It’s not easy being green. But researchers at Sandia are making green happen. Green — as in algae green.
As part of a project to create fuel out of algae, the researchers are growing green algae in a nutrient-rich liquid chemical equivalent of dairy effluent (the liquid remaining after bacterial digestion of the dairy manure). The algae are typically cultured for several days, followed by harvesting and dewatering, after which the algal oil is extracted and converted into a biofuel.
“People have been growing algae for centuries for food supplements for use by man and animals,” says Cecelia Williams (6313), project lead.
Beginning in the 1950s, algae were also recognized as a potential feedstock for energy and biofuels. Between 1978 and 1996, DOE funded the Aquatic Species Program with $25 million to investigate the production of biofuel from microalgae. That program was terminated in the mid-1990s due to low petroleum prices and other priorities. It has only been in the last few years that algae have received renewed interest as a potential source of fuel.
Recently Cecelia and other Sandia researchers grew green algae in a 12-by-30-foot greenhouse. They started by developing a simulated dairy effluent, a nutrient-rich liquid. The solids from the digestion of dairy manure can potentially be used to develop fertilizer and feed, and the liquid can be a nutrient source for algae
The algae produce lipids, the most useful being neutral oil made up largely of triacyglycerides (TAG) that can be converted to biofuels. The liquid-based algae are “dewatered,” followed by post-processing to extract the TAG.
Cecelia says that growing algae for biofuels eliminates many problems associated with traditional biofuels.
“The current generation of biofuels [starch-and sugar- based ethanol and oil crop-based biodiesel] rely on the use of commodity crops and therefore compete for use of food crops, primarily corn,” she says. “Also, they are very farm-intensive and use a lot of good farming land, fuel and fertilizer inputs, and fresh water.”
Algae ponds, on the other hand, can be put on marginal land and grown with non-fresh brackish water, water produced from energy mineral extraction (petroleum, natural gas, coal-bed methane), or nutrient-loaded wastewater from municipal and agricultural sources. The Southwest has the potential for being a leader in manufacturing this new type of biofuel because “it has lots of barren land that can’t be used for anything else, lots of sunlight, and a lot of marginal water,” Sandia researcher Brian Dwyer (6312) says.
Sandia scientist Ron Pate (6313) notes that Sandia is bringing into play its scientific and engineering expertise to grow and process specific types of algae for biofuels and other useful co-products. Sandia’s work in this area ties into broader biofuels efforts supported by DOE’s Office of Biomass Program (OBP) that focus on addressing challenges to commercially viable algal biofuels production. This includes Sandia participation in the development of the National Algal Biofuels Technology Roadmap Report, which is still in preparation, and partnering with others on proposals to establish consortia for algal biofuels and for advanced fungible biofuels with potential funding from OBP. The Algal Biofuels Consortium (ABC) specifically proposes a broad-based collaboration with Sandia and other national labs, industry, and university partners that would pursue research and development of algal biofuels as an affordable, scalable, and sustainable solution that can contribute significantly to meeting the nation’s transportation fuel needs.
Potential jobs for New Mexico
Cecelia anticipates the Sandia research to have the potential to provide new jobs and economic development to New Mexico, the seventh-largest dairy producing state in the nation. It employs more than 5,000 people and has an annual impact of nearly $2.7 billion.
The 340,000 dairy cows in New Mexico produce large quantities of manure and nutrient-rich effluent water that represent a significant waste management problem and regulatory expense to the state’s dairy industry. These and other agri-industrial waste streams represent a valuable and underused feedstock for recycling of energy, biofuels, reusable water, and other co-products. The DOE Algal Biofuels Technology Roadmap currently in draft suggests the use of non-freshwater sources, including agricultural effluent, for algal biomass production. Besides providing a source of non-fresh water and the recycling of needed nutrients, the use of these waste streams in an integrated biorefinery will help alleviate disposal regulatory requirements on dairies and other confined animal feeding operations (CAFOs) in New Mexico and the broader United States.
Making algal fuel competitive
Sandia’s greenhouse algae project was conceived by Ron Pate and Kyle Hoodenpyle (Ag2Energy) and has been funded by the New Mexico Small Business Association (SBA) and the New Mexico Technology Research Collaborative (TRC). The SBA funds Sandia to work with the private-sector partners Ag2Energy and the Pecos Valley Dairy Producers (PVDP), one of the largest collections of dairy producers in New Mexico. TRC funding lasted one year, and the SBA funding is in its final year of a three-year funding cycle.
Future money to research dewatering algae and monitoring the health of algae ponds will come from Sandia’s internal Laboratory Directed Research and Development (LDRD) program and possibly new direct-funded projects from DOE. This research will also allow the greenhouse algae ponds to support other aspects of Sandia’s algae biofuel research portfolio by using the data and information generated from these experiments to evaluate or verify both systems and process models. These models are essential for understanding the economics and risk associated with both the R&D and the up-scaling that will be required to make algae an economically viable fuel source for the nation. The ultimate goal is to make algae-derived biofuels competitive with petroleum-based fuels.
Algae project members include Sandia, University of New Mexico, and New Mexico State University. Members are collaborating with A2E and Pecos Valley Dairy Producers (PVDP) to convert dairy wastes to energy and other products.
Sandia is responsible for overall project management and reporting and provides technical leadership. As project leader, Cecelia Williams (6313) oversees and coordinates work and contributes to data analysis and assessments. Brian Dwyer (6312) is the lead field engineer to design the algae growth system and automated data collection system, as well as biological testing and field tests. Brian was assisted by Bruce Reavis (4133) on the system design, construction, and upgrading the greenhouse to a BSL1 status and Lucas McGrath (6316) assisted with the design and programming of the automated data collection system. Jackie Murton (8622) cultured the algae and provided stock algae solutions for inoculating the algae tanks in the greenhouse.
The primary role of David Hanson, UNM, was to isolate indigenous algae species and conduct growth experiments over a range of expected growth, nutrient, and environmental conditions. Shuguang Deng of NMSU provided the algae oil extraction and conversion expertise.
As the commercial partner, A2E conducted large- scale algae cultivation field tests and will work with the PVDP to lead business planning and commercialize the system. The PVDP have formed the Pecos Valley Biomass Cooperative (PVBC) to commercialize processes for converting dairy wastes to energy and other products. The PVBC is also exploring options to locate an algae plant in Roswell, N.M., close to the dairies. -- Lab News staff
By Neal Singer
Sandia’s silicon fabrication facility in Albuquerque has been accredited by DoD to provide “trusted foundry” services for both unclassified and classified integrated circuits. The foundry accreditation increases the scope of Sandia’s existing accreditation for design services. (For that information, see the Sandia news release dated March 12, 2009, at www.sandia.gov/news/ resources/releases/2009/trusted_design.html).
The accreditation program is part of DoD’s strategy to ensure that electronic components used in US military and national security applications are trustworthy. Certification is necessary because the increasing offshore migration of all sectors of the microelectronics industry comes at a time of increasing demand for high-performance, application-specific integrated circuits (ASICs) from military and national security agencies.
The trusted foundry accreditation is for Sandia’s strategically radiation-hardened, 3.3-volt, 0.35-micrometer, silicon-on-insulator (SOI) CMOS process that produces custom low-volume, high reliability ASICs. Sandia’s silicon fab is optimized for radiation-hardened, analog and mixed-signal microelectronics, custom digital ASICs, and discrete devices.
Sandia uses 0.35-micrometer geometry to optimize performance for analog circuits resulting in better device matching, higher supply voltages, and broader signal dynamic range than smaller geometry devices. Properly designed and fabricated, larger devices are more likely to continue to perform in extended operating environments including temperature, shock, and radiation.
In support of its primary mission as steward of the US nuclear stockpile, Sandia has developed and delivered microelectronics products for nearly three decades. This expertise has also been applied to other national security needs. These include ensuring the nonproliferation of nuclear weapons and materials, reducing the threat from chemical and biological weapons, and providing advanced custom designs for other agencies like DoD. Sandia’s ASIC development team provides custom microelectronics products and engineering services that fulfill the needs of a diverse set of customers.
Sandia focuses on high-reliability custom solutions for high-consequence applications. An efficient ISO 9001-certified process is said to enhance chances for first-pass silicon solutions. “Sandia offers a total supply chain solution for radiation-hardened integrated circuits and microsystems by combining trusted ASIC design and fabrication with other in-house capabilities in packaging, test, failure analysis, and reliability,” says Gil Herrera, director of Microsystems Science Technology and Components Center 1700.
For more information or questions, visit www.sandia.gov/mstc or email Trusted_ASIC@sandia.gov. -- Neal Singer
By Neal Singer
New Sandia fusion proposal marries Z’s electric pulse with laser preheating and magnetically contained plasma; increased efficiency sought over other concepts
An efficient way to harvest energy from a staccato, nanosecond burst of controlled fusion reactions was proposed in two Sandia technical papers and a number of related technical posters presented at the sixth international conference on Inertial Fusion Science and Applications (IFSA 2009), held two weeks ago in San Francisco.
The new ecumenical Sandia approach combines the Laboratories’ staple of extremely powerful, fast pulses of electricity with laser preheating and fuel magnetization, ordinarily thought to be the provenance of plasma-confining tokamaks and most recently ITER, the huge international thermonuclear experimental reactor under construction in southern France.
Research led by Steve Slutz (1684) suggests firing a burst of laser energy to preheat a deuterium-tritium plasma initially contained by a tiny metal tube (technically called a liner) that has been magnetized by external field coils. Almost immediately, a 26-megaamp electrical pulse from Sandia’s Z machine would further energize the plasma and amplify the magnetic field within the fuel. The resultant magnetic fields would confine and compress the heated plasma so that its isotopes fuse. They also are expected to keep alpha particles, composed of two protons and two neutrons, from leaving the mix so that their energy heats the plasma for further fusion. (This form of magnetic confinement would only be for nanoseconds rather than minutes, as ITER hopes to do.)
Idea minimizes power losses
“The basic idea of magnetizing fuel in an inertial fusion liner was first proposed decades ago,” says Steve, “but the combination of a laser to preheat the fuel and the power of Z were unavailable until recently.”
Sandia supercomputer simulations have indicated that the method could achieve efficiencies greater than 3 percent from wall-plug electricity to input into the plasma.
The method minimizes power losses inevitable when converting energy from one form to another with the aim of eventually producing fusion. Today’s approaches to inertial fusion involve many such conversions, including NIF’s use of electricity to power lasers, and then convert infrared light to ultraviolet; Z’s use of electricity to ionize wire arrays to form a plasma that then collapses to produce X-rays; or in the kinetic energy lost in both NIF and Z when X-rays ablate matter from a fusion capsule’s surface to drive, rocket-like, the remaining surface inward to fuse atoms.
It’s a question of economy, says Steve.
Consider that if the 0.15 megajoules of laser energy expected to enter a target capsule releases a fusion output of 10 to 20 megajoules, there would be dancing in the streets by physicists (figuratively speaking) at the achievement of this high yield. The capsule would have released roughly 100 times more energy than was put into it. But to the lay person, since the beams originate from a 400-megajoule capacitor bank, the process would seem an overall loss: 400 megajoules in, 20 out. The problem occurs because only 0.04 percent of the initial energy enters the target (0.15 divided by 400).
The idea of Steve, Mark Herrmann (1680), and their team is to minimize the number and types of power conversions to achieve higher efficiencies. They would use lessons learned from laser and pulsed power efforts. The result ideally would be efficient enough to produce a net overall power gain.
That said, the IFSA conference was devoted overwhelmingly to examining methods that might produce fusion itself rather than in improving the efficiency of the overall process.
Particularly notable was the impressive effort toward fusion made by the researchers at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory. (Other national labs, including Sandia, played a role in building sensors and other parts of the machine.) NIF management has proposed a high-yield fusion shot by the end of 2010.
“After 49 years, all the elements of ignition are in place,” NIF director Ed Moses told the assembled audience of 400 scientists.
Researchers from around the world presented ideas on modifying inertial fusion targets’ density, size, shape, temperature, and the velocity and frequency of light or ions striking them.
“It’s right that there’s so much money and attention given to lasers and NIF,” says Steve. “NIF is clearly the next step. There’s no reason for DOE or anyone else to put in big bucks to create a more efficient process for inertial confinement until we prove that it works at all.”
That, he says, would be putting the cart before the horse. "First NIF must show that high-yield inertial confinement fusion is possible. It’s very important that NIF succeed because it will show that it’s possible to compress a pellet using inertial confinement methods."
When it does, he says, scientists, engineers, and technicians at Z may have the next step half-completed, using a magnetically insulated, preheated plasma that would be much more efficient.
Inertial confinement typically applies a burst of energy — whether generated by electricity, light, or heavy or light ions — to compress a pellet filled with deuterium and tritium ions until they fuse. If the proper conditions are met, the pellet will ignite — achieve ignition, in the parlance of the trade — to release more energy than it absorbs, roughly following Albert Einstein’s famous equation, E=mc2.
Magnetic confinement, used by tokamaks and in particular by the upcoming ITER machine, creates a standing plasma confined by magnetic fields over relatively long periods of time – perhaps as much as 15 minutes.
The Sandia group proposes to use a sleeve (visually, a tube) less than a centimeter long, closed at both ends to maintain a deuterium-tritium (DT) mix. A single laser's pulse, two Helmholtz coils, and Z's enormous amperage should do the trick of producing more efficient fusion. Implosions would occur at 100-300 nanoseconds rather than the 10-30 microseconds proposed in earlier scenarios involving inertial fusion using magnetized fuel. Higher fuel densities will aid in trapping alpha particles. A sufficiently thick sleeve wall should maintain its integrity until the implosion is complete.
Peering into the maelstrom
In another paper presented with a separate poster at the IFSA conference, Kyle Peterson (1684) and Dan Sinars (1683) used a crystal as though it was sunglasses to transmit only a few selected frequencies to see into the maelstrom of Z when it fires. The enhanced view showed that sausage-like Rayleigh-Taylor instabilities predicted by LASNEX code were accurate; thus the code's veracity under these circumstances was established. A logical extension of the work is that the validated code may be used with provisional confidence to aid in design of the cylinder's dimensions, materials, electrical current requirements, firing time, and pulse- shaping in creating a system that mitigates instabilities past the point of energy generation.
A third poster by Ryan McBride, Mike Cuneo (both 1683), Christopher Jennings (1641), and Eduardo Waisman (1683) showed that a hollow metal torus that acts as a 2:1 current transformer when inserted in the transmission line of Z could amplify the current delivered to the liner. This should increase Z's electrical current flow to target from 26 megaamps to 40 megaamps, providing additional experimental capability. -- Neal Singer