Abelmoschus Esculemtus (Okra) and Raphanus Sativus (Labanos) as alternative feedstock for biodiesel

• Main Authors: Erasquin, Jane Louise A., Mendoza, Joanna Cecilia B., Uy, Danica C.
• Format: text
• Language: English
• Published: Animo Repository 2007
• Subjects: Biodiesel fuels > Philippines; Vegetable oils as fuels; Okra; Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etd_bachelors/6369
• Institution: De La Salle University

Biodiesel is defined as mono-alkyl esters of vegetable oils and animal fats. It is an alternative fuel that is continuously gaining attention and importance in our country. Coconut and jatropha are the biodiesel feedstocks being promoted in our country. But there are drawbacks in the use of these feedstocks. The unsafe handling of the jatropha as a feedstock will pose danger to health because it contains toxic components. On the other hand, coconut is one of our food products, thus the displacement of all diesel fuel with coconut methyl ester will not be possible. The use of vegetable oil as alternative feed stock for biodiesel was studied. Feed stocks used were the seeds of Abelmoschus Esculentus (Okra) and Raphanus Sativus (Labanos). The choice of feed stock was primarily based on its fatty acid profile which was used to predict an important fuel property such as cetane number. The oils of okra and labanos were extracted by solvent extraction and were found to contain high free fatty acid levels. Acid esterification was performed several times until the FFAs drop below the maximum limit of 0.5% prior to base-catalyzed transesterification. For labanos, a single acid step can be achieved using a 60:1 molar ratio of alcohol to FFA in the oil. For okra, an initial of 60:1 molar ratio and a second acid step using 80:1 to 100:1 molar ratio is necessary to lower the FFA to the limit. The biodiesel properties of okra and labanos were tested and compared to ASTM 6751-02, EN14214, and PNS 2020:2003/DOE002:2003. For labanos, its fuel properties such as density (876 kg/m³), free glycerol (0.02% mass), total glycerol (0.095% mass), acid value (0.17 mg KOH/g), sulfated ash (0.001 %mass), iodine value (113, predicted). cetane number (49, predicted) passed the three standards, while its kinematic viscosity (5.32 cSt) passed ASTM, sulfur ().02 % mass) passed PNS and ASTM and flash point (115°C) passed PNS and EN. For okra, kinematic viscosity (4.43 cST), free glycerol (0.02%mass), total glycerol (0.095%mass), acid value (0.28 mgKOH/g), sulfated ash (0.001%mass), iodine value (93, predicted), cetane number (52, predicted) passed the three standards, while sulfur (0.02%mass) passed PNS and ASTM, and flash point (82°C) and density (825 kg/m³) did not pass the standards.