Processes for the manufacture of secondary fatty alcohols, internal olefins and internal olefin sulfonates

A process P1 for the manufacture of a secondary fatty alcohol, said process P1 comprising:

• synthesizing an internal ketone K1 by a process P0 comprising the decarboxylative ketonization reaction of a fatty acid, a fatty acid derivative, or a mixture thereof in a liquid phase with a decarboxylative ketonization catalyst comprising a metal compound in a reaction medium, wherein a ketone K2 at liquid state, which is identical or similar to the internal ketone K1, is introduced into the reaction medium, and
• subjecting the internal ketone K1 to a hydrogenation reaction with hydrogen gas as hydrogenating agent to form the secondary fatty alcohol,
• wherein the fatty acid and the fatty acid derivative independently comprise one or more compounds derived from a fatty acid cut, wherein the one or more compounds comprise a hydrocarbon chain having from 4 to 28 carbon atoms attached to a terminal carboxyl group.