Dear Sir. Concerning your issue about the difference between absorption and scrubbing for acid gas sweetening. The common word used for acid gas sweetining is absorption more than scrub(which is mean to wash or clean). I think the following below attached file may help you in your issue:

Thanks

Dear sir,  if waste gas stream contains few/negligible amount of dust particle, removal technique word is absorption but waste gas stream contains more amount of dust particle then removal technique word is scrubbing.

For example: absorption: removal of CO2 from waste gas stream such as flue gas using liquid solvent.

scrubbing: removal of CH4 from waste gas stream such as coal gas using liquid solvent.

But both word are synonyms.

thanks.

also,

• If a component of the gas mixture, transferred to liquid, is a gas then it is called ABSORPTION.
• If a component transferred to liquid, is a vapor then it is called SCRUBBING.
• Below critical temperature, a gas is known as vapor( which could be saturated or superheated).

Absorber: which separates the particles based on the affinity between particles and stationary absorbent. Absorber a process equipment are used to remove one or more gaseous component from gaseous mixture by using suitable type solvent mostly present in lesser quantity.

Scrubber: which separates the heavier particles based on the velocity principle. whenever heavy particles collides with scrubber inclined surface, velocity will become zero. scrub out air pollutant ( mainly particulates, and acid gases) from exhaust system