(78d) Design and Performance Evaluation of Large 6-Pass C3 Splitter Columns

HPCL-Mittal Energy Limited (HMEL) operates a dual-feed cracker with a capacity of 1.2 MTPA of ethylene and 0.5 MTPA propylene. As the column diameter increases by two times, the tray active area and downcomer area can increase by four times, but the weir length increases only by a factor of two. In a high-pressure C3 splitter, the liquid load is high, which results in high weir loading. Since the C3 splitter feed capacity is large for this plant, the customer debated the need for multi-pass trays before deciding to go with a six-pass tray design. The column is designed with Sulzer VGPlus^TM trays with ModArc^TM downcomers. The plant was started in 2022 and has been in operation for the past years. This paper will discuss the design criteria for moving from a four to six-pass tray design and explain various deck and downcomer enhancements. Finally, we will also discuss the efficiency and capacity performance of this C3 splitter column.