An innovative process for biogas upgrading by the microbial electrolysis cell

Xiangdan Jin, Xiaohu Li, Nannan Zhao, Irini Angelidaki, Yifeng Zhang

Research output: Contribution to conferenceConference abstract for conferenceResearchpeer-review

Abstract

Biogas as an alternative energy source is getting more attention which can facilitate to reduce fossil fuel utilization and greenhouse gas emissions. However, biogas is a mixture of gases and typically composed of 60-70% v/v methane (CH4) and 30-40% v/v carbon dioxide (CO2), small amounts of hydrogen sulfide (H2S) and other gases. Rude biogas exhibits a significantly low Wobbe index, heating value and energy efficiency which hinder its application. Therefore, CH4 enrichment prior to use is crucial to improve the quality of biogas. In this work, a novel bipolar membrane-microbial electrolysis cell (BPMEC) was proposed to realize biogas upgrading. The system was composed of the anode, middle and cathode chamber which were separated by a bipolar membrane (BM) and an anion exchange membrane (AEM), respectively. With an external potential, water dissociation occurred and acid was produced in the middle chamber while electrolysis happened and alkali was generated in the cathode chamber. When rude biogas was injected into the cathode chamber, COwas absorbed chemically into the solution and migrated via AEM as the form of CO32- and HCO3- into the middle chamber where they reacted with H+ and CO2 was regenerated and released from the solution. The gas flow rates were varied, as well as the external voltage. Results revealed the highest cathodic pH was 10.03±0.21 and the lowest pH in the middle chamber was 1.34±0.21. The highest CO2 removal efficiency can be reached at 98.76±1.32% and the maximum CH4 content can be 98.13±1.12% with 19.64 ml/h gas flow rate and 1.2 V external potential. Organic matter was removed remarkably and COD of the last day was below 60 mg/l. Hydrogen (H2) was produced and collected in the enriched gas which is another benefit of the system. This study provides a simple, efficient and sustainable way to extend the application of electrochemical technology.
Original languageEnglish
Publication date2016
Number of pages1
Publication statusPublished - 2016
EventSustain-ATV Conference 2016: Creating Technology for a Sustainable Society - Technical University of Denmark, Kgs. Lyngby, Denmark
Duration: 30 Nov 201630 Nov 2016
http://www.sustain.dtu.dk/about/sustain-2016

Conference

ConferenceSustain-ATV Conference 2016
LocationTechnical University of Denmark
CountryDenmark
CityKgs. Lyngby
Period30/11/201630/11/2016
Internet address

Bibliographical note

Sustain Abstract R-1

Fingerprint

Dive into the research topics of 'An innovative process for biogas upgrading by the microbial electrolysis cell'. Together they form a unique fingerprint.

Cite this