Date of Publication

4-2008

Document Type

Master's Thesis

Degree Name

Master of Science in Chemical Engineering

Subject Categories

Chemical Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Adviser

Yolanda P. Brondial

Defense Panel Chair

Leonila C. Abella

Defense Panel Member

Joseph L. Auresenia
Nikko P. Quevada

Abstract/Summary

The continuous search for more desirable sources of energy, uncontrollable increase in cost of imported energy in the world market and increasing environmental problems brought by these existing sources led to the idea of blending ethanol to our fuels. Ethanol, an oxygenated fuel obtained by fermentation of starch-containing materials, is produced at a maximum concentration of 95.57% by weight by conventional distillation techniques. Rectification of these mixtures produces absolute ethanol through the addition of mass-separating agents and membranes. However, these methods are proven to render resulting ethanol unfit for industrial and pharmaceutical uses. One acceptable technique to purify azeotropic mixtures is salt distillation. This process involves the addition of salt that eventually modifies the molecular and ionic interactions in the solution. In this study, the potential of tetrasodium ethylenediamminetetraacetic acid as entrainer in salt distillation was determined by the establishment of a vapor-liquid equilibrium data. The presence of this widely known chelating agent was used in the generation of the VLE data with concentration ranging from 0.05 molal to 0.20 molal concentrations with respect to the mass of solvents present in solution using the VLE apparatus modified by Novianti (2007). The composition of the equilibrium phases was determined using gas chromatography and simulation was done using MATLAB® and Extended UNIQUAC and UNIFAC-Dortmund Model for the activity coefficient of the liquid phase. The VLE data was found to yield higher ethanol fractions in the vapor phase compared to the system without the chelating agent. However, temperature of the resulting mixture was found to be higher due to the prevalence of ion-dipole interactions. Data using 0.10 molal salt and higher resulted to higher vapor fractions of ethanol at concentrations of the salt with higher degree of saturation. The salt was able to shift the azeotropic point of the mixture to a maximum ethanol concentration of 99.39% by volume (99.22% by mass). The experimental data was best represented by the extended UNIQUAC model while unsatisfactory using the modified UNIFAC iv (Dortmund) model due to the inability of the system to interact as system with interacting functional groups.

Abstract Format

html

Language

English

Format

Electronic

Accession Number

CDTG004771; TG04771

Shelf Location

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

Physical Description

131 leaves ; 28 cm.

Keywords

Ethylenediaminetetraacetic acid; Ethanol; Vapor-liquid equilibrium

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