Patent ID: 9029615
Filing Date: 2015-05-12
Classification: C07C

Abstract:
1. An energetically efficient method for concentrating a C2-C6 alcohol from a dilute alcohol-water solution comprising: a) mixing the dilute alcohol-water solution with liquid phase dimethyl ether (DME), wherein the distribution coefficient for the alcohol in a mixture of the DME and the alcohol-water solution favors the transfer of the alcohol from the alcohol-water solution to the DME, thereby yielding a solution comprising a first phase and a second phase, the first phase comprising alcohol-saturated DME and the second phase comprising the dilute alcohol-water solution, thereby extracting a portion of the alcohol from the alcohol-water solution into the DME; b) separating the first phase and the second phase; c) vaporizing the liquid phase DME in the first phase to vapor phase DME, thereby releasing the alcohol from the DME, yielding a concentrated alcohol-water solution; d) recovering the vapor phase DME by condensing to liquid phase, wherein the vaporizing and the condensing of the DME is driven by a refrigerant circuit; and e) repeating steps a)-d), wherein the DME recovered in step d) is mixed with the dilute alcohol-water solution in step a).