ABSTRACT
Biofuels are dened in the beginning of this chapter, followed by the information about lipid-based biomasses and rst-generation feedstocks for biofuel production. Fatty acids commonly found in lipid-based biomasses, molecular weight of general plant oils, and acidity of lipid-based biomasses are briey described. Since the introduction of rst-generation biomasses, mostly plant oils have been utilized as transportation fuels and their costs keep uctuating due to food or fuel dilemma. Hence, many lipid-based biomasses were introduced as second-generation feedstock worldwide. e second-generation feedstock should not be aligned with the food industry. Wastes and industrial by-products are inexpensive feedstock, but their productivity and quality are not consistent. Sources of waste cooking oil (WCO), animal
Contents
fat, oilseed, and other industrial and municipal wastes are mentioned. Moreover, wastes’ and by-products’ costs are low; however, pretreatment, collection, and handling might increase their costs. Among these wastes and by-products, WCO from restaurants acquired earliest attention. us, advantages and disadvantages of biofuel production using WCO as feedstock are summarized. In contrast, lipid-based biomasses derived from nonedible oils, insects, and oleaginous microorganisms were demonstrated to resolve problems on unstable productivity and feedstock quality. However, their costs when produced in a large scale remain questionable because they are in initial developmental stages in a small scale. Moreover, agricultural science research is necessary for increasing nonedible oil plants’ productivity. Studies on insects having the abilities to convert several wastes to lipid-based biomasses have been recently reported. Although oleaginous microorganisms are promising due to high productivity and simplicity of genetic engineering, microalgal cultivation and harvesting systems have been debated. Carbon sources are used to cultivate oleaginous yeasts and fungi; however, resultant lipid-based biomasses are somewhat involved in food or fuel dilemma. In the conclusion section, the topics of practical importance for each lipid-based biomass are summarized.
