title: Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis.
abstract: Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.
authors: The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia.
authors: Hui-Wen
authors: HW
authors: Lin
authors: Photovoltaics and Optoelectronic Devices Group, Physics Department, Universitat Jaume I, 12071 Castelló, Spain.
authors: Rocío
authors: R
authors: Cejudo-Marín
authors: MAGNETO special anodes B.V., Calandstraat 109, 3125 BA Schiedam, The Netherlands.
authors: Adriaan W
authors: AW
authors: Jeremiasse
authors: The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia.|Laboratory of Microbial Ecology and Technology (LabMET), Ghent University, Coupure Links 653, 9000 Ghent, Belgium.
authors: Korneel
authors: K
authors: Rabaey
authors: The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia.
authors: Zhiguo
authors: Z
authors: Yuan
authors: The University of Queensland, Advanced Water Management Centre (AWMC), QLD 4072, Australia.|The University of Queensland, The School of Civil Engineering, QLD 4072, Australia.
authors: Ilje
authors: I
authors: Pikaar