METHOD OF PREPARING PROPIONIC ACID Russian patent published in 1999 - IPC

FIELD: chemical industry. SUBSTANCE: method comprises preparing propionic acid by hydroxycarbonytation of ethylene with carbon monoxide in water and organic C₂-C₄ carboxylic acid. Process is carried out at elevated pressure and temperature in the presence of catalyst system comprising halogen-free palladium compounds and tertiary organic phosphine with basic type additive. Additive includes one compound from among alkali or alkaline-earth metal oxide, hydroxide, carbonate, bicarbonate or carboxylate in amount of less than 0.05 wt %. Alkali or alkaline-earth metal carboxylate includes C₁-C₁₂ mono-dibasic or polybasic organic acid salt, e.g. aliphatic C₁-C₁₀ carboxylic acid salt, preferably sodium propionate. EFFECT: increased yield of propionic acid. 15 cl, 1 tbl