Engineering Commons^™

Novel Fed-Batch Process With In-Situ Product Recovery For Glycerol Fermentation To Butanol Using Clostridium Pasteurianum, Ammi Jani

Electronic Thesis and Dissertation Repository

Butanol, a next-generation biofuel, can be produced by fermenting glycerol using Clostridium pasteurianum. To address product inhibition, an integrated system that combined a fed-batch process with pervaporation was assessed against conventional batch and fed-batch fermentations. This study showed that with the novel process configuration, the productive fermentation time could be extended, translating to a 2.4-fold and 1.9-fold increase in butanol production relative to baseline fed-batch and batch operation, respectively. Further, it was demonstrated that butanol concentrations were able to be maintained below inhibitory levels throughout the fermentation. Despite this outcome, metabolic oscillations were revealed, indicating instability in the process. The …

Improved Fermentation Design And Screening Devices For Biobutanol Production, Garret Christopher Munch

Electronic Thesis and Dissertation Repository

A worldwide increase in demand for renewable fuels has revived interest in fermentatively produced butanol. However, butanol fermentation suffers from low product yields and productivity. The work presented in this thesis addresses part of these research and development needs at three levels: innovative fermentation process design; genetic manipulation for strain enhancement; and the development of a new tool for anaerobic process characterization and optimization.

Product yield could be increased through traditional fermentation engineering. Co-fermentation of butyric acid with glycerol increased the butanol yield from 0.45 mol/mol (mols C in butanol / mol C in substrates) to 0.51 mol/mol. In building …

Autohydrolysis Pretreatment Of Mixed Lignocellulosic Biomass, Claudio Lira

Electronic Thesis and Dissertation Repository

Lignocellulosic biomass, such as agricultural and forestry residues, can be transformed into valuable fuels and chemicals. However, the high cost of feedstock handling and the complex nature of cellulosic biomass processing and conversion remain two major challenges in biorefineries. This thesis aims to tackle these challenges by assessing the transformation of multi-feedstock using autohydrolysis pretreatment.

Corn cobs and stover (residues from corn processing), poplar chips (forestry residue), bagasse and wheat straw (agricultural residues) are abundant and often under-utilized cellulosic residues. These feedstocks were used to investigate the effects of biomass characteristics on the composition of the autohydrolysis pretreatment products. Moreover, …

Bioethanol Production Using Saccharomyces Cerevisae Cultivated In Sugarcorn Juice, Thirumalai Nambi Thiruvengadathan

Electronic Thesis and Dissertation Repository

For the first time, juice extracted from sugarcorn, a new Canadian energy crop, was used for bioethanol production. Physical and chemical characteristics of sugarcorn juice (SCJ) were determined. SCJ contained a maximum of 145 g/L of carbohydrates, with sucrose, glucose and fructose together contributing 80%. Effect of autoclaving and carbon filtration on juice sugars were investigated.

Shake flask fermentations using Saccharomyces cerevisiae grown in yeast extract supplemented SCJ produced a maximum of 45.6 g/L ethanol in 72 h. Bioreactor studies using un-supplemented SCJ achieved 40 g/L ethanol in 26 h, yielding a maximum of 0.46 g ethanol/g fermentable sugars, representing …

Co-Substrate Fermentation Of Jerusalem Artichoke Tubers And Crude Glycerol To Butanol With Integrated Product Recovery, Tahereh Sarchami

Electronic Thesis and Dissertation Repository

Butanol has long been considered a potential advanced liquid biofuel, in addition to its current application as an industrial solvent. It can be produced biologically; however, the conventional ABE fermentation suffers from many limitations, including low butanol titer, high cost of traditional raw materials, end-product inhibition and high butanol recovery costs. Possible solutions are the use of renewable low-cost feedstocks, genetic manipulations of Clostridia spp. to improve the strains’ butanol titer and tolerance, advanced fermentation techniques, and in-situ product recovery technologies.

In order to overcome some of these limitations, the overall goal of this thesis was to develop a process …