February 21st, 2009 – Alternative Energy
Tomorrow our vehicles may derive power by enzymes. These enzymes may originate from the cellulose of woodchips or grass and instead of emitting poisonous gases they will exhale hydrogen. We know that when hydrogen is burned, the only emission it makes is water vapor, so a key benefit of hydrogen fuel is that when burned, carbon dioxide (CO2) is not produced. Clearly, hydrogen is less of a pollutant in the air because it omits little tail pipe pollution. Hydrogen also has the potential to run a fuel-cell engine with better effectiveness over an internal combustion engine.
A team of scientists from Virginia Tech, Oak Ridge National Laboratory, and the University of Georgia says it has successfully generated hydrogen gas. Normally these kinds of fuels are derived from starch. Jonathan Mielenz, who is the leader of the Bioconversion Science and Technology Group at ORNL, says, “It is exciting because using cellulose instead of starch expands the renewable resource for producing hydrogen to include biomass.”
This hydrogen gas is clean enough to power a fuel cell by combining 14 enzymes, one coenzyme, cellulosic materials from non-eatable sources, and water heated to about 90 degrees Fahrenheit (32 C). The researchers utilized cellulosic materials which is isolated from wood chips. But researches also claim that crop waste or switchgrass could also be used for this purpose. These research outcomes are being published in ChemSusChem. The research is supported by the Air Force Office of Scientific Research; Zhang’s DuPont Young Professor Award, and the U.S. Department of Energy.
Percival Zhang who is assistant professor of biological systems engineering in the College of Agriculture and Life Sciences at Virginia Tech, states, “In addition to converting the chemical energy from the sugar, the process also converts the low-temperature thermal energy into high-quality hydrogen energy – like Prometheus stealing fire.” This group declares the benefits of their “one pot” process. The first advantage is they are using a unique combination of enzymes. The second advantage is that hydrogen generation rate is as fast as natural hydrogen fermentation. The third advantage is the chemical energy output is greater than the chemical energy stored in sugars. The maximum hydrogen yield is produced from the cellulosic materials.
Percival Zhang said that if we can utilize a small fraction (two or three percent) of annual biomass production (at global level) for sugar-to-hydrogen fuel cells for transportation, it can lead us to transformational fuel independence. For U.S.A. the figure varies a bit. If U.S. wants to get rid of fossil fuels from transport they actually need to convert about 10 percent of biomass – which would be 1.3 billion tons of usable biomass.