USE OF SIMULATION IN RATING AND DESIGN OF DISTILLATION UNITS

The appropriate level of modelling detail in steady state flowsheet si mulations is an important question for the calculation of thermal sepa ration operations such as absorption, distillation, and liquid/liquid extraction. The generation of consistent mass and energy balances may often be performed employing standard implementations for the various unit operations. Surprisingly, operability and sensitivity aspects of the process may be estimated with the help of black box mass balance c osiderations. As soon as flowsheet simulation is to serve as a basis f or the rating of existing or the design of new distillation units, the level of modelling detail has to be increased significantly and a Com plex Topology Simulation (CTS) is required. Thus, the level of the mod elling detail depends strongly on the current project state as well as the information desired. These aspects will be discussed through four examples of practical relevance concerning distillation feed sections and liquid distributors, reboiler section, condensation stage and ope rability aspects.