Date of Publication


Document Type


Degree Name

Doctor of Philosophy in Chemical Engineering

Subject Categories

Chemical Engineering


Gokongwei College of Engineering


Chemical Engineering

Thesis Adviser

Julius B. Maridable
Pag-asa D. Gaspillo

Defense Panel Chair

Leonila C. Abella

Defense Panel Member

Carmela R. Centeno
Jonathan W. L. Salvacion
Raymond Girard R. Tan
Bonifacio T. Doma


The Supercritical Fluid Extraction (SCFE) process is a powerful technique to develop for separating products with high added value. In this study, Supercritical fluid Carbon Dioxide (SC CO2) was used in the extraction of essential oil from two different parts of the lemongrass plant, the leaves and the stems. The batch extraction process was carried out in a stand alone compact unit of SCFE system. The lemongrass was loaded into the 500ml extractor with an up flow rate of 0.5 m3 per hour of CO2. The extraction temperature was varied from 350C to 500C while the extraction pressure applied was from 90 to 110 atmospheres and the length of material was varied from 4 mm to 8 mm. The extraction time was set at 3.0 hours. This study intends to compare the composition of essential oil extracted from lemongrass leaves and lemongrass stems using SC CO2 and Steam Distillation. The extracts from both methods were analyzed by GC-MS and the variations of the compositions were reported. Furthermore, the study attempts to formulate statistical experimental design using Design-Expert Software (version 7.0.1). The effects of temperature, pressure and length of material were analyzed employing the Response Surface Methodology (RSM) technique. The models of extraction for both leaves and stems were established with the extraction yield and citral content of the essential oil at the established responses. The optimum yields of essential oil from leaf and stem at the given extraction conditions were also determined.

Abstract Format






Accession Number


Shelf Location

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

Physical Description

xvii, 201 leaves ; 28 cm.


Supercritical fluid extraction; Liquid carbon dioxide; Carbon dioxide; Lemongrass

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