Performance Enhancement of Reactive Dividing-Wall Column via Vapor Recompression Heat Pump

Abstract

In this work, a novel energy-efficient distillation technology combining reactive dividing-wall column (RDWC) with vapor recompression heat pump (VRHP) is proposed. The integrated RDWC with VRHP models with intermediate reboiler or bottom reboiler are designed for reaching better energy-savings and economic performance. The results showed that the reactive dividing-wall column with vapor recompression heat pump and intermediate reboiler is more attractive than the reactive dividing-wall column with vapor recompression heat pump and bottom reboiler in this study. Adding a preheater to the reactive dividing-wall column with vapor recompression heat pump and intermediate reboiler (RDWC-VRHP-IR2) can further reduce the compression ratio and reach better performance. The RDWC-VRHP-IR2 saves 57.06% of total utility consumption, 31.31% of total annual cost with the payback period of 5 years, and 61.52% of CO 2 emissions compared with the conventional two-column reactive distillation system.

Performance Enhancement of Reactive Dividing Wall Column Based on Self-Heat Recuperation Technology

“…Since construction and installation of the dividing wall column are much more difficult than for the conventional column, a penalty of 20% , is assumed in this paper. A payback period of 8 years is used, with an 8000 h/year operating time. , The detailed calculation formulas for OC and CC are presented in Table S1 of the Supporting Information. Douglas’s cost formulas are transferred into the CEPCI inflation index based on the equation presented in the literature and adopted for the calculation of capital cost.…”

“…Douglas’s cost formulas are transferred into the CEPCI inflation index based on the equation presented in the literature and adopted for the calculation of capital cost. The minimum temperature difference of 5 °C is assumed in all the heat exchangers. − Compressor efficiency is assumed to be 80% in all the configurations …”

“…A payback period of 8 years is used, with an 8000 h/year operating time. 19,20 The detailed calculation formulas for OC and CC are presented in Table S1 CEPCI inflation index based on the equation presented in the literature 36 and adopted for the calculation of capital cost. The minimum temperature difference of 5 °C is assumed in all the heat exchangers.…”

“…Compared with the RDWC, the total annual cost was reduced by 9.6% with a payback period of 8 years and CO 2 emissions were reduced by 14.76%. Feng et al , proposed intensification schemes combining VRHP with an upper partitioned reactive dividing wall column and a lower partitioned reactive dividing wall column, respectively. With the intensified processes, significant reductions in total annual cost, total utility consumption, and CO 2 emissions were obtained in contrast to the RDWC.…”

Evaluation of a novel configuration of bottom flashing on dual distillation columns for saving energy

“…Various configurations of these systems have been presented in previous studies [7,8,18,[20][21][22][23][24][25]. These configurations include: vapor recompression with intermediate reboiler(s) [20,26,27], vapor recompression with self-heat recuperation [28], vapor recompression with extra heat transfer units [7], vapor recompression and bottom flashing on petlyuk column [8], simplified heat integrated distillation column [25], heat integrated distillation with additional heat transfer between top product and feed [12] and heat integrated distillation columns for separating ternary mixtures [14].…”