In this paper, Ping Chen et al. have shown the release of 17.8 wt% of hydrogen in 135–250 °C in a closed vessel, from the Co-catalyzed Li(NH3)4/3BH4.
The presence of the nanosized Co catalyst is shown to effectively promote the release of hydrogen.
Releasing 17.8 wt% H2 from lithium borohydride ammoniate
Xueli Zheng, Guotao Wu, Wen Li, Zhitao Xiong, Teng He, Jianping Guo, Hua Chen and Ping Chen
Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01480C
The overall cell is able to achieve a high conversion efficiency of 13.8%, and the authors say that it has not yet been fully optimised.
Read this exciting research at:
A novel high-performance photovoltaic–thermoelectric hybrid device
Ning Wang, Li Han, Hongcai He, Nam-Hee Park and Kunihito Koumoto
Energy Environ. Sci., 2011
DOI: 10.1039/C1EE01646F
Sodium-ion batteries could represent a cheaper alternative to lithium-ion batteries if their properties were suitable. Ceder et al. have investigated the difference between Na-ion and Li-ion based intercalation chemistries in terms of three key battery properties—voltage, phase stability and diffusion barriers. Their findings indicate that Na-ion systems can be competitive with Li-ion systems.
Read the Energy and Environmental Science article:
Voltage, stability and diffusion barrier differences between sodium-ion and lithium-ion intercalation materials
Shyue Ping Ong, Vincent L. Chevrier, Geoffroy Hautier, Anubhav Jain, Charles Moore, Sangtae Kim, Xiaohua Ma and Gerbrand Ceder
Energy Environ. Sci., 2011, Advance Article
DOI: 10.1039/C1EE01782A
Recently scientists have succeeded in making stretchable materials for capturing the huge amount of energy which is available from the sun. Such materials would have the advantage of being more hard wearing portable as well as being suitable for applications in which aerodynamics were important e.g. vehicles.
Read this Perspective feature review of recent developments in the field:
Stretchable, elastic materials and devices for solar energy conversion
Darren J. Lipomi and Zhenan Bao
Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01881G
http://xlink.rsc.org/?doi=10.1039/C1EE01881G
An exciting Energy Environmental Science Anaylsis article about algae-derived biodiesel which ‘could be the answer to the fossil fuel crisis’ has been featured in The Times newspaper today.
Using a life-cycle analysis, King and colleagues evaluate whether algal biodiesel production can be a viable fuel source in the near future.
Life cycle energy and greenhouse gas analysis for algae-derived biodiesel
Tara Shirvani, Xiaoyu Yan, Oliver R. Inderwildi, Peter P. Edwards and David A. King
Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01791H
Or read more about it on the Chemistry World Blog
Chemistry World Blog
Algae-derived biodiesel flying high
Posted by Elinor on Thu 11 Aug 2011
Two weeks ago, we read about agave as an alternative feedstock to corn or sugarcane in the production of bioethanol fuel in Mike’s story Tequila for your fuel tank. In it, Mike describes research by David King from the Low Carbon Mobility Centre at the University of Oxford and his team.
At the same time, King’s team has been busy putting research together to show that algae-derived biodiesel ‘could be the answer to the fossil fuel crisis’. Indeed, airlines have already been testing a range of biofuels in their planes, including algal-derived biofuels.
…Read the rest on the Chemistry World Blog
Journal Article:
Life cycle energy and greenhouse gas analysis for algae-derived biodiesel
Tara Shirvani, Xiaoyu Yan, Oliver R. Inderwildi, Peter P. Edwards and David A. King
Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01791H
US energy consumption study reveals that using renewable energy instead of fossil fuels to heat homes is viable.
An analysis on how the US uses thermal energy has revealed a perfect opportunity for renewable energy from geothermal and solar resources, say US scientists.
The study shows how renewable energy could provide a large fraction of the energy used for heating water and space at home that is currently supplied by high grade fossil fuels.
Read the Energy & Environmental Science article:
The thermal spectrum of low-temperature energy use in the United States
D B Fox, D Sutter and J W Tester
Energy Environ. Sci., 2011, DOI: 10.1039/c1ee01722e
In a real life display of the use of photovoltaics, a solar powered torch the size of a credit card has been developed by a team of scientists from Denmark, the Netherlands and the US.
Organic and polymer solar cells (OPV) have reached a technological level where they can be produced commercially using roll-to-roll methods that are cost effective. Frederik Krebs, from the Technical University of Denmark, Roskilde, and colleagues have made a new device that combines 16 solar cells connected in series that are used to charge a battery that powers a white light emitting diode.
Production required 35 steps, and combined the polymer solar cell with printed circuitry and flexible lithium polymer batteries. Tests were run on the lamp to determine its efficiency and study the effects of humidity and design on performance. This new pocket-sized flashlight was able to get a yield of 89 per cent and operated for hours at a time. Krebs explains: ‘Even if the flashlight is far from solving the world’s energy problem, it clearly demonstrates that polymer solar cells are capable of fairing outside the laboratory and can be made available to the public in an operational device.’
Until now, very few examples have been manufactured beyond a few units. This is the first time that a complex device has been commercialised at this scale – 10,000 units have already been made. Examples were even handed out at the most recent Large area Organic and Printed Electronics Conference (LOPE-C).
‘While the OPV powered lamp demonstrated in this work shows how this technology can be used in regions of the world where direct access to electricity by conventional sources is difficult, the methods developed will have a broader impact in the field of printable organic electronics in general,’ comments John Reynolds, an expert in conducting polymers from the University of Florida, US.
Krebs and his team are now tackling the next challenge, which is to make polymer solar cells with longer operational lifespans capable of working for years at a time in outdoor conditions.
Rebecca Brodie
The OE-A OPV demonstrator anno domini 2011
Frederik C. Krebs, Jan Fyenbo, David M. Tanenbaum, Suren A. Gevorgyan, Ronn Andriessen, Bart van Remoortere, Yulia Galagan and Mikkel Jørgensen
Energy Environ. Sci., 2011
DOI: 10.1039/c1ee01891d
Liquid fuel from sunlight, CO2, and water addresses a critical energy security issue with favorable energy efficiency, environmental, and economic metrics.
This investigation establishes a methodology for identifying opportunities, comparison, and assessment of impact on the efficiency, lifecycle impact, and economics for advanced system designs.
Analysis:
Methanol production from CO2 using solar-thermal energy: process development and techno-economic analysis
Jiyong Kim, Carlos A. Henao, Terry A. Johnson, Daniel E. Dedrick, James E. Miller, Ellen B. Stechel and Christos T. Maravelias
Energy Environ. Sci., 2011, DOI: 10.1039/C1EE01311D
Lithium–air batteries’ discharge rates can be increased substantially by using perfluorinated compounds as oxygen carriers, say scientists from the US. They were inspired to make oxygen carriers similar to artificial blood substitutes.
One of the challenges of making Li–air batteries viable is down to increasing oxygen solubility and diffusion coefficient, which should increase the discharge rate.
The perfluorinated compounds increase the oxygen’s solubility in non-aqueous electrolytes, which leads to an increase in the diffusion-limited current of oxygen reduction on the gas diffusion electrode in the battery.
A 5 mA.cm-2 discharge rate was achieved, an improvement over previous devices, which were limited to 0.01–5 mA.cm-2.
Reference:
High Rate Oxygen Reduction in Non-aqueous Electrolyte with the Addition of Perfluorinated Additives
Y Wang, D Zheng, X-Q Yang and D Qu,
Energy Environ. Sci., 2011, DOI: 10.1039/c1ee01556g
