Reducing energy requirements for ETBE synthesis using reactive dividing wall distillation column

Abstract

Production of ETBE is one of most important industrial processes. It is used both as biofuel and bio additive in gasoline. The motivation behind its use is that, its blend with gasoline reduces greenhouse gas emissions. Present work focuses on the synthesis of ethyl tertiary butyl ether (ETBE) by using Reactive dividing wall column (RDWC) and a comparative assessment with three other process alternatives as-reactor followed by distillation sequence, reactor plus reactive distillation (RD), and RD. The comparison was done in terms of energy requirements, CO2 emissions, total annual costs (TAC), total investment costs (TIC) and total operating costs (TOC). RDWC proved its forte in saving energy therefore cutting CO2 emissions and handling the reactions limited by chemical equilibrium. RDWC was found to be the most promising alternative out of the four process alternatives. It gave highest purity of the product ETBE 99.999% (mol.), the CO2 emissions were reduced by 74% and 43% as compared to conventional sequence and RD respectively, and also the energy requirements were very less as compared to the conventional sequence and RD. TIC reduction as high as 68% was observed, this also established RDWC as a lucrative option for the synthesis of ETBE.