Saline extractive distillation process for ethanol purification

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).…”

Reducing the Energy Demand of Cellulosic Ethanol through Salt Extractive Distillation Enabled by Electrodialysis

“…Efficient recovery and reuse of the salt used as the separating agent is, however, crucial. Potassium acetate (40,57,(60)(61)(62)(63)(64)(65)(66) and calcium chloride (56,58,62,66,67) have been reported for water-ethanol separation utilizing the "salting out" effect. The use of the salt separating agent in a process with tightly closed water cycles such as the cellulosic bioethanol plant requires that traces of the salt not impact other processing areas negatively.…”

“…There are many experimental and theoretical studies (40,(56)(57)(58)(60)(61)(62)(63)(64)(65)(66)(67) on producing fuel ethanol by utilizing the "salting out" effect, but most of them focus only on the salt extractive distillation step. Moreover, the studies (40,52,54,56,60,(63)(64)(65) which include both steps of salt extractive distillation and salt recovery do not generally consider techniques other than evaporation and drying for salt recovery.…”

Separation of ethanol and water by extractive distillation with salt and solvent as entrainer: process simulation

“…Besides, ethanol and gasoline mixtures can be used as fuels reducing environmental contamination and anhydrous ethanol addition improves octane index (Barba et al, 1985;Black, 1980;Chianese and Zinnamosca, 1990;Meirelles et.al., 1992). Several processes for ethanol dehydration are used such as heterogeneous azeotropic distillation, which uses different solvents such as benzene, pentane and cyclohexane; extractive distillation with solvents and salts as separating agents (Fu, 2004a,b); adsorption with molecular sieves and processes that include the use of pervaporation membranes (Black, 1980;Lynn and Hanson, 1988;Jacques et al, 1999;Pinto et al, 2000;Ulrich and Pavel, 1988). All these processes have had industrial application but some are no longer in use due to the high operating costs, operative problems and high energy consumption.…”

“…It is withdrawn as a bottom product with one of the components that are being separated and it is sent to a second regeneration column operated under vacuum. The most common solvents used in extractive distillation are glycols (Perry et al, 1992;Meirelles et al, 1992), glycerol (Lee and Pahl, 1985), gasoline (Chianese and Zinnamosca, 1990) (Barba et al, 1985;Furter, 1992;Ligero and Ravagnani, 2003;Llano and Aguilar, 2003;Pinto et al 2000;Schmit and Vogelpohl, 1983).…”