Energy-saving performance of reactive distillation process for TAME synthesis through multiple steady state conditions

We have previously reported the existence of steady-state solutions where reaction conversion is improved within multiple steady states, which appear in the reactive distillation column for tert-amyl methyl ether (TAME) synthesis. In the present study, we examined the energy-saving performance of a reactive distillation process that comprises a reactive distillation column and two recovery distillation columns for multiple steady state conditions using steady-state process simulation. Bifurcation analysis revealed that the multiple steady state did not exist under a reflux ratio of 1, but existed under reflux ratios of 2, 3, and 4. The reboiler duty required to obtain high-purity TAME increased with increase in reflux ratio. The evaluation of energy consumption revealed that the reboiler duties of the second recovery column at the steady-state solutions in the multiple steady state were lower than that at the steady-state solution of reflux ratio 1. Due to the high reaction conversion and reduction of the reboiler duty in the second recovery column, the energy inputs per mole of TAME product at steady-state solutions of the multiple steady state with reflux ratios of 2, 3, and 4 reduced by 17, 12, and 6%, respectively, compared to that for reflux ratio 1.