Separation of aqueous isopropanol by reactive extractive distillation

Abstract

A new separation method of reactive extractive distillation is proposed for the separation of isopropanol and water, using the mixture of ethylene glycol (C 2 H 6 O 2 ) and glycollic potassium (C 2 H 5 O 2 K) as an entrainer. Vapor-liquid-equilibrium (VLE) measurements confirmed that the entrainer was effective for this separation. Using a feed/solvent volume ratio of 1:1, isopropanol with a concentration over 96.0% weight fraction was obtained by the reactive extractive distillation process and the azeotropic point was eliminated. A novel process of separating isopropanol and water is designed on the basis of reactive extractive distillation to obtain the product with different concentrations, which may have a lasting value in industry. # 2002 Society of Chemical Industry Keywords: reactive extractive distillation; isopropanol; water; vapor-liquid-equilibrium (VLE); separation INTRODUCTIONWith the development of chemical technology and biotechnology, many aqueous alcohol solutions such as ethanol/water, isopropanol/water and tert-butanol/ water are usually dilute and required to be separated. It is known, however, that these alcohols form azeotropes with water, and cannot be extracted to a high concentration from the aqueous solutions by ordinary distillation methods. In this case azeotropic distillation and extractive distillation are often used.

Reducing energy consumption and CO2 emissions in extractive distillation: Part II. Dynamic behavior

“…Extractive distillation is widely used in several different processes: recovery of aromas or fragrances (Pollien et al, 1998;Chaintreau, 2001), separation of aqueous alcohol solutions (Pinto et al, 2000;Zhigang et al, 2002;Llano-Restrepo and Aguilar-Arias, 2003), mixtures which exhibit an azeotrope (Wu et al, 2007;Gil et al, 2009) and separation of hydrocarbons with close boiling points (Wentink et al, 2007;Abushwireb et al, 2007). Recently, the use of ionic liquids as entrainers in the extractive distillation of certain mixtures has also been introduced (Shiflett and Yokozeki, 2006;Zhang et al, 2007).…”

A preliminary study: Distillation of isopropanol–water mixture using fixed adsorptive distillation method

“…A modification technique, which is a combination of reactive and extractive distillation by using the mixture of ethylene glycol (C 2 H 6 O 2 ) and glycollic potassium (C 2 H 5 O 2 K) as additional components has been investigated [3]. By this way, with a volume ratio of feed and solvent of 1:1, IPA produced has purity over 96.0 mass%.…”

Application of the partially thermally coupled distillation flowsheets for the extractive distillation of ternary azeotropic mixtures

“…Extractive distillation is used in the industry for the separation of hydrocarbons with similar boiling points 2-4 , the recovery of aromas or fragrances [5][6][7][8][9] , the separation of aqueous alcohol solutions [10][11][12][13][14] , the separation of ether and alcohol mixtures 15,16 and the separation of methylal and methanol mixtures 17 .…”