The continuous use of the world’s crude oil reserve and a corresponding escalation in its price together with the limited coal reserves have stimu­lated the hunt for renewable sources of energy. The main sources of renew­able energy are biomass, biogas, methanol, ethanol, and biodiesel; solar active (photovoltaic), solar passive (preheating of water), wind, mini hydel, and mini tidal are important sources which produce less pollution and pro­tect the environment.

Much attention has been given to biomass and its modifications as a substitute for fossil fuels in the Western world. Among the modifications are biogas, alcohol, biodiesel, and manure. Presently, electrical power is attractive in many respects and the search is on for renewable and nonfinite resources to produce and supplement electrical energy.

The first chapter discusses energy and its biological sources. If bio­fuel is one of the expected solutions, we must know where is the begin­ning of the crisis and its solution. This chapter reviews the background story along with an optimistic outlook for a safe energy resource on our green earth. The second chapter discusses energy from photosynthetic plants and their inherent recycling nature, as well as the environmen­tal benefits involved. These sources of energy are the solution for energy management. The third chapter discusses bioethanol, which is now one of the main actors in the fuel market. Its market grew from less than a billion liters in 1975 to more than 39 billion liters in 2006, and is expected to reach 100 billion liters in 2015. The chapter discusses the variety of raw materials, such as sugars, starch, and lignocellulosic substances, that produces bioethanol and also covers some of the market issues. To extend the use of biodiesel, the main concern is the economic viability of producing biodiesel. Edible oils are too valuable for human feeding to run automobiles. So, the emphasis must be on low-cost oils, i. e., nonedible oils, animal fats, and used frying oils. There are many nonedible feed­stock crops growing in underdeveloped and developing countries; biodiesel programs here would give multiple social and economic benefits.

The fourth chapter discusses different plant sources used for production of biodiesel, properties of biodiesel, and processing of vegetable oils as biodiesel, and compares engine performance with different biodiesels.

Biodiesel is the methyl or other alkyl esters of vegetable oils, animal fats, or used cooking oils. Biodiesel also contains minor components such as free fatty acids and acylglycerols. Important fuel properties of biodiesel that are determined by the nature of its major and minor com­ponents include ignition quality and exhaust emissions, cold flow, oxida­tive stability, viscosity, and lubricity. The fifth chapter discusses how the major and minor components of biodiesel influence the mentioned properties.

Different techniques of biodiesel preparation and resulting engine performance are discussed in detail in Chap. 6. The seventh chapter dis­cusses ethanol and methanol as fuel in the internal combustion engine and emphasizes their advantages (such as a higher octane number) over gasoline. Cracking of lipids turns polar esters into nonpolar hydro­carbons. This is accompanied by a fundamental change in physical and chemical properties. Products formed give rise to new applications in the fuel sector and for chemical commodities, e. g., detergents. The eighth chapter explores routes to provide these alternative hydrocarbons from lipids. It concentrates on substrates (seeds, vegetable oils, animal fat) and conversion pathways as well as analytical tools.

The ninth chapter discusses the fuel cell, an electrochemical device and nonpolluting alternative energy source that converts the chemical energy of a fuel (hydrogen, natural gas, methanol, gasoline, etc.) and an oxidant (air or oxygen) into electricity with water and heat as by-products.

The book is organized in a manner to cater to the needs of students, researchers, managerial organizations, and readers at large. We welcome the reader’s opinions, suggestions, and added information, which will improve future editions and help readers in the future. Readers’ bene­fits will be the best reward for the authors.

Ahindra Nag, Ph. D.