Engineering Commons^™

Examining The Relationship Between Lignocellulosic Biomass Structural Constituents And Its Flow Behavior, Ekramul Haque Ehite

Doctoral Dissertations

Lignocellulosic biomass material sourced from plants and herbaceous sources is a promising substrate of inexpensive, abundant, and potentially carbon-neutral energy. One of the leading limitations of using lignocellulosic biomass as a feedstock for bioenergy products is the flow issues encountered during biomass conveyance in biorefineries. In the biorefining process, the biomass feedstock undergoes flow through a variety of conveyance systems. The inherent variability of the feedstock materials, as evidenced by their complex microstructural composition and non-uniform morphology, coupled with the varying flow conditions in the conveyance systems, gives rise to flow issues such as bridging, ratholing, and clogging. These issues …

Lignin Valorization Via Reductive Depolymerization Using Promoted Nickel Catalysts And Sub- And Supercritical Methanol, Julia Parker

Theses and Dissertations--Biosystems and Agricultural Engineering

While lignin has been regarded as the most promising renewable feedstock for the sustainable manufacture of aromatic compounds, lignin valorization is necessary to improve the economic viability of biorefineries. Reductive catalytic fractionation (RCF), which combines delignification and lignin depolymerization into a single stage while maintaining the structure and integrity of the cellulose component, has evolved as an effective method for processing biomass. The ability of Cu and Fe to promote the performance of a 20% Ni/alumina catalyst when converting native lignin to alkylphenols by RCF in sub- and supercritical methanol was tested. The effectiveness of lignin extraction as measured by …

Lignocellulosic Biomass Derived Activated Carbon For Energy Storage And Adsorption, Changle Jiang

Graduate Theses, Dissertations, and Problem Reports

Lignocellulosic biomass has been converted to hierarchical porous carbon materials which possess macro-, meso- and micro-pores. The natural structure of porous lignocellulosic structure was preserved during activation with further developed porosity by the activation. The activated carbon can be well applied to electrochemical double layer capacitor for transportation storage of ions as well as adsorbent materials for metal ion removal from wastewater.

The first chapter of this dissertation presents an introduction of biomass derived carbon and its applications. In the second chapter, both direct and indirect activation methods using carbon dioxide were adopted in this study. The results show that …

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, …

Understanding The Impacts Of Ammonia Fiber Expansion (Afex™) Pretreatment And Densification On Densified Products Quality And The Bioproducts Yield Through Enzymatic Hydrolysis And Fast Pyrolysis, Vijay Sundaram

Electronic Theses and Dissertations

Lignocellulosic biomass poses significant challenges during handling, transportation, and storage due to its low bulk density. Densification involves conversion of the low bulk density biomass into a highly compacted product which helps in improving the handling, transporting, and storage obstacles associated with biomass logistics. Besides the logistical challenges, the recalcitrant nature of the lignocellulosic biomass makes it even more challenging during the enzymatic hydrolysis. The carbohydrate components, cellulose and hemicellulose are not readily accessible by the enzymes during the hydrolysis process due to the presence of lignin. Pretreatment is the process to convert the native recalcitrant biomass in the form, …

Abe Fermentation From Low Cost Substrates, Kai Gao

Electronic Thesis and Dissertation Repository

The high cost of substrate and product inhibition in the fermentation broth remains two major problems associated with bio-butanol production. This thesis aims to solve these problems by examining abundant lignocellulosic biomass as potential feedstocks and exploring novel substrates such as carbohydrates derived from microalgae for ABE fermentation. The commonly observed toxic effect after pretreatment of lignocelluslosic biomass was removed by resin adsorption, where the resin could also serve as an in-situ butanol recvoery devices.

Corn cobs (an agricultural waste), switchgrass (an energy crop) and phragmites (an invasive plant in North America) were investigated as substrates for ABE fermentation by …