Master of Science, The Ohio State University, 2021, Chemical Engineering

Eutrophication is an environmental nuisance which costs goverments billions of US dollars every year. Precious nutrients whose reserves in nature remain limited are lost. In the course of tackling this problem, urban wastewater has become the focus of intensive research. Meanwhile, agricultural runoff which can be traced as a key source of nutrient pollution remains ignored. In this work, we present agricultural runoff as a lucrative opportunity for nutrient recycle. We identify current technologies capable of recycling nutrients with a focus on Phosphorus. Since the efficiency of best management practices at nutrient capture has been a topic of intensive research, we consider ecological solutions alongside technological solutions. We analyze the flow of materials through the system boundary for selected recycle routes. We examine the feasibility of implementing these technologies from a Techno-Economic (financial) as well as Life Cycle (environmental) point of view. Indicators are developed to assess the degree of circularity at different points in the process. We find that although the purely technological option outperforms the other routes in terms of recycle efficiency, the economic and emissions burden associated with it are too high. The purely ecological option appears to be a promising candidate on all accounts.

Committee: Bhavik Bakshi Dr (Advisor); Margaret Kalcic Dr (Committee Member) Subjects: Chemical Engineering

Master of Sciences (Engineering), Case Western Reserve University, 2019, Civil Engineering

Tornadoes are hazards of low probability of occurrence and high consequences that cost the United States billions of dollars each year. Electric power distribution systems are susceptible to damage due to tornadoes with the utility poles being the most vulnerable components. Additionally, the reliability of power distribution systems can be affected by the deterioration of the strength of utility poles with age. Many utility companies nowadays are considering the use of steel and prestressed concrete poles instead of wood poles, which are the most widely used in the United States. Up to date, very few studies have been performed to study the behavior of power networks when subjected to tornadoes. This research proposes a framework to perform reliability analysis, cost analysis, and target hardening of power distribution systems subjected to tornado hazard. It also offers a framework to compare the reliability of wood, steel, and prestressed concrete utility poles subjected to tornadoes through fragility analysis considering the deterioration of the strength of the poles with age.

Committee: Yue Li (Advisor); Xiong Yu (Committee Member); Michael Pollino (Committee Member) Subjects: Civil Engineering

Doctor of Philosophy, University of Akron, 2017, Civil Engineering

Chloride induced corrosion is known as the dominant cause of premature damage in reinforced concrete (RC) bridges in the United States. However, the current corrosion management strategies do not suggest a suitable procedure for performance evaluation and optimum design/repair of RC bridges in corrosive environments. Corrosion affects the integrity of the RC structure by deteriorating the material properties and the bond at the steel-concrete interface. In this study, first, a simple probabilistic model of bond strength considering corrosion effect is developed using multivariable regression technique based on a comprehensive database collected from the literature. The predictions are found to be accurate and unbiased when compared with the experimental results. The proposed bond model is employed in the nonlinear finite element models of intact and corroded RC beams to investigate the importance of steel-concrete bond modeling on evaluating flexural behavior of the beams. Then, the minimum required development length for a given corrosion level is calculated and its sufficiency is investigated through a numerical analysis. In the next step, an analytical procedure is proposed for predicting the nonlinear flexural behavior of intact and corroded RC beams with or without lap splices using the developed bond strength. The proposed analytical procedure can facilitate the performance evaluation and reliability assessment of the existing intact/corroded RC structures. The accuracy of the proposed procedure is verified through several experimental and numerical case studies. Furthermore, the proposed procedure is applied to predict the flexural behavior of intact and corroded T-beams of an RC bridge and the results are verified though the finite element analyses. Next, a module based on a reliability-based multi-objective design optimization (RB-MODO) technique using a non-dominated sorting genetic algorithm II (NSGA-II) is developed for the optimum design of RC bridge (open full item for complete abstract)

Committee: Qindan Huang (Advisor) Subjects: Civil Engineering

Doctor of Philosophy (Ph.D.), University of Dayton, 2016, Mechanical Engineering

One of the most promising applications of solar energy is water desalination, especially in regions where fresh water is scarce and sunlight is abundant. Desalination is a growing and necessary source of fresh water, but it is highly energy-intensive. Conventional desalination is currently supported with fossil fuels, and it is critical to explore renewable options to reduce pollution. Solar-powered desalination is currently being studied, with various small to medium scale plants at several locations around the world. Some methods use heat exchangers and medium fluids to transfer heat to the brine while others directly circulate the brine through solar array. Some systems produce distilled water during daylight hours only, while others employ control systems and thermal storage to achieve continuous production of distilled water. This work proposes two designs for solar powered thermal desalination. Both of the designs use a novel thermal storage system for efficiently managing and delivering solar energy to a desalination unit. The system consists of a pair of tanks that alternate roles each day between receiving energy from a solar array and delivering energy to the desalination unit. The first design couples the dual thermal storage tanks to an array of concentrating solar collectors and a multi-stage flash (MSF) desalination unit. MSF operates by partially flashing a stream of hot brine within a series of vacuum chambers, and condensing the vapors onto the outside of heat-exchange tubes that carry incoming feedwater. This process creates a flow of pre-heated brine which enters one of the storage tanks and is further heated by circulation through the solar array. The brine is directly heated in the array, such that no medium fluid or heat-exchangers are necessary. The other tank, which was charged in this same manner the previous day, provides hot brine to supply the MSF. The storage tanks alternate roles at approximately sundown each day. This design respond (open full item for complete abstract)

Committee: Choi Jun-Ki (Committee Chair); Hallinan Kevin (Committee Member); Usman Muhammad (Committee Member); Chiasson Andrew (Committee Member) Subjects: Mechanical Engineering

Master of Science, The Ohio State University, 2015, Food, Agricultural and Biological Engineering

With a growing global population and a higher demand for potable water, society relies on Reverse Osmosis (RO) for large-scale desalination. Reverse Osmosis is currently the most economic and commonly used method to desalinate saline or brackish water to produce potable drinking water. This research investigated the alternative use of Microbial Desalination Cells (MDCs), and compared MDC technology to RO by performing life cycle and economic analyses. The additional advantage of an MDC, as compared with an RO desalination plant, is the production of a small amount of electricity as a by-product of the microorganisms' anaerobic respiration in the MDC device. The goal of this project was to determine if this production of electricity was enough to make MDC technology a more sustainable and economically favorable long term desalination option. A currently operating reverse osmosis plant was analyzed along with a laboratory scale MDC. Given that the RO facility under investigation is much larger than the bench scale MDC, both analyses were normalized on a per cubic meter basis, for implementation in Columbus, Ohio, USA. Results indicate that although the MDC is not currently the more sustainable option, design improvements can be made to the MDC that will make this technology much more promising in the future.

Committee: Ann Christy (Advisor); Bhavik Bakshi (Committee Member); Matthew Roberts (Committee Member) Subjects: Agriculture; Alternative Energy; Environmental Management; Environmental Science; Sustainability; Water Resource Management

Doctor of Philosophy, The Ohio State University, 2024, Chemical Engineering

The ill effects of climate change are unfolding in real time, as species and ecosystems face irreversible destruction. Climate action is needed now more than ever, as ambitious targets set by the Paris Agreement seem far-reaching in the wake of global average temperatures above 1.5C over their pre-industrial levels recorded over a continuous 12 month period for the first time. Countries, organizations, and companies alike have pledged to limit their net greenhouse gas (GHG) emissions to the environment to zero, via nationally determined contributions and corporate net-zero commitments. Such commitments remain unattainable in the absence of guidance like convergent carbon accounting methods, systems models, and roadmapping frameworks. This dissertation seeks to bridge this gap for the chemicals and materials industry (CMI). The chemical industry generates the “hardest to abate” emissions among the industrial sector due to the fixed carbon content of its products. However, as chemical energy carriers such as hydrogen and methanol gain prominence as solutions to the intermittency issues of renewable energy, the net-zero transition of chemicals becomes tied to the net-zero goals of more expansive and ubiquitous industries such as the power sector. The decarbonization of chemicals to this end, requires estimation of material and carbon flows, and baseline emissions of its current global operations. The frameworks in literature lack appropriate structure and comprehensiveness for such analysis, and relevant process and price data are inaccessible and cost prohibitive. We therefore develop an inventory of first principle based, mass balance compliant, publicly available process and cost data for CMI processes, sourced from the public domain. We devise a regression framework capable of handling conflict ridden data, and an algorithm to map resource, intermediate, product, and emission flows of any chemical system with known product capacities. The resulting Global (open full item for complete abstract)

Committee: Bhavik Bakshi (Advisor); Joel Paulson (Committee Member); Lisa Hall (Committee Member) Subjects: Chemical Engineering; Climate Change; Energy; Engineering; Environmental Engineering; Technology

Doctor of Philosophy, The Ohio State University, 2022, Food, Agricultural and Biological Engineering

Corn (Zea mays L.) grain and stover are the primary feedstock for first- and second-generation biofuel production in the U.S. due to their abundant availability. While corn grain-based biofuel has already reached the mandated target, cellulosic biofuel production from corn stover has been a struggle. Harvest and post-harvest logistics of corn stover is one of the major challenges faced by the cellulosic biofuel producers. Existing corn stover harvest and post-harvest logistics system uses a multi-pass approach to bale the biomass in the field, collects biomass with high soil contamination, and produce bales with low bulk density that doesn't fulfill the payload capacity of the trucks used for transportation. The novel whole-plant (WP) corn harvest and post-harvest logistics system addresses all of these challenges by cutting the corn plant at the ear level and baling the corn plant with its ear intact corn ear in a single-pass, which also reduces the harvest operations and soil contamination of the biomass. In addition, with the inclusion of corn ear in the bale, the bulk density of the bales produced is increased, which improves the productivity of the post-harvest logistical operations including handling, storage and transportation. Thus, the main objectives of this dissertation were to evaluate the harvest timing and physico-chemical properties of WP corn in season, evaluate the storage characteristics of WP corn when densified into small and large rectangular bales, and assess the techno-economic feasibility and life-cycle energy use and greenhouse gas (GHG) emissions associated with the WP corn logistics system. Corn grain and stover harvest timing is mainly dictated by their moisture, where corn grain harvest is followed by stover harvest. Since they are harvested at the same time in this system, it was important to determine the suitable harvest timing for WP corn that would minimize storage losses. Moisture and dry matter of the corn plant were tracked we (open full item for complete abstract)

Committee: Ajay Shah (Advisor) Subjects: Agricultural Engineering

Master of Science (MS), Ohio University, 2021, Environmental Studies (Voinovich)

Life cycle analysis (LCA) allows for evaluation of the environmental costs of production systems from creation to disposal. Many LCA studies are available for various renewable energy production systems, however, there is a need for LCAs that quantify the benefits of energy coproduction systems. Coproduction systems refer to a partnership of energy production systems that reciprocate waste products in a mutually beneficial way, thereby decreasing waste streams and offsetting input streams from both systems. This study evaluates how biomass crop coproduction with an anaerobic digestion (AD) system affects the life cycle greenhouse gas emissions and material waste streams relative to standalone bioenergy systems. A literature meta-analysis was used to collect life cycle inventories, emissions, and cost for: 1) Advanced biofuel production from perennial grass, 2) Biogas production from AD. The reduction in emissions due to coproduction was 0.28 kgCO2eq per kWh electricity produced. Life cycle impacts were most influenced by the following categories: facility construction, harvest and lignin use, transportation and biorefinery, and effluent, fertilizer, and soil. The cost for coproduction of biogas from food waste and bioethanol from perennial grass was reduced by 10.8% and 7.0%, respectively, when compared to the cost for individually managed systems.

Committee: Sarah Davis (Committee Chair); David Bayless (Committee Member); Derek Kauneckis (Committee Member) Subjects: Agriculture; Alternative Energy; Biogeochemistry; Climate Change; Energy; Environmental Economics; Environmental Science

BA, Oberlin College, 2018, Environmental Studies

Plastic straws are one of the most abundant items found in oceans and coastal cleanups around the United States and internationally. Plastic does not decompose over time, so all the plastic we have ever made is still around, affecting every ecosystem on the planet. Drinking straws are made of 100% recyclable material, but because of their small size most recycling plants are not able to process them so they are sent to landfills. Petroleum-based plastic production is also a large source of greenhouse gas (GHG) emissions, making up 1-3% of the United States' carbon emissions alone. By considering green alternatives to PP drinking straws, we can see if there actually are affordable alternatives that can help reduce plastic waste and carbon emissions. This case study focuses on the Feve, a restaurant in the City of Oberlin, and aims to understand the cultural significance of drinking straws in town, and uses that information to suggest ways of changing straw distribution behavior and minimize plastic waste. This study also compares the environmental and financial costs of the Feve using petroleum-based polypropylene (PP) drinking straws versus “greener” alternatives by constructing a modified life cycle analysis to determine if switching to biodegradable polylactic acid (PLA) plastic drinking straws decreases the Feve's carbon and plastic waste footprint. By tracing GHG emissions created in the production of plastic resins, transportation of materials and products, and disposal of plastic straws, I compare the carbon footprint of three products to see if one is better for the environment than the others. I hope this study can be used as a model to help other restaurants make plans to reduce their plastic waste and carbon footprint at an affordable cost.

Committee: Cynthia McPherson Frantz (Committee Co-Chair); Roger H. Laushman (Committee Co-Chair) Subjects: Business Costs; Climate Change; Comparative; Conservation; Energy; Environmental Economics; Environmental Education; Environmental Science; Environmental Studies; Gases; History; Management; Marketing; Petroleum Production; Plastics; Polymers; Psychology; Sanitation; Social Psychology; Social Research; Sustainability; Transportation

Master of Science (M.S.), University of Dayton, 2018, Renewable and Clean Energy

The off-grid location and unreliable electricity supply to medical clinics in remote parts of India make it difficult to safely store vaccines and other medications using traditional refrigeration systems. The Engineers in Technical Humanitarian Opportunities of Service-learning (ETHOS) program at the University of Dayton, in collaboration with Solar Alternative and Associated Programmes (SAAP) of Patna India, are developing a novel refrigeration system which works on the principle of solar thermal adsorption. This refrigeration system does not require electricity for operation and uses safe, environmentally benign and locally available adsorption pair of ethanol-activated carbon. A bench -scale prototype was developed at the University of Dayton using ethanol-activated carbon as working pair which can generate evaporative temperatures between 2°C and 8°C. The existing horizontally oriented system can achieve targeted refrigeration temperatures (2 - 8°C) during the adsorption cycle and ethanol can be desorbed from the activated carbon during desorption. However, the horizontal geometry inhibited the return of liquid ethanol to the evaporation chamber. A new vertical oriented bench scale system was built to addresses the limitation of the original prototype. The effects of desorption heating temperature, desorption time duration, double activation of activated carbon on evaporative cooling, and possible decomposition of ethanol during desorption were analyzed. Experimental results suggested better desorption happens at elevated temperature (90-125°C) and most of the desorption happens in the first 1-2 hours of heating the adsorbent bed. The high pressure on the evaporator side for multiple adsorption-desorption process, and analysis of GC/MS of desorbed ethanol obtained from the analytical chemist showed possible decomposition of ethanol. The ethanol decomposition prevented multiple cycle operation of the system. The use of double activation techn (open full item for complete abstract)

Committee: Amy Ciric Ph.D. (Committee Chair); Jun Ki Choi Ph.D. (Committee Chair); Li Cao Ph.D. (Committee Member) Subjects: Alternative Energy; Chemical Engineering; Chemistry; Climate Change; Energy; Engineering; Environmental Science; Experiments; Materials Science; Mechanical Engineering

Master of Science (MS), Ohio University, 2017, Environmental Studies (Voinovich)

Ohio University demands over 120,000 Megawatt Hours of electricity annually and plans to reduce the institutional greenhouse gas emissions to 0 by 2075. The demand for electricity includes a significant environmental footprint under the current electricity procurement contract. Addressing the best option for an energy user therefore requires careful examination of the environmental, social, and financial costs and benefits of each scenario. This research develops optimal scenarios for a solar PV installation in Athens, OH and assesses the sustainability of four solar PV installation scenarios and two status quo scenarios. Finally, Analytical hierarchy process is used to simulate decision making process with multiple criteria. The criteria are categorized as environmental, social, and financial and decisions are simulated with three sets of weighting on each criterion. A solar installation helps verify modeled results within the research which concludes that a solar PV farm with tracking or rooftop would serve as the most sustainable electricity procurement decision for OHIO University.

Committee: Derek Kauneckis Ph. D (Advisor); Daniel Karney Ph. D (Committee Member); Greg Kremer Ph. D (Committee Member) Subjects: Environmental Management; Environmental Studies; Sustainability

Master of Science in Engineering, University of Akron, 2016, Engineering

Corrosion is one of the main deteriorating mechanisms that degrade the energy pipeline integrity, due to transferring corrosive fluid or gas and interacting with corrosive environment. Corrosion defects are usually detected by periodical inspections using in-line inspection (ILI) methods. In order to ensure pipeline safety, this study develops a cost-effective maintenance strategy that consists of three aspects: corrosion growth model development using ILI data, time-dependent performance evaluation, and optimal inspection interval determination. In particular, the proposed study is applied to a cathodic protected buried steel pipeline located in Mexico. First, time-dependent power-law formulation is adopted to probabilistically characterize growth of the maximum depth and length of the external corrosion defects. Dependency between defect depth and length are considered in the model development and generation of the corrosion defects over time is characterized by the homogenous Poisson process. The growth models unknown parameters are evaluated based on the ILI data through the Bayesian updating method with Markov Chain Monte Carlo (MCMC) simulation technique. The proposed corrosion growth models can be used when either matched or non-matched defects are available, and have ability to consider newly generated defects since last inspection. Results of this part of study show that both depth and length growth models can predict damage quantities reasonably well and a strong correlation between defect depth and length is found. Next, time-dependent system failure probabilities are evaluated using developed corrosion growth models considering prevailing uncertainties where three failure modes, namely small leak, large leak and rupture are considered. Performance of the pipeline is evaluated through failure probability per km (or called a sub-system) where each sub-system is considered as a series system of detected and newly generated defects within that sub-sys (open full item for complete abstract)

Committee: Qindan Huang Dr (Advisor); Qindan Huang Dr (Committee Chair); Ping Yi Dr (Committee Member); Shengyong Wang Dr (Committee Member) Subjects: Civil Engineering; Engineering; Industrial Engineering

BA, Oberlin College, 2016, Environmental Studies

Eutrophication presents a serious threat to America's aquatic ecosystems, negatively impacting both the aquatic life and the communities dependent on these bodies of water. Reducing nutrient inflow of nitrogen and phosphorus into waterways from point and non-point sources is critical in reversing the environmental degradation caused by eutrophication. Municipal wastewater treatment plants are one of the primary point sources of nutrient-rich effluent, and as such, implementing nutrient reduction strategies within the treatment process is an impactful step towards mitigating eutrophication. Grey infrastructure technologies that use mechanical or chemical treatment have historically been used for wastewater nutrient reduction. However, constructed wetlands have also been implemented for wastewater nutrient reduction. These systems mimic the biological and chemical processes that occur in natural wetlands to remove nutrients but in a more controlled environment. A life-cycle cost analysis is conducted to analyze differences between the total life cycle costs of constructed wetland systems and grey infrastructure improvements for nutrient removal from municipal wastewater treatment facilities. Furthermore, this paper evaluates whether the inclusion of ecosystem services generated by constructed wetlands significantly reduces their life-cycle costs. The results of this study suggest that CW systems are more cost-effective than grey infrastructure technologies for nutrient reduction when ecosystem services are included in the analysis. This study lays the groundwork for future research on the inclusion of ecosystem services into future life-cycle cost analysis for nutrient reduction and cost analyses for constructed wetland systems.

Committee: Carl McDaniel (Committee Chair); Benjamin Fitch-Fleischmann (Committee Member); Rumi Shammin (Committee Member); Sean Hayes (Committee Member) Subjects: Environmental Economics; Environmental Health; Environmental Science; Environmental Studies

Doctor of Philosophy, University of Akron, 2016, Civil Engineering

Self-centering concentrically braced frame (SC-CBF) systems have been developed to increase the drift capacity of braced frame systems prior to damage to reduce post-earthquake damages in braced frames. However, due to special details required by the SC-CBF system, the construction cost of an SC-CBF is expected to be higher than that of a conventional CBF. While recent experimental research has shown better seismic performance of SC-CBF system subjected to design basis earthquakes, superior seismic performance of this system needs to be demonstrated for both structural and nonstructural components in all ground motion levels and more building configurations. Moreover, Stakeholders would be attracted to utilize SC-CBF if higher construction cost of this system can be paid back by lower earthquake induced losses during life time of the building. In this study, the seismic performance and economic effectiveness of SC-CBFs are assessed and compared with CBF system in three building configurations. First, probabilistic demand formulations are developed for engineering demand parameters (inter-story drift, residual drift and peak floor acceleration) using results of nonlinear time history analysis of the buildings under suites of ground motions. Then, Seismic fragility curves, engineering demand (inter-story drift, peak floor acceleration and residual drift) hazard curve and annual probabilities of exceeding damage states are used to evaluate and compare seismic performance of two systems. Finally, expected annual loss and life cycle cost of buildings are evaluated for prototype buildings considering both direct and indirect losses and prevailing uncertainties in all levels of loss analysis. These values are used evaluate economic benefit of using SC-CBF system instead of CBF system and pay-off time (time when the higher construction cost of SC-CBF system is paid back by the lower losses in earthquakes) for building configurations. Additionally, parametric study is per (open full item for complete abstract)

Committee: Qindan Huang Dr. (Advisor); Qindan Huang Dr. (Committee Chair); David Roke Dr. (Committee Member); Craig Menzemer Dr. (Committee Member); Akhilesh Chandra Dr. (Committee Member); Hamid Bahrami Dr. (Committee Member) Subjects: Civil Engineering; Economics; Engineering; Finance; Mechanical Engineering

Master of Science (M.S.), University of Dayton, 2015, Mechanical Engineering

Rising cost of energy and resources with stringent environment regulations, manufacturing industries are seeking for a solution to increase energy and resource efficiency of their production process. This research provides a systematic methodology to improve resource efficiency in manufacturing industries. We developed a publicly available computational tool with systemized methodology called “Resource Efficiency Guidebook (REG).” REG provides an Integrated Resource plus Principle Matrix methodology that integrates six types of resources: water, raw materials, chemical agents, process scraps, packaging wastes, and equipment. The purpose of REG is not only to assist industry to become more efficient but also to provide the user with real world examples and computational resources. In addition to real industry examples and savings calculations, REG includes industry's best practices and Streamlined Life Cycle Analysis (S-LCA) tool to quantify the positive environmental impact of resource savings.

Committee: Jun ki Choi (Advisor); John Kelly Kissock (Committee Member); Vinod Jain (Committee Member) Subjects: Environmental Engineering; Mechanical Engineering

MS, University of Cincinnati, 2005, Engineering : Civil Engineering

This study examines the development, utilization and application of performance prediction and life cycle costing for rigid pavements. Emphasis is laid on selecting an appropriate computer application that comprises mechanistic-based prediction equations and life cycle costing, for application to the Ohio Route 50 Project. A thorough literature review examining methods of collection and processing pavement performance data, development of performance prediction equations for flexible and rigid pavement systems, computer programs for rigid pavement performance prediction and life cycle cost analysis, and usage of performance prediction and life cycle costing methods by selected state highway agencies for planning and maintenance is presented. Pavespec 3.0, developed for the Federal Highway Administration, is selected, and over two hundred simulations of the program are completed, using the as-constructed pavement system data from the Ohio Route 50 Project as inputs. Observed distress data trends are used for calibration, and predictions for the service life of the Ohio Route 50 pavement system are generated. Life cycle cost analysis methods are utilized to determine the relative cost effectiveness of various joint sealing options on the Project. From the comparisons of predicted and observed distresses for the eastbound and westbound sections of the Ohio Route 50 pavement, it is established that data points spaced out over a longer period of time provide better regression curves, and subsequently, a more reliable analysis. The slopes of observed distress curves for the international roughness index, for transverse slab cracking and for spalling, are found to be many times higher than the slopes of the corresponding predicted curves obtained from Pavespec 3.0. The differences are most pronounced in the case of transverse slab cracking. Previous mechanistic analysis of this pavement system had attributed the very high cracking percentage to longer slab length. In addit (open full item for complete abstract)

Committee: Anastasios Ioannides (Advisor) Subjects: Engineering, Civil

MS, University of Cincinnati, 2004, Engineering : Industrial Engineering

To respond to increasing competition, decreasing life cycle of products and manage the business in an effective manner more firms are now embracing the concept of Supply Chain to increase their overall rofitability. Reduced Life Cycle has increased the rate of products returns and product disposals. Companies have realized the value they could recover by remanufacturing or recycling the returned or disposed products. The tool to streamline and optimize this task of collecting the used products, refurbish them and finally sell it is Reverse Supply Chain. The paper starts by giving a background and definition of the Reverse Supply Chain. It enumerates the major issues involved in designing the reverse chain and the cost concentrations for implementing it. A comparison of the reverse chain with traditional forward chain points out their differences. A linear model has been formulated for a hypothetical case of reverse chain, which attempts to minimize the cost by considering the maximum number of collection and refurbishing sites, which should be open, and the cost of transporting the used products throughout the chain. As we are concerned with End of Life products, the concept of Greening the Supply Chain for creating environmentally safe chain has been introduced. A mass balance model has been formulated and used to compare two scenarios for used lead acid batteries viz. Refurbishing and Disposal. This mass balance equation could be used for comparing the feasibility of these two options with real time data.

Committee: Dr. RICHARD SHELL (Advisor) Subjects: Engineering, Industrial

Doctor of Philosophy, University of Toledo, 2011, Industrial Engineering

Methodologies used to calculate life cycle inventory (LCI) of the functional unit have been developed since the 1970's to include hybrids of process analysis and input-output methods. Most of the current techniques do not take into account the usage of the product and end of life product aspects, or limit such applications (e.g. Method V of Tiered Hybrid LCI). The goal of this dissertation is to introduce a comprehensive method that takes strong consideration of inventory costs of use and end of life of the functional unit by combining manufacturing and de-manufacturing into the centerpiece of the hybrid analysis. In order to obtain this goal, a new disaggregated methodology is constructed by enhancing currently developed hybrid methods of life cycle inventory compilations. The new methodology is then compared to existing methodologies and to ISO14040 standards. The results of the sample calculations have shown that under right conditions use of disaggregated method will result in significant changes (lowest experimental result: 17% change in CO2 equivalent). The theoretical comparison of ISO14040 requirements had proved that disaggregated hybrid is at least as good on some areas and better in other areas then currently accepted hybrid methods.

Committee: Matthew Franchetti Dr. (Committee Chair); Defne Apul Dr. (Committee Member); Robert Bennett Dr. (Committee Member); Cyndee L. Gruden Dr. (Committee Member); Ashok Kumar Dr. (Committee Member) Subjects: Engineering

Doctor of Philosophy, The Ohio State University, 2005, Chemical Engineering

As one of the greenhouse gases, it is essential to reduce CO2 emissions in order to stabilize CO2 levels in the atmosphere while allowing the continued use of fossil fuels. The overall goal of this study was to investigate the kinetics and mechanisms of the aqueous reactions of CO2 with Mg-bearing minerals. From the investigation of serpentine dissolution in various solvents, it was found that a mixture of 1 vol% orthophosphoric acid, 0.9 wt% of oxalic acid and 0.1 wt% EDTA greatly enhanced the Mg leaching process of ground serpentine while preventing the precipitation of Fe(III) on the surface of the mineral particles. When this acidic solvent was used for the aqueous mineral carbonation, the overall process was limited by the rates of dissolution of CO2 and dissociation of carbonic acid, rather than the dissolution rate of the mineral. Next, the effect of the physical activation on the dissolution of serpentine was investigated and a pH swing scheme was developed to improve the overall conversion of the CO2 mineral sequestration process. Various methods of the surface agitation such as ultrasound, acoustic, and internal grinding were examined for their effectiveness in removing the diffusion limiting SiO2 layer in order to promote further dissolution of the inner Mg layer of serpentine. It was found that the fluidization of the serpentine slurry with 2 mm glass beads was most effective in refreshing the surface of the serpentine particles during the dissolution process. Unlike the external attrition grinding, this method is much less energy intensive. It was also found that the mechanical agitation via the internal grinding alone did not enhance the dissolution of serpentine, while the combination of the internal grinding and Mg-leaching solvent resulted in rapid serpentine dissolution. Using the proposed pH swing scheme, the overall conversion of the mineral carbonation radically improved. By controlling the pH of the system, three solid products were generated f (open full item for complete abstract)

Committee: Liang-Shih Fan (Advisor) Subjects: Engineering, Chemical