HCHO PROCESS

Application

A process for the continuous manufacture of formaldehyde and urea/formaldehyde concentrate from methanol.

Description

Vaporized methanol is mixed with air and recycled gas and reacted over an iron-molybdenum oxide catalyst in a fixed-bed reactor which consists of a number of catalyst-filled tubes surrounded by boiling Dowtherm A. The Dowtherm system employs process and startup heat transfer, enabling rapid startup with no secondary fuel heaters or offsite steam. Conversion of methanol is above 99%, with selectivity to formaldehyde of 94%. The reacted gases are cooled by transferring the sensible heat back to the reactant gases in a unique heat exchange process. The reacted gases are quenched with water or urea water in the absorber; yielding aqueous formaldehyde or urea/formaldehyde concentrate. A special vent-gas absorber is utilized to recover much of the vent Methanol and the Formaldehyde content to the Catalytic converter can be reduced to below 10ppm (wt) for UFC-85 productions, and below 25ppm for 50% Formaldehyde production. A catalytic converter is available to further reduce formaldehyde emissions below 1 ppm and is totally sustained by the fuel value of the vent gas. Process metallurgy is stainless steel.

Product

Raw Materials and Utility Requirements: ( Per metric Ton 37% Formaldehyde )