📝 SummarXiv

Abstract

Separation of hydrocarbon isomers with closely matched physicochemical properties remains an energetically demanding challenge in the petrochemical refineries. This study presents a comparative analysis of three methods: the fractional distillation, the Molex process, and the Levi-Blow (LB) technique. Using experimentally validated thermodynamic data and heat-transfer estimates, we quantify the energy expenditure and number of cycles required to achieve ultrahigh-purity separation. The LB method achieves eight-9s purity in a single cycle with just 39.4~kJ/mol, while fractional distillation and Molex require multiple iterations and up to five orders of magnitude more energy. Each method is also benchmarked against the thermodynamic minimum work of separation of the mixture of interest. It is found that the LB technique operates within a factor of 23 of this lower bound, compared to $\sim 10^2$ for Molex (Molex is a trademark and/or service mark of UOP Inc.) and $\sim 10^5$ for fractional distillation, demonstrating its thermodynamic and operational superiority.