Method for preparing methane by using magnetosomes to promote reduction of CO2(subscript) with microbial electro-fermentation

Abstract

The invention relates to a biomass energy utilization technique, and aims to provide a method for preparing methane by using magnetosomes to promote the reduction of CO2(subscript) with microbial electro-fermentation. The method comprises the following steps: (1) extracting purified magnetosomes from magnetospirillum gryphiswaldense in the logarithmic growth phase; (2) adopting a three-electrode system in a microbial electro-fermentation system; weighing small molecule organic acid salt as a carbon source, adding the small molecule organic acid salt and anaerobic activated sludge into the system, and adding the magnetosomes into the system as an exogenous conductive additive; and (3) sealing the system, introducing pure nitrogen into the sealed system to remove air, connecting the system with an electrochemical workstation, electrolyzing the small molecule organic acid salt at the graphite-rod anode to generate CO2(subscript) after starting operation, and reducing CO2(subscript) at thegraphite-rod cathode to generate methane. The invention can effectively improve the concentration of biomethane and reduce the subsequent biogas purification cost; and the invention can effectively optimize the electron transfer performance of the system, improve the contents of extracellular polymeric substances with oxidation-reduction activity and effectively enrich microorganisms responsiblefor the reduction of CO2(subscript) to generate the methane.

Description

technical field [0001] The invention relates to biomass energy utilization technology, in particular to a magnetosome promoting microbial electric fermentation to reduce CO 2 Method for producing methane. Background technique [0002] Under the situation of the energy crisis and the increasing environmental pollution, the use of alternative raw materials to produce advanced bio-energy has attracted more and more attention. Anaerobic fermentation is a widely used method for organic waste treatment and energy utilization to produce biomethane. It is a multi-stage and multi-phase biochemical process under the synergistic action of various microorganisms. Complex macromolecular organics (such as polysaccharides, proteins, lipids, etc.) are first degraded by hydrolyzing bacteria into small molecular organics such as monosaccharides and amino acids, and then continue to be degraded into small molecular volatile fatty acids and alcohols under the action of acid-producing bacteria....

AI Technical Summary

Problems solved by technology

[0004] Although the above-mentioned technology of inserting electrodes into the fermentation system and applying electric current can improve the electron transfer between microorganisms and electrodes, the direct electron transfer between microorganisms still needs to be strengthened by adding exogenous conductive substances; the above-mentioned adding conductive materials to the fermentation system Material technology also has some disadvantages, such as poor dispersion of metal nanoparticles, poor biocompatibility, relatively small specific surface area of ​​traditional carbon-based conductive materials, difficult to recycle, etc., which limit its application in anaerobic fermentation. application

In general, the technology of applying a certain potential or adding conductive materials alone has a limited effect on improving the performance of the fermentation system. The concentration of biomethane produced by the system is not high enough, and further biogas purification is required, and the process is cumbersome; the electron transfer performance of microorganisms in the system is not good. Difficult to meet the reduction of CO 2 electron transfer requirements; the content of redox-active extracellular polymers that play an important role in microbial extracellular electron transfer is not high; the system is responsible for the reduction of CO 2 Methanogenic microorganisms need to be further enriched, etc.

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