Enhancing Multi-Product Fractionator Efficiency Using Properly Designed Vapor and Liquid Distribution Devices

Number of trays and packed column height are both primary parameters determining the degree of separation of a distillation column. However, this factor alone cannot guarantee targeted distillation column efficiency. Vapor and liquid distribution devices play a vital role and overlooking these critical items often brings inferior results. The importance of vapor and liquid distribution design is emphasized more for a multi-product fractionator or packed column where column efficiency is more sensitive to liquid and vapor distribution.

This paper will discuss commonly overlooked items in vapor and liquid distribution devices. Useful methodologies for vapor and liquid devices evaluation and remedies are also illustrated. Actual retrofits for multi-product fractionators, which examine how column efficiency enhancements are achieved through careful analysis and design procedures, are demonstrated through three case studies: two crude atmospheric columns for petroleum refineries and one demethanizer for gas processing.