4.8 Electroporation
Electroporation is a process in which microalgae cell wall is exposed to high
intensities generated by electric fields during certain periods, destabilizing the cell
wall with the object to extract the intern compounds of microalgae (Joannes et al.
2015). Electroporation is one of the most used transfection methods due to high
efficiency and convenience in comparison with other transfection methods (Kang
et al. 2015). This technology is called to be a promising method for cell lipid
extraction due to low energy consumption, economic and possibility to be scaled-up
(Toepfl et al. 2006).
5 Process of Biodiesel Production
Biodiesel production is developed using vegetable oils, animal fats, and short-chain
alcohols. Methanol is the most common used alcohol and presents the best conversions, although ethanol is also used (Demirbas 2005). For the transesterification
reaction advance, the use of a catalyst is needed. In last years, the biodiesel production has been investigated from the use of chemical homogeneous catalyst like
acids (sulfuric acid) or basics (sodium hydroxide, sodium methoxide, potassium
hydroxide, etc.); chemical heterogeneous catalyst, acids (Amberlyst 15, SO 4
2− ), and
basics (KNO 3 , Al 2 O 3 , MgO); lipases from animal, vegetables, or microorganism
sources (Chromobacterium Viscosum, Candida Rugosa, and pork pancreas)
(Shahid and Jamal 2011).
6 Exergetic Analysis in Process
From the analysis of energy and especially of the exergy, it is possible to identify
the zones of the process in which the main energy changes occur. In this way, it is
possible to take measures in order to obtain maximum yields in terms of conversion
or separation processes and above all the energy yield involved in each stage
(Emets et al. 2006; Ruiz-Mercado et al. 2012; Young and Cabezas 1999).
To determine the change of exergy in the streams of a system can be used, the
mathematical model presented in (Zhang et al. 2012):
Ex ¼ Ex
ph
þ Ex
ch
þ Ex
ki
þ Ex
po
ð1Þ
where Ex
ph
; Ex
ch
; Ex
ki and Ex
po denote the physical, chemical, kinetic, and potential
exegetical flows of each stream, respectively. Usually, the kinetic (Ex
ki
¼ mV
2
=2)
and potential (E ¼ mhZ) exergy not present significant values for which Eq. 1 is:
9 Biofuels from Microalgae: Energy and Exergy Analysis for the …
189
Electroporation is a process in which microalgae cell wall is exposed to high
intensities generated by electric fields during certain periods, destabilizing the cell
wall with the object to extract the intern compounds of microalgae (Joannes et al.
2015). Electroporation is one of the most used transfection methods due to high
efficiency and convenience in comparison with other transfection methods (Kang
et al. 2015). This technology is called to be a promising method for cell lipid
extraction due to low energy consumption, economic and possibility to be scaled-up
(Toepfl et al. 2006).
5 Process of Biodiesel Production
Biodiesel production is developed using vegetable oils, animal fats, and short-chain
alcohols. Methanol is the most common used alcohol and presents the best conversions, although ethanol is also used (Demirbas 2005). For the transesterification
reaction advance, the use of a catalyst is needed. In last years, the biodiesel production has been investigated from the use of chemical homogeneous catalyst like
acids (sulfuric acid) or basics (sodium hydroxide, sodium methoxide, potassium
hydroxide, etc.); chemical heterogeneous catalyst, acids (Amberlyst 15, SO 4
2− ), and
basics (KNO 3 , Al 2 O 3 , MgO); lipases from animal, vegetables, or microorganism
sources (Chromobacterium Viscosum, Candida Rugosa, and pork pancreas)
(Shahid and Jamal 2011).
6 Exergetic Analysis in Process
From the analysis of energy and especially of the exergy, it is possible to identify
the zones of the process in which the main energy changes occur. In this way, it is
possible to take measures in order to obtain maximum yields in terms of conversion
or separation processes and above all the energy yield involved in each stage
(Emets et al. 2006; Ruiz-Mercado et al. 2012; Young and Cabezas 1999).
To determine the change of exergy in the streams of a system can be used, the
mathematical model presented in (Zhang et al. 2012):
Ex ¼ Ex
ph
þ Ex
ch
þ Ex
ki
þ Ex
po
ð1Þ
where Ex
ph
; Ex
ch
; Ex
ki and Ex
po denote the physical, chemical, kinetic, and potential
exegetical flows of each stream, respectively. Usually, the kinetic (Ex
ki
¼ mV
2
=2)
and potential (E ¼ mhZ) exergy not present significant values for which Eq. 1 is:
9 Biofuels from Microalgae: Energy and Exergy Analysis for the …
189