The separation of the by-product (The volume fraction of 3-picoline is 68.472 2% and 4-picoline 26. 517 6% .) in the synthesis of pyridine by dissociation extraction wasstudied. Six separation conditions of the dissociation extraction-the kind and the dosage ofextractant and organic solvent, the concentration of the extractant and separation temperature-wereinvestigated. Different levels of each factor were chosen to form an orthogonal test of six factorsand five levels. The results show that the volume ratio of 3-picoline and 4-picoline in organicphase is the highest when 24 mL picolines are separated at 0 t by 2. 0 mol/L p-toluenesulfonic andn-heptane whose dosages are 40 mL and 48 mL, respectively. The effect of the separation isconsiderably improved with repetition test. This process of dissociation extraction has commendablepotential for industrial exploitation.
