Design data for high purity toluene recovery from platformate by extractive distillation with phenol

were obtained by a pilot plant study. The extractive distillalations column

200mm in diameter

possessed 44 bubble cap plates and had a Capacity o?processing 250 kilograms of feed per day. The platformate was first prefractionated to 70-117℃

which contained 0.8% benzene and 48% toluene by weight. The heart cut was then used as the feed for the extractive distillation. The recommended operating conditions were as follows: phenol/feed ratio

4; reflux ratio

4-5; feed temperature

120℃; phenol inlet temperature

130℃. The actual plates of rectifying

stripping and phenol recovery section were 19

20 and 5 respectively. The recovery of nitration grade toluene from the feed was 97-98%. When losses in prefractionation

acid washing and redistillation were included

the net recovery of toluene from the platformate was 93%. The result of this study gave the data for designing of full scale production plants.