Iradah, most oil in water emulsions are very fine oil droplets stabilised by surfactants. Surfactants can be charged molecules, you need break these away from the oil droplets, Simple use cationic in same process upstream in the emulsion leg. let it react, then po;lish off the water with anionic...
Butanoic acid is smelly. Naphthenic acids cause some emulsions acting as salts or soaps, Fine water drops are other types of emulsions in oils. You need break the nap acids soap surfactants. butanoic acid may reduce the inherent pH releasing the cations from the salts resolving emulsions...