Effect of container depth and sedimentation time on quality of Jatropha curcas L. oil

Jatropha curcas oil production in rural areas might improve the living standards of rural communities inducing economic growth and welfare of rural farmers. Rural communities have the potential to become independent with respect to the production of fuel for cooking, lighting and heating. The oil produced for energy in rural areas should not require to be highly processed, in order to produce it locally at low costs. The main objective of this study was to analyze the effect of two sedimentation systems on J. curcas oil quality, namely a horizontal and a vertical sedimentation container. Chemical analyses for J. curcas raw and sedimented oil were analyzed according to DIN-norm standards. The sedimentation time needed to achieve a relative clarified fluid of 80% was about 3.5 times shorter for a horizontal container than for a vertical one. Among the characteristic chemical properties only the kinematic viscosity of raw and sedimented oil exceeded the threshold according to DIN 51605. The limit values of variable chemical properties for fulfilling plant oil stove requirements were reached after 117 h for the horizontal sedimentation system and after 378 h for the vertical one. The horizontal sedimentation system showed better clarification efficiency in a shorter time. Moreover, chemical qualities such as characteristic and variable chemical properties were improved after clarification. Total contamination in the sedimented oil was reduced to a value of about 100 mg/kg after 55 days of sedimentation, which is sufficient to meet the standard for oil used in plant oil stoves. By reducing the total contamination the variable chemical properties were also improving, and aside from the phosphor content, quality requirements for use in plant oil stoves could be met by sedimentation. (C) 2013 Elsevier Ltd. All rights reserved.