Sulphite treatment to enhance the ethanol production of softwood whole slurries
department or school: Forestry, Faculty of
data provider: DSpace
degree campus: UBCV
creator: Zhong, Na
issued: 2018-05-24T15:57:08Z
issued: 2018
related degree: Doctor of Philosophy - PhD
degree grantor: University of British Columbia
description: To try to compete with conventional bioethanol production from sugar/starch feedstocks, âwhole-slurryâ, high solids loading hydrolysis and fermentation of steam pretreated softwood biomass was employed to obtain high sugar, high ethanol concentrations. However, two major challenges were encountered; substrate recalcitrance limiting effective enzymatic hydrolysis and high concentrations of inhibitors inhibiting effective sugar fermentation. The major focus of the work described in this thesis was to assess the benefits of integrating sulphite treatments prior, during and after steam pretreatment to enhance the effectiveness of the enzymatic hydrolysis of the whole cellulose and hemicellulose derived slurry and the fermentation of the biomass derived sugars. Initial work focused on improving fermentation at high sugar concentrations (up to 25% w/v) by improved strain selection, nutrient supplementation and the use of high cell density growth Subsequently, sulphite post treatment was assessed to see if it could improve both the hydrolysis of the whole slurry, containing both cellulose and hemicellulose, and the fermentation of the softwood derived sugars. To try to maximize the beneficial influence of sulphite treatment the softwood chips were treated prior to steam pretreatment, to result in sulphonation ahead of lignin condensation, hopefully improving the extent of sulphonation with less sulphite loading. This approach resulted in some improvements. However, it proved difficult to balance some of the factors that influence the effectiveness of enzyme mediated hydrolysis, such as the extent of suphonation, substrates size reduction and lignin condensation, although an improvement in whole slurry fermentation was observed. To try to further improve this strategy a two stage, alkali- followed by acid-sulphite approach was assessed, using sulphite in the first stage to sulphonate the lignin and SOâ in the second stage to further sulphonated the lignin while decreasing p…
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/66057
note: SULPHITE TREATMENT TO ENHANCE THE ETHANOL PRODUCTION OF SOFTWOOD WHOLE SLURRIES by Na Zhong A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENT FOR THE DEGREE OF DOCTOR OF PHILOSOPHY in The Faculty of Graduate and Postdoctoral Studies (Forestry) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) May 2018 © Na Zhong, 2018 ii The following individuals certify that they have read, and recommend to the Faculty of Graduate and Postdoctoral Studies for acceptance, the dissertation entitled: Sulphite treatment to enhance the ethanol production of softwood whole slurries. Submitted by Na Zhong in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Wood Science Examining Committee: Jack Saddler, Wood Science Supervisor Richard Chandra, Wood Science Supervisory Committee Member Scott Renneckar, Wood Science Supervisory Committee Member Jim Lim, Chemical and Biological Engineering Universiy Examiner Shahabaddine Sokhansanj, Chemical and Biological Engineering University Examiner iii Abstract To try to compete with conventional bioethanol production from sugar/starch feedstocks, âwhole-slurryâ, high solids loading hydrolysis and fermentation of steam pretreated softwood biomass was employed to obtain high sugar, high ethanol concentrations. However, two major challenges were encountered; substrate recalcitrance limiting effective enzymatic hydrolysis and high concentrations of inhibitors inhibiting effective sugar fermentation. The major focus of the work described in this thesis was to assess the benefits of integrating sulphite treatments prior, during and after steam pretreatment to enhance the effectiveness of the enzymatic hydrolysis of the whole cellulose and hemicellulose derived slurry and the fermentation of the biomass derived sugars. Initial work focused on improving fermentation at high sugar concentrations (up to 25% w/v) by improved strain selection, nutrient supplementation and the use of high cell density growth Subsequently, …
has type: Thesis/Dissertation
date issued: 2018-09
is shown at: 10.14288/1.0367000
language: eng
degree discipline: Forestry
provider: Vancouver : University of British Columbia Library
publisher: University of British Columbia
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/66057