In batchwise rectification of linseed oil fatty acids, yields of the distillate were observed to lower as the pressure increased.
Fatty acid of high N.V. was obtained by acidifying after saponification of the rectification residue, and about 60% of the distillate was recovered by redistillation.
In vacuum heating under reflux condition of fatty acids, depression rates of N.V. were observed to become greater as the pressure or temperature rose, where by the rate is much greater in linseed oil fatty acids than in stearic acid.
The lesser loss of both S.V. and I.V. in this case meant the formation of fatty acid anhydrides.caused by the dehydration of carboxyl groups.
Furthermore, following results were obtained by introducing various gases into linseed fatty acids under aforesaid conditions.
The depression rates of N.V. were about the same among nitrogen, air and little amount of steam.
On the other hand, using much more steam showed tendency of decreasing loss in N.V. and the loss became lesser under no agitating condition.