Abstract:
A binary phase diagram of m- and p-chloronitrobenzene (CNB) was constructed to study the effects of feed composition on the crystallization. The results show that the feed composition below the eutectic composition resulted in crystals rich in m-CNB, while the feed above the eutectic composition resulted in crystals rich in p-CNB. At the eutectic composition, amorphous precipitates with the composition close to the feed were obtained. KY zeolite was then added to the feed solution to investigate the effects of the zeolite on the crystallization of m-CNB and p-CNB. A binary phase diagram with the KY zeolite was created. It was found that, at the eutectic composition (62.9 wt% m-CNB), the composition was rich in p-CNB, and the amorphous solids became crystal, the crystallization temperature at the eutectic composition was shifted from 23ºC to 20ºC. Above the eutectic composition (65 wt% m-CNB), its crystallization resulted in the crystal rich in p-CNB instead of rich in m-CNB as in the case without the zeolite. And below the eutectic composition, the composition was rich in p-CNB.
