Lipase catalyzed preparation of biodiesel from Jatropha oil in a solvent free system Shweta Shah, Munishwar N. Gupta * Department of Chemistry, Indian Institute of Technology-Delhi, Hauz Khas, New Delhi 110016, India Received 16 May 2006; received in revised form 8 September 2006; accepted 29 September 2006 Abstract The monoethyl esters of the long chain fatty acids (biodiesel) were prepared by alcoholysis of Jatropha oil, a non-edible oil, by a lipase. The process optimization consisted of (a) screening of various commercial lipase preparations, (b) pH tuning, (c) immobilization, (d) varying water content in the reaction media, (e) varying amount of enzyme used, and (f) varying temperature of the reaction. The best yield 98% (w/w) was obtained by using Pseudomonas cepacia lipase immobilized on celite at 50 8C in the presence of 4–5% (w/w) water in 8 h. It was found that yields were not affected if analytical grade alcohol was replaced by commercial grade alcohol. This biocatalyst could be used four times without loss of any activity. # 2006 Elsevier Ltd. All rights reserved. Keywords: Biodiesel; Jatropha oil; Pseudomonas cepacia lipase; Solvent free biocatalysis; Transesterification 1. Introduction The monoalkyl esters of fatty acids are considered environmental friendly fuel for diesel engines [1–3]. These esters are generally prepared from vegetable oils (renewable resources) and have been called biodiesel [2,4]. Generally, these are prepared by alkali-catalyzed transesterification of the oils. There are several disadvantages associated with this process [5]. This has prompted attempts to use lipase for catalyzing this transesterification. Many starting materials such as soybean oil [6,7], sunflower oil [8,9], cotton seed oil [10], rapeseed oil [4], palm oil [11,12] and restaurant kitchen waste [13] have been tried for preparation of biodiesel by the enzymatic route. Several advantages of the enzymatic method have been mentioned [3,5]. In many countries, like India, as edible oils are not in surplus supply, there is a need to search for alternative starting oils such as from non-edible oil seeds. Jatropha oil, due to the presence of toxic phorbol esters is considered a non-edible oil [3]. The seed kernel contains 40–60% (w/w) oil. Saturated fatty acids constitute 20% of this, whereas those remaining are unsaturated ones. Oleic acid is the most abundant (44.8%) followed by linoleic acid (34%), palmitic acid (12.8%), and stearic acid (7.3%). Jatropha curcas is a low-growing tree, generally planted as a hedge for protecting crops from animals. It can be grown on barren land under harsh conditions and can be cultivated as a part of the strategy for reclaiming degraded lands [14]. Keeping all this in view, the Indian Government has announced a ‘National Mission on Biodiesel’ for Jatropha plantations in wasteland regions that is to be implemented on an area of 400,000 ha over the next 5 years [14]. At present worldwide all large-scale production of biodiesel is carried out by using a chemical catalyst. This continues to be so in spite of several above stated disadvantages. This is due to two major factors: (a) the perception that enzymes, per se are costly catalysts and (b) this is one system where enzyme catalyzed reaction is slower than the reaction catalyzed by chemical catalysts! The causes of this have been identified [15]. The cost factor actually gets related to this ‘rate factor’ as well. Apart from this, the production cost of an enzyme is likely to be lower if and when larger demand of enzyme leads to scale up of the production process. Earlier, we have explored the conversion of Jatropha oil to the ethyl esters of the long chain fatty acids by Chromo- bacterium viscosum lipase [16]. As one of the constraints associated with the enzymatic route is the cost of enzyme, it is vital to identify a lipase, which is already available as an industrial enzyme and which works well for catalyzing the www.elsevier.com/locate/procbio Process Biochemistry 42 (2007) 409–414 * Corresponding author. Tel.: +91 11 26591503/6568; fax: +91 11 26581073. E-mail address: munishwar48@yahoo.co.uk (M.N. Gupta). 1359-5113/$ – see front matter # 2006 Elsevier Ltd. All rights reserved. doi:10.1016/j.procbio.2006.09.024