**Biocatalytic Production of Biodiesel from Vegetable Oils**

Eda Ondul, Nadir Dizge, Bulent Keskinler and Nedim Albayrak

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/59949

### **1. Introduction**

[10] Oomah, B.D., Ladet, S., Godfrey, D.V., Liang, J. & Girard, B. (2000). Characteristics of

[11] Nehdi, I., Omri, S., Khalil, M.I. & Al-Resayes, S.I. (2010). Characteristics and Chemi‐ cal Composition of Date Palm (*Phoenix canariensis*) Seeds and Seed Oil. Industrial

[12] Yong, Y. & Salimon, J. (2006). Characteristics of *Elateriospermum tapos* Seed Oil as a

[13] Veeresh Babu, S.V., Veeresh, B., Patil, A. & Warke, B. (2009). Lauric Acid on Myristic Acid Prevent Testosterone Induced Prostatic Hyperplasia in Rats. Eur. J. Pharmacol.,

[14] Junninger, M, Faaij, A, Van den Broek, R., Koopmans, A, & Hulscher, W, Fuel Supply Strategies for Large-Scale Bio-Energy Projects in Developing Countries, Electricity

[15] Chhetri, AB.; Watts,KC.; and Islam, MR. (2008). Waste Cooking Oil as an Alternate Feedstock for Biodiesel Production. Energies, 1: 3-18; DOI: 10.3390/en1010003.

[16] Sharma, Y. C., Singh, B. & Upadhyay, S. N. (2008). Advancements in Development

[17] Sheehan, J., Dunahay, T., Benemann, J., Roessler. P. (1998). A Look back at the US De‐ partment of Energy's Aquatic species Program – Biodiesel from Algae. National Re‐ newable Energy Laboratory (NREL) Report: NREL/TP-580-24190. Golden, CO.

[18] Chisti Y. (2007). Biodiesel from Microalgae. Biotechnology Advances, 25: 294-306.

[19] Afify AMR, Shalaby EA, Shanab SMM. (2010). Enhancement of biodiesel production

[20] Hossain, A.B.M., Salleh, A. (2008). Biodiesel Fuel Production from Algae as Renewa‐

and Characterization of Biodiesel: a Review. Fuel, 87: 2355-2373.

from different species of algae. Grasas Y. Aceites, 61 (4): 416-422.

ble Energy. Am. J. Biochem. and Biotechn., 4(3): 250-254.

Generation from Agricultural and Forest Residues in Northeastern Thailand.

Raspberry (*Rubus idaeus* L.) Seed Oil. Food Chemistry, 69: 187-193.

New Source of Oil Seed. Ind. Crops Prod., 24: 146-151.

Crops and Products, 32: 360-365.

22: 193-199.

20 Biofuels - Status and Perspective

Alcoholysis of vegetable oils is an important reaction to produce fatty acid alkyl esters which are excellent substitutes for diesel fuel and valuable intermediates in oleochemistry [1, 2]. Fatty acid methyl esters, a mixture of mono-alkyl esters are also known as biodiesel, obtained from both vegetable oils such as sunflower oil, canola oil, soyabean oil, jatropha oil, palm oil, rapeseed oil, peanut oil, cotton seed oil and animal fats such as beef tallow, and lard. Biodiesel can also be produced from other sources such as waste cooking oil, algae, and greases [3]. Biodiesel production has attracted considerable attention in the past two decades because of biodegradable, renewable, non-toxic, and environmentally friendly and socially responsible fuel [4]. Biodiesel can be produced by several methods: direct use or blending, microemulsion, thermal cracking (pyrolysis), and transesterification including acid-catalyzed processes, basecatalyzed processes, lipase-catalyzed processes, non-ionic base-catalyzed processes, and heterogeneously catalyzed processes [5, 6]. Among these methods, alkali catalyzed process including an alkali catalyst (usally NaOH, KOH, or sodium methoxide) has been accepted industrially due to its high conversion of triglycerides to methyl esters in a short reaction time and high reaction rates. In spite of these advantages of chemical transesterification process, it also possesses some disadvantages such as the need to eliminate the catalyst and salt from the biodiesel phase, to remove saponification products, the difficulty of recycling glycerol, and their energy-intensive nature, leading to development of alternative processes [7-9]. Alcohol‐ ysis is also carried out under acidic conditions, but this process requires higher reaction temperatures. In order to overcome these drawbacks, recently, enzymatic transesterification has attracted much attention for biodiesel production since it produces high purity product and provides an easy separation from the by-product glycerol. The use of enzymes (lipases) as catalysts in biodiesel production overcomes the problems inherent to alkali catalysts. It is reported that the enzymatic reactions are insensitive to free fatty acid (FFA) and water content

© 2015 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

in the raw material [10]. So far, many attempts have been made to develop enzymatic process by using either extracellular or intracellular lipase as a biocatalyst [1, 11]. Lipases (EC 3.1.1.3), also defined as triacylglycerol acylhydrolases, catalyze the hydrolysis of ester bonds in long chain triacylglycerols (TAGs) to produce free fatty acids (FFAs) and glycerol. In general, the active site of lipases is formed by serine, aspartic (or glutamic) acid and histidine amino acid groups. Interfacial activation, which is unique to the class of lipases for its use in transesteri‐ fication of fats and oils, takes place in presence of a substrate and lipase active site structure. Lipases are used in a wide range of fields due to their ability in utilizing all mono, di, and triglycerides as well as the FFA, low product inhibition, high activity and yield in non-aqueous media, low reaction time, temperature and alcohol resistance, but the high cost of enzyme remains a barrier for its industrial applications [10]. In order to decrease the cost of the process, the enzyme can be immobilized on a suitable carrier and reused many times. So far, many techniques and different carriers have been employed for immobilization of lipases to produce biodiesel. They have been successfully immobilized on porous kaolinite particle, biomass support particles, macroporous resin, gel-entrapped, celite, silica, and Eupergit C250L [12-16]. Several oils have been catalyzed with lipase enzymes until now. Lipase catalyzed production of biodiesel from soybean oil, sunflower oil, palm oil, kernel oil, coconut oil, rice bran oil, mixture of vegetable oils, grease and tallow oil, microbial oil, and waste oil containing vegetable oils have been reported in the past decades [17-25]. In this chapter, focus will be given toward enzymatic biodiesel production from various vegetable oils. *Thermomyces lanuginosus* lipase and *Candida antarctica* lipase A were immobilized on cotton cloth which is a low cost carrier. Transesterification of sunflower, canola, and waste cooking oil with methanol and ethanol was carried out by continuous operation system. The essential aim of this study was to investigate the production of biodiesel from vegetable oils by enzymatic transesterification with immobilized lipases on fibrous matrix by polyethyleneimine in a packed bed bioreactor at industrial scale.
