Patent ID: 6410793
Filing Date: 2002-06-25
Classification: C07C

Abstract:
A process for producing formaldehyde from a gas containing carbon oxide and hydrogen sulfide (H2S) comprising contacting the gas stream with a first catalyst comprising a supported metal oxide of a metal selected from the group consisting of vanadium (V), niobium (Nb), molybdenum (Mo), chromium (Cr), rhenium (Re), tungsten (W), manganese (Mn), titanium (Ti), zirconium (Zr) and tantalum (Ta) and mixtures thereof, wherein said support is selected from titania, zirconia, niobia, ceria, tin oxide and mixtures thereof with the proviso that the support and the supported metal are not the same, to convert said carbon oxide and hydrogen sulfide (H2S) to an intermediate compound selected from the group consisting of CH3SH, CH3SCH3, CH3SSCH3 and mixtures thereof, and then contacting said intermediate compound with a second catalyst selected from a supported metal oxide of a metal selected from the group consisting of vanadium (V), niobium (Nb), molybdenum (Mo), chromium (Cr), rhenium (Re), tungsten (W), manganese (Mn), titanium (Ti), zirconium (Zr), tantalum (Ta) and mixtures thereof, and a bulk metal oxide catalyst selected from the group consisting of molybdates (Mo), chromates (Cr), vanadates (V), rhenates (Re), titanates (Ti), niobates (Nb), tungstates (W), and mixtures thereof, under oxidizing conditions for a time sufficient to convert at least a portion of said intermediate compound to formaldehyde and sulfur dioxide, and recovering said formaldehyde.