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Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan
Modeling Solvent Extraction Of Lignin From Hardwoods, Su Pan
McKelvey School of Engineering Theses & Dissertations
This study interprets the observed behavior of solvent extraction of lignin from hardwoods by adapting the framework of the FLASHCHAIN theory (Niksa and Kerstein, 1991; Niksa, 2017). A constitution submodel specifies distributions of molecular weight and reactive sites for native lignin. The model simulates delignification as depolymerization of lignin macromolecules into fragments small enough to be soluble. This process competes with intrachain condensation that consumes labile bridges without forming new fragments, and with recombination that forms larger chains and inhibits further depolymerization. After the soluble fragments are transported from the particle into the bulk solvent, all chemistry continues as long …
Bimetallic Catalyst For Lignin Depolymerization, Qishen Lyu
Bimetallic Catalyst For Lignin Depolymerization, Qishen Lyu
McKelvey School of Engineering Theses & Dissertations
This thesis is motivated by concerns regarding the need to develop more sustainable and economic technologies to meet rising global manufacturing and energy demands. These concerns have renewed governmental, industrial, and societal determination to reduce the world’s dependence on conventional natural resources and has led to considerable research on producing fuels and chemicals from feedstocks other than petroleum. Lignocellulosic biomass represents an abundant and renewable resource that could displace petroleum feedstock producing biofuels and multiple valuable chemical products with reduced greenhouse gas emissions. Lignin is the second abundant biopolymer source in nature and is found almost everywhere. Since the 1950’s, …
Exploring Methodologies To Improve Lignin Utilization In Biorefineries, James Meyer
Exploring Methodologies To Improve Lignin Utilization In Biorefineries, James Meyer
McKelvey School of Engineering Theses & Dissertations
The increasing world population, coupled with an improving quality of life, has driven a rapidly increasing demand for fuels, chemicals, and materials. Fossil carbon feedstocks, such as petroleum, are currently being consumed to meet these demands. The utilization of these feedstocks has negative impacts on human and environmental health, which are undoubtedly intensifying as a result of the increased reliance required to meet these demands. As an alternative way to meet these demands, biorefineries generate a wide range of fuels, chemicals, and materials from biomass, a renewable and sustainable resource. Current second-generation biorefineries use a plant-based feedstock, lignocellulosic biomass, comprised …
Lignin Conversion To Value-Added Products Via Heterogeneous Catalysts, Yu Gao
Lignin Conversion To Value-Added Products Via Heterogeneous Catalysts, Yu Gao
McKelvey School of Engineering Theses & Dissertations
Increasing world population has led to great demands for fuels, chemicals, and materials, and has raised concerns over the depletion of non-renewable resources and the environmental impacts of their processing and utilization. However, the biorefinery concept suggests lignocellulosic biomass can be used as an alternative resource for producing a range of fuels, chemicals and materials to fulfill these demands in a sustainable way. Hence, fermentation technologies are widely developed to efficiently utilize lignocellulosic carbohydrates. However, the non-carbohydrate fraction of biomass, lignin, is still considered as waste and is under-utilized as low-grade fuel, mainly for local heat and electricity production. Since …