Engineering Commons^™

Hydrolytic Depolymerization Of Lignin For The Preparation Of Polyols And Rigid Polyurethane Foams, Nubla Mahmood

Electronic Thesis and Dissertation Repository

This doctoral study was aimed to produce bio-polyols from Kraft lignin (KL) and hydrolysis lignin (HL) via depolymerization and utilize the lignin-derived bio-polyols in the preparation of bio-based rigid polyurethane (BRPU) foams at high percentage of bio-contents (50-70 wt.%). This study demonstrated that depolymerization is a practical and effective approach to unleash the potential of utilization of lignin, of complex structures and low reactivity/functionality, for bioproducts and biomaterials.

Depolymerization of KL was realized in alkaline medium using water alone as a solvent or employing water-ethylene glycol (EG) mixture via a low pressure (psig) proprietary process, both effective for producing low …

Impact Of Local Bed Hydrodynamics On Jet-Bed Interaction, Maryam Mohagheghi Dar Ranji

Electronic Thesis and Dissertation Repository

In Fluid Coking^TM or Fluid Catalytic Cracking liquid feedstocks are injected into a bed of fluidized particles. Uniform distribution of liquid feed on fluidized particles increases the yield of valuable products and improves operability in these processes. Contact between the injected liquid and the bed particles can be greatly affected by the liquid properties and local bed hydrodynamics.

The impact of parameters such as liquid properties, fluidization velocity, nozzle atomization gas flowrate, nozzle location and inclination were investigated on the distribution of liquid sprayed into a fluidized bed with a reliable and fast response capacitance meter. This method was …

Studies Of Anode Electrodes For The Biogenerator, Vahid Vajihinejad

Electronic Thesis and Dissertation Repository

The BioGenerator as a fundamentally new type of H₂-to-electricity conversion system offers a quite sustainable and cost effective solution to the challenges associated with the use of fuel cells in renewable power grids.The development of an anode electrode for the BioGenerator was subject of this work. The unique features of the BioGenerator require unique electrodes, and more specifically anode. The combination of biological cathodic liquid and the hydrogen gas fuel require specific hydrophobic/hydrophilic properties of the anode. Several different methods for anode formation were studied. The spreading technique was found to be most appropriate for the conditions in …

Surfactant Assisted Dispersion Of Single-Walled Carbon Nanotubes In Polyvinylpyrrolidone Solutions, Tennison Yu

Electronic Thesis and Dissertation Repository

Obtaining stable aqueous dispersions is one of the main challenges hindering a widespread and effective use of single-walled carbon nanotubes (SWNT) in many applications. Although it has been recognized that their versatility makes them an extremely attractive material, the unique molecular structure that gives SWNTs their unmatched electronic, mechanical, and thermal properties is also responsible for strong van der Waals interactions. This, combined with extremely high aspect ratios and flexibility, causes SWNTs to adhere strongly into tightly bundled ropes. In these bundles, SWNTs are not as useful as their linearized unbundled equivalents. Thus, in order to take advantage of their …