Distillation under electric fields

Conference · Sat Nov 01 04:00:00 EST 1997

OSTI ID:548865

Shah, V M ^[1]; Blankenship, K D; Tsouris, C ^[2]

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1. Univ. of Tennessee, Knoxville, TN (United States). Chemical Engineering Dept.
2. Oak Ridge National Lab., TN (United States)

Distillation Is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 548865
• Report Number(s): ORNL/CP--94962; CONF-9710103--; ON: DE98001053
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
BINARY MIXTURES
DISTILLATION
DISTILLATION EQUIPMENT
ELECTRIC FIELDS
HEAT TRANSFER