Patent ID: 6392102
Filing Date: 2002-05-21
Classification: C07C,C10L,Y02P

Abstract:
A process for dehydrogenation of dimethyl ether to form a source of formaldehyde comprising continuously contacting a gaseous feedstream comprising dimethyl ether, dioxygen and diluent with a catalytically effective amount of an oxidation promoting catalyst comprising tungsten oxide as an essential catalyst component at elevated temperatures in a range from about 350Â° to about 600Â° C. to form a gaseous mixture comprising formaldehyde, dimethyl ether, dioxygen, diluent, carbon monoxide, carbon dioxide and water vapor; cooling the gaseous dehydrogenation mixture with a liquid by using at least one continuous adsorption column with cooling to temperatures in a range downward from about 100Â° C. to 15Â° C. and separating the resulting liquid source of formaldehyde which contains about 30 to about 85 percent by weight formaldehyde in methanol solution containing less than 5 percent water from a mixture of gases comprising dioxygen, diluent, carbon monoxide, carbon dioxide and water vapor; and recycling at least a portion of the mixture to the continuously contact gaseous feedstream with the oxidation promoting catalyst.