Optimal design of an intensified column with side-reactor configuration for the methoxy-methylheptane process

Abstract

In an effort to diminish energy consumption and improve economic performance, a distillation column coupled with an adiabatic side-reactor column configuration is proposed. The production of 2-methoxy-2-methylheptane is examined to show the promising potential of process intensification using the proposed side-reactor column configuration. In order to design a side-reactor that restricts the temperature of catalyst activity to 423K, the pressure of the column and the flow rate of the feed stream withdrawn for the side-reactor are examined. An economic steady-state flowsheet is developed that minimizes the total annual cost by optimizing the column pressure, side-stream flowrate, side-stream withdrawn location, and reactor effluent reentry location. For the 2-methoxy-2-methylheptane process, the proposed side-reactor column configuration appears overwhelmingly superior in terms of capital, energy, and total annual cost compared to that of a conventional energy-intensive scheme. In addition, compared to a reactive distillation process, the proposed configuration reduces total capital investment by decreasing column diameter with a smaller catalyst load. Furthermore, additional benefits such as less expensive hardware requirement, easy catalyst removal/regeneration could be achieved. Finally, a multi-effect heat integration sequence is suggested to improve the energy and economic performance of the proposed configuration.