Michael D. Boyette

Development of a Charcoal Slurry for Low-speed Diesel Engines: A Preliminary Study

Liquid fuels have become the de facto standard for internal combustion engine systems. Biomass has been considered in recent years a very important feedstock for sustainable energy systems. Thermal conversion of biomass generates several usable forms of fuel, but the most commonly produced are low caloric gases, oils, and charcoal. The charcoal produced from this process retains up to 80% of the energy contained in the parent biomass but exists as a solid fuel. This study focuses on the derivation of a liquid fuel from this charcoal as a preliminary step towards the use of a charcoal-based fuel in compression ignition engines. A biomass pyrolysis apparatus was used to produce charcoal at controlled temperatures. Charcoal-oil slurries were produced and used as fuel for a diesel engine as a proof of concept.

Advanced oxidation of toluene using Ni-olivine catalysts: Part 1. Synthesis, characterization, and evaluation of Ni-olivine catalysts for toluene oxidation.

This research focused on advanced oxidation of toluene by evaluating Ni-olivine catalysts in combination with ozone. Specifically, our objectives were to: (1) synthesize catalysts via electroless plating (ELP) and thermal impregnation (TI) techniques to impregnate nickel onto the olivine surface; (2) characterize Ni-olivine catalysts by Brunauer-Emmett-Teller specific surface area, electron microscopy, energy dispersive spectroscopy, and x-ray photoelectron spectroscopy to understanding the mechanisms of toluene oxidation; (3) determine the catalytic activity of the newly synthesized Ni-olivine catalysts in the oxidation of toluene; and (4) evaluate the influence of varying toluene and ozone concentrations on Ni-olivine oxidation efficiencies. Testing was performed in a continuous packed bed reactor (200°C). Toluene (200 to 600 ppmv) and ozone (70 to 800 ppmv) were injected into the heated reactor, while inlet and outlet concentrations were measured using gas chromatography. Results indicated that 90% of toluene was oxidized within a 1 s residence time using ELP and TI catalyst synthesis techniques and 70 ppmv ozone. Microscopic and spectroscopic analyses revealed porous structures and a nickel film uniformly coating the electroless plated olivine surface, mostly comprised of Ni-P-O, while the thermally impregnated Ni-olivine possessed sparingly deposited Ni2O3 compounds on the surface. An increase in ozone concentrations increased toluene oxidation efficiencies, whereas an increase in toluene concentrations temporarily decreased toluene oxidation efficiencies. Knowledge obtained from this research can be used for synthesizing advanced catalysts for toluene oxidation at significantly lower temperature.

Advanced Oxidation of Toluene Using Ni-Olivine Catalysts: Part 2. Toluene Oxidation Kinetics and Mechanism of Ni-Olivine Catalysts Synthesized via Electroless Deposition and Thermal Impregnation

The production of synthesis gas (syngas) involves the gasification of biomass under oxygen-limited conditions, which also produces tars. Tars pose significant problems for mechanical devices by depositing on piping, resulting in clogging and engine fouling. While recent research has shown that thermally impregnated Ni-olivine has been effective in reforming tars into H2 and CO, this technique possessed limited economic feasibility due to high input energy requirements. Thus, stable, active, and inexpensive catalysts are required for effective and efficient conditioning of syngas. This research compared the activity of Ni-olivine catalysts synthesized via electroless plating (ELP) (35°C) and thermal impregnation (TI) (1400°C) for oxiding toluene in a flow-through reactor. The objectives were to (1) determine the kinetics of toluene oxidation, (2) propose a reaction mechanism for toluene oxidation, and (3) investigate the effect of syngas on toluene oxidation. Conversion of toluene using Ni-olivine catalysts increased with increasing ozone concentration and temperature, as well as decreasing toluene molar flow rate, and facilitated the complete oxidation of toluene. The information obtained from this research is expected to provide opportunities for efficient cleanup of tars from biomass gasification facilities at lower temperatures.

DESIGN OF A POST-FRAME BURLEY TOBACCO CURING STRUCTURE FOR WIRE-FRAME RACKS

Abstract The purpose of this research was to develop a post-frame structure to utilize wire-frame racks in the curing of burley tobacco in nontraditional growing areas. Since the 2004 federal tobacco quota buyout legislation, burley tobacco production has moved into the piedmont and coastal plain regions of North Carolina, where there was no existing burley curing infrastructure. This presented a unique opportunity to build curing infrastructure based on the most efficient and least costly alternatives. The current trend for mechanically harvested burley tobacco utilizes the cut-notch method. Wire-frame racks are used by many growers as part of an infield curing structure for cut-notch harvested plants. Incorporating wire-frame racks into a post-frame structure provides greater protection from adverse weather than a typical in-field wire-frame curing structure. All of the in-field advantages and mechanisms of wire-frame racks are retained with this design. A 2-tier test building was designed and construct...

DESIGN OF A PNEUMATIC BALING SYSTEM FOR BURLEY AND FLUE-CURED TOBACCO

Abstract Current on-farm tobacco-baling technology generally utilizes hydraulic power to press tobacco into bales prior to marketing. The high system pressures at which hydraulic systems operate pose a potential risk to workers. Further, hydraulic systems are costly and subject to hydraulic oil leaks, which can contaminate baled tobacco. A pneumatically driven, vertically oriented, multistroke baler was designed as a safe and affordable alternative to current hydraulic balers. Pneumatics were chosen because of the lower system operating pressure, potentially lower costs, and much reduced risk of tobacco-bale contamination. The transmission of power was achieved through a reversible pneumatic gear motor operating opposing left- and right-hand acme threaded rods coupled together to form a power screw. The power screw actuated the bale plunger through a scissor-jack design, which was used to counter the nonlinear force response of compressed tobacco. The completed baler was tested with burley tobacco grown d...