Methanol opportunities for electricity and hydrogen production in bioelectrochemical systems

• Syntrophic consortia development for methanol-driven bioelectrochemical systems.
• Methanol is reported as a potential substrate for power generation.
• Homoacetogenic bacteria avoid net H2 production from methanol in single chamber MEC.
• Hydrogen is produced from methanol in double chamber MECs for the first time.

An anodic syntrophic consortium (exoelectrogenic plus fermentative bacteria) able to use methanol as sole carbon source was developed for the first time in a bioelectrochemical system. In this frame, promising results were obtained in single chamber MFC, comparable to those obtained with readily biodegradable substrates. Regarding MEC operation, the presence of homoacetogenic bacteria led to electron recycling, avoiding net hydrogen production in single chamber MEC. In a double chamber MEC, satisfying results (in terms of coulombic efficiency and cathodic gas recovery) were obtained even though energy recovery still restrained the feasibility of the process. The approach used in this work with methanol opens a new range of possibilities for other complex substrates as electron donors for bioelectrosynthesis.