Originally published July 8th, 2013
As alternative fuel vehicles (AFVs) continue to become more economically viable, fuel source and renewability remains a key point of discussion. Although AFVs like fuel cell electric vehicles (FCEVs) can eliminate fossil fuel dependence while reducing air pollution and greenhouse gas emissions, many interested parties take a life-cycle approach by questioning the source of the energy used. If the energy carried in a fuel cell doesn’t come from a clean or renewable source, then the vehicle powered by that fuel cell isn’t exactly clean or renewable.
For FCEVs, cost remains the primary challenge to produce 100 percent renewable hydrogen.
The commercial hydrogen market is currently around $100 billion. According to the U.S. Department of Energy’s Alternative Fuels Data Center, 9 million tons of hydrogen is produced annually in the United States, 95% of which is produced through natural gas reformation. Natural gas reforming is currently the cheapest, most common and efficient method for producing hydrogen. When used in a FCEV, natural gas derived hydrogen reduces greenhouse gas emissions approximately 50%, when compared to conventional gasoline. However, to reach long-term climate goals, we need close to 100% reduction.
A potential solution to the challenges of production costs and environmental impact lies in the research conducted by Y.H. Percival Zhang at Virginia Tech’s College of Agriculture and Life Sciences. Zhang and his team successfully developed a process to produce large quantities of hydrogen from the simple plant sugar xylose, an abundant renewable resource. The innovative technology avoids using expensive metals and releases close to zero greenhouse gases. This could shorten the timeline for making renewable hydrogen commercially available, which would have huge environmental and economic impacts.
When applied at commercial scale, Zhang’s research has the potential to deliver affordable, renewable, emissions-free hydrogen., It does so simply and efficiently, eliminating costs at each step of the process. Researchers isolate the necessary enzymes and catalytic reactions required to produce the highest yields of hydrogen from sugar and water. This specific enzyme cocktail works in toxic environments, which removes an expensive detoxification step, and can be produced by one bacterium. By using recyclable enzyme-based solvents, Zhang found lower cost replacements for the traditional high-heat, high-pressure process. Using biomass to generate hydrogen drastically reduces greenhouse gas emissions. Additionally, the process allow for energy efficiency above 100% – meaning that the energy of hydrogen produced is greater than the combined input energies of xylose and polyphosphate.
This efficient, environmentally friendly method of hydrogen production is just one example of many potential pathways for creating renewable hydrogen. With the science in place, the right economics can lead this, and other, renewable hydrogen production methods to commercial viability and success. Such as outcome would be a victory for everyone: a clean, domestic, renewable, and affordable fuel to power our mobility.