Editorial pubs.acs.org/IECR
Introduction to the Special Section on Alternative Energy Systems: Hydrogen, Solar, and Biofuels his issue of Industrial & Engineering Chemistry Research includes a special section on the alternative energy systems of hydrogen, solar, and biofuels. It is the result of recent work of the American Chemical Society’s Committee on Science (ACS ComSci). The committee has focused recent efforts on a new initiative entitled Alternative Energy Systems (AES) to inform scientists on alternative energy research and technologies. A variety of informational resources have been developed in this initiative by the Science and Technology subcommittee of ComSci, including educational events, resource-filled web pages, and special symposia held at various ACS national meetings. The subcommittee chose to focus on four alternative energy areas: nuclear, hydrogen, solar, and biofuels. This is not meant to be an all-inclusive list, but it does cover areas that involve a great deal of chemistry-related research. This special section is the product of the symposia on Hydrogen, Solar, and Biofuels Energy held at the Fall 2010, Spring 2011, and Spring 2012 ACS national meetings, respectively. The symposia were entitled (1) “Hydrogen as a Resource”, organized by Katherine Glasgow, Nomacorc LLC, and Mark Cesa, INEOS Nitriles; (2) “Solar Energy as an Alternative Energy Source”, organized by Michael Berman, Air Force Office of Scientific Research and Nate Lewis, Caltech; and (3) “Towards Sustainable Biofuels”, organized by Hessy Taft, St. John’s University. These well-attended sessions pulled technical experts in the fields, plus participants from the U.S. Department of Energy and from Europe. This special section follows one published earlier in 2012 on nuclear energy.1 Hydrogen energy is focused on the technical improvements that are needed in order to make hydrogen generation and storage a cost-effective reality. A natural partner to renewable energy sources such as solar and wind energy, hydrogen can harness and store power from these sources while managing their natural intermittency. The use of hydrogen is multifaceted, including use in fuel cells (as in vehicle fuel) and in portable solar-powered mini-generators that could be used in developing countries. To make hydrogen energy a reality, improvements must be made to the catalysts that generate hydrogen, to the methods for storage, and to the efficiency of generating electrical energy from hydrogen in order to achieve a cost-effective energy alternative. Solar energy is focused on utilizing some of the 120 000 TW of the sun’s energy that bathes the Earth each year to meet our energy needs in a sustainable way without producing greenhouse gases. Since the solar flux at any location on Earth is diffuse and intermittent, an efficient means of storing solar energy is needed if the sun’s energy is going to satisfy all of our energy needs. Solar energy research is focused on both solar photovoltaics, which directly produce electricity, and solar fuels or artificial photosynthesis, which stores the sun’s energy in chemical bonds for later use on Earth (an inherently chemical problem!). Photovoltaic systems are striving to lower costs to become competitive with other energy technologies.
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© 2012 American Chemical Society
Solar fuels are not yet produced in a cost-effective way by current technology, but, with additional research, they will be an important part of the long-term approach to producing sustainable fuels to satisfy our energy needs in the future. Biofuels are focused on the development of transportation energy that provides a viable alternative to our current unsustainable trajectory for fossil fuels. Exponential population growth increases our dependence on fossil fuels, which exacerbates greenhouse gas emissions, making investment in biofuel technologies a much needed priority. In 2010, worldwide biofuel production reached 105 billion liters, an increase of 17% over 2009. Biofuels represented 2.7% of the fuel consumed for road transport vehicles in 2010, with Brazil and the United States producing 90% of the world’s ethanol and the European Union contributing 53% of all biodiesel. However, ethanol from corn is not a viable energy source, because it impacts on food availability, freshwater consumption, and yields low net energy gain. Thus, there is a need for second-generation biofuels produced from sustainable feedstock. These include, among others, conversion of cellulosic biomass from nonfood crops or inedible waste products by catalytic pyrolysis, acid/alkali digestion, and/or enzymatic fermentation to yield alcohols, and algae cultures that are able to grow in wastewater or even saline, producing high yields of triglycerides for biodiesel production. Significant strides have been attained, but challenges remain, including attaining high net energy yields at competitive costs and enhancing performance of algal mass culture technology. This special section strives to cover much of these important topics as they relate to chemistry and the Alternative Energy Systems focus of the ACS ComSci, and the topics covered in the related special symposium. A diverse collection of papers has been accepted that represent various chemistry-related research needs present today. In the area of Hydrogen Energy, Wang and co-workers present a combination of first principles modeling and material science of the effects of cation doping on LaFeO3 perovskites for hydrogen storage in Ni/MH batteries.2 In the area of Solar Energy, several material science papers are included that cover topics such as metal oxide catalysts for solar fuel production from H2O and CO2 (Smestad et al.3), nanostructured TiO2 for enhanced photocatalytic charge separations (Li et al.4), and polyoxometallate catalysts for water oxidation in photochemical systems (Lian et al.5). Examples in the area of Biofuels include work by Xiao et al.,6 who present a catalytic study of hydrotalcites for biodiesel production, Gogate et al.,7 who present a biodiesel synthesis production optimization using nonedible oils as a feedstock, and Sharma, et al.,8 who interestingly use both waste materials Special Issue: Alternative Energy Systems Received: June 13, 2012 Accepted: June 26, 2012 Published: September 19, 2012 11819
dx.doi.org/10.1021/ie301555t | Ind. Eng. Chem. Res. 2012, 51, 11819−11820
Industrial & Engineering Chemistry Research
Editorial
(mollusk shell exoskeleton) and waste feedstock (used fying oil) for the "green" method of synthesizing biofulels. These topics are just a small sample of the rich and diverse research and engineering needs in these alternative energy systems. Presentations from the four ComSci symposia and further details on the hydrogen, solar, biofuels, and nuclear alternative energy systems can be found at the ACS web page (www.acs.org).
Tina M. Nenoff
Sandia National Laboratories, PO Box 5800, MS 1415, Albuquerque, New Mexico 87185, United States (E-mail:
[email protected])
Michael R. Berman
Air Force Office of Scientific Research, 875 N. Randolph St., Arlington, Virginia 22203, United States
Katherine C. Glasgow
Nomacorc LLC, 400 Vintage Park Drive, Zebulon, North Carolina 27597, United States
Mark C. Cesa
INEOS Nitriles, LLC 150 W. Warrenville Road, Naperville, Illinois 60563, United States
Hessy Taft
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St. John’s University, 8000 Utopia Parkway, Jamaica, New York 11439, United States
ACKNOWLEDGMENTS Sandia National Laboratories is a multiprogram lab managed and operated by Sandia Corp., a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. DOE’s NNSA, under Contract No. DE-AC04-94AL85000. The authors wish to thank Dr. Makund Chorgade for his help in this manuscript.
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REFERENCES
(1) Nenoff, T. M. Alternative Energy Systems: Nuclear Energy, Introduction to the Special Section on Nuclear Energy. Ind. Eng. Chem. Res. 2012, 51 (2), 605−606 and articles therein. (2) Wang, Q.; Chen, Z.; Chen, Y.; Cheng, N.; Hui, Q. Hydrogen Storage in Perovskite-Type Oxides ABO3 for Ni/MH Battery Applications: A Density Functional Investigation. Ind. Eng. Chem. Res. 2012, 51, DOI: ie202284z. (3) Smestad, G. P.; Steinfeld, A. Review: Photochemical and Thermochemical Production of Solar Fuels from H2O and CO2 Using Metal Oxide Catalysts. Ind. Eng. Chem. Res. 2012, 51, DOI: ie3007962. (4) He, H.; Liu, C.; Dubois, K. D.; Jin, T.; Louis, M. E.; Li, G. Enhanced Charge Separation in Nanostructured TiO2 Materials for Photocatalytic and Photovoltaic Applications. Ind. Eng. Chem. Res. 2012, 51, DOI: ie300510n. (5) Huang, Z.; Geletil, Y. V.; Musaev, D. G.; Hill, C. L.; Lian, T. Spectroscopic Studies of Light-driven Water Oxidation Catalyzed by Polyoxometallates. Ind. Eng. Chem. Res. 2012, 51, DOI: ie202950h. (6) Xiao, Y.; Gao, L.; Xiao, G.; Fu, B.; Niu, L. Experimental and Modeling Study of Continuous Catalytic Transesterification to Biodiesel in a Bench-Scale Fixed-Bed Reactor. Ind. Eng. Chem. Res. 2012, 51, DOI: ie202312z. (7) Gole, V. L.; Gogate, P. R. Intensification of Synthesis of Biodiesel from Nonedible Oils Using Sonochemical Reactors. Ind. Eng. Chem. Res. 2012, 51, DOI: ie2029442. (8) Agrawal, S.; Singh, B.; Sharma, Y. C. Exoskeleton of a Mollusk (Pila globosa) as a Heterogeneous Catalyst for Synthesis of Biodiesel Using Used Frying Oil. Ind. Eng. Chem. Res. 2012, 51, DOI: ie202404r.
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