TOP > 外国特許検索 > Microbial fuel cell

Microbial fuel cell

外国特許コード F110005801
整理番号 E08901WO
掲載日 2011年10月5日
出願国 アメリカ合衆国
出願番号 93487609
公報番号 20110236725
公報番号 8852765
出願日 平成21年3月27日(2009.3.27)
公報発行日 平成23年9月29日(2011.9.29)
公報発行日 平成26年10月7日(2014.10.7)
国際出願番号 JP2009056385
国際公開番号 WO2009119846
国際出願日 平成21年3月27日(2009.3.27)
国際公開日 平成21年10月1日(2009.10.1)
優先権データ
  • 特願2008-086195 (2008.3.28) JP
  • 特願2008-249178 (2008.9.26) JP
  • 2009JP056385 (2009.3.27) WO
発明の名称 (英語) Microbial fuel cell
発明の概要(英語) It is an object of the present invention to provide a microbial fuel cell capable of increasing a current density without employing a mediator.
The microbial fuel cell 1 includes a 3-dimensionally structured agglomerate formed from conductive fine particles 2 and microorganisms 3.
In the agglomerate 4, the conductive fine particles 2 disperse among pieces of Shewanella 3 and the conductive fine particles 2 are coupled to one another to hold Shewanella 3, thus forming the 3-dimensional structure as a whole.
Accordingly, with respect to Shewanella 3, conductive fine particles 2 hold Shewanella 3a on a surface of an electrode 103 and even Shewanella 3b positioned vertically away from the surface of the electrode 103.
Hence, it becomes possible that more pieces of Shewanella 3 are allowed to transfer electrons.
従来技術、競合技術の概要(英語) BACKGROUND ART
A microbial fuel cell is equipped with a pair of electrodes, an external circuit for electrically connecting the electrodes, and a separating film for separating the pair of the electrodes.
Microorganisms with an extracellular electron transfer capability, such as Shewanella or the like are held on one electrode.
Here, the extracellular electron transfer capability means the capability to obtain biogenic electric energy and at the same time transfer electrons to electron accepters by utilizing metallic ions and their oxidative products as the electron accepters to reduce the ions and the products (see nonpatent document 1).
The forgoing extracellular electron transfer capability is found in part of bacteria acting as microorganisms.
That is, a specific electron transfer mechanism that discharges electrons to the outsides of microorganisms via cytochrome localized in a cell membrane is found in part of bacteria, such as a Shewanella group (hereunder, simply referred to as Shewanella) such as Shewanella loihica and Shewanella oneidensis, a Geobacter group, a Rhodoferax group, a Pseudomonas group or the like (see nonpatent documents 2, 3, 4).
The microbial fuel cell thus structured is a device in which microorganisms transfer electrons to the above one electrode, thereby producing electric energy.
As fuel for producing electric energy, a regenerable biomass and organic pollutants contained in human sewage or the like can be utilized and hence the microbial fuel cell has recently received widespread attention as a sustainable energy source.
Besides, there also exist microorganisms with a capability to reduce and fixate a metallic element, which has been noted as means for sewage treatment and environmental purification, too.
The microbial fuel cell falls into the two general classifications which are a system for employing a single kind of microorganism, and a mixed bacterial culture system for directly employing a microbial group living in sewage or the like (e.g., see patent document 1).
Shewanella is a microorganism most extensively employed in the former system.
Patent document 1: Japanese unexamined patent application publication No. 2006-81963.
Nonpatent document 1=Lovely D. R.; Nat. Rev. Microbiol., 2006, 4, 497-508
Nonpatent document 2: Gralnick, J. A.; Newman, D. K.; Molecul. Microbiol. 2007, 65, 1-11
Nonpatent document 3: Hernandez, M. E.; Newman, D. K.; Cell. Mol. Life Sci. 2001. 58, 1562-1571
Nonpatent document 4: Journal of Japanese Society of Microbial Ecology (2008) Vol. 23, No. 2, P. 58

特許請求の範囲(英語) [claim1]
1. A microbial fuel cell equipped with a pair of electrodes and an external circuit electrically connecting a pair of said electrodes, wherein on a negative electrode that is one of said electrodes, 3-dimensionally structured agglomerates are spontaneously formed in a solution containing conductive fine particles and microorganisms with an extracellular electron transfer capability, said 3-dimensionally structured agglomerates being formed from said conductive fine particles and microorganisms by allowing said microorganisms to specifically adsorb said conductive fine particles; and said microorganisms are held by said conductive fine particles over a range of zone extending vertically away from a surface of said negative electrode, in a manner such that said conductive fine particles are distributed among said microorganisms; and said conductive fine particles comprise alpha -Fe2O3, alpha -FeOOH, gamma -Fe2O3, epsilon -Fe2O3 or Fe3O4 or ferric sulfide, and then said conductive fine particles transfer electrons from said microorganisms to said negative electrode.
[claim2]
2. The microbial fuel cell according to claim 1, wherein said conductive fine particles include ferric oxide.
[claim3]
3. The microbial fuel cell according to claim 1, wherein said conductive fine particles are obtained by biosynthesis of microorganisms in an environment where ferric ions and sulfide ions coexist, said microorganisms being metal-reducing bacteria.
[claim4]
4. The microbial fuel cell according to claim 1, wherein said conductive fine particles include manganese oxide.
[claim5]
5. The microbial fuel cell according to claim 3, wherein said metal-reducing bacteria include bacteria of a Shewanella group, a Geobacter group, a Rhodoferax group or a Pseudomonas group.
[claim6]
6. The microbial fuel cell according to claim 3, wherein said metal-reducing bacteria contain Shewanella loihica or Shewanella oneidensis.
[claim7]
7. The microbial fuel cell according to claim 1, wherein said 3-dimensionally structured agglomerates are spontaneously formed by mixing said conductive fine particles and said microorganisms in said solution.
[claim8]
8. The microbial fuel cell according to claim 7, wherein said 3-dimensionally structured agglomerates comprises agglomerates of conductive fine particles.
[claim9]
9. The microbial fuel cell according to claim 1, wherein said 3-dimensionally structured agglomerates comprises agglomerates of conductive fine particles.
[claim10]
10. A method for manufacturing a negative electrode of a pair of electrodes used in a microbial fuel cell that is equipped with said pair of electrodes and an external circuit electrically connected thereto, comprising: a step of preparing a solution for said negative electrode by mixing conductive fine particles and microorganisms with an extracellular electron transfer capability;
a step of allowing said conductive fine particles to hold said microorganisms over a range of zone extending vertically away from a surface of said negative electrode, in a manner such that said conductive fine particles disperse among said microorganisms and are further coupled to one another to hold said microorganisms; and;
a step of causing 3-dimensionally structured agglomerates to be spontaneously formed by allowing said microorganisms to specifically adsorb said conductive fine particles.
[claim11]
11. The method for manufacturing the negative electrode according to claim 10, wherein said microorganisms are metal-reducing bacteria.
[claim12]
12. The method for manufacturing the negative electrode according to claim 11, wherein said metal-reducing bacteria include bacteria of a Shewanella group, a Geobacter group, a Rhodoferax group or a Pseudomonas group.
[claim13]
13. The method for manufacturing the negative electrode according to claim 11, wherein said metal-reducing bacteria contain Shewanella loihica or Shewanella oneidensis.
[claim14]
14. The method for manufacturing the negative electrode according to claim 10, wherein said conductive fine particles comprise alpha -Fe2O3, alpha -FeOOH, gamma -Fe2O3, epsilon -Fe2O3 , Fe3O4or ferric sulfide.
[claim15]
15. The method for manufacturing the negative electrode according to claim 14, wherein said microorganisms are metal-reducing bacteria.
[claim16]
16. The method for manufacturing the negative electrode according to claim 15, wherein said metal-reducing bacteria include bacteria of a Shewanella group, a Geobacter group, a Rhodoferax group or a Pseudomonas group.
[claim17]
17. The method for manufacturing the negative electrode according to claim 15, wherein said metal-reducing bacteria contain Shewanella loihica or Shewanella oneidensis.
  • 発明者/出願人(英語)
  • HASHIMOTO KAZUHITO
  • NAKAMURA RYUHEI
  • KAI FUMIYOSHI
  • WATANABE KAZUYA
  • KATO SOICHIRO
  • UNIVERSITY OF TOKYO
  • JAPAN SCIENCE AND TECHNOLOGY AGENCY
国際特許分類(IPC)
米国特許分類/主・副
  • 429/2
  • 429/401
参考情報 (研究プロジェクト等) ERATO HASHIMOTO Light Energy Conversion AREA
ライセンスをご希望の方、特許の内容に興味を持たれた方は、問合せボタンを押してください。

PAGE TOP

close
close
close
close
close
close