Supercapacitive microbial desalination cells: New class of power generating devices for reduction of salinity content. (15th December 2017)

• Record Type: Journal Article
• Authors: Santoro, Carlo; Abad, Fernando Benito; Serov, Alexey; Kodali, Mounika; Howe, Kerry J.; Soavi, Francesca; Atanassov, Plamen
• Is Part Of: Applied energy. Volume 208(2017)
• Page Start: 25
• Page End: 36
• Publication Date: 2017-12-15
• Subjects: AC activated carbon -- AdE additional electrode -- AEM anion exchange membrane -- BES bioelectrochemical system -- Canode anode capacitance -- CB carbon black -- Ccathode cathode capacitance -- Ccell cell capacitance -- CDI capacitive deionization -- Cell ESR equivalent series resistance of the cell -- CEM cation exchange membrane -- DC desalination chamber -- DI deionized water -- EDLC electrochemical double layer capacitor -- Epulse energy obtained by the pulse -- Fe-AAPyr iron aminoantypirine -- GLV galvanostatic discharges -- ipulse, current pulses -- KCl potassium chloride -- KPB potassium phosphate buffer -- MDC membrane capacitive deionization -- MDC microbial desalination cell -- MFC microbial fuel cell -- MFC microbial fuel cell -- NaCl sodium chloride -- NaOAc sodium acetate -- OCV open circuit voltage -- ORR oxygen reduction reaction -- PGM-free platinum group metals-free -- Pmax maximum power -- Ppulse power obtained by the pulse -- PTFE polytetrafluoroethylene -- RA anodic anode ohmic resistance -- RC cathodeic ohmic resistance -- RO reverse osmosis -- SC-MDC-AdE supercapacitive microbial desalination cell with additional electrode -- SC-MDC supercapacitive microbial desalination cell -- SC-MFC supercapacitive microbial fuel cell -- SC solution conductivity -- SHE standard hydrogen electrode -- tpulse time of the pulse -- trest rest time -- V− oc, anode potentials in open circuit -- V+ oc, cathode potential in open circuit -- Vmax OC, original maximum voltage in open circuit condition -- Vmax practical voltage -- ΔVcapacitive difference between Vmax and Vfinal (at the end of tpulse), voltage capacitive decrease drop -- ΔVohmic cathode, cathode ohmic drop -- ΔVohmic difference between Vmax, OC and Vmax, ohmic drop; Supercapacitive Microbial Desalination Cell (SC-MDC) -- Additional Electrode (AdE) -- Power/current pulses -- High power generation -- Transport phenomena; Power (Mechanics) -- Periodicals; Energy conservation -- Periodicals; Energy conversion -- Periodicals; 621.042
• DOI: 10.1016/j.apenergy.2017.10.056
• Languages: English
• ISSNs: 0306-2619

Abstract

Graphical abstract: Supercapacitive Microbial Desalination Cell is here presented with unprecedented performances. Anode and cathode act as negative and positive electrode of an internal supercapacitor that is discharged and self-recharged. Maximum power of 3 W m −2 is recorded. Highlights: The concept of supercapacitive microbial desalination cell is here presented. The device is able to degrade organics, desalinate and generate power simultaneously. An additional electrode overcomes cathode ohmic losses and boost up power output. Maximum power achieved was 3.0 W m −2 (2.1 mW). 7600 discharge/self-recharge cycles were demonstrated over 44 h. Abstract: In this work, the electrodes of a microbial desalination cell (MDC) are investigated as the positive and negative electrodes of an internal supercapacitor. The resulting system has been named a supercapacitive microbial desalination cell (SC-MDC). The electrodes are self-polarized by the red-ox reactions and therefore the anode acts as a negative electrode and the cathode as a positive electrode of the internal supercapacitor. In order to overcome cathodic losses, an additional capacitive electrode (AdE) was added and short-circuited with the SC-MDC cathode (SC-MDC-AdE). A total of 7600 discharge/self-recharge cycles (equivalent to 44 h of operation) of SC-MDC-AdE with a desalination chamber filled with an aqueous solution of 30 g L −1 NaCl are reported. The same reactor system was operated with real seawater collected from Pacific Ocean for 88 h (15, 100 cycles). Maximum power generated was 1.63 ± 0.04 W m −2 for SC-MDC and 3.01 ± 0.01 W m −2 for SC-MDC-AdE. Solution conductivity in the desalination reactor decreased by ∼50% after 23 h and by more than 60% after 44 h. There was no observable change in the pH during cell operation. Power/current pulses were generated without an external power supply.