Process for manufacturing alkanesulfonic acids

A process for the production of alkanesulfonic acid from an alkane and SO3 with an initiator comprising a distillation step, the distillation step comprising providing a feed comprising unpurified alkanesulfonic acid to at least one distillation column,

• wherein total energy consumption of the process is reduced by heat integration, and
• wherein the feed is heated by heat integration with a stream of purified alkanesulfonic acid leaving the distillation step, and/or the feed is heated by heat integration with a distillation residue leaving the distillation step, and/or the feed is first heated by heat integration with the stream of purified alkanesulfonic acid leaving the distillation step and then by heat integration with the distillation residue leaving the distillation step, and/or the feed is heated by heat integration with a stream from mixing the purified alkanesulfonic acid leaving the distillation step with water to yield an aqueous solution.