Answer to Question #120586 in General Chemistry for Naveen

Question

To produce formaldehyde using the reverse reaction provide 3 different ways to increase the production of formaldehyde explain each method

Answer 1

2CH3OH_(g) + O2_(g) → 2HCHO_(g) + 2H2O_(g) - the main reaction of formaldehyde production in industry.

Under normal conditions the reaction is reversible and has a low conversion rate, because the rate of direct reaction is very low.

An increase in temperature or pressure cannot help us, because in the first case both reactions are accelerated, and an increase in pressure accelerates the reverse reaction.

Therefore, the ways to increase production are as follows:

1. Selection of an effective, selective and long-lasting methanol oxidation catalyst. So from the use of platinum, and then copper, then came to silver and iron-molybdenum catalysts, in which the metal catalytic centers are adsorbed on an asbestos or aluminosilicate substrate.
2. Introduction of one of the initial components in excess and repeated run of the reaction mixture over the catalyst. This way we speed up the direct response and increase the conversion rate. More often, methanol is introduced into the reaction in excess.
3. Removal of reaction products from the mixture. To do this, use the absorption of the reaction products with liquid water. As a result, we get a saturated solution of formaldehyde and methanol in water-formalin. Excess methanol is distilled by heating the solution and sent back to oxidation. Water vapors do not interfere with the reaction, but allow to reduce the explosiveness of the reaction mixture.