Title

Characterization of fatty acids from locally available algae strains for use as biodiesel feedstock

Date of Publication

2009

Document Type

Thesis

Degree Name

Bachelor of Science in Chemical Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Adviser

Auresenia, Joseph

Defense Panel Chair

Borja, Josephine Q.

Defense Panel Member

Bacani, Florinda Tiangco
Yu, Dennis Ng

Abstract/Summary

Biodiesel is commonly being used today. However, the sources of the vegetable oil used in the production of biodiesel today compete with the market thus increasing its price and reducing its supply. Thus, it is necessary to find other alternatives that are feasible for use in biodiesel but at the same time does not compete for use in the food market. One alternative is to use algae oil as biodiesel feedstock. In this study, five algae strains are studied by evaluating their growth. The cetane numbers were also determined from their FAME profile. Lastly, the optimal conditions for growing the algae strains were determined.

In this study, the following algae were used: Hapalosiphon welwitschii, Nostoc commune Anabaena Laxa, Anabaena variabilis, and Chlorella sorokiniana. Their growth pattern was studied. It was found out that their relative rate constant is 0.2567 (N. commune), 0.1845 (H.welwitschii), 0.4359 (A. variabilis), 0.3372 (A. laxa), and 0.4359 (C. sorokiniana). On the other hand, it was found out that their mean doubling time was determined as follows: 2.7 days (N. commune), 3.76 days (H.welwitschii), 1.59 days (A. variabilis), 2.056 days (A. laxa) and 1.59 days (C. sorokiniana). It was concluded that the fastest growing algae are A. variabilis and C. sorokiniana.

The fatty acid profile of the algae strains was also determined via GC-FID after direct transesterification. Their cetane number was predicted as follows: 48.74 (N. commune), 53.06 (H. welwitschii), 59.21 (A. variabilis), 49.09 (A, laxa) and 46.40 (C. sorokiniana). The algae strain with the highest predicted cetane number among the five algae strains is A. variabilis.

By using the Taguchi method, the optimum algae strain that produced the highest biomass productivity rate is determined to be C. sorokiniana. The optimum operation conditions to yield the highest biomass productivity rate were determined to be 24 light hours in the photoperiod, 30 watts of light intensity and 1.0 L/min of air flow rate. The algae strains studied in this experiment were found to be suitable for use as biodiesel feedstock. However, due to the large number of algae strains available, other algae strains should also be suited.

Abstract Format

html

Format

Print

Accession Number

TU15943

Shelf Location

Archives, The Learning Commons, 12F Henry Sy Sr. Hall

Physical Description

xii, 143 leaves ; col. ill. ; 28 cm.

Keywords

Fatty acids; Algae; Biodiesel fuels

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