Comparative analysis of ethyl ester biodiesel from purified and crude Calophyllum inophyllum L. oil

Date

4-2009

Degree

Bachelor of Science in Chemical Engineering

College

College of Engineering and Agro-Industrial Technology (CEAT)

Adviser/Committee Chair

Catalino G. Alfafara

Co-adviser

Veronica P. Migo

Committee Member

Jewel A. Capunitan, Amelia E. Parao

Abstract

Modifications in the two-step process for biodiesel production from Calophyllum inophyllum (CI) L.oil (initiated by Migo, 2008) were investigated. The aim was to improve oil and biodiesel properties and optimize reaction conditions.The added step of vacuum-drying of kernels effected improvement in the oil characteristics such as FFA content (18.42% as compared to 21.23% without drying of kernels) and viscosity (62.20 cSt in contrast to 116.86cSt with fresh kernels). The peroxide value obtained (1.70 meq O₂/kg) was lower than 2.39 meq O₂/kg for the oil from fresh kernels thus the oil lower oxidative rancidity. The saponification number (189mg KOH/g) gave the mean molecular weight of 889g/mol for the crude oil. These values were comparable with those Dela Cruz (227) who utilized sun-dried CI kernels. Although the presence of non-hydratable phosphatides was confirmed through visible gum settling after acid-degumming with 5% (w/v) H₃PO₄, the process resulted to an increased FFA content (19.58%) and viscosity (86.76cSt) of the oil due to the incomplete residual acid and gum removal. With the presence of MG and DG spots in the chromatogram of the acid-degummed oil, the purification of oil (aimed at increasing TG purity by reducing MG, Dg and FFA contents) was performed. The purification scheme consisted of liquid adsorption column chromatography with activated alumina as adsorbent. However, the chromatographic procedure did not result to high TG purity in the supposed to be 'purified' oil due to the overloading of the column with the high FFA content of oil. Nevertheless, there was significant reduction in the FFA content of the oil (13.02% FFA content at elution rate of 2mL/min and 7.35%FFA content at 0.30mL/min).Further optimization of the ethanol to FFA and ethanol ratios for the acid esterification (AE) and base-catalyzed transesterification (BCT) of both purified and crude oils were performed. The ethanol to FFA ratios of 7:1 (7.5% FFA) and 5:1 (1.51% FFA) were established optimum for the AE of CO and Po, respectively. The lower optimum ratio for PO was attributed to lower starting FFA content of PO. Meanwhile, the ethanol to oil ratios of 8:1 (35.51% ethyl ester content by net area obtained through QuantiScan) and 10:1 (14.43% ethyl ester content) were set to be optimum for CO and PO, respectively in the BCT.The lower ethyl ester content for the optimized ratio of 10:1 for PO despite its higher TG purity and lower FFA content was an uncommon result highly recommended for further research and studies. Large batch biodiesel production was done for the CO only due to its higher ethyl ester percentage compared to PO. Results of the fuel analysis showed that bitaog biodiesel has favorable stability characteristics (in terms of oxidative rancidity). In addition, its low pour point and flash point proved its suitability for low temperature applications. However, the biodiesel had very high moisture content (10000ppm), acid value (8mg/g KOH), kinematic viscosity (14.02 cSt) and total glycerol (6%). These were attributed to the ineffective water removal method after BCT, high FFA of the esterified oil prior BCT and the low degree of conversion of oil to esterts.

Language

English

Location

UPLB College of Engineering and Agro-Industrial Technology

Call Number

LG 993.5 2009 E62 /V55

Document Type

Thesis

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