Process parameter impacts on adiponitrile current efficiency and cell voltage of an electromembrane reactor using emulsion-type catholyte

The major route for the synthesis of adiponitrile (ADN) involves electrosynthesis, starting from acrylonitrile (AN) in an electrochemical reactor. In this paper the effects of various operating parameters on both the ADN current efficiency (CE) and the overall cell voltage in a laboratory-scale membrane reactor were studied. The electrochemical system includes a DSA/O2 electrode as anode, a lead electrode as cathode, Nafion® 115 membrane as separator, and tetra methyl ammonium chloride as the supporting electrolyte. Taguchi method was used for experimental design and ANOVA technique was employed for data analysis. Five process parameters studied include (1) cell temperature, (2) initial AN concentration, (3) current density, (4) catholyte flow rate and (5) catholyte pH which were determined at four levels. According to the results obtained, catholyte flow rate and current density were found to have the most striking impacts on the CE of ADN with contribution percentage (P value) of 35% and 28%, respectively. Current density and initial AN concentration were also found to be the most dominant parameters on the overall cell voltage with contribution percentage of 40% and 30%, respectively.

► The effect of process parameters on synthesis of adiponitrile (ADN) is investigated.
► Response parameters include current efficiency of ADN and cell voltage.
► ADN current efficiency adversely decreases with current density.
► Overall cell voltage favorably decreases with temperature, flow rate and pH.