Natural solar intermittent-powered electromethanogenesis towards green carbon reduction

TY - JOUR

T1 - Natural solar intermittent-powered electromethanogenesis towards green carbon reduction

AU - Wang, Bo

AU - Liu, Wenzong

AU - Zhang, Yifeng

AU - Wang, Aijie

N1 - Publisher Copyright: © 2021 Elsevier B.V.

PY - 2022/3/15

Y1 - 2022/3/15

N2 - Microbial electromethanogenesis (EM), as a sustainable bioderived carbon-neutrality catalyzing platform, can be accelerated and regulated by weak power input for carbon fixation into value-added bioenergy. Solar electricity as a day-night intermittent renewable resource has been verified to effectively drive microbes to capture carbon dioxide (CO2). However, understanding the influence mechanisms of higher CO2 loading on EM is of intrinsic significance yet lacking. Herein, natural solar-powered bioelectrocatalytic CO2 reduction to methane (CH4) under increasing bicarbonate concentrations was investigated. CH4 recovery for the long-term measurement showed that CH4 production rate positively responded to improved bicarbonate concentrations from 2.5 to 10.0 g HCO3−·L−1, exhibiting a robust and potent competence in CH4 yield compared to reported EM. Whereas exceed bicarbonate mainly contributed to raised pH in the solution resulting in the proton limitation despite the intermittent driven-mode could mitigate pH shock. Electrochemistry results demonstrated that higher bicarbonate concentrations promoted the redox activity of electrode biofilm and lowered the system resistances, especially the charge transfer resistance. Adequately improving CO2 loading can dynamically optimize the structure of anodic electroactive microorganisms and facilitate electron transfer. Furthermore, more functional cathodic mcrA genes were upregulated with elevated bicarbonates and the species of basophilic Methanobacterium alcaliphilum occupied predominated at the cathode. These findings open up a perspective avenue to carbon reduction using natural solar intermittent-powered EM.

AB - Microbial electromethanogenesis (EM), as a sustainable bioderived carbon-neutrality catalyzing platform, can be accelerated and regulated by weak power input for carbon fixation into value-added bioenergy. Solar electricity as a day-night intermittent renewable resource has been verified to effectively drive microbes to capture carbon dioxide (CO2). However, understanding the influence mechanisms of higher CO2 loading on EM is of intrinsic significance yet lacking. Herein, natural solar-powered bioelectrocatalytic CO2 reduction to methane (CH4) under increasing bicarbonate concentrations was investigated. CH4 recovery for the long-term measurement showed that CH4 production rate positively responded to improved bicarbonate concentrations from 2.5 to 10.0 g HCO3−·L−1, exhibiting a robust and potent competence in CH4 yield compared to reported EM. Whereas exceed bicarbonate mainly contributed to raised pH in the solution resulting in the proton limitation despite the intermittent driven-mode could mitigate pH shock. Electrochemistry results demonstrated that higher bicarbonate concentrations promoted the redox activity of electrode biofilm and lowered the system resistances, especially the charge transfer resistance. Adequately improving CO2 loading can dynamically optimize the structure of anodic electroactive microorganisms and facilitate electron transfer. Furthermore, more functional cathodic mcrA genes were upregulated with elevated bicarbonates and the species of basophilic Methanobacterium alcaliphilum occupied predominated at the cathode. These findings open up a perspective avenue to carbon reduction using natural solar intermittent-powered EM.

KW - Carbon reduction

KW - Functional community evolution

KW - Microbial electromethanogenesis

KW - Power-to-gas

KW - Solar energy

UR - http://www.scopus.com/inward/record.url?scp=85122185221&partnerID=8YFLogxK

U2 - 10.1016/j.cej.2021.134369

DO - 10.1016/j.cej.2021.134369

M3 - Journal article

AN - SCOPUS:85122185221

SN - 1385-8947

VL - 432

JO - Chemical Engineering Journal

JF - Chemical Engineering Journal

M1 - 134369

ER -