Double-effect integration of multicomponent alcoholic distillation columns

The growing need to expand the use of renewable energy sources in a sustainable manner, in order to provide energy supply security and to reduce the environmental impacts associated with fossil fuels, finds in bioethanol an alternative economically feasible and with significant potential of expansion. Despite its high energetic demand, distillation is one of the most widely used techniques for separating liquid mixtures. Thus, this work aimed to study distillation columns thermally integrated to produce bioethanol, considering a large amount of minor compounds so that the actual conditions can be better represented. In order to evaluate energy requirements, steady-state simulation of the distillation process was carried out using the software Aspen Plus. As a preliminary step, the simulator results for the current distillation columns configurations were compared with industrial data through analysis of samples collected from mills in operation. Although it has presented, in the case of some minor components, significant deviations, the simulator was able to reproduce satisfactorily the industrial process of alcoholic distillation. The thermally integrated configuration showed good results, with a reduction in the specific steam consumption of 54%. It was observed that minor compounds had a great influence in the steam consumption of the process.

► The simulation was able to reproduce industrial processes of alcoholic distillation.
► The thermal integration reduced by 54% the specific steam consumption.
► Minor compounds exhibit high content in the bottom trays of rectifying section.
► Minor compounds had a great influence in the steam consumption of the process.
► The simulator Aspen Plus proved to be useful for analysis of bioethanol process.