SEPARATION AND RECOVERY OF INDOLE

摘要

PROBLEM TO BE SOLVED: To efficiently separate and recover indole by carrying out absorptive separation of indole from an indole-containing oil using a faujasite type zeolite as an absorbent. SOLUTION: An indole-containing oil is subjected to absorptive separation using a faujasite type zeolite having a water content of 1-25wt.% based on the zeolite and represented by the formula 0.9±0.2 M2/n O: Al2 O3 : xSiO2 :yH2 O [M is a cation; (n) is its valence; (x) is 2-3 or 3-6; (y) is different by the extent of hydration] as an absorbent at a room temperature to 350 deg.C under atmospheric pressure to 10Mpa pressure, preferably at 50-200 deg.C under atmospheric pressure to 5Mpa pressure in a liquid phase. The indole-containing oil comprises a coal tar fraction having 220-270 deg.C boiling point and consists essentially of methylnaphthalene and dimethylnaphthalene and usually contains about 0.5-10wt.%. indole. Indole is separated and absorbed from the indole-containing oil by making absorption volume of an absorbent large and enhancing separation performance.