Engineering Commons^™

Evaluation Of Biomass As Bio-Additive In 3d Printing, Shuyang Zhang

Doctoral Dissertations

The petrol-based polymer has been widely applied in current daily life. The end-of-life of polymeric products has drawn environmental concerns. One of the solutions to such issues is to use bio-renewable materials to replace or reduce the use of petrol-based materials. Lignocellulosic materials are one of the potential candidates. Along with the features of 3D printing and the unique properties of biomass, 3D-printed biomass-based materials could be promising in preparing sustainable alternatives.

In this dissertation, lignin and other biomass were applied to various 3D printing techniques for sustainable composites. Stereolithography (SLA) was first used, and the kraft softwood lignin was …

Improving Lignin Recovery From Paper Mill And Biorefinery Waste Streams Via Liquid-Phase Splitting, Carter Fitzgerald

All Dissertations

Lignin is an abundant biopolymer with significant promise due to its aromaticity. It has been targeted as a replacement for a number of petroleum-based products including adhesives, coatings, polyurethane foams, activated carbon, and carbon fibers. However, commercially available bulk lignins are too polydisperse, and contain too many residual metals from the pulping process that are detrimental to the properties of the final product.

The Sequential Liquid-lignin Recovery and Purification (SLRP) process was developed by Michael Lake and John Blackburn, in collaboration with Clemson, with the intention of creating a continuous method for recovering lignin from paper-mill black liquors. Thies and …

Hydrothermal Liquefaction (Htl) Of Lignocellulosic Biomass For Biocrude Production: Reaction Kinetics And Corrosion-Resistance Performance Of Candidate Alloys For Reactors, Haoyu Wang

Electronic Thesis and Dissertation Repository

In recent years, the rapid increase in the demand for clean energy and green chemicals as well as concerns over the supply and environmental impacts associated with fossil. resources have stimulated intensive research on conversion of bioresources, such as lignocellulosic biomass and biowaste, into energy, fuels, chemicals, and materials.

Hydrothermal liquefaction (HTL) is a unique thermochemical conversion process, particularly applicable for the conversion of wet biomass and biowaste feedstocks. Most of the biomass HTL studies are conducted in batch reactor and focus on the effects of catalysts, reaction temperature and time on production efficiency and chemical properties of the products. …

Engineering Lewis Acidic Materials For Biomass Conversion And Battery Applications., Md Anwar Hossain

Electronic Theses and Dissertations

My long-term goal is to develop catalytic systems to produce renewable energy for a sustainable society. The overall research objective of my dissertation is to advance understanding of Lewis acidic materials for (1) conversion of renewable lignin into phenolics and (2) enhanced cycling stability of lithium metal batteries to safely store renewable electricity from wind and solar, thereby laying the groundwork for our transition to a sustainable society. Petroleum is a conventional feedstock for current transportation fuels (gasoline, diesel, and jet fuels). However, petroleum is a finite resource and produces greenhouse gases (CO₂ and CH₄) upon processing, …

Co-Gasification Of Biomass And Plastic Waste In A Bubbling Fluidized Bed Reactor, Islam Elghamrawy

Electronic Thesis and Dissertation Repository

Plastics are versatile, durable, and can be manipulated to match different needs. The COVID-19 pandemic has demonstrated the importance of reducing plastic waste and is believed to be responsible for increasing the generation of plastic waste by 54,000 tons/day which was reported in 2020. Another widely available waste is biomass waste. Agriculture and agroforestry, forest and wood processing, municipal waste, and the food industry are all considered major producers of biowaste. Co-gasification is considered one of the most promising methods of chemical recycling that targets the production of syngas (hydrogen and carbon monoxide) and light hydrocarbon gases. In this study, …

Room Temperature Alkali Treatment Of Rice Straw For Enhanced Enzymatic Hydrolysis., Seth Mains

Electronic Theses and Dissertations

Due to the pollution of fossil fuels due to greenhouse emissions, researchers continue to search for alternative methods that allow for the clean production of energy, fuels, and polymer fibers. A method currently under investigation is the use of lignocellulosic biomass as a solution to current problems with energy and polymer fiber production. Through the process of pretreatment, possibilities for lignocellulosic biomass expand due to improved accessibility of the cellulose and hemicellulose which can be broken down via enzymatic hydrolysis into C5 and C6 sugars such as xylose and glucose. This study investigated the fermentation of the rice straw into …

Biomass-Derived Electrode Materials And Sustainable Processes For Supercapacitors, Katelyn M. Shell

Theses and Dissertations

Biomass is one of the most abundant natural resources and has been used as a source of energy for thousands of years. Biomass as a precursor for energy storage materials is still relatively novel and faces several obstacles before becoming commonly used in today’s electrical devices. Currently, energy storage devices, such as batteries, capacitors, and supercapacitors, utilize petroleum-derived graphitic carbons for anodes, generating a need for more sustainable materials. Biomass, as a carbon-rich source for electrode materials, presents a viable and economically feasible alternative due to the prevalent lignocellulosic compounds: lignin, cellulose, and hemicellulose. Preliminary studies on the solid residues …

Understanding Biomass Upgrading Through Hydrogenolysis Reactions: Kinetics And Mechanism, Jalal Tavana

Electronic Theses and Dissertations

This dissertation involves several hydrogenolysis reactions but is mainly focused on hydrodechlorination (HDC) of chlorobenzene (PhCl) and hydrodeoxygenation (HDO) of 2-furancarboxylic acid (FCA). Hydrodechlorination of PhCl has been the subject of research for some time. Here, we used a Pd/C catalyst to study this reaction though rigorous kinetics and mechanistic analyses in a CSTR reactor. The H₂/D₂ kinetic isotope effect (KIE) experiment revealed that H₂ is not involved in a rate controlling step. The kinetics data are in agreement with similar systems reported before and follow a first-order dependence on chlorobenzene, half order for hydrogen and …

Reaction Kinetics And Mechanism Investigations Of Renewable Chemicals Production From Biomass, Hussein Talib Abdulrazzaq

Electronic Theses and Dissertations

The development of the technologies and the improved processes for the production of high value bio-based chemicals is one of the most important challenges at the present time. This new movement is not only important from an environmental perspective, but also it is a profitable approach to provide affordable and efficient processes. Therefore, the chemical catalytic upgrading processes over various homogenous and heterogeneous catalysis could be an outstanding modification to upgrade biomass-derived platform molecule to high value applications. In this dissertation, we highlight our recent progress in developing new chemistries and processes for upgrading biomass-derived molecules and address the challenges …

Development And Characterization Of Robust And Cost-Effective Catalysts For Selective Biomass Upgrading To Fuels And Chemicals By Deoxydehydration, Bryan E. Sharkey

Doctoral Dissertations

The use of biomass-derived ligno-cellulose as a possible alternative source of fuels and chemicals to fossil-based hydrocarbons, however, biomass offers many challenges based on processing and its high oxygen content. One promising upgrading route is deoxydehydration, a reaction which combines a deoxygenation by a sacrificial reductant and dehydration in a single step to selectively convert vicinal diols into an olefin. This reaction is highly selective when using homogeneous oxo-rhenium catalysts, which can easily undergo the necessary changes in coordination and oxidation state, however the high cost of rhenium and difficulty of homogeneous catalyst recovery make these catalysts untenable for large …

Bubble Dynamics In A Sand Fluidized Bed In The Presence Of Biomass Pellets, Nicolas Torres Brauer

Electronic Thesis and Dissertation Repository

Given the worldwide concerns regarding fossil fuel availability, global warming, water, and air pollution and economy needs, there is an urgent requirement to develop and implement alternative energies. Biomass gasification can consume vegetal waste to produce syngas, which is a mix of carbon monoxide, hydrogen, and carbon dioxide. When biomass gasification is carried out in a fluidized bed, the process is highly efficient.

The experimental study of the present Ph.D. dissertation took place in a Plexiglas 0.44 m diameter unit, equipped with a CREC Optiprobe system and a video camera. The unit was filled with 200-900 µm sand particles and …

Elucidating The Properties And Mechanism For Cellulose Dissolution In Tetrabutylphosphonium-Based Ionic Liquids Using High Concentrations Of Water, Brad Crawford

Graduate Theses, Dissertations, and Problem Reports

The structural, transport, and thermodynamic properties related to cellulose dissolution by tetrabutylphosphonium chloride (TBPCl) and tetrabutylphosphonium hydroxide (TBPH)-water mixtures have been calculated via molecular dynamics simulations. For both ionic liquid (IL)-water solutions, water veins begin to form between the TBPs interlocking arms at 80 mol % water, opening a pathway for the diffusion of the anions, cations, and water. The water veins allow for a diffusion regime shift in the concentration region from 80 to 92.5 mol % water, providing a higher probability of solvent interaction with the dissolving cellulose strand. The hydrogen bonding was compared between small and large …

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 …

Heterogeneous Catalysis For The Upgrading Of Biomass Derived Chemicals Via Hydrodeoxygenation, Elizabeth Barrow

Theses and Dissertations

An important step in the upgrading of biomass derived chemicals is the removal of excess oxygen. The works reported here are focused on studying the heterogeneous catalysts that can be utilized for that upgrading through hydrodeoxygenation. This work begins with a discussion of the alkylation of short chain platform chemicals for chain growth and also demonstrates the proof of concept of combining alkylation and hydrodeoxygenation in a single step. Then, because of the promising nature of ReOx- Pd/CeO2 for selective hydrodeoxygenation, a detailed study of ReOx/CeO2 is presented. Finally, a new surface structure interpretation is presented for P/Ni(111) which could …

Literature Survey Of Wet-Waste And Hydrothermal Carbonization System: A Comparative Evaluation, Ramat Olaide Yusuf

Dissertations and Theses

This thesis describes the process of Hydrothermal carbonization and a comparative assessment on recent work done on the process using different feedstocks such as Raw Apple (RA), Apple chip pomace (ACP), apple juice pomace (AJP), grape pomace (GP), macadamia nut-shell (MNS), Sewage Sludge (SS), Poultry Litter (PL) and Grape Marc (GM). The data obtained from the literature survey was compared with the data obtained by the CCL team on the SWPS gasifier (HTC of poultry litter) to obtain how carbon conversion efficiency, syngas composition, thermal efficiency, char production rate, gas production rate and energy utilization vary with carbonization process conditions, …

Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation, Mohammad Saeed Safdari

Theses and Dissertations

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. Prescribed burning (controlled burning) is used as an effective tool in managing a variety of ecosystems in the United States to reduce accumulation of hazardous fuels, manage wildlife habitats, mimic natural fire occurrence, manage traditional native foods, and provide other ecological and societal benefits. During wildland fires, both live and dead (biomass) plants undergo a two-step thermal degradation process (pyrolysis and combustion) when exposed to high temperatures. Pyrolysis is the thermal decomposition of organic material, which does not require the presence …

Modeling Soot Formation Derived From Solid Fuels, Alexander Jon Josephson

Theses and Dissertations

Soot formation from complex solid fuels, such as coal or biomass, is an under-studied and little understood phenomena which has profound physical effects. Any time a solid fuel is combusted, from coal-burning power plants to wildland fires, soot formation within the flame can have a significant influence on combustion characteristics such as temperature, heat flux, and chemical profiles. If emitted from the flame, soot particles have long-last effects on human health and the environment. The work in this dissertation focuses on creating and implementing computational models to be used for predicting soot mechanisms in a combustion environment. Three models are …

Thermochemical Conversion Of Biomass: Detailed Gasification And Near-Burner Co-Firing Measurements, Jacob B. Beutler

Theses and Dissertations

An increasing emphasis on mitigating global climate change (global warming) over the last few decades has created interest in a broad range of sustainable or alternative energy systems to replace fossil fuel combustion. Biomass, when harvested responsibly, is a renewable fuel with many uses in replacing fossil fuels. Cofiring biomass with coal in traditional large-scale coal power plants represents one of the lowest risk, least costly, near-term methods of CO₂ mitigation. Simultaneously, it is one of the most efficient and inexpensive uses of biomass. Alternatively, biomass can be transformed into useful products through gasification to produce clean syngas for …

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 …

Experimental And Numerical Investigation On Tar Production And Recycling In Fixed Bed Biomass Gasifiers, Jia Yu

Doctoral Dissertations

"Bioenergy has been utilized for domestic purposes since pre-recorded history and it catches the highlight in the recent decades because it naturally benefits the world climate and energy security. Gasification is one of the key technologies to efficiently and economically convert biomass into syngas and further into biofuels. Despite these outstanding advantages, biomass gasification suffers from the formation of unfavorable byproduct tar and the consequential tar elimination. Moreover, the collected tar is toxic and thus requires storage and strict deposit method to avoid environmental pollution.

To understand the mechanisms of biomass gasification and tar production, simulations with Aspen Plus were …

Characterization Of Catalysts For Hydrodeoxygenation Of Bio-Oils Using Phenol As A Model Compound, Abdulazeez Mohammed Khlewee

Electronic Theses and Dissertations

Due to the environmental considerations, depletion of fossil fuel reserves and fluctuating non-renewable fuel price, converting non-edible lignocellulosic biomass into renewable energy resources has gained significant importance. Phenol has been chosen as a model compound for catalytic screening because it is abundant in bio-oil composition and shows a high resistance to oxygen removal during hydrodeoxygenation (HDO) reactions. HDO of phenol produces chemicals that can be used as transportation fuels (Aromatics) or fuel additives. Theoretically, HDO of phenol has two distinct reduction pathways: direct deoxygenation (DDO) and hydrogenation (HYD). The previous results published by our group showed a precedent activity and …

So2-Alcohol-Water Fractionation Of Sugarcane Straw, Asif Sharazi

Electronic Theses and Dissertations

Climate change resulting from fossil fuels combustion is motivating researchers to explore feasible routes to convert renewable biomass into biofuels and biochemicals for a sustainable society. Typically, biofuel is produced from corn or sugarcane but both feedstocks compete with human food supply. Thus, lignocellulosics as renewable feedstock represent a more ethical and ecofriendly approach. Sugarcane straw (SCS) is a cheap and abundantly available feedstock which potentially can be used for biofuels/biochemicals production. It can also help to mitigate environmental and health problems resulting from conventional practice of SCS burning in the fields.

There are different biomass conversion technologies for production …

Batch And Fed Batch Cultivation And Harvesting Of Nannochloropsis Gaditana For Environmental Applications, Roopa P. Devasya

Electronic Thesis and Dissertation Repository

Two challenging problems facing our world are the exhaustion of fossil fuels and climate change. Microalgae are eukaryotic phototrophs or prokaryotic cyanobacteria (blue green algae) that are able to capture CO₂ and produce lipids suitable for biodiesel, thus can mitigate these challenges. The potential application of microalgae biomass for biofuel production is a clean and sustainable approach to replace fossil fuels. An important consideration for reducing the cost of biofuel is the economical production of algal biomass with high lipid yields. In this study, the marine microalgae Nannochloropsis gaditana were investigated for biomass and lipid production using two …

Magnetic Stimulation On The Growth Of The Microalga Nannochloropsis Oculata, Manuella Oliveira

Electronic Thesis and Dissertation Repository

Fossil fuels, our principal sources of energy supply, are non-renewable and research is needed on alternatives that are renewable and potentially more environmentally friendly. Microalgae have been investigated as a future feedstock alternative to petroleum but the technology is still expensive and improvements are needed. Reduction in costs might be achieved by increasing algal biomass and lipid productivity. The lipids can be used to produce biofuels such as biodiesel and biojet fuel. The marine microalga Nannochloropsis oculata grows well and can accumulate high lipid content. In this study, the effects of static magnetic field stimulation (SMF) of 0 (control), 5, …

Designing And Development Of A Photobioreactor For Optimizing The Growth Of Micro Algae And Studying Its Growth Parameters, Sarmila Katuwal

Electronic Theses and Dissertations

This thesis presents the estimated value of materials required to grow 1g of biomass and the analysis of the light intensity with respect to flow path and flow rate. This thesis aims to design the sparger for a flat plate Photobioreactor, study the flow patterns at different flow rate of air flow and check the performance of flat plate PBR by growing the cyanobacteria. The estimated value to produce 1g of biomass (C_44.6H₇O₂₅N_7.68P_0.9S_0.3) was 0.099g of N, 0.493g of C, 0.160 g of Na, 0.026 g of P, …

Heat Transfer Analysis In A Paddle Reactor For Biomass Fast Pyrolyis, Ankith Ullal

Dissertations, Master's Theses and Master's Reports

Heat transfer analysis was performed on a novel auger reactor for biomass fast pyrolysis. As part of this analysis, correlations for specific heat capacity and heat transfer coefficients for biomass (sawdust) and sand (used as heat transfer medium) were developed. For sand, the heat transfer coefficient followed a power law distribution with reactor fill level and temperature. For raw biomass, the heat transfer coefficient also showed similar dependence on fill level, but was independent of temperature up to 300°C. These correlations were used in a one dimensional heat transfer model developed to calculate the heating time and heating rate of …

Understanding Glycoside Hydrolase Processivity For Improved Biomass Conversion, Suvamay Jana

Theses and Dissertations--Chemical and Materials Engineering

In nature, organisms secrete synergistic enzyme cocktails to deconstruct crystalline polysaccharides, such as cellulose and chitin, to soluble sugars. The cocktails consist of multiple classes of processive and non-processive glycoside hydrolases (GH) that aid in substrate accessibility and reduce product inhibition. Processive GHs attach to chain ends and hydrolyze many glycosidic linkages in sequence to produce disaccharide units before dissociation, and as such, are responsible for the majority of hydrolytic bond cleavages. Accordingly, processive GHs are targets for activity improvements towards efficient and economical biomass conversion. However, the mechanism and factors responsible for processivity are still not understood completely at …

Enzymatic Liquefaction Of Untreated Corn Stover, Neal N. Hengge

Open Access Theses

There is an ever increasing need for renewable alternatives to fossil fuels derived from petroleum. This makes feedstocks in the form of lignocellulosic biomass attractive substrates for the production of ethanol and value added chemicals. However, the economics of converting lignocellulosic materials involve high processing costs attributed with pretreatment of the biomass and the use of enzymes for saccharification. Corn stover was obtained for the examination of an upstream processing step to transform the material into a pumpable slurry for subsequent pretreatment and saccharification. Biomass liquefaction was carried out using the enzyme Depol 692L (Biocatalysts, Wales, UK) at 50°C with …

Bed Agglomeration Behavior In A Bubbling Fluidized-Bed Combustor, Ehsan Ghiasi

Electronic Thesis and Dissertation Repository

Agglomeration is a major operational problem during the combustion of biomass containing a high amount of alkali compounds. The agglomerate formation is mainly due to the presence of alkali elements in biomass ashes that form low-melting compounds in the combustion.

In the first part of this project, the critical amount of liquid that would lead to a severe agglomeration/de-fluidization was studied and determined in a lab scale bubbling fluidized bed (BFB) heated at elevated temperatures. To simulate the biomass ashes, various percentages of KCl and KCl-K₂SO₄ compounds at eutectic composition were mixed with silica sand as the …

Experimental And Theoretical Investigation Of Sustainable Fast Pyrolysis Biofuels From Woody Biomass, Bethany Jean Klemetsrud

Dissertations, Master's Theses and Master's Reports

Biofuels are an important advancement in alternative energy that can provide substantial environmental benefits compared to their conventional fossil fuel counterparts Said benefits are usually measured using life cycle assessments. However, it is not well understood yet how different methodological choices such as system boundaries, biomass feedstocks, conversion pathways, geographical data, etc. affect the conclusions drawn from biofuels LCA. This research shows large variability in life cycle assessment results and limits comparison across different biofuel pathways due to methodological choices set forth by policy and certification schemes. Advanced biofuels have not reached large scale production due to a limited understanding …