Distillation Efficiencies of an Industrial-Scale i-Butane/n-Butane Fractionator

Abstract

Rarely published industrial-scale distillation efficiency data are presented. The Murphree tray efficiencies are determined from the i-butane/n-butane fractionator performance data. Point efficiencies, numbers of overall vapor phase transfer units, numbers of vapor and liquid phase transfer units, and liquid phase resistances of mass transfer are backcalculated from the Murphree tray efficiencies. Various efficiency prediction and scale-up methods have been tested against experimental results. A new model for the prediction of the numbers of vapor and liquid phase transfer units has been developed. The model can be applied to hydrocarbon systems at high pressure. The influence of the mass-transfer coefficients, the interfacial area, and the vapor and liquid residence times on mass transfer has been analyzed separately, and as a result the NTU correlations for vapor and liquid phases are obtained. The constants of the model can be obtained by fitting the model to experimental efficiency data from a similar system.

Economic feasibility of heat pumps in distillation to reduce energy use

“…Klemola and Ilme [22] reported data from an industrial i-butane/n-butane fractionator working with an optimal column top pressure of 658,6 kPa. This is in accord with the value obtained in this work for the optimal top column pressure.…”

Butane isomer transport properties of 6FDA–DAM and MFI–6FDA–DAM mixed matrix membranes

“…The alkylation process catalytically combines C3-C5 olefins with iC4 to produce motor fuel alkylates, which is ideal for producing reformulated gasoline. However, the current process producing iC4 uses a large, energy intensive distillation column to recycle unconverted nC4 back to a reactor [2]. The efficiency and costeffectiveness of isomerization process can be increased by using a membrane separation unit that would significantly reduce capital and operating costs associated with C4s separation.…”

Research on Mass Transfer Columns: passé?

“…The three entrainment flood correlations used gave predictions that widely differed; the differences were up to 50 to 60 percent." Klemola and Ilme [11] came to the same conclusions by comparing two-pass valve tray efficiency data from an industrial i-butane/n-butane fractionator with experimental data from FRI and 18 different prediction methods. The differences between predictions and measured tray efficiencies approached 50 %.…”