Caustic Tower Performance Changes from Lighter Feedstock

Caustic tower performance is critical in the production of high quality ethylene for effective removal of acid gases from the cracked gas. However, an undesired polymerization reaction in caustic towers can result in accumulation of polymer, “red oil”, resulting in fouling, plugging and overall decreased asset availability. At the BASF Total Petrochemicals cracker in Port Arthur, a shift toward lighter feedstocks due to market conditions resulted in higher red oil levels and increased inhibitor demand. This report investigates the correlation between lighter feedstocks and increased red oil in caustic towers, as well as effective control strategies which may decrease inhibitor demand.