Methane aromatization catalyst, method of making and method of using the catalyst

Abstract

A catalyst for converting methane to aromatic hydrocarbons is described herein. The catalyst comprises an active metal or a compound thereof, and an inorganic oxide support wherein the active metal is added to the support in the form of metal oxalate. The metal oxalate-derived catalyst exhibits superior performance in the conversion of methane-rich feed to aromatics products relative to catalysts prepared from non-oxalate metal precursors. A method of making the catalyst and a method of using the catalyst are also described.

What is claimed is: 
     
         1 . A process for preparing a methane aromatization catalyst comprising: contacting an active metal oxalate with an inorganic oxide support to form a mixture, and calcining the mixture. 
     
     
         2 . A process as claimed in  claim 1  wherein the active metal oxalate is in the form of a solution that is used to impregnate the inorganic support. 
     
     
         3 . A process as claimed in  claim 1  wherein the active metal compound comprises molybdenum. 
     
     
         4 . A process as claimed in  claim 1  wherein the inorganic oxide support is a zeolite or zeolite-containing support. 
     
     
         5 . A process as claimed in  claim 1  wherein the support comprises ZSM-5 type zeolite 
     
     
         6 . A process as claimed in  claim 1  wherein the support contains zeolite and a binder 
     
     
         7 . A process as claimed in  claim 1  wherein contacting the metal oxalate with the inorganic oxide support is carried out at a temperature in the range of from 0° C. to 100° C. 
     
     
         8 . A process as claimed in  claim 1  wherein contacting the metal oxalate with the inorganic oxide support is carried out at a temperature in the range of from 15° C. to 40° C. 
     
     
         9 . A process as claimed in  claim 1  further comprising a drying step before the calcining. 
     
     
         10 . A process as claimed in  claim 9  wherein the drying and calcining comprises:
 a. subjecting the impregnated support to a temperature of from 70° C. to 120° C. for at least 20 minutes; 
 b. increasing the temperature at a rate of from 1° C. to 10° C. per minute to a temperature of from 275° C. to 325° C.; 
 c. maintaining the temperature achieved in step (b) for at least 20 min; 
 d. increasing the temperature at a rate of from 1° C. to 30° C. per minute to a temperature of from 475° C. to 650° C.; and 
 e. maintaining the temperature achieved in step (d) for at least 20 min. 
 
     
     
         11 . A process as claimed in  claim 16  wherein the drying and calcining comprises:
 a. subjecting the impregnated support to a temperature of from 70° C. to 120° C. for from 20 minutes to 240 minutes; 
 b. increasing the temperature at a rate of from 1° C. to 10° C. per minute to a temperature of from 275° C. to 325° C.; 
 c. maintaining the temperature achieved in step (b) for from 20 minutes to 240 minutes; 
 d. increasing the temperature at a rate of from 1° C. to 30° C. per minute to a temperature of from 475° C. to 550° C.; and 
 e. maintaining the temperature achieved in step (d) for from 20 minutes to 240 minutes. 
 
     
     
         12 . A process as claimed in  claim 8  further comprising cooling the impregnated support after calcination. 
     
     
         13 . A process for producing aromatic hydrocarbons comprising contacting a gas stream comprising methane with a catalyst comprising molybdenum where the catalyst was prepared by contacting a molybdenum oxalate with a zeolite-containing support. 
     
     
         14 . A process as claimed in  claim 13  wherein the gas stream comprising methane has a methane concentration of from 75 to 100 volume percent. 
     
     
         15 . A process as claimed in  claim 13  wherein the gas stream comprising methane is derived from biogas. 
     
     
         16 . A process as claimed in  claim 13  wherein the gas stream containing methane is natural gas.