3.7. Thermodynamic parameters
Tables 5 and 6 show the values of equilibrium constant and
thermodynamic parameters for the oil extraction process of coconut
waste. Fig. 6 shows the plot of lnK vs. 1/T which was used to
determine the value of thermodynamic parameters. The values of the enthalpy were in the range of 10.94–12.37 kJ/mol for soxhlet
extractor and 12.01–13.35 kJ/mol for batch extractor using hexane.
The value obtained was in the range (4–13.5 kJ/mol) obtained by
other researches for extraction of melon, rubber seed and olive
cake oil (Ibemesi and Attah, 1990; Meziane and Kadi, 2008). These
values was also similar with Topallar (2000) finding which was
11.2 kJ/mol for oil extraction from sun flower seed. Positive enthalpy
change indicates the endothermic nature of the extraction process
and requires energy during the process with agreement with
previous studies (Amin et al., 2010; Topallar, 2000