Date of Award

January 2014

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Chemical Engineering

First Advisor

Yun Ji

Abstract

A biochemical process was investigated in the conversion of lignocellulosic biomass into biofuels and value added chemicals. Kenaf, two species of sorghum (brown mid rib (BMR) & non brown mid rib (NBMR)), sunn hemp, sunflower hulls, and cornstover were used as feedstocks in this study.

Lignocellulosic biomass primarily consists of three different components, cellulose, hemicellulose and lignin. In order to separate different fractions, and acid pretreatment is generally employed. This was achieved by using a 300 ml internal volume batch reactor. The heating source used was steam. During acid pretreatment most of the hemicellulose is hydrolyzed into the liquid fraction. The remaining solid fraction that is rich in cellulose and lignin is subjected to enzymatic hydrolysis. The maximum hemicellulose hydrolysis for four feed stocks (two species of sorghum, sunn hemp and kenaf) ranged between 72 wt% to 95 wt%. The maximum enzymatic hydrolysis yield ranged between 68 wt% to 90 wt%.

In the case of acid pretreatment of sunflower hulls, the maximum hemicellulose and cellulose yield were observed to be 59 and 53.5wt%, respectively. This difference was explained by a high lignin and wax content of the hulls cell walls, which could act as a barrier to the hydronium ions resulting in lower yields.

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