Rahmath Abdulla and Ravindra Pogaku

Abstract This chapter focuses mainly on biodiesel production from the “future green gold” namely Jatropha curcas. The importance of this plant as biodiesel feedstock, oil extraction methods from the seeds, and different routes of bio­diesel production are discussed in the first part. Nowadays, immobilization of lipase has gained immense potential in the biofuel industry mainly to reduce the production costs and to make the method more economical. Different approaches of lipase immobilization are briefed in the second part. The final part of this chapter shows stability studies of Burkholderia cepacia lipase immobilized in hybrid matrix and its application and biodiesel optimization from crude J. curcas oil.

Keywords Biodiesel • Jatropha curcas • Transesterification • Immobilization • Lipase

12.1 Introduction

With rapidly increasing energy demand day by day, the world is in an energy crisis. The growing population depends mainly on energy from fossil sources such as petroleum, coal, and natural gas. Today, these fossil fuels are on the verge of maxi­mum production and limited reserves concentrated on fewparts of the world. In short, these fuels are shortening day by day and will soon be exhausted in near future. In search for alternative sources of renewable and sustainable energy, biofuels which can be obtained from biomass feedstock occupy the top ladder.

R. Abdulla • R. Pogaku (*)

Chemical Engineering, School of Engineering and Information Technology, Universiti Malaysia Sabah, Kota Kinabalu, Malaysia e-mail: ravindra@ums. edu. my

R. Pogaku and R. Hj. Sarbatly (eds.), Advances in Biofuels, 191

DOI 10.1007/978-1-4614-6249-1_12, © Springer Science+Business Media New York 2013

In addition, biofuels are also an answer to the environmental concerns like air pollution and global warming which is mainly caused by fossil fuel combustion (Demirbas 2009; Gui et al. 2008; Lam et al. 2009).

The first use ofbiofuel was in 1900 at the World Exhibition in Paris when Rudolf Diesel demonstrated the use of peanut oil as fuel in diesel engines. Recently, with the realization of fast depletion of petroleum reserves, environmental friendly fuels received great attention and opened an era of research in these areas of renewable and sustainable energy. Biofuels include biodiesel, bioethanol, biomethanol, and biohydrogen (Agarwal and Das 2001; Murugesan et al. 2009).

Among these biofuels, biodiesel is gaining much importance recently since it has been strongly recommended as petroleum diesel substitute. The term bio­diesel (Greek, bio, life+ diesel from Rudolf Diesel) refers to a diesel equivalent, processed fuel which can be derived from biomass. Biodiesel is defined as a mix­ture of monoalkyl esters of long fatty acids which can be obtained from renewable lipid feedstock, such as vegetable oils or animal fats. The production and applica­tion of biodiesel are expected to increase steadily in the next few decades. Already, biodiesel has been implemented as a blending component with diesel in many countries such as Brazil, United States, Germany, Austria, Italy, and Australia (Yusuf et al. 2011).

The main advantages of biodiesel over conventional fuels are lower toxicity, bio­degradability, and substantial reduction in sulfur oxide gases, carbon monoxide, polyaromatic hydrocarbons, smoke, and particulate matter. Biodiesel, which is environmental friendly, reduces the greenhouse effect. Since its properties are close to that of diesel, biodiesel is regarded as a strong candidate to replace diesel in trans­portation industry. “Future fuels” such as biodiesel should be focused with the growing concern of protecting the environment and as an energy reserve for the upcoming generations. For this reason, researchers and scientific organizations worldwide are involved in development of commercial biodiesel and optimization parameters to meet the various standards and diesel engine specifications (Sharma et al. 2008; Fukuda et al. 2001).

Use of edible oils such as soybean oil, rapeseed oil, and palm oil for biodiesel production has led to the concern of “food versus fuel.” This is mainly because the developing countries with lack of enough edible oils for consumption cannot afford to use these oils for production of biodiesel. In such a situation, easily available nonedible oils obtained from sources like Jatropha, microalgae, neem, karanja, rub­ber seed, mahua, silk cotton tree, and so on play an important role. Out of these, Jatropha curcas seed oil with considerable potential is gaining importance in bio­diesel production (Abdulla et al. 2011).

Biodiesel can be produced by a number of ways. Out of these, the most com­monly used is the transesterification of vegetable oils. This can be done by chemical method or enzymatic method. In terms of reaction kinetics, the chemical transesteri­fication is faster, but due to many disadvantages such as difficulty in recovery of glycerol, biodiesel impurities, highly energy intensive process, and need for waste treatment. On the other hand, these disadvantages can be overcome through enzymatic transesterification reactions which can yield specific alkyl esters of high purity, no soap formation, easy separation of glycerol from biodiesel, less treatment for waste, and even use of oils with high free fatty acids which can be easily converted to biodiesel (Rathore and Madras 2007; Nelson et al. 1996). Researchers have proved that enzymatic transesterification is thus a promising alternative to overcome the drawbacks associated with chemical methods. In short, we can say that enzymes mainly lipases are potential replacements for conventional catalysts used in bio­diesel synthesis. The use of lipases for biodiesel production through transesterifica­tion has already stepped into commercial scale with the introduction of pilot plants in few countries including China. But the main hurdle for commercialization is still the high price of lipases which can be overcome to a certain extent through reusing immobilized lipases.

This chapter throws an insight into the future fuel plant—J. curcas—for bio­diesel production, immobilization techniques, and finally development of a new enzyme catalyst for biodiesel production and its application in transesterification of crude J. curcas oil (CJO).