MULTIPLICITY AND PSEUDO-MULTIPLICITY IN MTBE AND ETBE REACTIVE DISTILLATION

Multiplicity of steady states can exist in three forms: input multipli city, output multiplicity, and pseudo-multiplicity, which are describe d here. Input multiplicity is Likely to be common in reactive distilla tion and places substantial restrictions on the selection of controlle d variables. Output multiplicity is also possible in reactive distilla tion and also has less significant implications for operation and cont rol as it may influence the choices of control structure and the opera ting region. Pseudo-multiplicity parallels output multiplicity but is only present in terms of molar inputs. It has only minor implications for operation and control but is an important discovery as it reconcil es recent reports of material balance output multiplicity with earlier conjecture which claimed that this was unlikely.