A team of researchers at Lawrence Livermore National Laboratory in California is claiming the world's record for distance in a hydrogen-fueled car, thanks to a new high-pressure cryogenic tank they have developed. The group ran a Prius around the Livermore lab's campus for a total of 1,050 kilometers on one tank containing 150 liters of liquid hydrogen. It worked out to 105 km per kilogram of hydrogen, they said.

One of the researchers, Salvador Aceves, told us the claim is based on publicly available information. Last May, General Motors claimed a record with a fuel cell car that ran for 300 miles on a single tank of hydrogen. That would be just under 500 km.

The Livermore team has been in pursuit of a traveling container for hydrogen for some years now. The cover article, "Fill'er Up—With Hydrogen," in our February 2002 issue reported on the group's tests of a version of the cryogenic tank. They had roasted one in a fire and shot one with a .30-caliber round to establish that the design was safe enough to install in an automobile.

Aceves, a former chairman of ASME's Advanced Energy Systems division, said the group has made a lot of progress since 2002. "We did two demonstrations in two different vehicles: a Ford Ranger pickup truck and the record-breaking Toyota Prius," Aceves said.

Vernon Switzer (left) and Tim Ross of the Lawrence Livermore laboratory refuel what they believe to be the world's longest-range hydrogen vehicle.

He said the new pressure vessel carried by the Prius is 47 inches long and 23 inches in diameter, or about 120 cm by 58 cm, considerably smaller than earlier versions, like the one in the pickup truck, but it stores more hydrogen. The larger tank capacity and the fuel efficiency of the hybrid Prius produced the world record driving distance. The Prius uses a small internal combustion engine and an electric motor. According to Toyota, Prius models burning gasoline average 46 miles per gallon, which translates to roughly 20 km per liter.

Aceves, who leads the Energy Conversion and Storage Group in the lab's Engineering Directorate, said the Livermore team expects to enter a collaborative agreement with an automobile manufacturer to develop the technology as an option for hydrogen storage in cars.

The tank developed at Livermore uses a vessel of aluminum coated with carbon fiber as the high-pressure inner vessel. It is surrounded by a vacuum space filled with reflective plastic and an outer stainless steel jacket. It is designed to accept liquid hydrogen—that is, chilled as low as 20 kelvin, or -253°C—or compressed gaseous hydrogen.

According to Aceves, the inner tank is a commercially available vessel of a sort commonly used to store compressed gases. The aluminum liner, about 6 mm thick, is wrapped in layers of carbon fiber tape wetted in epoxy resin. The carbon fiber provides strength and the aluminum liner provides containment for the hydrogen.

"Our contribution was demonstrating that we can use these same vessels for storing cryogenic liquids," Aceves wrote in an e-mail. "Storing cryogenic liquid hydrogen increases the system density by a factor of 1.5-2 with respect to compressed hydrogen tanks (due to the higher density of liquid hydrogen). It also eliminates evaporative losses under practical vehicle-use scenarios. Evaporative losses have been the limiting factor in widespread utilization of liquid hydrogen tanks."

The tank remains at liquid-hydrogen temperature (33 kelvin or colder) for about one day when initially full. Today's low-pressure liquid hydrogen tanks typically start losing hydrogen to evaporation at low temperature (typically 28 kelvin).

The Lawrence Livermore team says its experimental tank can contain the hydrogen until it reaches about 65 kelvin. This ability allows three extra days before evaporative losses occur. If the vehicle is driven during the four days, the dormancy rapidly increases. Travel of perhaps as little as 10 miles a day can eliminate evaporative losses.

The rated pressure of the tank is 5,000 psi. If the pressure is exceeded, a relief device opens to release some of the hydrogen.

The research team has 13 members besides Aceves: Gene Berry, Francisco Espinosa-Loza, Rich Fairchild, Dan Flowers, Jim Fugina, Brian Kelly, Fernando Luna, Mark McCuller, Blake Myers, Sue Pierce, Tim Ross, Vern Switzer, and Andrew Weisberg.

According to the Livermore Lab, the research group's work on the fuel tank, which began more than a decade ago, has come under the Department of Energy's National Hydrogen Storage Project, a component of President Bush's Hydrogen Fuel Initiative, which began in 2003.

Installing fieldbus architecture can be like giving a plant a brain. It tells plant managers what's going on and helps them keep processes flowing.

Of course, it requires electric current to work, and if the plant is a designated hazardous area—say, if flammable gases may be present during operation—electric current may present difficulties. That was the situation facing a manufacturer of bulk pharmaceutical ingredients, Boehringer Ingelheim Chemicals Inc. in Petersburg, Va.

According to C. Bruce Bradley, electrical and instrumentation & controls project engineer at BI Chemicals, the company has three primary production buildings all electrically classified as hazardous areas. The classification for the buildings is generally Class 1, Divisions 1 and 2, which means that flammable gases, vapor, or liquids (Class 1) can be present all of the time or some of the time under normal operating conditions (Divisions 1 and 2).

"Engineers in the chemical and pharmaceutical industries have to deal with hazardous areas, where chemicals, fumes, or dust can explode if an electrical spark occurs," Bradley said. "This classification can make it especially difficult to install electronic instrumentation and control system equipment."

The company manufactures bulk active pharmaceutical ingredients. The plant handles a variety of hydrocarbons, and the exact nature of the chemicals is proprietary.

In a fieldbus system, a variety of instruments, such as pressure and flow transmitters, connect to device couplers, which are in turn connected by cable to a control system. Power supply/conditioners power the fieldbus network. For plants where explosive hazards can appear, barriers are placed in safe areas to limit the electric current that can flow into process areas.

BI Chemicals needed a design to keep electrical energy at the instruments below the explosive limits of the area. The company also had to be sure that, even in the event of an electrical short or component failure, the energy levels would not spike to cause an explosion.

According to Bradley, the company's solution is the Route-Master system from MooreHawke of Moore Industries, based in North Hills, Calif. Route-Master systems are based on a split architecture that separates the barrier into two parts. This design allows for 350 mA dc on the trunk, which equates to 17 devices. Because each fieldbus segment on a control system requires an interface card, a power supply, and a device coupler—about $5,000 worth of hardware—the number of devices on a segment saved a considerable amount of money over an option using a different standard.

Bradley said that BI Chemical ended up installing 15 fieldbus segments based on the Route-Master, with more than 100 instruments operating on the segments. Because the system can accommodate more instruments, there is room for expansion on each segment.

From the Pulaski Skyway to the Golden Gate Bridge, millions of lives depend daily on the integrity of steel structures that take a constant beating. As the bridge collapse four months ago in Minneapolis so severely reminded everyone, those structures must be properly examined. But metal cannot be inspected without first removing protective coatings and patinas of rust.

There are various options for removing a coating. You can chip it away or sand blast it, use chemicals, or even try sanding by hand.

An alternative method to removing protective coatings and rust from a surface is to use soda blasting. SodaBlast Systems LLC of Houston describes it as a nondestructive method of surface preparation. SodaBlast claims that the process removes coatings of any kind from a substrate safely and efficiently. It is very similar to traditional sand blasting, yet has the advantage of cleaning the surface without causing any harm to the substrate or the environment.

A technician soda blasts a surface, a nondestructive way to clean structural metals for inspection. Soda blasting also eliminates electrolytes, such as acid and chlorides.

Basically, a machine blasts baking soda, or sodium bicarbonate, through a pressure vessel and onto the structure being cleaned, said Jerry LeCompte, president of the company. "Soda blasting costs less than conventional methods; prices are generally calculated by square footage of the item being cleaned. It also takes less time and the waste is easy to dispose of," he added.

"Imagine the task of stripping paint from a car," LeCompte said. "Using normal methods, that's a job that could take two to three days. With soda blasting, however, it can be done in two to three hours."

According to LeCompte, soda blasting has been around since the 1980s, when it was first used to clean the Statue of Liberty's substrate.

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