Process and apparatus for the semicontinuous extraction of nicotine from tobacco

A process is provided for the improved removal of nicotine from tobacco. An essentially nicotine-free solvent in the supercritical or liquid state is fed into a first end of an extraction flow system containing tobacco and a nicotine-rich solvent is discharged from a second end of the extraction flow system. Periodically a portion of extracted tobacco is discharged from the first end of the extraction system while simultaneously a portion of an unextracted tobacco is charged to the second end of the extraction system. Nicotine is then entrapped in an entrapment material or otherwise removed from the solvent and solvent is recycled through the extraction flow system. Various materials are provided as entrapment materials. Among the entrapment materials provided are aqueous solutions containing absorbent selected from various acids and salts. Among the acids and salts provided as entrapment materials are sulfuric acid, phosphoric acid, nitric acid, tartaric acid, citric acid, malic acid, lactic acid, malonic acid, succinic acid, acetic acid, glutamic acid and monopotassium citrate.