Abstract: A fuel cell includes an anode including a current collector and microorganisms; a cathode; and a source of a sulfur-containing compound; wherein the fuel cell is poised for the microorganisms to selectively oxidize the sulfur-containing compound to elemental sulfur. Purification of a sulfur-contaminated fuel may be completed using such fuel cells. A method of carbon sequestration includes providing a fuel cell that includes a cathode including a conductor and oxygen; and an anode including a current collector and microorganisms; and introducing carbonic acid to the cathode to react with the oxygen to produce water and a carbonate or bicarbonate salt.

Abstract: The present disclosure generally relates to fuel cells and, in particular, to microbial fuel cells. In one aspect, the fuel cell can use microorganisms (microbes) to oxidize fuel, especially methane. For instance, the fuel cell may use one or more types of methanotrophs, such as Methylomonas methanica. The methanotroph may be anaerobic and/or aerobic, and the fuel cell may be open (e.g., to the atmosphere) or sealed. In some cases, a population of methanotrophs is used. In some cases, syntrophic associations may be formed between different species of microorganisms. In one embodiment, the fuel cell is of a columnar design, e.g., a packed bead column. Other inventive aspects relate to techniques for forming such fuel cells and fuel cell components, techniques for using such fuel cells, systems involving such fuel cells, and the like.