Comparison of dilute acid and alkaline pretreatments of Gmelina arborea sawdust prior to bioethanol production.

Date

10-2010

Degree

Bachelor of Science in Chemistry

College

College of Arts and Sciences (CAS)

Adviser/Committee Chair

Veronica P. Migo

Abstract

SATIOQUIA. KAYE DEE CARL D. University of the Philippines Los Banos, October 2010. COMPARISON OF DILUTE ACID AND ALKALINE PRETREATMENTS OF Gmelina arborea SAWDUST PRIOR TO BIOETHANOL PRODUCTION.

ADVISER: Dr. Veronica P. Migo

Constant oil price hikes around the globe, together with some environmental and health issues accompanied in using fuels served as the springboard for developing alternative ways of providing energy. One of these is the utilization of biomass to generate bioethanol. Bioethanol can be obtained through saccharification and fermentation of cellulose. However, pretreatment is necessary to increase the accessibility of the cellulose to favor enzymatic hydrolysis.

The lignocellulosic biomass used was Gmelina arborea sawdust. The optimization procedure of the pretreatment techniques was done using the Response-Surface Method (RSM). This method uses DesignExpertT" v.8 software. The acid-insoluble lignin (AIL) left in the residue was determined using standard analytical procedure. The % AIL in both the dilute acid and dilute alkaline pretreatment served as the response in the program. The optimum solutions with the highest desirability, wherein the three factors (concentration, time and temperature) are all kept in range while the response (%AIL) is minimized is at 9% (v/v) HeSOa, for 20 minutes at 121 °C, for the dilute acid pretreatment and 9% (w/v) NaOH, for 20 minutes at 121°C for the dilute alkaline pretreatment. These optimum solutions give a % AIL of 23.30% and 19.75% for the acid and base pretreatment, respectively. Moreover, the optimum solutions with the highest desirability wherein all the factors are minimized, including the response, is at 3.00% (v/v) H,SO4, for 20 minutes at 83.62 °C for the dilute acid pretreatment and 4.07% (w/v) NaOH, for 20 minutes at 80 °C for the dilute alkaline pretreatment. The optimum solutions give a % AIL of 26.42% and 24.44% for the acid and base pretreatments, respectively.

The two pretreatment techniques were compared in terms of the %AIL left in the residue after the pretreatment process. From the results, dilute alkaline pretreatment is more efficient in delignifying the substrate than the dilute acid pretreatment.

Language

English

Location

UPLB Main Library Special Collections Section (USCS)

Call Number

Thesis

Document Type

Thesis

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