Abstract

An intensified process for carbon dioxide capture and conversion is proposed and analyzed, considering an electrochemical parallel plate reactor which processes a CO2-charged stream from an absorption unit at 40 degrees C and atmospheric pressure and where the target product of the conversion is methanol. The task-specific ionic liquid 1-(3-aminopropy1)-3-methylimidazolium bromide was selected, synthesized and characterized. This ionic liquid has shown a good absorption capacity, high ionic conductivity, high chemical-electrochemical stability and acts as a charged intermediate (CO2*(-)) stabilizer, enabling the electrochemical reduction of absorbed CO2. The electrical energy in the electrochemical reactor was estimated to be 8.683 kWh kg (CO2)(-1) or 115.16 g (CO2) kWh(-1), too high to ensure the environmental sustainability of the process. A low concentration of carbon dioxide in the liquid phase, at ambient conditions, implies the need for a high electrode area for the process and is a major hindrance to improving the economy of the process. (C) 2014 Elsevier B.V. All rights reserved.