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Assessment Of Corn Stover Torrefaction On-Farm Biochar Production, Christina M. Gerometta
Assessment Of Corn Stover Torrefaction On-Farm Biochar Production, Christina M. Gerometta
Electronic Theses and Dissertations
Torrefaction is a thermochemical pretreatment process that is typically achieved by slowly heating biomass (<50°C/min) within the temperature range of 200 – 300°C under an inert atmosphere. This process yields a storable solid product with enhanced fuel characteristics that are influenced by the ligno-cellulosic composition of the original feedstock and the imposed torrefaction conditions (time and temperature). This study is an assessment of corn stover properties that are relevant for designing an on-farm torrefaction system. The first portion of this study compared the thermal decomposition behaviors of corn stover fractions (leaf, stalk, cob) to the respective ligno-cellulosic composition using thermo-gravimetric analysis. It was found that the thermal decomposition pattern correlates to the structure and ratio of ligno-cellulosic polymers and provides design guidelines for an on-farm torrefaction system capable of handling large quantities of mixed fraction stover. The second part of this study investigated the effects of torrefaction time and temperature on the mass and energy yield of mixed fraction corn stover using a 46.3 L batch style reactor. It was found that longer reaction times and higher temperatures were required to obtain mass and energy yields similar to those found using lab-scale reactors and finely milled samples. Non-uniform torrefaction occurred between fractions due to chemical composition of each fraction and proximity to the heating elements.
Using Acoustic Emission Monitoring For Energy-Based Fatigue Life Prediction, Sepehr Nesaei
Using Acoustic Emission Monitoring For Energy-Based Fatigue Life Prediction, Sepehr Nesaei
Electronic Theses and Dissertations
The study of fatigue and fracture mechanics is crucial to the health monitoring and overall safety of aerospace and civil structures. The materials used to manufacture these industry parts have inherent anomalies that eventually grow under cyclic loadings during regular operation. The ASTM and/or military testing guidelines used to analyze and qualify structures and materials for use are costly and time consuming. Therefore, any additional methods or knowledge that can be used to reduce the number of tests will be useful to the industry to avoid unnecessary costs. Acoustic emission (AE) monitoring is currently used in many applications to assess …
Modeling The H2s Concentrations Affected By Shelterbelts Downwind From A Swine Facility, Brett D. Pettigrew
Modeling The H2s Concentrations Affected By Shelterbelts Downwind From A Swine Facility, Brett D. Pettigrew
Electronic Theses and Dissertations
Odor from swine facilities can be a nuisance to the nearby residences and communities. Shelterbelts have been shown to positively impact the downwind air quality, but the impacts are dependent on wind speed and direction, and shelterbelt configuration. The first objective of this research was to develop an empirical model of shelterbelt-induced hydrogen sulfide (H2S) concentration reductions as a function of horizontal distance beyond a swine facility, based on data from a previous study by Hofer (2009). The Hofer (2009) study measured H2S concentrations at a swine facility at four discrete distances beyond the barn (55, 246, 510, and 805 …