Radiated heat flux emanating from flames helps researchers evaluate the effectiveness of a barrier wall in mitigating the risks of hydrogen releases in a dispensing station setting.

The US Department of Energy’s domestic FreedomCAR and Fuels presidential initiative has now gone global, and researchers at Sandia National Laboratories are playing a key role in that worldwide effort.
Late last year Sandia joined a European consortium called “HYPER,“ for HYdrogen PERmitting. The endeavor, part of the international goal of making hydrogen one of the dominant carriers of energy, is driven by wide optimism that the so-called “hydrogen economy“ will eventually become a reality, and by a feeling that developing alternative sources of energy is no longer a choice but a necessity, RenewableEnergyAccess.com reported.
“We’re all working toward a similar goal--making hydrogen a dominant energy carrier sooner rather than later,“ says Jay Keller, hydrogen program manager at Sandia. “We’re better off all playing together than alone, so this international research effort is essential.“
Sandia’s primary contribution to HYPER, says Keller, is in the area of safety codes and standards, work it has been carrying out on DOE’s behalf.
HYPER has 15 partners from France, Germany, Greece, Italy, the Netherlands, the Russian Federation, the United Kingdom and the US. HYPER’s research focus is on small (10 kilowatts), stationary hydrogen fuel cells that could be used to provide auxiliary power in homes. Even though this differs from the FreedomCAR focus on transportation, there is enough overlap for a fruitful collaboration, says Keller.
Sandia is addressing the science and technology that goes into understanding unintended releases of hydrogen. This work will ultimately aid in developing codes and standards that will suggest how to design and operate a hydrogen fueling station in the safest possible manner. This year DOE has asked Sandia to focus specifically on barriers and how they might impact safety. Several HYPER partners are collaborating with Sandia on this barrier work.
“Everyone needs to consider barriers as a mitigation strategy,“ says Bill Houf, a principal investigator for Sandia’s work with HYPER. “The question we are trying to answer is ’does a barrier mitigate the effects of an unintended release, or does it create conditions that exacerbate the release?’“
An unintended release of hydrogen at 2,500 psi (pounds per square inch) could result in a 12-foot-long jet flame. A barrier would block that flame but could cause unintended detrimental effects, such as a significant and possibly damaging overpressure.
The overpressure, explained Houf, could induce a more dangerous situation than a jet flame. If the overpressure gets high enough it could break glass, damage walls, or eardrums. Modeling is key to hydrogen research, so a lot of the experimental results will go toward validating models. Modeling is also used to refine tests to maximize use of money and resources.
“We can’t test everything. Most of our tests are done for supply pressures of 2,500 to 6,500 psi, but vehicles may be fueled at 10,000 psi,“ says Houf.
Sandia is involved in two projects for HYPER, one on modeling and the other on barrier interaction experiments. At a HYPER meeting in Pisa, Italy, in May, Sandia’s work plan was touted as an example to be emulated by other members of the consortium.
Along with Sandia, the University of Ulster, University of Pisa, the UK’s Health and Safety Executive (HSE), Germany’s Forschungszentrum Karlsruhe (FZK) and Russia’s Kurchatov Institute are collaborating on the two projects. Each partner brings its own strengths to the project. For example, Keller points out that FZK’s modeling capability will be used to complement Sandia’s efforts in understanding the overpressure issue.
HSE has larger test facilities that will allow consequence and behavior work on a massive scale--what Keller called the “big bang.“ Kurchatov Institute has enclosed facilities capable of testing explosive mixtures, something that Sandia does not have access to in the US.
Some of the international partners have an advantage in terms of government support and funding. For example, Germany has enjoyed strong funding for fuel cell research for much longer than the US.
“Europe has been pretty aggressive at pushing hydrogen into their infrastructure,“ says Keller. “This partnership helps us leverage international activities in science. The energy problem is too important to work in isolation.“

A variety of end products including jet fuel, gasoline, carbon anodes and heating oil may be possible using existing refineries and combinations of coal and refinery by-products, according to a team of Penn State researchers.
“One idea is based on the coal-to-jet fuel work that we have been doing for a long time,“ says Caroline E. Burgess Clifford, research associate at Penn State’s Energy Institute. “Our aim is to integrate the processes and products into existing refinery structures and streams.“
The coal-to-jet fuel work is in the pilot plant stage, but along with the jet fuel, the process produces other hydrocarbon products. For every eight barrels of a Jet A equivalent, the process produces a half barrel of fuel oil, one barrel of diesel and a half barrel of gasoline, Eurekalert reported.
“We need to be sure that these components fit into the refinery stream that they are close enough in composition to be mixed with the components coming from crude oil,“ says Clifford.
So far, the researchers, including Harold Schobert, professor of fuel sciences; Maria M. Escallon and Utaiporn Suryapraphadilok, graduate students; Gareth D. Mitchell, Omer Gul, Josefa M. Griffith and Parvana Gafarova, research associates, Energy Institute, characterize the gasoline and fuel oil as fitting within the standard crude oil refinery stream. The diesel fuel is different from standard diesel fuel.
Other participants in this project tested the products in real units, including Andre Boehman, professor of fuel science and his group who tested the gasoline and diesel in engines; Bruce Miller, senior research associate and his group who tested the fuel oil in a pilot scale boiler; and Chunshan Song, director of the Energy Institute and professor of fuel science and his group who did related catalyst research.
“The produced diesel can be blended with the petroleum diesel without changing the fuel properties significantly,“ says Clifford. “It has not been shown to be bad or have bad effects, it is just different. We are also examining the produced jet fuel to see if it could be used as a diesel fuel, as the jet fuel has undergone extensively more processing than the other products.“
The pilot plant demonstration process uses coal tar and refinery solvent blended, cleaned and treated to produce the various fractions. In another process aimed at producing jet fuel, they mix raw, clean coal with decant oil--the liquid found at the bottom after catalytic cracking Ð and then co-coke. Fuel-grade coke, which is a standard fuel in the steel industry, sells for about $20 a ton. This co-coking process aims to produce coke or carbon of much higher quality usable in manufacturing carbon anodes for a variety of uses. The coke used in these anodes is a much higher value than fuel coke.
“So far the process has produced really good carbon, but it contains too many residual minerals for anode use,“ says Clifford. “The liquid component does include jet fuel, but the liquid products are very heavy in fuel oil.“ The researchers report at the American Chemical Society meeting today (Aug. 20), in Boston that future work will strive to reduce impurities in the solid carbon product. Researchers will also investigate either fractionating the fuel oil component or improving the liquid yield.
Another approach to achieving liquid fuels from coal is to extract the liquids from coal using refinery liquid. This method uses light cycle oil to extract the liquid components of coal and then the liquid portion, without separation, travels on through the refinery hydrotreater. In initial bench testing, this method produced a 50 percent yield of liquids. When processed in a multistage reactor, 70 percent extraction took place. The researchers are continuing this work to reduce the amount of light cycle oil necessary, develop a method to separate liquids and solids, and scale up the process.

The list of possible plants goes far beyond the established crops such as corn, maize and sugar cane that are already grown commercially for fuel uses.

Plants that can be grown for fuel are often touted as a vast, clean energy source--except by those who say precious food is being diverted into gas tanks, and that biofuel crops are using up dwindling land and water. Enter willow, hemp and switchgrass.
Scientists say research into a new generation of biofuel sources could yield cheap energy supplies that do not compete with food crops--or with nature--for water or space.
The day may be decades away, but some say plants might even cover a large share of the world’s energy needs, Reuters reported.
Goran Berndes, a researcher at Chalmers University of Technology in Sweden, says the list of possible plants goes far beyond the established crops such as corn, maize and sugar cane that are already grown commercially for fuel uses.
“Bioenergy is much broader,“ he said. “Most people working in bioenergy expect other crops to dominate in the long term.“
One promising energy source is the willow, a northern plant used to make baskets and sport bats. Others include hemp, known for its rope-making and mind-altering qualities, and switchgrass, a reedy plant found in the US Midwest.
A new crop that is being used already is jatropha, a resilient, oil-rich, tropical plant that can be grown on waste land and even introduces nutrients to the soil. Its oil is already used in India to power diesel cars and turbines.
Jatropha has grabbed headlines because it avoids the biggest controversy surrounding biofuels: the ethical debate over whether agricultural resources should be used for energy when millions across the planet go hungry.
This can mean using up water as well as land--a reminder that biofuel crops themselves can carry severe risks for the environment, especially if hitherto unfarmed land is converted to agriculture with large amounts of fertilizer and irrigation.
The International Water Management Institute, which led a five-year global study on water involving more than 700 researchers, found that if China and India pursued their current biofuel plans, they faced water scarcity by 2030.
Berndes has built models that try to peer even further into the future, assuming that crop yields will continue to climb as agricultural science advances, and new biofuel crops will become more productive.
One scenario--highly optimistic, perhaps, but theoretically possible--suggests that an area of agricultural land twice the size of Mexico could become surplus to current requirements by 2050.
If this were all used to grow biofuels, it could yield 400 exajoules of energy-- almost the equivalent of the world’s current energy consumption.
Of course, such scenarios are hugely complex, and it is not merely a question of finding enough land.
The assumed higher crop yields are likely to tax the environment harder by requiring more irrigation and fertilization. “If you need less land, you cannot be sure you need less water,“ Berndes says.
Hence the need to ensure that the new generation of biofuel crops are not also hungry for scarce resources--for instance getting their water from rain rather than irrigation.
And they will need to be commercially attractive.
“You have many different ways of producing transportation fuels from these new biomass sources that are not there yet commercially,“ he said.
At least one business sector is prepared to lobby for biofuel crops that do not compete so hard with food production.
Nestle, the world’s largest food company, says the subsidies being applied to current biofuel crops are distorting the market and pushing up the prices of food crops, and that second-generation biofuels could be an answer.
“If it works, and if it can be made to work economically, that certainly would be--both from an environmental and from an economic point of view--a much better solution than this strong focus on the current first-generation food crop biofuels,“ said Claus Conzelmann, Nestle vice president for safety, health and the environment.
But there are those who say the entire debate is misguided.
Vaclav Smil, a professor at the University of Manitoba, says that with relatively straightforward changes to the cars we drive, we could do without extra energy altogether.
“I’m astonished that people even think about biofuel,“ Smil told a conference in Stockholm. “Do we need more biofuels to feed our cars? We don’t.“

Green energy devices such as wind turbines and solar panels are to be made compulsory on millions of new homes and offices under government plan to boost green energy.
Housing minister Yvette Cooper is determined to push ahead with moves to force developers to cut their carbon emissions by using renewable sources of power.
New planning policy guidance will make clear that ministers stand by council planners who refuse permission for buildings which fail to generate their own energy.
The measures are part of Gordon Brown’s aim to make all new homes “zero-carbon“ by 2016 and to meet a target for Britain to obtain 20 per cent of its energy from renewable sources by 2020.
According to The Evening Standard newspaper the guidance, to be published later this year, will impose an obligation on town halls to adopt targets for green energy.
In some cases, new developments will have to obtain all their electricity from renewable sources, with others having a 50 per cent target.
Contrary to fears expressed by some environmentalists, Ms Cooper will not be abolishing the Merton Rule, a policy that lets councils insist that all new commercial buildings must take at least 10 per cent of their energy from green sources.
The rule, named after the London borough that pioneered it, has been adopted by more than 150 local authorities. Last year, Ms Cooper gave it her full backing, even suggesting all councils should take it up.
The House Builders Federation, which fears the measure will be applied to housing, has been lobbying strongly to abolish it, claiming it imposes unnecessary costs on developers and is too heavy-handed.
The federation’s chairman, Stewart Baseley, wants a national strategy phased in over 10 years and says action at local level will lead to confusion and higher costs.
Renewable energy companies say the rule is much more important to them than the Government’s low carbon buildings programme, which provides grants but has run out of money repeatedly and had its rules changed.
But according to the Standard, ministers intend to “widen, not abolish“ the rule. “In some instances, we want to see councils going way beyond 10 per cent,“ a Whitehall source said.
“The rule is not ours to abolish. We want a wider use of renewable energy, for housing as well as commercial buildings.“
In areas such as Woking, where the council has pioneered combined heat and power generators, all new housing may have to be linked to such schemes.
A spokesman for the Department of Communities and Local Government denied the planning guidance would ditch the Merton approach.
“Councils will be required to deliver more ambitious carbon-saving measures and set tougher targets for renewable energy for new developments,“ he said.
The Merton Rule was introduced in 2003. Merton council’s cabinet member for the environment, Tariq Ahmad, said: “We would strongly urge the Government to continue letting councils implement renewable energy policy at a local level.“
One development where the rule has had a big impact is the housing estate on Arsenal’s former ground, Highbury. The scheme will obtain 10 per cent of its energy supplied from renewable sources on the site.