Ahmed Tafesh and Sobhi Basheer

Abstract Biodiesel has emerged as one of the most growing biofuels to replace diesel fuel. Its preference as one of the most popular alternative fuels was based on its characteristics as it is environment friendly, sustainable, biodegradable, and non-toxic. Biodiesel is mandated by many governments worldwide for incorporation into their diesel supply base. Biodiesel is easily produced through transesteriflcation reactions of vegetable oils (triglycerides). However, current commercial usage of refined vegetable oils for biodiesel production is impractical and uneconomical due to high feedstock cost and priority as food resources.

Low-grade oils, typically waste cooking oils, brown greases, crude corn oils, etc., can be better alternatives; however, the high free fatty acids (FFAs) content in such oils has become the main constrain for those potential feedstocks, and therefore pre­treatment methods become necessary to prepare such feedstocks to make biodiesel. The chapter highlights the pretreatment methods to utilize and convert the FFAs from various feedstocks to biodiesel and presents the advantages and limitations of using enzymes and conventional catalysts, distillation, blending, and glycerolysis meth­ods to lower FFAs in the feedstocks. An overview on the current status of biodiesel production, the feedstocks and the FFAs factors are also discussed. With the proper pretreatment methods, the high-FFAs feedstocks can indeed become the next ideal feedstocks for the production of biodiesel.

Keywords Enzymes ■ Vegetable oil ■ Biodiesel ■ Pretreatment ■ FFA ■ Triglyceride

18.1 Introduction

Biodiesel production is a globally advancing field, with biodiesel fuel increasingly being used in compression diesel engines to replace diesel fuel which stands at a market value of $200 billion US dollars per year worldwide. The biodiesel, which

A. Tafesh (H) ■ S. Basheer

TransBiodiesel Ltd, Nazareth Street 79, P. O. Box 437, Shefar-Am 20200, Israel e-mail: atafesh@transbiodiesel. com

Z. Fang (ed.), Pretreatment Techniques for Biofuels and Biorefineries,

Green Energy and Technology,

DOI 10.1007/978-3-642-32735-3_18, © Springer-Verlag Berlin Heidelberg 2013 is becoming one of the most popular alternative and environment-friendly fuels, is mandated by many governments for incorporation into their diesel-supply base. Society’s concerns with the environment have made governments, industries, and businesses start to assess how their activities affect the environment. Such biodiesel is a more natural, more sustainable biofuel known to reduce carbon dioxide emission by 78 % when compared to regular diesel and its energy content is 88-95 % that of diesel [1].

Production scale of biodiesel in the European Union in 2006 was estimated to be approximately 4.8 million tons, which constitutes about 77 % of the produced biodiesel in the world followed by the US with 13 %, and the rest of the world to be 10 %. Market growth rate data in Europe was over 50 % in 2006 after growth of 37 % in 2005. It is estimated that biodiesel will reach 3.3 billion gallons by 2022, an increase of 2.5 billion gallons from 2011, where nearly 80% of the increase comes from three feedstocks: soybean oil (31 %), corn oil (22 %), and palm fatty acid distillate (26 %) [2]. The volume of all biodiesel is growing at a 10 % rate per year and stood at $22 billion market value in 2007, and is estimated to reach $88 billion by 2020 [3, 4].