Solvent extraction of Nigella-Sativa Oil from black seed

Extraction of Nigella-Sativa Oil from its black seeds using petroleum ether (boiling range 60-80 °C) was investigated. The maximum amount of Nigella- Sativa oil content obtained was 42.01% (by weight of the seed). Thermodynamic and kinetic studies yielded results that show the parameters necessary for the extraction of the oil. The ultimate capacity of the petroleum ether (60-80°C) as a solvent increased with temperature. The rate parameter for different temperatures is correlated by the equation KT = - 0.088 (T K)-0.011 The major part of oil was extracted from seeds surface rather than from its pores (the activation energy was found to be = 2.146 kJ/mol) of oil extracted. The extraction-rate parameter for various solvent-feed ratios (S/F) agrees with the equation K(S/F) = 1/0.995 (S/F) -0.142. Also, the relation between the extraction-rate parameter and the mixing intensity can be represented by Kr.p.m. = -1.688 (r.p.m.)0.806. The values of the free energy and the enthalpy were evaluated.