n - PATh :.: Process and Product Applied Thermodynamics research ...

General Introduction
micro-strip sensors include perfluoro-n-propane, perfluoro-n-butane, trifluoro-iodo-
methane (CF3I) and custom C3F8/C4F10 mixtures (Vacek et al., 2000).
4) In cell culture aeration: one of the first reported works in this field came out in
1988 with the work of Cho and Wang. Inadequate supply of oxygen is one of the major
problems in industrial as well as in lab-scale production of biomass, since oxygen is
sparingly soluble in aqueous media. An approach to the problem of limited oxygen supply
is to modify the medium in such a way that it dissolves more oxygen. This approach
consists of the inclusion of oxygen carriers such as haemoglobin, hydrocarbons and
perfuorocarbons (Elibol and Mavituna, 1999). PFCs and their emulsions can facilitate
respiratory-gas delivery to both procaryotic and eucaryotic cells in culture, including those
in bioreactor systems. Such gaseous enhancement often stimulates biomass production and
yields of commercially important cellular products. The recoverability, and hence recycle
ability, of otherwise expensive PFCs from aqueous culture medium makes their routine use
commercially feasible (Lowe, 2002).
I.3.3. For Environmental Purposes
Due to the exceptional solubility of carbon dioxide in perfluoroalkanes these
compounds are being studied for industrial and environmental applications as the removal
of carbon dioxide from gaseous effluents (Wasanasathian and Peng, 2001).
Biological carbon dioxide fixation has been extensively investigated as part of
efforts to solve the global warming problem. Several researchers have reported using algae
culture to sequester carbon dioxide in the flue gas discharged from a boiler and a power
plant (Negoro et al., 1993; Hamasaki et al., 1994 and Kishimoto et al., 1994). Besides the
advantage of the removal of the pollutant gases, most of the times these algae have the
ability to produce a commercial valuable product as is the case of hydrogen or -carotene
(Miura et al., 1997). One of the intrinsic problems for scaling up the algae culture system is
the accumulation of photosynthetic produced oxygen, which in the case of photosynthetic
microalgae works as an inhibitor for cell growth. To overcome this limitation, oxygen must
be quickly remove out of the culture systems. An innovative approach for removing high
concentration of oxygen is by the introduction of a perfluoroalkanes in the medium Cho
and Wang (1988). In this case, carbon dioxide is the nutrient and oxygen is the waste.
Therefore, the function of perfluoroalkanes used for algae will be inverse to that for
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