Reactive distillation columns can exhibit multiple steady states for the same feed and operating conditions. Two hybrid columns have been investigated here using both steady-state and dynamic simulations. In the first column, ETBE synthesis was considered and a physically realizable multiplicity was found for the case with a constant mass reflux rate. The high-conversion steady state was associated with high concentrations of ethanol and high temperatures in the reaction zone. In the second column, MTBE synthesis was considered and a different type of multiplicity (with up to five possible steady states) was observed for the physically realizable case of constant reboiler duty. In this case, the high-conversion steady state was associated with low concentrations of methanol and low temperatures in the reaction zone. Mechanistic explanations for both multiplicities are presented using the simulation results, and these explanations are related to the fundamental and underlying causes of the multiplicities.