Materials For Energy

Pipeline Alternatives to Reduce Carbon Emissions during the Operations of Liquid and Gas Fuels Transmission and Distribution in Mexico

By Lorenzo Martinez-Gomez, Corrosion Y Protecction

Last November at the 2010 International Materials Research Congress in Cancun, many countries confirmed strong environmental commitments and established long-range initiatives to reduce global CO₂ emissions into the atmosphere. The Cancun meeting triggered many initiatives in Mexico after the government increased the market value of Mexican carbon bonds. While Mexican carbon bonds are still priced lower than ones traded in Europe, the Mexican valuation is now priced significantly higher than U.S. carbon offsets.

The petroleum industry is a major contributor to the greenhouse gas (GHG) emissions of Mexico. Currently, production practices in the region involve large quantities of gas being burned or released to the atmosphere. Refineries and petrochemical plants are also major sources of GHGs. Transmission and distribution of liquid and gas fuels by trucking are still common practices in Mexico. Cancun and the Riviera Maya together consume over 7 million liters per day of jet fuel, diesel, and gasoline. These fuels have traditionally been transported over land from cities on the Gulf of Mexico such as Merida, Coatzacoalcos, or even Salina Cruz on the Pacific coast, averaging over 400 to 500 km in trucking transport distances per month. In central Mexico, the highly populated and industrialized valley of Cuernavaca, Cuautla, and large parts of Guerrero also rely on fuels transported by truck from Mexico City, Tlaxcala, Puebla, or Toluca.

CO₂ emissions associated with liquid or gas hydrocarbon transmission and distribution are remarkably different when the transportation method is considered. Whereas trucking is heavy in fuel consumption, pipeline delivery is by far the most reliable, cost-effective, and environmentally friendly means of fluid transportation.

Engineering projects have calculated the potential tonnage of CO₂ emissions to be saved by constructing pipeline networks to feed hydrocarbons to both the Cancun – Riviera Maya region and Cuernavaca valley, with many projects benefitting from funding based on carbon dioxide bonuses. Accurate calculations of this sort may sustain the costs of important pipeline projects based on the long-term value of the savings of carbon dioxide emissions.

Software has been developed to combine and analyze all research results involved in the calculation of the carbon signatures of pipeline and truck transportation of liquid and gas hydrocarbons. Geographical information systems were employed to perform calculations for alternative potential right-of-way trajectories, as well as the fuel consumption associated with the current trucking routes. Other considerations are related to the carbon signature of trucking as a whole, including the excess of human resources, the differential needs of metering, tanking, and logistics, and the overall critical storage facility involved.

Considering European and Mexican carbon dioxide bond values, the resulting financing opportunities for pipeline projects are significant. For the case of supplying hydrocarbons by pipeline to Cancun and the Rivera Maya, the projected carbon dioxide emission savings over 30 years could finance an important segment of the pipeline construction project. Pipeline construction to supply hydrocarbons to the Cuernavaca – Cuautla Valleys would also result in saving millions of tons of CO₂ 
emissions.

 

 

Canada Has Plenty of Oil, but Does the United States Want It?

By Dr. Russell Chianelli, The University of Texas at El Paso, M.R.T.I

A recent Wall Street Journal article¹ describes what is well known to people in the energy industry. Canadian tar sands (bitumen) contain a massive amount of petroleum hydrocarbons and provide a major source of U.S. imports.

Reference 1

The article goes on to discuss “pros and cons” of using this very heavy source, including environmental issues. Canadian tar sand producers have a respected record of producing tars effectively and controlling environmental pollution. Discussions against using the Canadian tar sands include greenhouse arguments regarding the use of petroleum hydrocarbons. However, it is clear that the United States needs secure, friendly sources for security reasons, and, in addition, there are great economic benefits to using this nearby source.

Besides offering energy security, the oil sands offer numerous opportunities for materials scientists. These include novel catalyst and catalytic processes for upgrading the bitumen, metallurgical improvement for advanced reactors, and environmental improvements. It appears that petroleum resources in North America and growing natural gas production offer the promise of “energy independence.”

1. C. Cummins, E. Welsch, Wall Street Journal, July 8, 2011.

Waiting for the Hydrogen Economy

By Dr. Russell Chianelli, University of Texas at El Paso, M.R.T.I.

The term hydrogen economy was coined in the 1970s, and we are still waiting for it to develop.¹ It is the proposed system of delivering energy using hydrogen. Why did it disappear? Well, perhaps it doesn’t make sense for many reasons, as described in a recent PHYSORG article.²  However, one certain limitation is the inability to store hydrogen. Hydrogen storage materials have been too heavy and too expensive. New materials that are lighter and more efficient are needed. In the accompanying article from SSRL, a new hydrogen storage material with this potential is discussed. These materials are carbon nanotubes that when properly functionalized may have the potential to re-open the hydrogen economy that was hoped for. What other areas of sustainable energy will be subject to inadequate materials science?

Refrences

1. Wikipedia. Creative Common Attributions. 2010. Wikimedia. June 2011
2. Lisa Zyga. "Why a Hydrogen Economy Doesn't Make Sense". Physorg. Dec 2006.

Hydrogen Storage in Platinum-Single-Walled Carbon Nanotube Composites at Near Ambient Conditions through "Spillover" Mechanism SSRL Science Highlight - 2011

Contact: Srivats Rajasekaran, Stanford Synchrotron Radiation Lightsource

The proposal by Dillon et al.¹ that carbon nanotubes (CNTs) could store large quantities of hydrogen by physisorption has led many groups to investigate the possibility of CNT-based hydrogen-storage materials. Theoretical predictions suggest that it is possible to achieve 100% hydrogenation of single-walled nanotubes (i.e., one hydrogen atom for every carbon atom) through a chemisorption mechanism in which stable C−H bonds are formed.² As a result, carbon has been considered as an attractive option with its ability to store a high weight percentage of hydrogen. The mechanism of CNT hydrogenation would involve the breaking of the C−C π-bonds and the conversion of carbon atoms from sp² to sp³ hybridization upon coordination with hydrogen. While previous studies have generated large concentrations of C−H bonds using atomic hydrogen sources, practical implementation of hydrogen storage in CNTs requires the development of low-barrier pathways for hydrogenation.

Fig.1: Schematic of the "spillover" mechanism

In this work, the concept of the “spillover” mechanism in heterogeneous catalysis was exploited to store hydrogen in carbon nanotubes. Researchers from Stanford University and SLAC National Accelerator Laboratory examined how the hydrogen uptake of single-walled carbon nanotubes (SWNTs) is influenced by the addition of a platinum nanoparticle catalyst. In-situ electrical conductivity measurements showed that the electrical conductivity of platinum-sputtered single-walled carbon nanotubes (Pt-SWNTs) decreased upon gaseous hydrogen exposure. Asteady increase in the resistance of the Pt-SWNTs during exposure to molecular hydrogen gas was observed. Figure 2a shows a typical resistance response for the Pt-SWNT composite samples under exposure to molecular hydrogen, with different amounts of deposited platinum. The rate of resistance change depended on catalyst particle size (figure 2a) as well as nature of the SWNTs (figure 2b). It was found that composites with maximum density of platinum nanoparticles showed the highest resistance change.

Fig. 2 - (a) Change in resistance of Pt-SWNTs with different nominal thicknesses of Pt. (b) Change in resistance of different SWNT films with the same nominal thickness of Pt (6Å).

Ex-situcarbon 1s x-ray photoelectron spectroscopy (XPS) measurements were performed at SSRL Beam Line 13-2 to understand the origin of the resistance increase. After exposure to hydrogen at a pressure of 8.27 bar for 6 hours at room temperature, significant changes in the peak shape of the carbon 1s spectra were observed in the high-binding-energy region: in addition to the previously observed peak associated with sp²-hybridized carbon, a new feature appears at 0.85 eV higher energy. This new spectral contribution is assigned to carbon atoms that have undergone rehybridization from sp² to sp³ due to the breaking of C−C π-bonds and C−H bond formation³ and seen as direct evidence for the proposed spillover effect. Moreover, XPS measurements confirm that up to 16 ± 1.5 atomic percent of the carbon atoms undergo hydrogenation in the dispersed Langmuir−Blodgett (LB) films. LB films yield the highest hydrogenation capacity. Since the preparation method unbundles the SWNTs,⁴ these have higher surface area in contact with the platinum nanoparticles.

Fig 3 - (a) XPS spectra of LB film before and after hydrogen exposure. Peak fits before (b) and after (c) hydrogen exposure is also displayed.

XPS and conductivity measurements indicate that the Pt-SWNTs store hydrogen by means of chemisorption, i.e. covalent C–H bond formation, which supports a hydrogenation mechanism, facilitated by “spill-over” of dissociated hydrogen from the platinum nanoparticles. It is also evident that for high storage capacity, samples with high catalyst particle density and SWNT surface area are required.

This work was supported by the Global Climate and Energy Project operated by Stanford University and carried out at the Stanford Synchrotron Radiation Lightsource, a National User Facility operated by Stanford University on behalf of the U.S. Department of Energy, Office of Basic Energy Sciences.

Primary Citation:

Bhowmick, R., Rajasekaran, S., Friebel, D., Beasley, C., Jiao, L., Ogasawara, H., Dai, H., Clemens, B., Nilsson, A.,“Hydrogen Spillover in Pt-Single-Walled Carbon Nanotube Composites: Formation of Stable C−H Bonds” J. Am. Chem. Soc., 133(14), pp 5580–5586, 2011(doi: 10.1021/ja200403m)

References

1. A. C. Dillon, K. M. Jones, T. A. Bekkedahl, C. H. Kiang, D. S. Bethune, and M. J. Heben, Nature (London) 1997, 386, 377-379.
2. S. Park, D. Srivastava, and K. Cho, Nano Lett.2003, 3(9), 1273–1277.
3. A. Nikitin, H.Ogasawara, D. Mann, R. Denecke, Z. Zhang, H. Dai, A. Nilsson, Phys Rev Lett. 2005, 95,225507.
4. X. Li, L. Zhang, X. Wang, I. Shimoyama, X. Sun, W-S. Seo, and H. Dai, J. Am. Chem. Soc. 2007, 129, 4890-4891

France’s Nuclear Power Program Continues in Force

By Dr. Russell Chianelli, The University of Texas at El Paso, MRTI

In spite of the recent Japanese nuclear accident, France’s nuclear power program continues in force. As reported in the Energy Quarterly section of the June issue of MRS Bulletin, France decided to expand its nuclear program shortly after the oil crisis in 1974, while simultaneously reducing its use of coal. The country shut down its coal mining industry in 2004. Currently, 75% of their electric power comes from 58 nuclear reactors. France is now the largest exporter of electric power in the world, and it has the lowest CO₂ emissions per capita of any country. Also, their nuclear efficiency is improving with each generation of reactor designs. These are just some of the reasons why France continues to heavily pursue nuclear energy.¹

French Nuclear Reactor – Saint Laurant -Nouan²

As a frequent visitor to France, I can attest to the beauty of the French countryside and the popularity of nuclear reactors because of low-cost electricity and clean air. The Energy Quarterly section of the June issue of MRS Bulletin also discusses advances in fuel processing, reactor design, and waste disposal issues in France.

1. Jon Palfreman, "Why the French Like Nuclear Energy", PBS: Frontline, June 2011;
2. T.A.F.K.A.S., Saint-Laurent Nuclear Power Plant, Wikipedia, 18 July 2006;
3. Philip Ball (2011). France’s nuclear power program continues in force. MRS Bulletin, 36, pp 418-421 doi:10.1557/mrs.2011.140

Learning from Failures

In the Energy Quarterly section of the June issue of MRS Bulletin, Angela Saini discusses what we have learned from notable technological failures around the world, namely the Space Shuttle Challenger disaster in 1986, last year’s Macondo Oil Spill, and now the Japanese Fukushima Daiichi accident. Officials in the United States and worldwide are closely scrutinizing nuclear reactors to determine future policy.^1,2 In each accident scenario, new engineering techniques and safety inspection technologies were developed and applied over time, but in spite of our best efforts “accidents happen.” In addition to reducing risk with better equipment and procedures we need to be prepared to respond to unexpected accidents.

A good example was the 2010 Macondo oil spill in the Gulf of Mexico.³ Safety measures and equipment have been rightly called into question, but in this instance, panic ensued because the media, and the public did not understand a basic fact about the ocean environment: Huge amounts of oil are naturally being put into the sea on a daily basis, and natural organisms called “hydrocarbon degraders” are constantly turning the petroleum into natural food sources for higher organisms. So responding to oil spills requires stockpiling dispersants to make the oil more easily available to the organisms and adding nutrients to enhance the rate at which the hydrocarbon degraders can grow. Where oil production is present, these materials and the ability to apply them need to be readily available. They were not.

This type of deep understanding is needed to be prepared for future accidents that have the potential to create large disasters.

1. “U.S. Boosts Scrutiny of Nuclear Reactors”, Chemical Engineering News, 19, May 23(2011).
2. “What is the Future for Nuclear Energy?” MRS Bulletin, Energy Quarterly, June 2011.
3. “The Microbes Come Through”, Materials Research Society, Materials for Energy Blog, 2011.

What is the Future of Nuclear Power?

The Energy Quarterly section of MRS Bulletin’s June issue discusses, in detail, the future of nuclear power throughout the world, starting with an editorial by Robin Grimes of Imperial College London. With the recent Japanese nuclear disaster, current and future nuclear nations are examining the options for nuclear powered electricity and maintenance of existing nuclear facilities, some of which are entering old age. Germany has decided to halt nuclear energy production¹, whereas the French would prefer to continue with nuclear power.² China and India, with emerging economies and large, growing populations, consider nuclear power a necessity. All of this must be tempered with the global situation regarding the availability of hydrocarbons and coal. The United States is also actively debating the future of nuclear energy. A projection of world energy demand is included below.

Can we learn from our failures and previous accidents? Although much can be done regarding introspections of safety rules and monitoring, there are numerous challenges for the materials community.

1. Bernd Radowitz and Jan Hromadko, "Merkel:German Nuclear Exit Gradual; 2022 Irreversible End-date," The Wall Street Journal, Monday, June 6, 2011;
2. Jon Palfreman, "Why the French Like Nuclear Energy", PBS: Frontline, June 2011;

Shale Rock Fracking Keeps U.S. Economy from Cracking

By Russell R. Chianelli, The University of Texas at El Paso, MRTI

In a recent article in The Wall Street Journal titled “Stepping on the Gas,” Daniel Yergin, noted for his book The Prize, which covers the rise of the major oil companies, describes how gas from shale rock can lead the United States out of dependence on foreign oil imports.¹  In this article, he discusses how independent energy producers in the Houston, Texas, area have tapped a resource called the Barnett Shale reserve located around Dallas/Forth Worth, Texas. This is now producing massive amounts of natural gas using techniques developed over the past 30 years to open reservoir rocks. Specifically, a technique called fracking expands rock fractures, releasing gas. Fracking has changed the U.S. energy equation. As part of the so-called Unconventional Natural-Gas Revolution, the technique has turned a natural gas shortage into a surplus, resulting in lowering of the price of natural gas. It is now estimated that the United States has a resource base of natural gas across the country of 2,500 trillion cubic feet (see Reference 2 for worldwide production). This makes it probable that the United States will become a net exporter of natural gas.

Fracking has critics who speak about threats to groundwater and the handling of water recovered from the operation. However, the industry states that they have a long, untarnished safety record. In an accompanying article titled “The Road to Clean Energy?” environmentalist Mark Brownstein discusses the risks and appeals to the industry to allay such fears. Besides the obvious direct uses of natural gas for energy applications, the abundance of natural gas also offers opportunities to the catalytic materials community to convert it to useful transportation liquids. Future blog entries will discuss this in more detail.

1. D. Yergin, “Stepping on the Gas,” The Wall Street Journal, Saturday/Sunday, April 2-3, 2011;
2. M. Brownstein, “The Road to Clean Energy?,” The Wall Street Journal, Saturday/Sunday, April 2-3, 2011;

EQ Interview: Brazil’s energy policies: An interview with Sérgio Rezende, former S&T minister

(See interview in Energy Quarterly (EQ) in the March 2011 issue of MRS Bulletin)

Brazil’s efforts in science and technology only emerged in the last 40 years and investment in it increased by a factor of 10 in just the last 10 years. Until recently, their Minister of Science and Technology was Sérgio Rezende (2005–2010), a materials researcher himself. He recently addressed questions from MRS Bulletin representative Guillermo Solórzano for Energy Quarterly about Brazil’s plans for the energy challenges ahead.

It is well known that Brazil has invested in renewable energy sources such as hydro and biofuels “long before the issues of a low-carbon economy entered the global agenda,” Rezende said. By the mid-1980s ethanol had replaced over 30% of gasoline there. Yet, Brazil does not rely only on biofuels. All possible energy sources are needed, Rezende said, and their aim is to achieve the lowest possible cost to allow economic growth at reasonably high rates for the majority of the population. Brazil has been developing offshore petroleum along with environmental remediation, stimulating the private sector to deploy wind farms, and pursuing a nuclear energy program. Rezende said that with only 30% of its territory prospected, Brazil has the sixth largest world reserve of uranium mineral. Brazil has self-sufficiency in the exploration, mining, processing, and production of uranium oxide (yellowcake); the production of powder and tablets; and the fabrication of fuel elements; and expects to become self-sufficient in uranium enrichment by 2015, he said.

In the area of biofuels, after the expansion of ethanol from sugarcane into the 1980s, the amount of ethanol used in the 1990s declined when subsidies were lifted, Rezende said. Then in 2003 flexible-fuel vehicles were introduced, making biofuels competitive again. Now over 90% of cars manufactured in Brazil are flex-fuel and more ethanol is used for fuel than gasoline. Rezende also said that while Brazil has plenty of sugarcane to produce ethanol using conventional methods, they also have a major effort in producing cellulosic ethanol, estimating that conversion efficiency can be increased by about 30% by using the stalks and leaves of the plants and also improving fermentation technology.

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Elizabeth L. Fleischer, Principal Development Editor
Materials Research Society (MRS)

EQ Energy Sector Analysis: Variable States

Corinna Wu
Feature Editor: Paulina Jaramillo

(Article in Energy Quarterly (EQ) in the March 2011 issue of MRS Bulletin)

On August 14, 2003, a downed high-voltage power line in Ohio triggered a massive blackout across eight states in the Northeast and throughout Southeastern Canada. A total of 50 million people lost power for up to two days. The episode cost an estimated $6 billion and is considered to be the worst electrical system failure in the history of the United States.

The cascade of failures—due to both human error and equipment malfunction—made clear the problems of the United States’ aging and balkanized electrical transmission grid. The blackout spurred the U.S. Congress to pass the Energy Policy Act of 2005, which enforces mandatory reliability standards. Investment in the transmission grid had fallen during the 1980s and 1990s, but after the blackout, funding picked up again.

Against this backdrop, power companies and regulating authorities now have another challenge to face: how to integrate variable and intermittent renewable resources such as solar and wind into the mix. Currently, electricity from non-hydro renewable resources accounts for 3.8% of the total electricity produced in the United States, according to the U.S. Energy Information Administration. In 2009, half of non-hydro renewable electricity came from wind and less than one percent from solar.

Although wind and solar are attractive because they do not produce greenhouse gases, they also pose difficulties because of their inherent variability. If wind and solar must supply a third of the energy generated, the job of meeting changing demand for electricity throughout the day becomes much more difficult. Power plant operators must meet the net load—the difference between user demand and this highly variable renewable output—by scheduling power generation from conventional sources.

An Energy Sector Analysis article published in the Energy Quarterly section in the March 2011 issue of  MRS Bulletin discusses various options to manage net load variability in the electric grid, with a focus on energy storage technologies. For materials scientists, a lot of potential research for grid-level energy storage lies in developing advanced battery technologies. Superconducting magnetic energy storage (SMES) systems are another option and have been used since the 1970s, mostly to release short bursts of energy to smooth out fluctuations in the power supply.

_________________________________
Gopal R. Rao
Editor, MRS Bulletin
Materials Research Society (MRS)

 

EQ Editorial: Materials for energy: Energy, economy, and the environment

Russell R. Chianelli

(Editorial in Energy Quarterly (EQ) in the March 2011 issue of MRS Bulletin)

Last year we welcomed interested scientists, engineers, students, and the general public to the Materials Research Society’s (MRS) “Materials for Energy” blog. As the world advances into the 21st century, issues of energy, the economy, and the environment move to the center of our concern for the future. Materials science plays a key role in addressing these issues and providing both current and potential solutions. These are the issues that are addressed in our blog.

We all recognize the importance of energy in the coming years for global economic growth and security. We also recognize that energy production in any form has environmental consequences that must be considered. Materials research is key to the development and maintenance of reliable and safe energy sources, which are affordable and environmentally acceptable. For example, electric vehicles are considered by many as the future “environmentally friendly” mode of personal transportation in the developed and developing countries. However, the electric motors used require rare earth metals such as neodymium, whose mining presents environmental issues. Additionally, the ability to store energy with the batteries currently available is still limited (~100 miles range), and a sobering fact is that per liter, diesel or jet fuel has the highest energy content per unit volume or weight of any practical energy storage medium (~350 miles range or better depending on car model), except for nuclear energy fuel pellets. And then there is the question about where the electricity with which we charge these cars will come from. If it is from a coal-fired power station, then what about the CO₂ produced? Materials research should be able to provide answers.

It is the purpose of the “Materials for Energy” blog to discuss the scientific issues surrounding all areas of materials for energy: basic research, scale-up and commercialization, deployment, environmental impact and send your ideas, including raw materials acquisition, as well as recycling and disposal technologies. To effectively discuss these issues, we have invited a series of experts as co-hosts to assist in guiding the discussions and to present current articles and resources for discussion.

We invite all to participate. Please join the fun and send your ideas!