Alternative fuels for transportation vehicles: A technical review B.L. Salvi a,b,n , K.A. Subramanian a , N.L. Panwar b a Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi-110016, India b College of Technology and Engineering, Maharana Pratap University of Agriculture and Technology, Udaipur 313001, Rajasthan, India article info Article history: Received 28 April 2012 Received in revised form 12 April 2013 Accepted 20 April 2013 Keywords: Alternative fuels F-T fuels Biodiesels Biofuels DME Hydrogen Bio-oil abstract Recent petroleum crises, rapidly increasing its prices and uncertainties concerning petroleum availability threaten the sustainable development of the world economy. Both the environmental concern and availability of fuels greatly affect fuel trends for transportation vehicles. The present work aims to compile a holistic scenario of different resources, production technologies, and properties of alternative fuels for transportation vehicles. Detailed descriptions of production technologies and fuel properties would help to refine and further enhance the technologies. While many production technologies have been developed, still more attention is needed to develop an effective, economical and efficient conversion process. As a broad overview of the subject, this article includes information based on the research carried out globally by scientists according to their local socio-cultural and economic situations. The integration of different technologies and hybridization is the demand of the present time for sustainable power generation and economic development. & 2013 Elsevier Ltd. All rights reserved. Contents 1. Introduction ........................................................................................................ 405 1.1. Internal combustion engines and emissions ........................................................................ 405 2. Alternative fuels..................................................................................................... 405 2.1. Methanol .................................................................................................... 406 2.2. Ethanol ...................................................................................................... 406 2.3. Dimethyl ether ................................................................................................ 407 2.4. Butanol ...................................................................................................... 407 2.5. Biodiesel ..................................................................................................... 407 2.6. Biodiesel production ........................................................................................... 407 2.7. Ester preparation .............................................................................................. 408 2.7.1. Methyl esters .......................................................................................... 408 2.7.2. Ethyl esters............................................................................................ 408 2.8. Monitoring of transesterification reactions.......................................................................... 408 2.8.1. Gas chromatographic method (GCM) ....................................................................... 408 2.8.2. High performance liquid chromatography method (HPLC) ...................................................... 408 2.8.3. Gel permeation chromatography method.................................................................... 408 2.8.4. NIR spectroscopy ....................................................................................... 409 2.9. Biodiesel from microalgae ....................................................................................... 409 2.10. Bio-oil ....................................................................................................... 410 2.11. Pyrolysis ..................................................................................................... 410 2.12. F-T Fuels ..................................................................................................... 410 2.13. Hydrogen fuel ................................................................................................ 411 2.13.1. Steam reforming ....................................................................................... 411 Contents lists available at SciVerse ScienceDirect journal homepage: www.elsevier.com/locate/rser Renewable and Sustainable Energy Reviews 1364-0321/$ - see front matter & 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.rser.2013.04.017 n Corresponding author at: Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016, India. Tel.: +91 294 2470510; fax: +91 294 2471056. E-mail address: salvibl@yahoo.in (B.L. Salvi). Renewable and Sustainable Energy Reviews 25 (2013) 404–419