Experimental evaluation of the separation of aromatic compounds using falling film distillation on a pilot scale

This study evaluated a new process for separation of aromatic compounds based on falling film distillation at thermosyphon-assisted atmospheric pressure (Destubcal Technology), in order to obtain enriched mass fractions of toluene in the distillate stream. Two compact experimental units were used: single-tube and multi-tubes on a pilot scale. The experimental tests were divided into two groups: isothermal and non-isothermal condition. The optimal feed mass flow rate, evaporator temperature and feed temperature conditions were found to be 25.13 kg h−1, 102.10 °C and 132.90 °C, respectively, starting from a feed concentration of 43% (m/m). The best result was found by using the single-tube unit with about 25.24% (m/m) enrichment of mass fraction of toluene in the distillate stream. There was no relevant difference in results between the isothermal and non-isothermal conditions. The results found in the single-tube and multi-tubes pilot scale units were similar, showing toluene mass flow values at the distillate stream of 2.96 kg h−1 and 44.76 kg h−1 respectively; thus, they indicate high productivity. The new alternative for distillation of aromatic compounds proposed in this article shows a satisfactory result when compared to conventional distillation, because the Destubcal Technology had a lower energetic requirement.