Microwave-irradiated zinc chloride catalyzed glycerolysis of high free fatty acid vegetable oil

Date of Publication

2015

Document Type

Master's Thesis

Degree Name

Master of Science in Chemical Engineering

College

Gokongwei College of Engineering

Department/Unit

Chemical Engineering

Thesis Adviser

Susan A. Roces
Nathaniel P. Dugos

Defense Panel Chair

Luis F. Razon

Defense Panel Member

Cynthia F. Madrazo
Gerardo L. Augusto
Arnel B. Beltran

Abstract/Summary

Biodiesel, a popular alternative to fossil-based diesel, can be produced from cheap and sustainable sources like waste cooking oil. However, waste cooking oil, with its inherent FFA content, requires a pre-treatment step to lower the FFA content, making it available for alkali-catalyzed transesterification.

The catalytic glycerolysis of FFA can be a practical, alternative pre-treatment step for high-FFA feedstocks. This pre-treatment method is coupled with microwave irradiation in this study to provide possible improvements on current reaction parameters of zinc chloride catalyzed glycerolysis using conventional heating.

This study investigated the effect of microwave irradiation, as well as the reaction parameters: reaction temperature (160-200°C), reaction time (30-150 min), glycerol-to-oil mass ratio (1-3), and catalyst amount (0-2 wt.% mixture), to the zinc chloride catalyzed glycerolysis reaction of high-FFA simulated waste cooking oil by determining the FFA conversion during glycerolysis.

The glycerolysis reaction rate slows down as time progresses and as FFA is consumed, as observed in the effect of time with FFA conversion. The effect of temperature with FFA conversion is linear within the 40°C temperature range. The increase in temperature favors the increase in FFA conversion since glycerolysis is an endothermic reaction. Also, the increase in temperature increases reaction rate according to the Arrhenius equation. FFA conversion is affected by the amount of glycerol relative to oil. A smaller amount of glycerol is favored for better homogenization of the two phases. FFA conversion and reaction rates were found to be limited by the catalyst amount at low catalyst concentrations while at high catalyst amount above optimum, reaction rate is only limited by FFA concentration.

Consequently, the optimum conditions for the microwave-irradiated catalytic glycerolysis are 200°C, 2 hours reaction time, 1:1 glycerol-to-oil mass ratio, and catalyst amount of 1.217 % wt. of mixture.

Abstract Format

html

Format

Electronic

Accession Number

CDTG006367

Shelf Location

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

Physical Description

computer optical disc.

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