Towards the scale-up of bioelectrogenic technology: stacking microbial fuel cells to produce larger amounts of electricity

Abstract

Experimental work carried out in this work has investigated the scale-up of microbial fuel cell (MFC) technology by studying the stacking of single microbial fuel cells, paying attention to the electric and hydraulic connections between each unit. To do this, the performance of three stacks (which were set up with different configurations) was studied for more than three months. The first stack (two hydraulically non-connected cells) was operated for 80 days without any electric connection between them, in order to determine the reproducibility of the performance of a single MFC, and then it was electrically connected in parallel for 20 days to determine if the electricity produced by each single cell was added when they were joined in the stack. The other two stacks (with five and ten cells, hydraulically connected) were connected electrically in series during the first 80 days and in parallel during the last 20 days. The results confirmed that connection in parallel allows higher current intensities and power to be obtained, and that the total electrode surface area attained with the stack is directly related to the production of electricity and to the removal of COD, although not in a linear way.

A state of the art review on electron transfer mechanisms, characteristics, applications and recent advancements in microbial fuel cells technology

“…The main challenge which hampers the improvement of MFC technology is to engineer systems for power generation at a larger scale for prolonged operations with continuous feeding of the waste stream. (99). The works of Gajda et al (100) aim to answer this challenge.…”

Same but different–Scale up and numbering up in electrobiotechnology and photobiotechnology

“…Several other studies showed the possibility to stack fuel cells in lab scale. A remaining question is how to connect the single modules in the stacks, parallel or serial . For parallel connection, it seems that a slightly higher power production can be obtained, but more research is needed here to allow a final conclusion which method should be used for numbering up.…”

Factors Affecting the Effectiveness of Bioelectrochemical System Applications: Data Synthesis and Meta-Analysis

“…For wastewater treatment, multiple MFC or MEC units should be connected as stacks, in order to further increase their power generation, biohydrogen recovery, and treatment efficiency. However, the MFC and MEC stacks are plagued by low efficiency and instability, due to the nonlinear nature of the unit systems [43]. Unlike conventional fuel cell stacks, which are based on stable chemical reactions in each unit, the MFC and MEC units depends on relatively instable microbial activities for power and hydrogen outputs.…”