Optimization of Jatropha curcas pure plant oil production

The use of pure plant oils as fuel, either directly or after conversion of the oil to bio-diesel, is considered to be one of the potential contributions to the transformation of the current fossil oil based economy to a sustainable bio-based one. The production of oil producing seeds using plants that do not interfere with food production or which make use of fertile land that might be needed for food production is seen as an attractive option. The use of Jatropha curcas which is a non-food oilseed producing plant that can be grown on marginal land, has therefore been stimulated during the last decade. However, commercial scale use for the production of pure plant oil or bio-diesel has so far not been developed. From a product technology viewpoint, in which the final product specification is the leading criterion for the processing steps needed to obtain the final product from the plant-based feedstock, each unit operation in the processing chain has to be considered, optimized and integrated with others such that the best result is achieved. The research described in this thesis is therefore aimed at developing this optimum pathway from harvesting seeds, through storage, drying, pre-treatment, oil extraction, purification and stabilization of the oil. The research described in this thesis is therefore aimed at developing this optimum pathway from harvesting seeds, drying, through storage, pre-treatment, oil extraction, purification and stabilization of the oil

SUPERCRITICAL CARBON DIOXIDE EXTRACTION OF CITRONELLA OIL FROM CYMBOPOGON WINTERIANUS USING TAGUCHI ORTHOGONAL ARRAY DESIGN

Objective: Optimum condition for the extraction of citronella oil from citronella (Cymbopogon winterianus) using supercritical carbon dioxide (SC-CO2) was investigated.Methods: In order to determine the optimum extraction condition, a Taguchi experiment with L9 orthogonal array design was used. Effects of pressure, temperature and dynamic extraction time on citronella oil yield were investigated at levels ranging between 10-15 MPa, 35-45 °C and 60-180 min, respectively.Results: The highest citronella oil yield (3.206%) was achieved at a factor combination of 15 MPa, 50 °C and 180 min. The obtained citronella oil yield from SC-CO2 extraction was higher than that of percolation as the solvent extraction method using ethanol, which gave a citronella oil yield of 1.4%. The experimental oil yield at optimum condition was in accordance to the values predicted by a computational process using Taguchi method. Analysis of variance (ANOVA) with 95% confidence interval indicates that extraction temperature is the most significant factor in maximizing citronella oil yield, followed by dynamic extraction time and pressure.Conclusion: Optimization process for oil yield from SC-CO2extraction of citronella (Cymbopogon winterianus) was successfully performed using Taguchi L9 orthogonal array design. This study demonstrates that Taguchi method was able to simplify the experimental procedure of SC-CO2 process.Â

Optimization of mechanical oil extraction from Jatropha curcas L. kernel using response surface method

Extraction of oil from Jatropha curcas L. kernel was investigated using a lab-scale hydraulic press. A face centered composite design of experiments was employed to study and optimize the effect of applied pressure, pressing temperature and moisture content on oil recovery. A quadratic polynomial model was generated to predict oil recovery and was found to cover 98% of the range for the factors studied, namely 10–20 MPa applied pressure, 60–90 °C pressing temperature and 3–5% (w.b.) moisture content. Among the process parameters studied, pressing temperature had the most significant effect on the recovery followed by applied pressure and quadratic of moisture content. Model validation experiments show good correspondence between actual and predicted values. The optimal extraction condition for oil yield within the experimental range of the variables researched was at 19 MPa applied pressure, 90 °C pressing temperature, and 3.8% (w.b.) moisture content. At this condition, the yield of oil was predicted to be 87.8%

Mechanical extraction of oil from Jatropha curcas L. kernel:Effect of processing parameters

Mechanical extraction is considered to be the best option for oil expression of Jatropha curcas in rural areas. Lab scale hydraulic pressing experiments were conducted to investigate the effect of process parameters on oil recovery from Jatropha kernel. The ranges of pressing parameters investigated were: compression speed, 0.05–2.5 MPa/s; applied pressure, 5–25 MPa; moisture content, 1–6%; pressing temperature, 25–105 °C; pressing time, 1–30 min; shell removal, 0–100%; preheating time, 0–30 min; and particle size, fine, coarse and whole kernel. Chemical analyses such as acid value, phosphorus content, oxidative stability index and water content were carried out to determine the quality of the oil. Moisture content was found to influence oil recovery at any applied pressure and pressure rates. Oil recovery increased to some extent with an increase in temperature or pressing time. The preferred moisture content was found to be about 4% (w.b.). The presence of Jatropha shell and size reduction of the kernel reduce oil recovery.<br/

Experimental and modelling studies on the solvent assisted hydraulic pressing of dehulled rubber seeds

A systematic study on the expression of rubber seed oil from dehulled rubber seeds in a hydraulic press was performed in the presence and absence of ethanol. The effect of seed moisture content (0–6 wt%, w.b.), temperature (35–105 °C), pressure (15–25 MPa) and ethanol to seed ratio (0–21%v/w) on the oil recovery was investigated. An optimum oil recovery of 76 wt%, d.b. was obtained (1.6 wt% moisture content, 14%v/w ethanol, 20 MPa, 75 °C, 10 min pressing time). The experimental dataset was modeled using two approaches, viz (i) the Shirato model and (ii) an empirical model using multi-variable non-linear regression. Good agreement between models and experimental data was obtained. Relevant properties of the rubber seed oil obtained at optimum pressing conditions (free fatty acid content, viscosity, density, water and P-content, cold flow properties and flash point) were determined. The pressed rubber seed oil has a relatively low acid value (2.3 mg KOH/g) and is suitable for subsequent biodiesel synthesis