Improved hydrogen gas production in microbial electrolysis cells using inexpensive recycled carbon fibre fabrics.

Growing energy demands of wastewater treatment have made it vital for water companies to develop less energy intensive processes for treating wastewater if net zero emissions are to be achieved by 2050. Microbial electrolysis cells (MECs) have the potential to do this by treating water and producing renewable hydrogen gas as a product, but capital and operational costs have slowed their deployment. By using recycled carbon fibre mats, commercially viable MECs can brought closer to reality, where recycled carbon fibre anode MECs treating real wastewater (normalised ~3100 L d-1) were producing 66.77 L H2 d-1 while graphite felt anode MECs produced 3.65 L H2 d-1 per 1 m3 reactor, anodes costing £5.53 m-2 and £88.36 m-2 respectively, resulting in a total anode cost saving of 93%. This could incentivise the development of larger pilot systems, opening the door for generating greater value and a more sustainable wastewater treatment industry.