Scale-Up of Bioelectrochemical Systems for Energy Valorization of Waste Streams

Bioelectrochemical systems (BES) have become mature enough to make the leap from the laboratory to the pilot-scale level of development. This has been especially visible during the last 10 years as the number of papers devoted to large-scale developments has steadily increased. Most of these experiences have shown that BES can become a feasible technology but, more importantly, have helped to identify where the main bottlenecks are and to devise strategies to overcome them. This chapter briefly analyzes some of these difficulties and discusses the way researchers have dealt with them in the endeavor of developing technically and commercially feasible BES for energy valorization of waste streams. As the internal resistance (overpotentials) explains to a large extent the energy efficiency in these devices, the chapter pays special attention to how adequate reactors architecture and flow configurations can help to maintain it low. It also reviews some of the most significant large-scale developments (MFCs and MECs), providing benchmarks and current performance levels. In addition, as BES demand/require electrical energy at low voltage levels, a section is devoted to energy management systems and strategies. The chapter ends by exploring some of the potential commercial niches where BES can find an easy and fast entrance into the market of environmental technologies.