**8. Conclusion**

Silica gel supported KHSO4 acidic catalyst prepared for production of biodiesel from refined castor oil containing 8.4% free fatty acid has been found to be a simple, cheap, ecofriendly and recyclable catalyst system for excellent yield of castor oil biodiesel under mild condition. The activity of the catalyst system is not affected by the presence of free fatty acid. The system is so simple that it does not require any special design compared to other solid supported acidic catalysts.

It may be mentioned in this context that the leading oil companies in the whole world are looking to tap the business opportunities of biodiesel. In the developed process such as the one discussed in this chapter is scaled up to commercial levels by more and more oil companies, it could be a major step towards creation of an eco-friendly transportation fuel that is relatively clean on combustion and provides farmers with substantial income.

#### **9. References**

Akoh, C.C., Chang, S.W., Lee, G.C. and Shaw, J.F. (2007). Enzymatic approach to biodiesel production*. J. Agric. Food. Chem*., 55, 8995-9005. DOI: 10, 1021/jf071724y

Canakei,M. and Van,G.J. (1999). Biodiesel production via acid catalysis *Trans. ASAE*, 49,1203-1210.

whereby KHSO4 is retained on the surface of silica. The catalyst was washed several times with petroleum ether and then dried completely at 1500C for 8-10 hours. On use of this catalyst for 5 runs with same amount of castor oil and methanol the yield of CastMe

Silica gel supported KHSO4 acidic catalyst prepared for production of biodiesel from refined castor oil containing 8.4% free fatty acid has been found to be a simple, cheap, ecofriendly and recyclable catalyst system for excellent yield of castor oil biodiesel under mild condition. The activity of the catalyst system is not affected by the presence of free fatty acid. The system is so simple that it does not require any special design compared to other solid

**12345**

**Resuability (time)**

It may be mentioned in this context that the leading oil companies in the whole world are looking to tap the business opportunities of biodiesel. In the developed process such as the one discussed in this chapter is scaled up to commercial levels by more and more oil companies, it could be a major step towards creation of an eco-friendly transportation fuel

Akoh, C.C., Chang, S.W., Lee, G.C. and Shaw, J.F. (2007). Enzymatic approach to biodiesel production*. J. Agric. Food. Chem*., 55, 8995-9005. DOI: 10, 1021/jf071724y Canakei,M. and Van,G.J. (1999). Biodiesel production via acid catalysis *Trans. ASAE*,

that is relatively clean on combustion and provides farmers with substantial income.

decreased was subtle even at fifth reuse (Fig. 11).

Fig. 11. Catalyst recycling

**82**

**84**

**86**

**88**

**% Yield of Castme**

**90**

**92**

**94**

**96**

supported acidic catalysts.

49,1203-1210.

**8. Conclusion** 

**9. References** 


**19** 

*1México 2Bulgaria* 

CH2-OH

CH-OH

CH2-OH

**The Immobilized Lipases in** 

Margarita Stoytcheva1, Gisela Montero1,

R1-C-O-R

O

R2-C-O-R

+

mono-alkyl esters glycerol

O

R3-C-O-R

(biodiesel)

O

Lydia Toscano1, Velizar Gochev2 and Benjamin Valdez1 *1Universidad Autónoma de Baja California, Instituto de Ingeniería,* 

The leading standard setting organization ASTM International, formerly ASTM (American Society of Testing and Materials), defines biodiesel as a fuel comprised of mono-alkyl esters of long chain fatty acids (ASTM D6751). It is usually manufactured by triglycerides transesterification with methanol or ethanol in the presence of a catalyst, according to the

catalyst

Recently, biodiesel production by lipase catalyzed transesterification has been suggested as a promising alternative to the conventional chemical catalysis, in spite of the high conversion and reaction rates of the latter (Akoh et al., 2007; Bajaj et al., 2010; Bisen et al., 2010; Demirbas, 2009; Fjerbaek et al., 2009; Fukuda et al., 2001, 2009; Ghaly et al., 2010; Helwani et al., 2009; Jegannathan & Abang, 2008; Man Xi Ao et al., 2009; Marchetti et al., 2007; Ranganathan et al., 2008; Robles-Medina et al., 2009; Semwal et al., 2011). The enzymatic process enables eliminating the drawbacks of the alkali- or acid-catalyzed transesterification, namely: product contamination, wastewater release, free fatty acids and water interferences, and difficult glycerol recovery. Nevertheless, the commercialization of

**1. Introduction** 

following reaction:

CH2-O-C-R1

CH -O-C-R2

CH2-O-C-R1

 triglycerides (vegetable oil, animal fat)

O

O

O

+ 3ROH

alcohol

**Biodiesel Production** 

*2Plovdiv University "Paisii Hilendarski,* 

