Production of methyl ester biodiesel by sodium hydroxide-catalyzed transesterification of Jatropha curcas L.oil with Petroleum ether as dispersal medium.

Date

5-2009

Degree

Bachelor of Science in Chemical Engineering

College

College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Rex B. Demafelis

Committee Member

Manolito E. Bambase, Jewel A. Capunitan

Abstract

Petroleum ether’s efficiency as a dispersal medium for the sodium hydroxide- catalyzed methanolysis of Jatropha curcas L. oil was tested. The effects of methanol to oil and sodium hydroxide to oil molar ratio on the system were also considered. Jatropha curcas L. oil was pre-treated by water degumming and acid esterification before proceeding to the transesterification studies. Fatty acid methyl ester purity was determined using quantitative thin layer chromatography. Addition of 1:5 petroleum ether to methanol volumetric ratio to a transesterification system with 1:6.89:0.2 oil/methanol/NaOH molar ratio attained essential completion (~100 % fatty acid methyl ester purity) within ten minutes at 50-55 oC. This was faster compared to the same system without petroleum ether. Increasing the petroleum ether to methanol volumetric ratio to 1:4 and 1:3 did not seem to improve the reaction within ten minutes but FAME purity was lower within ten minutes when 1:7 petroleum ether to methanol volumetric ratio was used. A significantly higher purity compared to the system without petroleum ether was still achieved after 20 minutes when the 1:7 petroleum ether to methanol volumetric ratio was used. These results showed that petroleum ether was an effective dispersal medium for the transesterification of J. curcas oil. The best petroleum ether to methanol volumetric ratio was taken to be 1:5. Lowering the methanol to oil ratio to 5:1 and 6:1 resulted to lower FAME purity but these were still faster compared to a system with 6.89:1 methanol to oil molar ratio without petroleum ether. Thus, these strengthened that petroleum ether was an effective dispersal medium. The best methanol to oil molar ratio was taken as 6.89:1. The sodium hydroxide to oil molar ratio was also decreased to 0.1:1 and 0.15:1. The system with 0.1:1 NaOH to oil molar ratio was lower for the system with 0.2:1 NaOH to oil molar ratio with and without petroleum ether while the 0.15:1 ratio gave a statistically similar yield compared to the system with a 0.2:1 ratio without petroleum ether, thus proving once more that petroleum ether was an effective dispersal medium and increased rates can only be achieved at minimal amounts of catalysts when a cosolvent or a dispersal medium is used. The best conditions for the transesterification of Jatropha. curcas L. oil was found to be 1:6.89:0.2 oil:methanol:NaOH molar ratio with 1:5 petroleum ether to methanol volumetric ratio reacted at 50-55 oC for ten minutes.

Language

English

Location

UPLB College of Engineering and Agro-Industrial Technology

Call Number

LG 993.5 2009 E62 V53

Document Type

Thesis

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