14.1 Introduction
• In this lecture, we present the production technology for formaldehyde and chloromethanes.
• Formaldehyde is produced from methanol
• Chloromethanes are produced from methane by chlorination route.
14.2 Formaldehyde production
14.2.1 Reactions
a. Oxidation: CH3OH + 0.5 O2 → HCHO + H2O
b. Pyrolysis: CH3OH → HCHO + H2
c. Undesired reaction: CH3OH + 1.5 O2 → 2H2O + CO2
In the above reactions, the first and third are exothermic reactions but the second reaction is endothermic. The reactions are carried out in vapour phase.
Catalyst: Silver or zinc oxide catalysts on wire gauge are used.
Operating temperature and pressure: Near about atmospheric pressure and 500 – 600°C