Intensification of Processes for the Production of Ethyl Levulinate Using AlCl 3 ·6H 2 O

A process for obtaining ethyl levulinate through the direct esterification of levulinic acid and ethanol using AlCl 3 ·6H 2 O as a catalyst was investigated. AlCl 3 ·6H 2 O was very active in promoting the reaction and, the correspondent kinetic and thermodynamic data were determined. The reaction followed a homogeneous second-order reversible reaction model: in the temperature range of 318–348 K, E a was 56.3 kJ·K −1 ·mol −1 , whereas K eq was in the field 2.37–3.31. The activity of AlCl 3 ·6H 2 O was comparable to that of conventional mineral acids. Besides, AlCl 3 ·6H 2 O also induced a separation of phases in which ethyl levulinate resulted mainly (>98 wt%) dissolved into the organic upper layer, well separated by most of the co-formed water, which decanted in the bottom. The catalyst resulted wholly dissolved into the aqueous phase (>95 wt%), allowing at the end of a reaction cycle, complete recovery, and possible reuse for several runs. With the increase of the AlCl 3 ·6H 2 O content (from 1 to 5 mol%), the reaction proceeded fast, and the phases’ separation improved. Such a behavior eventually results in an intensification of processes of reaction and separation of products and catalyst in a single step. The use of AlCl 3 ·6H 2 O leads to a significant reduction of energy consumed for the final achievement of ethyl levulinate, and a simplification of line-processes can be achieved.