A single microbial electrochemical system for CO2 reduction and simultaneous biogas purification, upgrading and sulfur recovery. (February 2020)

• Record Type: Journal Article
• Authors: Fu, Xian-Zhong; Li, Jie; Pan, Xin-Rong; Huang, Liang; Li, Chen-Xuan; Cui, Shuo; Liu, Hou-Qi; Tan, Zhou-Liang; Li, Wen-Wei
• Is Part Of: Bioresource technology. Volume 297(2020)
• Publication Date: 2020-02
• Subjects: Biogas upgrading -- Elemental sulfur -- CO2 reduction -- Methanococcus maripaludis; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2019.122448
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Anodic H2 S reduction was coupled with cathodic CO2 reduction. Anodic reaction was mediated by Fe 2+ to produce pure element sulfur particles. CO2 reduction at methanogenic biocathode was mediated by electrolytic H2 . High biogas upgrading level and stability was achieved in continuous operation. Abstract: In this work, a single microbial electrochemical system was developed for multiple goals simultaneously – CO2 reduction, biogas purification, upgrading and sulfur recovery. This system consists of a methanogen-inoculated biocathode for CO2 reduction and a ferrous ion (Fe 2+ )-mediated abiotic anode for hydrogen sulfide (H2 S) oxidation. In the cathodic chamber, methane production rate of 20.6 ± 1.0 μmol·h −1 and high upgrading level (up to 98.3% methane content) were achieved. In the anodic chamber, H2 S was completely removed and selectively converted into elemental sulfur particles. The system showed stable performance during continuous operation for treating both pure CO2 and mixed gases, with a cathodic coulombic efficiency of up to 85.2%. This simple system holds a great potential for practical application for biogas upgrading and sulfur recovery from waste water/gases.