The Grass Is Greener On The Other Side

Researchers at Penn State University have developed a process whereby bacteria is used to extract Hydrogen from almost any biodegradable organic substance (from grass clippings to wastewater).

The discovery, published in Proceedings of the National Academy of Sciences, is very promising given that the researchers were able to use existing technology meaning the process can be put to use immediately.

Professor Bruce Logan and his research assistant Shaoan Cheng discovered a method whereby bacteria called exoelectrogens break down acetic acid (produced by fermenting cellulose, glucose or other biodegradable organic matter) in a microbial electrolysis cell to create Hydrogen.

The way the process works is that when the bacteria consume the acid, electrons are transferred to a graphite anode. During the process the bacteria also release protons (which are Hydrogen atoms stripped of electrons) that are held in solution. As the electrons are then transferred to a platinum cathode they combine with the protons and generate 0.3 volts of electricity. When another 0.2 volts is added to the process it creates Hydrogen gas.

This is all very promising especially given that this method produces up to 82 percent more energy than the electricity and biomass needed to produce it.

http://www.wired.com/cars/energy/news/2007/11/hydrogen_bacteria

The Basics of Hydrogen

Hydrogen gas (H2) represents nearly 75% of the universes elemental mass and is the most abundant of chemical elements. It is odorless, colorless, tasteless, nonmetallic, and highly flammable. Hydrogen is lighter than air and since it rises into the atmosphere it is not found on earth by itself but rather compounded together with other elements. When combined with oxygen it is water (H2O) and when combined with carbon, it forms other compounds such as methane (CH4), coal, and petroleum. Hydrogen is also found in biomass and is an abundant element in the earths crust.

Since Hydrogen is not an energy source itself it has to be produced by either electrolysis of water or reforming of fossil fuels. Electrolysis of water is a process whereby electricity is used to split water molecules (H2O) to create pure Hydrogen and oxygen. Although this process can be done just about anywhere it is the more expensive of the two processes. In the reforming of fossil fuels, a device called a fuel processor or reformer is used to split Hydrogen off the carbon in hydrocarbons that are found in oil and natural gas (methane) to create pure Hydrogen and carbon, the latter being discarded into the atmosphere as carbon dioxide.

In order to create a true Hydrogen Future pure Hydrogen should be derived from renewable sources and not fossil fuels so that there is no release of carbon into the atmosphere. Today this can be achieved only by generating pure Hydrogen through electrolysis utilizing electricity that is not generated itself by fossil fuels. There are several non fossil fuel options for generating the electricity needed for electrolysis which include wind turbines, solar cells, hydroelectric dams, nuclear power, geothermal power, wave and tidal power and co-generation.

The Hydrogen Future will be driven in large part by the non fossil fuel option that becomes not only the safest, most feasible and most efficient source of electricty needed to produce pure Hydrogen but also the most affordable.