Purification of tetrahydrofuran from its aqueous azeotrope by extractive distillation: Validation of model and simulation

ABSTRACT

Tetrahydrofuran (THF) purification by distillation is difficult due to the existence of its homogeneous, minimum boiling azeotrope with water. Previously conducted extractive distillation runs were used in this work to validate a rigorous model.

The validated model was then used to arrive at a feasible range of operating parameters by performing sensitivity analysis. It is shown through simulations that with the correct operating parameters, use of dimethyl sulfoxide can help obtain almost pure THF.

KEYWORDS:

• Tetrahydrofuran (THF)
• extractive distillation
• dimethyl sulfoxide (DMSO)
• simulation
• sensitivity analysis
• feasible parameters

Nomenclature

Abbreviations and acronyms	=
THF	=	Tetrahydrofuran
BD	=	1,4-Butanediol
PD	=	1,2-Propanediol
DMSO	=	Dimethyl sulfoxide
PTMEG	=	Poly-tetramethylene glycol
DMF	=	Dimethyl formamide
PSD	=	Pressure swing distillation
VLE	=	Vapour liquid equilibrium
RADFRAC	=	Rigorous 2 or 3 phase fractionating column
NRTL	=	Non Random Two Liquid method
NRTL-RK	=	Non Random Two Liquid-Redlich Kwong equation
UNIQUAC	=	Universal Quasi Chemical equation
UNIFAC	=	UNIQUAC functional group activity coefficient method
CHAO-SEA	=	Chao Seader method
WILSON	=	Wilson ideal gas and liquid enthalpy reference state
van Laar	=	Van der Waals equation
RR	=	Reflux ratio
Rb	=	Reboiler duty
RCM	=	Residue curve map
MESH	=	Material balance, Equilibrium, Summation and Enthalpy balance relations

HIGHLIGHTS

• Tetrahydrofuran (THF) purification by extractive distillation was simulated.

• Validation of a rigorous distillation model and simulation thereof was performed.

• A feasible range of operating parameters is obtained by sensitivity analysis.

• Complete recovery process is indicated by use of residue curve maps.

• Use of dimethyl sulfoxide (DMSO) is shown to produce highly pure THF.