Organic waste and bioelectrochemical systems: a future interface between electricity and methane distribution grids

Abstract

In a very near future, renewable electricity produced by photovoltaic and eolic is destined to be the cheapest form of energy. As these sources can’t be constant in time, new industrial research challenges have already been shifted to electricity storage from the grid. Here we present an innovative concept of electricity storage system, based on the field of bioelectrochemical systems. Electromethanogenesis is one of the most recent applications in this field, where methanogenic microorganisms of the Archaea domain can fix CO2 to methane, under electrical stimulation. In other words, electricity can be efficiently converted into CH4, i.e. one of the most commonly used fuels, territorially-distributed with a capillary grid in most EU-Countries. What is needed, to implement this process, is a relatively concentrated source of CO2 in an anaerobic acqueous environment. Currently in our society, huge concentrated streams of CO2 are released into the atmosphere every day from wastewater and waste treatment facilities, as well as from landfills. To treat sewage and organic waste, organic matter is degraded to inorganic carbon, mainly by microbial oxidation processes, which are strongly energy-intensive. In perspective, every wastewater treatment, anaerobic digestion, organic waste composting facility and controlled ladfill could be a key hotspot to transform excess grid electricity into biomethane, while treating waste with the same energy. Biomethane could be injected to the distribution grid and the waste-management facilities would become the interface between the two grids. To achieve this scenario, efforts in scaling up electromethanogenesis systems and new bioelectrodes materials (e.g. electro-active biochar) are needed. Here, we summarize some key steps in this field of research and the constraints that are to be overcome.

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Identifiers

DOI

10.26403/DETRITUS/2018.6

Journal

SHILAP Revista de lepidopterología

Year

2018