Thermodynamic Analysis of Thermally Coupled Distillation Sequences

Abstract

Thermodynamic efficiency calculations have been performed for the separation of ternary and quaternary mixtures of hydrocarbons in both conventional and thermally coupled distillation sequences. When ternary mixtures were considered, energy savings achieved in the thermally coupled distillation sequences were between 10 and 30% in comparison to the two conventional distillation sequences. Regarding thermodynamic efficiency, thermally coupled distillation sequences presented the highest values in almost all of the cases considered. When the analysis was extended to the separation of quaternary mixtures, the thermally coupled distillation sequences show acceptable energy savings and the thermodynamic efficiency of a thermally coupled distillation sequence linked to a side stripper and a side rectifier was better than that obtained in the conventional distillation sequence; however, for the thermally coupled distillation with prefractionator (Petlyuk-type column), the second law efficiency was low when compared to that of the conventional distillation sequence for the separation of a quaternary mixture with a low content of intermediate components.

Exergy Rate Profile of Multicomponent Distillation System

“…Application of equation (3.7), (3.8), (3.9), and (3.10) to the multicomponent distillation process considered in this study gave exergy efficiency and irreversibility equations; (8) (9) where (10)…”

“…According to recent estimates, 40% of energy used in refinery and other continuous chemical processes are consumed by distillation [19]. Therefore designing energy efficient distillation processes had been an important issues discussed in various literatures [14,9]. These analyses have focused only on energy and ignored the quality of energy.…”

Advanced exergy analysis of distillation tower and simulation and optimization by hysys

“…Where Tcondenser=Tdisillate -Avg temperature difference between the condenser and the stream (9) useful exergy var iation Exergy efficency = __________________________ (10) consumed energy tranformation Treboiler =T reboiler+ Avg temperature difference between the reboiler and the stream (11)…”

“…According to some recent estimates, about 40% of energy involved in refinery and other continuous chemical processes are consumed in distillation [21]. For this reason, the energy-efficient design and operation of distillation processes is an important issue discussed in various literatures [15], [9]. These analyses have focused only on energy and ignored the quality of energy.…”

Production of Methyl Oleate in Reactive‐Separation Systems

“…However, its main disadvantage is associated with the large amount of energy required in the reboiler to purify the mixture [2,3]. Several approaches have been applied in order to save energy, e.g., the use of thermal links in distillation columns can provide significant energy savings [4].…”