摘要

This study aims to investigate the effect of caustic tower operation temperature on red oil formation and clogging of the tower. For this aim, the caustic tower of Tabriz Petrochemical Plant was used. The operation temperature of the tower was varied from 38 up to 50 degrees C, and the amount and composition of the red oil formed were investigated. Our results indicate that the amount and composition of the red oil formed inside the tower were different at varied temperatures. At 42-45 degrees C, minimum amount of the red oil formed, whereas at other temperatures, the products with 2 phases (oil phase on the top and aqueous phase in the bottom) were produced. The red oil formed is mainly alkanes, alkenes, dienes, and also aldehydes. They are produced from the cracking of naphtha, which some could undergo polymerisation reactions in the caustic tower, resulting in the formation of red oil. This formation of the red oil could decrease the efficiency of absorption column due to the problem of chocking. In addition, the red oil will accumulate on internal surfaces of equipment and the bottom of the column, leading to fouling and eventually plugging. The analysis showed that the polymerisation reactions produce heavy alkanes, aromatics, and cyclic compounds. Via optimisation of caustic tower operation temperature, the red oil formation could be drastically decreased.

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