Temperature influence on chemical properties of jatropha curcas L. oil extracted with mechanical screw press

Abstract

Pure plant J.curcas oil has been used in direct injection compression engines and plant oil stoves without any engine modification necessary. Oil quality information and preservation are essential knowledge to avoid the wear and breakdown of combustion engines. This study focused on investigating the generated temperature during mechanical extraction with a mechanical screw press type (Komet D85-1G) on J.curcas oil quality. Chemical properties of extracted J.curcas oil were analyzed and the results were compared with the chemical extraction method (soxhlet) and DIN 51605. Most of the characteristic chemical properties of J.curcas oil extracted with a mechanical extraction method did not exceed the threshold norm DIN 51605. The standard deviation and coefficient of variation between all experiments was very small. This means, that the characteristic oil quality was not influenced by temperatures generated when alternating different screw parameters. The analyzed variable chemical properties of J.curcas oil extracted by mechanical extraction (AV, FFA, TC, P, Ca, K and WC) were above the allowed limit described by standard norm DIN 51605, except CR and Na contents, which fulfill the standard norm. The standard deviation and coefficient of variation of analyzed experiments varied from 13 to 46%. These proved that oil extraction is influenced by temperature generation when using different screw press design parameters. The highest temperature was generated on point T3 and the best correlation values were achieved between temperature T3 and variable chemical properties.

The temperature at the cohesion zone T3 is an indicator for oil quality determination. Mechanical extraction temperatures below 90 °C at the compression zone and 70 °C at the oil outlet would produce oil quality, which allows the direct use of the oil as fuel or for biodiesel production.

Graphical Abstract

Keywords:

• Jatropha curcas L.
• mechanical extraction
• chemical properties
• oil quality

Acknowledgements

We are grateful to the Bundesministerium für Bildung und Forschung, Berlin for financial support of Project 0330799A.