Energy Fuels 2010, 24, 6221–6222 Published on Web 11/11/2010
: DOI:10.1021/ef101391h
Introduction to the Virtual Issue of Energy & Fuels on Biofuels Received October 11, 2010 problems of agricultural lands in Western Australia. Zamboni et al.4 (Energy Fuels, DOI: 10.1021/ef900456w) provide a formulation for the rational design of an enterprise for Italy based on ethanolic fuels [solely for reasons of space, the companion paper5 (Energy Fuels, DOI: 10.1021/ef9004779) following ref 4 was not included in this collection]. Evidently, the optimization of the farming, collection, and processing of biomass will depend upon the targeted type of fuel, which, in turn, will depend upon the mix of end uses, with the latter being a function of history, geography, and past developments in prime movers. Lifecycle. While there is no single best renewable fuel, there are certainly sub-optimal fuels and processes. Many proposed approaches and technologies turn out to exhibit significant deficiencies unless the system is carefully optimized or the envelope of the production system is extended to include co-products. The paper on algaculture by Stephenson et al.6 (Energy Fuels, DOI: 10.1021/ef1003123) illustrates the need for careful design, even when the production system uses vertical reactors that offer high areal productivity. The paper on oil seed crops in Ireland by Thamsiriroj and Murphy7 (Energy Fuels, DOI: 10.1021/ef901432g) illustrates the need to include other energy co-products, such as residual plant material and seed cake, as replacements for peat to achieve targeted reductions in greenhouse gas emissions. Conversion. Much of the energy content of biomass arrives in the form of polymers that must be converted into smaller molecules that have acceptable volatility and viscosity, to ensure compatibility with the operation of internal combustion engines. The review by Zakrzwezka et al.8 (Energy Fuels, DOI: 10.1021/ ef901215m) surveys the use of ionic liquids to solubilize polymeric carbohydrates, such as cellulose and starch, to make them accessible to liquid-phase processing. The hydrothermal process investigated by Brown et al.9 (Energy Fuels, DOI: 10.1021/ ef100203u) offers a way to deliver much of the heating value of the initially wet biomass as fuel-range molecules, albeit with the production of a contaminated water stream that will likely incur some clean-up costs. End Use. The last two papers in this collection deal with the practicality of using biomass-derived fuels in current day engines. McCormick and Westbrook10 (Energy Fuels, DOI: 10.1021/ef900878u) discuss the critical issue of storage stability of fuels based on biodiesel, recognizing that consumers will expect that renewability does not compromise utility. Um and Park11 (Energy Fuels, DOI: 10.1021/ef901092h) explore the use of biodiesel in engines based on homogeneous charge compression ignition (HCCI). HCCI is an engine cycle that, over narrow ranges of operation, can reduce the engine-out concentrations of regulated pollutants, especially soot and NOx,
American Chemical Society (ACS) Publications present a virtual issue on biofuels, an online compilation between Energy & Fuels, Environmental Science & Technology, and Journal of Agricultural and Food Chemistry found at http://pubs.acs.org/ page/vi/2010/biofuels.html. The research, featuring peerreviewed articles published in 2009 and 2010, shows progress on using biomass for fuel production, a hotbed of research, with global implications on agricultural, energy, and environmental policy. Editors Jerald L. Schnoor (Environmental Science & Technology) and James N. Seiber (Journal of Agricultural and Food Chemistry) and Associate Editor Robert Weber (Energy & Fuels) comment on their selection of these papers in editorials appearing in their respective journals and on the virtual issue on biofuels website. As interest in biofeedstocks for energy and material grows, these three journals encourage continued submission of high-quality and impactful manuscripts. Note that papers in the virtual issue on biofuels are indicated in the below text as both citations and hyperlinks by digital object identifier (DOI; 10.1021/zzXXXXXXX for all ACS journals) in the HTML version. Readers can use the DOI to locate any ACS paper online in two ways: (1) The search box at the top right of the ACS journal (and Symposium Series) webpages permits entry of a DOI (e.g., http://pubs.acs.org/). (2) Direct your browser to http://dx.doi.org/ “DOI”, where “DOI” should be replaced by that in question (zzXXXXXXX) to electronically locate the paper. Energy & Fuels has sought to publish original research on renewable fuels since the inception of the journal1 (Energy Fuels, DOI: 10.1021/ef00001a600) more than 20 years ago. I am pleased to note that a paper on the detailed chemistry of biomass pyrolysis2 (Energy Fuels, DOI: 10.1021/ef00002a001), which appeared in the first volume, is still being cited (7 times thus far in 2010). This virtual issue on biofuels appears in concert between Energy & Fuels and our sibling journals, Environmental Science & Technology and Journal of Agricultural and Food Chemistry, to call attention to recent work on the complex of timely and critical topics that span our three disciplines. The title of the virtual issue contains the term “biofuels”. I prefer, instead, to use the phrase “renewable fuels” to emphasize the operational lifecycle of the fuels rather than the provenance of the molecules comprising them. For this collection, I have selected eight, recent papers from Energy & Fuels that deal with the logistical analyses, lifecycle analyses, and the chain of technologies required to select, produce, transform, deploy, and use renewable fuels, so that society can exploit them sustainably and economically. Logistics. The first two papers consider the implications of the spatially distributed production of the biomass feedstock for renewable fuels. Yu et al.3 (Energy Fuels, DOI: 10.1021/ ef900103g) look at the logistics of farming and collecting mallee, a byproduct of managing serious, dryland salinity
(4) Zamboni, A.; Sha, N.; Bezzo, F. Energy Fuels 2009, 23, 5121. (5) Zamboni, A.; Sha, N.; Bezzo, F. Energy Fuels 2009, 23, 5134. (6) Stephenson, A. L.; Kazamia, E.; Dennis, J. S.; Howe, C. J.; Scott, S. A.; Smith, A. G. Energy Fuels 2010, 24, 4062. (7) Thamsiriroj, T.; Murphy, J. D. Energy Fuels 2010, 24, 1720. (8) Zakrzewksa, M. E.; Bogel-Łukask, E.; Bogel-Łukasik, R. Energy Fuels 2010, 24, 737. (9) Brown, T. M.; Duan, P.; Savage, P. E. Energy Fuels 2010, 24, 3639. (10) McCormick, R. L.; Westbrook, S. R. Energy Fuels 2010, 24, 690. (11) Um, S.; Park, S. W. Energy Fuels 2010, 24, 916.
(1) Larsen, J. Energy Fuels 1987, 1, 1. (2) Evans, R. J.; Milne, T. A. Energy Fuels 1987, 1, 123. (3) Yu, Y.; Bartle, J.; Li, C.-Z.; Wu, H. Energy Fuels 2009, 23, 3290. r 2010 American Chemical Society
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: DOI:10.1021/ef101391h 10.1021/es802162x) and Clarens et al.13 (Environ. Sci. Technol., DOI: 10.1021/es902838n). Namely, how will energy plantations, which will cover many thousands of hectares, affect local weather patterns and hydrology? How can large populations of organisms that reproduce rapidly enough to intensify the production of fuels be contained and maintained? We appear to have the tools and computational resources to address the first question.14 Our ability to answer the latter questions requires borrowing from ecology, evolution, and population biology. These larger scale questions will be addressed in a symposium, supported by the ACS, that is currently being planned for early 2011.
thereby decreasing the burden on downstream emission controls. HCCI offers a path toward the confluence of high fuel efficiency, low emissions, and less costly powertrains but requires, as Um and Park have shown, careful attention to the nature of the fuel. In the 2009 and 2010 period covered by this virtual issue, there were many excellent contributions to Energy & Fuels dealing with aspects of renewable fuels. Winnowing my selection to just these eight was difficult. However, despite the collective breadth of these papers and the population from which they came, I was hard-pressed to find contributions that dealt explicitly with the macroscopic ecological landscape and regulatory issues that will likely accompany the scaling up of the nascent renewable fuels industry. At larger scale, there appear issues beyond the water and CO2 balances that have been discussed elegantly in the lifecycle analyses mentioned above or in other papers in this virtual issue, for example, by Dominguez-Faus et al.12 (Environ. Sci. Technol., DOI:
Robert S. Weber Sunrise Ridge Algae, 211 Seaton Glen, Suite 209, Houston, Texas 77094, United States (13) Clarens, A. F.; Resurreccion, E. P.; White, M. A.; Colosi, L. M. Environ. Sci. Technol. 2010, 44, 1813. (14) Pielk, R. A. Rev. Geophys. 2001, 39, 151.
(12) Dominguez-Faus, R.; Powers, S. E.; Burken, J. G.; Alvarez, P. J. Environ. Sci. Technol. 2009, 43, 3005.
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