Comparative environmental assessment of distillation without hot utilities, vapor recompression, and conventional distillation

Abstract

The substantial demand for hot and cold utilities in the operation of close-boiling distillation systems has prompted the development of various process configurations, including vapor recompression and distillation without hot utilities (DWHU). However, despite their advanced technical capabilities, DWHU configurations have yet to undergo comprehensive environmental assessments or optimizations, nor have they been compared to alternative separation systems to identify the most sustainable process options. This study addresses this gap by conducting process simulations, environmental evaluations, and optimizations utilizing genetic algorithms (GA) to compare various conceptual designs of distillation processes—both conventional and intensified—specifically for a sample propylene/propane separation system. Notably, the results indicate that with the appropriate configuration of DWHU, it is feasible to achieve substantial reductions in global warming, acidification, marine eutrophication, and terrestrial eutrophication potentials. Also, global warming, fossil depletion, and eutrophication potentials were evaluated and compared for different process configurations. © 2025 American Institute of Chemical Engineers.