Production of hydrogen via water electrolysis would require a doubling of electricity production in the US. However, by using the energy stored in waste biomass it is possible to produce hydrogen gas directly by bacterial electrolysis of organic matter in a modified microbial fuel cell (MFC) process called the BEAMR (bioelectrochemically assisted microbial reactor) process. This requires only one tenth of the electricity input compared to water electrolysis. In an MFC, bacteria degrade organic matter and transfer electrons to an electrode (anode) where they flow to the counter electrode (cathode) to combine with oxygen and protons to form water, producing electricity. In a BEAMR process the oxygen is omitted, and by adding a small voltage (0.11 V in theory, but 0.25 V in practice) it is possible to generate hydrogen gas at the cathode. Because hydrogen is sparingly soluble in water, it bubbles out of water, creating a pure hydrogen gas stream that originated with the electrons and protons produced by the bacterial decomposition of organic matter. For an acetate-fed BEAMR system, the hydrogen yield represents nearly a six-fold energy increase over the electricity investment.

Any biodegradable material can be used to produce either electricity or hydrogen gas in these systems. Tested substrates include glucose, acetate, butyrate, ethanol, amino acids, proteins, starch, fatty acids, and domestic, animal, and food industry wastewaters. The use of agricultural materials as sources of energy or hydrogen has also become a national interest as these materials are highly abundant and contain vast reserves of energy in the form of cellulose. Raw cellulose can be used to make hydrogen via fermentation processes, with the resulting volatile acids (primarily acetic and butyric) used to generate electricity or hydrogen in the MFC or BEAMR processes. Also, it is possible to use cellulose directly in an MFC process for electricity production. Alternatively, a steam explosion process can be used to convert the hemicellulose in agricultural waste materials such as corn stover into soluble sugars. When used in an MFC, all sugars (monomeric or oligomeric) are completely utilized, with overall removal efficiencies of all biodegradable organic matter of ~93±2%. Power output in this earlier MFC system approached 1 W/m2 with these corn stover hydrolysates, which was typical of power production using pure compounds for this reactor set up.

The MFC and BEAMR systems are now moving towards commercialization, with two pilot studies being planned to be conduced within two years. These new systems are based on recent discoveries and improvements that have increased power densities to above 2 W/m2. Additional benefits of using MFCs or BEAMRs for wastewater treatment include cost savings associated with reduction solids production (bacterial biomass) and the lack of energy input via aeration commonly used in treatment plants. These technologies will open whole new methods of energy and hydrogen production in the next few years as the process is moved from the laboratory into field applications.