title: Using cathode spacers to minimize reactor size in air cathode microbial fuel cells.
abstract: Scaling up microbial fuel cells (MFCs) will require more compact reactor designs. Spacers can be used to minimize the reactor size without adversely affecting performance. A single 1.5mm expanded plastic spacer (S1.5) produced a maximum power density (973±26mWm(-2)) that was similar to that of an MFC with the cathode exposed directly to air (no spacer). However, a very thin spacer (1.3mm) reduced power by 33%. Completely covering the air cathode with a solid plate did not eliminate power generation, indicating oxygen leakage into the reactor. The S1.5 spacer slightly increased columbic efficiencies (from 20% to 24%) as a result of reduced oxygen transfer into the system. Based on operating conditions (1000Ω, CE=20%), it was estimated that 0.9Lh(-1) of air would be needed for 1m(2) of cathode area suggesting active air flow may be needed for larger scale MFCs.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, No. 73 Huanghe Road, Nangang District, Harbin 150090, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Yang
authors.forename: Yujie
authors.initials: Y
authors.lastname: Feng
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Logan
mesh_terms: D001674:Bioelectric Energy Sources; D019149:Bioreactors; D004566:Electrodes