(142a) Distillation Column Steady State Identifier

Fractionation Research, Inc. (FRI) collects hydraulic and mass-transfer data on distillation column internals in its 4-foot diameter low-pressure and high-pressure distillation columns in Stillwater, OK using several hydrocarbon systems. Almost all of these data are collected at steady-state conditions.

A typical FRI test involves several transitions between steady-state conditions ranging from the maximum operating capacity (flood point) to the minimum operating capacity. In addition, column dynamics are influenced by the operating pressure (deep vacuum to 500 psia), internals (trays or packing), and the system physical properties.

This paper describes a new real-time multi-variable steady-state identifier (SSID), based on the Brown and Rhinehart (2000) R-statistic technique, implemented at the FRI unit. The steady-state identifier was implemented in Microsoft Excel™ and Yokogawa Exaquantum™ for real-time steady-state detection.

The success of the steady-state identifier was experimentally demonstrated at the FRI unit over a wide range of test conditions. The steady-state identifier methodology and preliminary results are described in the paper. Potential industrial applications that could benefit from the steady-state identifier are identified.