Wednesday, January 29, 2014

Hydrogen production cost-effective soon

Hydrogen is the most abundant element in entire Universe so it comes to very little surprise that scientists are working on different ways to cost-effectively produce hydrogen. One of the recently talked about solutions for hydrogen production, as a potential source of almost unlimited energy for fuel cells, is silicon. The US scientists at the University of Buffalo have recently discovered that super-small particles of silicon react with water to produce hydrogen almost instantaneously.

This was confirmed by the series of numerous experiments in which the scientists created spherical silicon particles about 10 nanometers in diameter. When combined with water, these particles reacted to form silicic acid and hydrogen. The benefits of these experiments include the facts that the reaction didn't require any light, heat or electricity, and the production rate was excellent as it enabled production of hydrogen about 150 times faster than similar reactions using silicon particles 100 nanometers wide, and 1,000 times faster than bulk silicon, according to the study.

The produced hydrogen was defined as relatively pure by testing it successfully in a small fuel cell that powered a fan. What this means is that in processes that include splitting water to produce hydrogen, nano-sized silicon looks like a lot better solution than the more obvious choices aluminum that people have studied for a while. The researchers hope that with the further development, this technology could form the basis of a 'just add water' approach to generating hydrogen on demand and have also revealed that the most practical application for this process would be for various portable energy sources.

Particularly surprising was the speed at which the 10-nanometer particles reacted with water. In under a minute, these particles produced more hydrogen than the 100-nanometer particles produced in about 45 minutes. The maximum reaction rate for the 10-nanometer particles was about 150 times as fast.

The reason of this discrepancy is said to be geometry because larger particles form non-spherical structures whose surfaces react with water less readily and less uniformly than the surfaces of the smaller, spherical particles. The downside is that it still takes significant energy and resources to produce these super-small silicon balls, but nonetheless these particles could help power portable devices in situations where water is readily available and portability is more important than low cost (such as military operations).

Hydrogen can be rapidly produced from silicon, one of Earth's most abundant elements, and this paves to way for future discovery which could one day turn hydrogen into one of the most important energy sources in the world.

The things were taken even further when Stanford University scientists recently created a silicon-based water splitter that is both low-cost and corrosion-free. This new splitter, which is basically a silicon semiconductor coated in an ultra thin layer of nickel -- could help pave the way for large-scale production of clean hydrogen fuel from sunlight, according to the Stanford scientists.

As researchers reported solar cells only work when the sun is shining meaning that when there is no sunlight, power needs to be generated from conventional power plants that run on fossil fuels such as coal or natural gas. The greener solution to this dependence on coal and natural gas fired plants would be to supplement the solar cells with hydrogen-powered fuel cells that generate electricity at night or in times when demand is especially high.

The first thing that needs to be enabled prior to using this greener solution is to produce clean hydrogen. The novel hydrogen research uses technology called water splitting. The working principle of this technology is as follows: Two semi-conducting electrodes are connected and placed in water where they absorb light and use the energy to split the water into its basic components, oxygen and hydrogen. At the end, the oxygen is released into the atmosphere, while the hydrogen is stored as fuel. When energy is needed, the process is reversed as stored hydrogen and atmospheric oxygen are combined in a fuel cell to generate electricity and pure water.

The entire process is sustainable and environmentally friendly because it emits no greenhouse gases. But finding a cost-effective way to split water still looks to remain a major challenge and researchers continue searching for inexpensive materials that can be used to build water splitters efficient enough to be of practical use for hydrogen production.

Some researchers have turned to xylose as the solution for hydrogen production. One of the most notable researches on hydrogen production comes from the Virginia Tech where scientists have discovered a way to extract large quantities of hydrogen from basically any plant. This discovery has the potential to revolutionize the entire hydrogen fuel production because of its high potential to bring cost competitive and environmentally friendly hydrogen fuel as a viable alternative to our current dependence on fossil fuels such as coal and natural gas.

The major accomplishment that researchers have achieved was that they used xylose, the most abundant simple plant sugar, to produce a large quantity of hydrogen. Prior to this study this process was pretty much attainable only in theory, and had no practical proof.

The main benefits of this brand new hydrogen fuel production process include focus on renewable natural resources, negligible greenhouse gas emissions, and no need for costly or heavy metals. The majority of previously used methods led to significant greenhouse gas emissions, and were connected with high cost and low efficiency.

This process is yet to become commercially available, but has the possibility of making an enormous impact, from both environmental as well as economic point of view. The lead author Y.H. Percival Zhang said that "hydrogen market capacity would soon be at least $1 trillion in the United States alone."

Zhang's team were able to liberate high-purity hydrogen under mild reaction conditions at 122 degree Fahrenheit and normal atmospheric pressure by separating a number of enzymes from their native microorganisms to create a customized enzyme cocktail that does not occur in nature. These enzymes, when combined with xylose and a polyphosphate, were able to liberate the unprecedentedly high volume of hydrogen from xylose, resulting in the production of about three times as much hydrogen as compared to other hydrogen-producing microorganisms.

Hydrogen is definitely one of the most acceptable alternative fuels from the environmental point of view. When hydrogen burns in air, it produces nothing but water vapor, meaning it is totally ecologically acceptable. With little luck and more research hydrogen could even become the most important energy source in the world. The potential is already there, and it is up to science to create solutions to cost-effective harness this enormous energy potential that hydrogen has.

No comments: