and Ni/Mo.  
   
   
       14 . The process according to  claim 13 , wherein the catalytic compositions contain Y-zeolite and Pd, Y-zeolite and Pt, Y-zeolite and Ni, Y-zeolite and Zn, Y-zeolite and Mo, Y-zeolite and Zn together with Mo, Y-zeolite and Zn together with Cu, Y-zeolite and Pd together with Ti, Y-zeolite and Mo together with Ni.  
   
   
       15 . The process according to  claim 6 , wherein the catalytic compositions contain Y-zeolite and La together with Zn and Mo, Y-zeolite and La together with Zn and Cu.  
   
   
       16 . The process according to  claim 1 , wherein the element Me is present in the catalytic composition in the form of an oxide, ion, metal or a mixture of these forms.  
   
   
       17 . The process according to  claim 1 , wherein Zn, Mo, Cu, Ga, In, W, Ta, Zr or Ti are in a quantity from 0.1 to 50% by weight with respect to the total weight of the catalytic composition.  
   
   
       18 . The process according to  claim 17 , wherein the quantity of the element Me is from 0.5 to 30% by weight.  
   
   
       19 . The process according to  claim 1 , wherein the metal belonging to group VIII is in a quantity ranging from 0.001 to 10%, by weight.  
   
   
       20 . The process according to  claim 19 , wherein the metal of group VIII is in a quantity from 0.1 to 5% by weight with respect to the total weight of the catalytic composition.  
   
   
       21 . The process according to  claim 6 , wherein the lanthanide is lanthanum.  
   
   
       22 . The process according to  claim 6 , wherein the lanthanide is in the form of an oxide, ion or a mixture of these forms.  
   
   
       23 . The process according to  claim 6 , wherein the lanthanide is in a quantity, expressed as an element, from 0.5 to 20% by weight with respect to the total weight of the catalytic composition.  
   
   
       24 . The process according to  claim 23 , wherein the lanthanide is in a quantity ranging from 1 to 15% by weight with respect to the total weight of the catalytic composition.  
   
   
       25 . The process according to  claim 1 , wherein the catalytic composition contains a binder.  
   
   
       26 . The process according to  claim 25 , wherein the binder is selected, from the group consisting essentially of silica, alumina, clay.  
   
   
       27 . The process according to  claim 3 , wherein the alkanes, alkenes or mixtures thereof are mineral oil fractions, or derive from the hydrogenation of mineral oil fractions, or from the hydrogenation of fractions from conversion plants.  
   
   
       28 . The process according to  claim 2 , wherein the mixtures containing aromatic compounds are fractions coming from thermal or catalytic conversion plants, or mineral oil fractions.  
   
   
       29 . The process according to  claim 28 , wherein said fractions are pyrolysis gasolines, fractions coming from pyrolysis gasolines or residual fractions coming from production plants of aromatic compounds and reforming.  
   
   
       30 . The process according to  claim 2 , wherein the aromatic compounds are toluene, ethyl benzene, xylenes, benzene, C 9  aromatic compounds, derivatives of naphthalene and their mixtures.  
   
   
       31 . The process according to  claim 29 , wherein said fractions are mixed with heavy fractions coming from fuel oil from steam cracking (FOK) or Light Cycle Oil (LCO) from fluid bed catalytic cracking.  
   
   
       32 . The process according to  claim 28 , wherein the mixtures are heavy fractions coming from fuel oil from steam cracking (FOK) or Light Cycle Oil (LCO) from fluid bed catalytic cracking, previously treated to remove the asphaltenes.  
   
   
       33 . The process according to  claim 1 , wherein the resulting fraction of n-alkanes are selected from the group consisting essentially of ethane, propane, n-butane and n-pentane.  
   
   
       34 . The process according to  claim 33 , wherein the fraction of n-alkanes containing from 2 to 5 carbon atoms comprises from 50 to 90% by weight of the resulting product.  
   
   
       35 . The process according to  claim 1 , carried out in the presence of hydrogen at a pressure ranging from 5 to 200 bar, at a temperature ranging from 200° C. to 700° C.  
   
   
       36 . The process according to  claim 35 , carried out in the presence of hydrogen at a pressure ranging from 25 to 100 bar, at a temperature ranging from 300° C. to 600° C.  
   
   
       37 . The process according to  claim 35 , carried out at a weight ratio H 2 /charge ranging from 0.1 to 1.4.  
   
   
       38 . The process according to  claim 37 , carried out at a weight ratio H 2 /charge ranging from 0.1 to 0.7.  
   
   
       39 . The process according to  claim 35 , wherein a paraffin is used as diluent.  
   
   
       40 . Catalytic compositions comprising: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, metals of group VIII, Fe, Co, Ni, Ru, Rh, Pd, Os, Ir, Pt,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    with the exclusion of a catalytic composition comprising at least one lanthanide, at least one metal belonging to group VIII and a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B.    
   
   
       41 . The catalytic compositions according to  claim 40 , additionally containing one or more lanthanides.  
   
   
       42 . A process for preparing the catalytic composition according to  claim 40 , which comprises treating the zeolite with a compound of the element Me with ion exchange or impregnation, drying and calcining.  
   
   
       43 . A process for preparing the catalytic composition according to  claim 41 , which comprises treating the zeolite with a lanthanide compound, treating the product thus obtained with a compound of the element Me, drying and calcining.  
   
   
       44 . The process according to  claim 43 , wherein the lanthanide is inserted in the zeolite in acidic form by ion exchange, optionally calcining the product thus obtained, depositing the element Me by ion exchange, and drying and calcining the product.  
   
   
       45 . A process for the production of linear alkanes containing less than 6 carbon atoms from mixtures containing aromatic compounds having a structure with at least 6 carbon atoms, in presence of hydrogen, using a catalytic composition consisting of: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, mixed with one or more metals of group VIII,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    c) one or more lanthanides.    
   
   
       46 . A catalytic composition consisting of: 
 a) at least one element Me selected from the group consisting essentially of Zn, Mo, Cu, Ga, In, W, Ta, Zr, Ti, mixed with one or more metals of group VIII,    b) a zeolite selected from Y-zeolite and Y-zeolite modified by partial or total substitution of the Si with Ti or Ge and/or partial or total substitution of the aluminum with Fe, Ga or B,    c) one or more lanthanides.    
   
   
       47 - 48 . (canceled)