Hydrogen generated from sunlight and ethanol
Hydrogen generated from sunlight and ethanol
An international team of scientists has announced success in creating hydrogen at ambient temperature and pressure using a combination of sunlight and ethanol. The team of researchers from Spain's Universitat Politècnica de Catalunya, Scotland's University of Aberdeen and New Zealand's University of Auckland say the method is potentially cheaper, produces higher yields and, because no high temperatures or pressures are required, uses less energy than conventional methods.
The process begins by placing a powdered photocatalyst and ethanol in a container, then agitating the mixture while exposing it to ultraviolet light. A titanium dioxide semiconductor within the container generates electrons when exposed to the light, and those electrons are captured by metallic gold nanoparticles in the catalyst. Those captured electrons proceed to react with the ethanol's alcohol molecules, producing hydrogen.
While the hydrogen yield depends on the amount of photocatalyst used and the size of area exposed to the light, so far the researchers have been able to produce up to 5 liters of hydrogen per kilogram of catalyst (1.32 U.S. gallons per 2.2 lbs) within in one minute. They believe that if 9 kilograms (19.84 lbs) of the catalyst were used, and the hydrogen then powered a fuel cell, 3 kW of electricity would be the result - enough, they say, to meet the needs of a typical household.
This isn't the first time that sunlight has been used to generate hydrogen. While some of those other techniques rely largely on water, the researchers claim that they also require expensive secondary materials, and that their yields haven't been as impressive. Ethanol, by contrast, is relatively inexpensive and comes from renewable plant-based sources. The photocatalyst is also said to be fairly economical, as the gold particles it contains are very small.
The team is now looking at designing reactors, that could generate hydrogen for use in providing electricity for homes.
The research was recently published in the journal Nature Chemistry.
About the Author
An experienced freelance writer, videographer and television producer, Ben's interest in all forms of innovation is particularly fanatical when it comes to human-powered transportation, film-making gear, environmentally-friendly technologies and anything that's designed to go underwater. He lives in Edmonton, Alberta, where he spends a lot of time going over the handlebars of his mountain bike, hanging out in off-leash parks, and wishing the Pacific Ocean wasn't so far away.
All articles by Ben Coxworth
This sounds like a nonsense research. With all due respect to the scientists behind this study, this method of getting hydrogen from ethanol looks inefficient.
Why can\'t they just use ethanol as fuel? Why do they have to use extra materials just to get hydrogen? Ethanol can be used in a direct ethanol fuel cell, which does not require expensive platinuim materials like hydrogen fuel cells.
So it looks like they are taking ethanol, which AFAIK has pretty much been shown to be a pointless source of energy (the energy output is little more than twice the energy required to produce it, and it consumes valuable farm land), and to this they add more energy in the form of sunlight to produce hydrogen.
Or am I missing something?
Why a detour? The Efuel Microfueler makes ethanol from waste material and allows you to plug in a power generator directly to the system, giving you engine fuel and electricity without the hassle.
Yeah, this doesn\'t make sense to me either. Considering the inefficiencies of ethanol production wouldn\'t it be better use of that sunlight to use photovoltaic or solar-conversion?
There is a factory that produces fuel from the sun with a byproduct of oxygen. I am amazed when scientist are put to shame by something as simple as the green leaf. They cannot even explain how it got here and will never be able to duplicate it. If they could just recreate [the accident]!
This seems like an effort to lock the technology into corporate distribution schemes.
By creating a complex technology and one that involves safety concerns from fire and explosions this process will be industrial and never for home producers. With solar cells becoming both better and cheaper one need not be overly concerned with efficiency for making a supply of hydrogen. Since sunlight or wind power are free whether you get 5% efficiency or 3% efficiency is a mute point. Add a larger solar cell unit and up your personal production or increase the windmills size a tiny bit and you are set. The technology involved is simple enough for most high school dropouts to apply.
I agree that ethanol isn\'t a good choice as a hydrogen source. Even if we ignore the costs of the gold catalyst, titanium dioxide, and fuel cell, the amount of ethanol required would easily show that this process isn\'t cost efficient. The average cost per kWh in the U.S. is about $0.13 and the average home uses about 30 kWh per day so the average daily cost is $4/day. I\'m confused as to why the article state the energy produced as kW instead of kWh.If ethanol costs over $2/gallon then this system would need to use less than 2 gallons per day to be cost effective. The article states that the researchers have been able to produce 1.32 gallons per minute with 1kg of catalyst and the researchers estimate a typical household would require 9kg of catalyst. Based on this it would be safe to say that the system would be using much more than 2 gallons of ethanol per day. Ethanol (CH3-Ch2-OH) has 5 hydrogen atoms however I\'d guess that only 1-2 hydrogen atoms could be extracted before the ethanol became unstable or is converted into unusable byproducts. This means that this process would extract 1.3-2.6 gallons of hydrogen per gallon of ethanol.
I think everyone\'s missing the point. The ethanol is a catalyst. That means they\'re getting more energy out (as hydrogen gas) then is in the ethanol consumed by the process. From what I read in the above, it\'s 4 to 5 times the energy. So, yes, it\'s worth the extra effort.
@shawnhcorey, no, the ethanol is the hydrogen source. The Gold is the catalyst. Go back and read the Article again. The original article makes it clear that Hydrogen is produced from ethanol.
ethanol sucks wind as a car fuel additive, with 10% of that in my tank my Audi loses 20% in highway mileage ethanol is not efficient, why does our government insist to put it in my fuel tank?
Given the real cost of ethanol it has to have massive subsidies to survive as a fuel source, and increases the price of food by using farmland as a fuel source. this is just a bad idea.
there are projects which tries to extract ethanol from non edible sources like algae and various plants that can survive in conditions in which farming crops cannot. With other renewable energy sources like wind, thermal, and solar(depending on circumstances) couldn\'t bio fuels(ethanol, butanol) be plausible? Especially with the United States there are lots of desert land to use?
Hydrogen from Solar/wind is already in practice. Why this sun/ethanol just to appear in the news?
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