Optimizing mechanical oil extraction of Jatropha curcas L. seeds with respect to press capacity, oil recovery and energy efficiency

The objective of this study was to optimize the mechanical oil extraction of Jatropha curcas seeds by increasing the efficiency of oil recovery and decreasing oil residues in press cake. The experiments were carried out with mechanical screw press type – Komet D85-1G. Four setups were created by parameter combination of two different screws (16 and 21.5 mm choke ring size), with two different press cylinders (1 and 1.5 mm bore size), three different nozzles (8, 10 and 12 mm nozzle diameter) and three rotational speeds (low, medium and high). Oil recovery reduced when rotational speed increases for all setups; highest oil was 89.4% (m/m). The oil recovery was increasing when energy input increased and decreasing when seed material throughput increased. The relations between energy input and seed material throughput followed a strict pattern, which correlated with oil recovery. This correlation can be used for determining the optimal operation parameters.

► Temperatures above 100 °C were recorded with screw press R8.
► Maximal Jatropha oil extraction efficiency was achieved with screw press R8 than R11.
► Specific energy consumption and oil recovery efficiency correlate with material throughput; this dependency enables determination of optimal operation point.
► Seed material throughput above 11 kg/h does not lead to further increase of oil production but decreases it.