Studies on the Production of Formaldehyde from Methanol IV.

Studies on the Catalysts for the Production of Formaldehyde

Abstract

The kinds of catalyst, their forms, and packing conditions for manufacturing of formaldehyde, as well as the effects of iron and hydrogen sulfide, have been investigated.Experiments on using of silver, copper, and silver-plated copper catalyst indicated that the silver catalyst was the most excellent, while the copper catalyst showed lower reaction rate, as well as the formation of higher amount of carbon dioxide, and it was unsuitable for application in industrial scale.The result of investigation on the form of silver catalyst indicated that using of finely cut silver was the most suitable.Also, the diameter of silver line for making of silver gauze and the size of mesh have been investigated.Although there were many problems left for using the gauze in a rolled form, but the effect of form became almost without influence by using of finely cut pieces of the gauze and cooled by spraying. The relations among the packing states of rolled-form catalyst, the distributions of temperature under catalyst layer and the composition of gas were clarified. The effects of iron and hydrogen sulfide haye been investigated and it was found that the iron adhered on catalyst caused the formation of a considerable amount of carbon monoxide as well as the deposition of carbon on the catalyst: The silver catalyst poisoned by hydrogen sulfide was found to cause difficulty' for starting of the reaction besides the formation of by-product but this effect was not of permanent nature.