Formaldehyde Economic data

Formaldehyde pxooucnoN. Economic data (France conditions, mid-1986)... 

Table 121 summarizes the average economic data concerning formaldehyde manufacturing processes using silver and iron molybdenum catalysts. They refer to the latest technologies and a capacity of 7,500 t/year of 37 per cent weight formalin. 

This equation was used to calculate the reaction rates as a function of temperature and rongalite/Ni(II) concentration ratio, and Table 11.6 shows the results for a ratio of 1.5/0.5. The data in this table confirm the previous conclusion that a temperature of about 333 K should be used in order to have an economical and technologically acceptable reaction rate for the reduction of Ni(II) by rongalite and to avoid the large influence of autoinhibition by formaldehyde, an unfavourable effect that increases with temperature. 

In the past few years, there have been many active research programs around the world on the direct conversion of methane to methanol and/or formaldehyde, C2 hydrocarbons, and others. Methanol and formaldehyde can be produced by partial oxidation of methane under controlled conditions in a homogeneous or catafytic reaction process. Many catalysts, such as Mo-based oxides, aluminosilicates, promoted superacids, and silicoferrate, have been used for the reaction. Since the activation energy for the subsequent oxidation of methanol and formaldehyde to carbon oxides is usualfy smaller than that for partial oxidation, hi selectivities for methanol and formaldehyde have been demonstrated onfy at low methane conversions. Reaction conditions (e.g., 02 or N2Q to CH4 ratio, temperature, and resistance time) and surface area of supports play important roles in methanol and formaldehyde yield. In neral, low pressure favors the formation of formaldehyde. Hi pressure and low 02/methane ratios favor the formation of methanol The low yields achieved to data are a major obstacle to economical commercialization of this route. 

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