Commercial activated carbon and newly polymer-derived carbon were utilized to selectively remove the model fermentation inhibitor, furfural, from water solution during bio-ethanol production. Morphology, pore structure and surface chemistry of the sorbents were characterized. The oxygen groups on the carbon surface were believed to have contributed to the decrease on the selectivity of activated carbon between furfural and sugars (Sugars are the valuable source of bio-ethanol production and should not be separated from solution). Oxidization of activated carbon by nitric acid generated more information which supports the above assumption. Different adsorption isotherm models and kinetic models were studied to fit commercial activated carbon and polymer-derived carbon individually. Bacterial cell growth, sugar consumption, and ethanol yield during the fermentation were investigated after inhibitors were selectively removed from the broth. The fermentation time was reduced from one week to one day after inhibitor removal. Different methods of sorbent regeneration were investigated, including thermal regeneration, pH adjustment and organic solvent stripping. Low ethanol-containing water solution appears to be the most cost-effective way to regenerate the spent sorbent in the industrial application. A sorption/desorption cycle was designed and the sorbents were regenerated in a fixed-bed column system using ethanol-containing liquid from fermentation. The results were stable after running 20 times of sorption/desorption cycle.

Univ., Diss.--Utrecht, 2007.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 104-105). Also available on the Internet.

Thesis (M.S.)--University of Missouri-Columbia, 2003. / Typescript. Includes bibliographical references (leaves 104-105). Also available on the Internet.

Thesis (M. S.)--Chemical Engineering, Georgia Institute of Technology, 2010. / Committee Chair: Banerjee Sujit; Committee Member: Deng Yulin; Committee Member: Haynes Danny. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Thesis--Auburn University, 2010. / Abstract. Includes bibliographic references (p.111-129).

The second generation bioenergy crops Miscanthus x giganteus and short rotation coppice (SRC) willow are the two main bioenergy crops in the UK and have become an integral part of legislation to provide an alternative to fossil fuels and to reduce national greenhouse gas (GHG) emissions. To reach emission targets, it is estimated that approximately 350,000 ha of land could be made available for bioenergy crops by 2020. Despite the promise of these crops, there have been very few field-studies regarding soil GHG (CO2, CH4 and N2O) emissions and many of the published studies are life cycle analyses or modelled fluxes from soils using default values from the IPCC. The first aim of this research was to quantify the in situ soil GHG budget and to establish the drivers of these GHG fluxes for Miscanthus and SRC willow. The second aim of this research was to provide a more in-depth understanding of C cycling under Miscanthus i.e. litter and roots through two field experiments. Overall, the results from this work confirm minimal emissions of CH4 and N2O from soil under Miscanthus and SRC willow. CO2 flux was found to be the major efflux from soils and it was found in Miscanthus, that the majority of this flux was derived from below ground respiration. Litter played an important part in providing nutrients to the soil, which is vital in systems that are not fertilised. Litter also contributed to SOM accumulation on the soil surface and may promote long-term C sequestration. The results from this work combined with other literature would suggest that these second generation crops offer advantages to first generation crops, but more field-based studies are required to say if they can offer the large-scale GHG savings needed to be a viable alternative to fossil fuels.

Development of biomass energy plantations is one approach to mitigate and adapt to climate change and the energy challenges related to it; however, climate change will affect the climate conditions and in turn the selection of crops and trees suitable for renewable energy sources. In Estonia, electricity is mainly based on oil shale but since their integration in the European Union they are required to increase the share of energy from renewable sources. In this study, the possible changes of suitable species are assessed by examining the current and the future prospects and potentials with biomass energy derived from energy plantations in Estonia, taking climate change into consideration. The biomass energy potentials for the species that are climate suitable in current and future time are manually estimated, using a case study approach when determining the yields. The study result suggests that biomass energy from crops and trees have great development possibilities and that climate is not a key limitation for the selection of suitable species; in addition, the energy crops and trees appear to suit the future climate conditions better than the current. The results indicate that the established national target of 25% of energy from renewable sources in gross final consumption of energy by 2020 could be achieved to a large extent by putting energy plantations into practice.

The feasibility of wood based energy plants in the off-grid Brochet community in Manitoba were analyzed by survey, interviews and document review in this research. Four areas were explored to assess the suitability of biomass energy generation, namely: the community’s perspective, resource assessment, technology availability, and cost attractiveness. Harvesting sufficient woody biomass from local wild fire burnt areas, in particular, as well as local green forests could be an appropriate and feasible option. A heat only plant is considered to be the best choice for biomass plant establishment in Brochet, followed by combined heat and power plants. A cost analysis showed that a biomass plant at Brochet is more economical than the current planned investment in the diesel power facility. The lack of resolve about who wants to run and pay for the operation and the uncertainty of the reliability of biomass technologies are two large barriers to biomass energy generation in the community. Overall, biomass energy generation options are promising to eliminate or reduce the use of fossil fuel in Brochet.

The Knoevenagel reaction was applied to form a carbon-carbon double bond between the aldehydes (HMF, furfual) and an alpha di-carbonyl compound. The alpha di-carbonyl compound used was malonic acid, which can be bio-derived from glucose along fermentation routes. The effects of solvents (THF, water, ethanol, isopropanol, ethyl ether, toluene) and catalysts (e.g. homogeneous and heterogeneous amines, solid basic oxides) on the yields of alpha-beta unsaturated acids were investigated. It was found that the homogeneous amines worked well in THF solvent (90-100% conversion, 99% selectivity for furfural and HMF), while the poly(styrene) supported ethylenediamine gave a higher conversion and selectivity for HMF (65± 5%, 99% selectivity) over furfural (58 ± 7%, 99% selectivity). This trend was also present in competition reactions where both HMF and furfural were reacted in the same vessel. á-â Unsaturated mono-acids for both HMF and furfural were identified as minor side products. However, levulinic acid did not work as well under the conditions studied. Lastly, among the solvents studied, several caused precipitation of the Knoevenagel products.