Browsing by Author "Quinn, Jason C., advisor"
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Item Open Access A dynamic engineering model of algal cultivation systems(Colorado State University. Libraries, 2017) Compton, Samuel Lighthall, author; Quinn, Jason C., advisor; Marchese, Anthony, committee member; Peers, Graham, committee memberProper assessment of the sustainability of algal products is constrained by the onerous process of pilot-scale experimental study. This study developed a bulk growth model that utilizes strain characterization, geospatial data, and cultivation platform geometry to predict productivity across different outdoor systems. The model interprets a minimum of measureable algal strain characteristics along with characteristics of the growth architecture to calculate a time-resolved algal concentration. Validation of the model illustrates an average accuracy of 7.33%+/5.65% for photobioreactors (PBR) and 6.7%+/5.33% for an open raceway pond (ORP) across five total species: Chlorella vulgaris, Desmodesmus intermedius, Galdieria sulphuraria, Galdieria sulphuraria Soos, and Nannochloropsis oceanica. The validated model assesses productivity at several locations in the United States with Chlorella vulgaris, grown in open raceway ponds and Galdieria sulphuraria grown in vertical flat panel photobioreactors. The model investigates seasonal variability through geospatially and temporally resolved extrapolation.Item Open Access A probabilistic and environmental impact assessment of a cyanobacteria-based biorefinery(Colorado State University. Libraries, 2021) Beattie, Audrey, author; Quinn, Jason C., advisor; Arabi, Mazdak, committee member; Marchese, Anthony, committee memberMicrobial based biofuels represent a potential promising solution as an environmentally favorable transportation fuel. Cyanobacteria have many of the same advantages as microalgae: ability for rapid growth in otherwise non-arable regions, suitability for genetic engineering, and simple nutritional needs. Additionally, cyanobacteria can be engineered to secrete valuable co-products that can be harvested independent from the produced biomass. However, little work has been done to identify the processes and the economic and environmental impacts associated with a large-scale cyanobacteria-to-fuels facility. The present study is a concurrent techno-economic and life cycle assessment of a facility that generates fuels and methyl laurate, an oleochemical, from the cyanobacterial species Synechocystis sp. PCC 6803. The biorefinery model includes all aspects of cultivation, separation of the secreted methyl laurate, biomass harvesting and fuel processing via hydrothermal liquefaction (HTL) of the dewatered biomass. The assessments leverage Monte Carlo analysis (MCA) to address uncertainty and variability inherent in the most significant input parameters, replacing them with probabilistic functions. For the facility configuration producing both fuels and the oleochemical co-product, the MCA average minimum fuel selling price (MFSP) is $2.47 per liter or $9.34 per gallon of gasoline equivalent (gge) with the corresponding average global warming potential determined to be 118 g CO2-eq/MJ-1. The case producing only fuels results in an MCA average MFSP of $2.01/L-1 ($7.60/gge) and an average environmental impact of 100 g CO2-eq/MJ-1. These results are compared to static optimistic and conservative scenario analysis estimates, illustrating the over- and under-estimation of outcomes associated with non-stochastic methods. Suggested facility improvements include increases in pond productivity of both the biomass and methyl laurate oil production, as well as improvements to carbon utilization and bio-crude yield from HTL processing.Item Open Access Algae-to-fuel pathways: integration of cultivation studies, process modeling, techno-economic analyses, and life cycle assessments(Colorado State University. Libraries, 2022) Chen, Peter H., author; Quinn, Jason C., advisor; Bradley, Thomas, committee member; Marchese, Anthony, committee member; Reardon, Kenneth, committee memberResearchers have recognized the potential of microalgae for renewable fuels for several decades, with a sharp increase in interest in the past decade. Though progress in algal cultivation and conversion has been substantial, commercialization of algal fuels has not yet been achieved. Economic metrics must be balanced with renewable fuel goals such that algal fuels can be competitive with conventional petroleum fuels. Through process modeling, techno-economic analysis (TEA), and life cycle assessment (LCA), the work in this dissertation seeks to illuminate improvements to algal fuel systems and outline the steps required to advance algal fuels toward commercialization. This work heavily focuses on hydrothermal liquefaction (HTL), a thermochemical process that converts whole wet biomass into biocrude, a petroleum crude oil analog. An aqueous phase, a gaseous phase, and a solid phase are created alongside the primary biocrude product. The aqueous phase of HTL notably contains a high content of nitrogen, which could potentially be recycled back to algae cultivation. At a scale where algal biofuels would meet a significant portion of transportation fuel needs, the demand for nutrients, specifically nitrogen and phosphorus, would exceed current global agricultural production. While recycling the aqueous phase could alleviate the demand for fresh nutrients in algae cultivation, it also contains toxic components, which include heterocyclic nitrogen compounds and phenolic compounds. The first phase of this research is an experimental component that focuses on methods for improving the recyclability of nutrients in the aqueous phase. A novel use of adsorbents (activated carbon and ion-exchange resins) was discovered for reducing the presence of components that are toxic to algae growth. The second research phase is a comprehensive modeling effort of the HTL process. A process model was developed in Aspen Plus from a robust assessment of current literature. These results are fed into TEA and LCA models to fully demonstrate the effects that process uncertainties have on the viability of HTL. For example, the high-temperature conditions that define HTL require the material to maintain a subcritical liquid state, which complicates the assessment of accurate thermochemical properties due to the required pressure. To clarify this issue, the work in this research phase compares the estimated performance of algal HTL between different thermodynamic models. HTL environmental metrics beyond global warming potential and net energy ratio are also discussed for the first time. Uncertainties in conversion performance are bounded through a scenario analysis that manipulates parameters such as product yield and nutrient recycle (as discussed in the first research phase) to establish a range of economic results and environmental impacts. The work is supplemented with a publicly available model to support future hydrothermal liquefaction assessments and accelerate the development of commercial-scale systems. The third and final research phase compares HTL with a fractionation train called Combined Algal Processing (CAP) and takes into consideration the possibility of integrating HTL downstream of CAP. CAP can be described as a pretreatment and fermentation step followed by a lipid extraction step to extract carbohydrates and lipids, respectively, for fuel products. However, CAP cannot convert proteins to fuels, making the process highly dependent on feed composition from the cultivation stage. HTL's advantage over CAP is its relative agnosticism to composition, but it requires greater capital costs and is more energetically intensive. A fuzzy logic approach is proposed to compare CAP and HTL process models through relevant performance metrics and to map algal feed conditions that lead to optimal algae-to-fuel pathways. Thresholds are set for fuzzy membership functions in relevant performance objectives: minimum fuel selling price (MFSP), global warming potential (GWP), and net energy ratio (NER). The membership functions yield "satisfaction scores" for each objective and factor into an overall satisfaction score. Individual and overall satisfaction scores for each pathway are mapped to the full range of feed compositions (proteins, carbohydrates, and lipids). A composition-based algal growth model was then implemented to perform an uncertainty analysis through Monte Carlo simulations. The impact on satisfaction scores from varying other key process model parameters, such as algae productivity, individual process yields, process operating parameters, and life cycle inventory uncertainty are highlighted in these select scenarios.Item Open Access An economic and environmental assessment of guayule resin co-products for a US natural rubber industry(Colorado State University. Libraries, 2023) Silagy, Brooke, author; Reardon, Kenneth, advisor; Quinn, Jason C., advisor; Kipper, Matthew, committee member; Bradley, Thomas, committee memberGuayule (Parthenium argentatum) is a natural rubber producing desert shrub that has the potential to be grown in semi-arid areas with limited water resources. Numerous studies have examined the costs and environmental impacts associated with guayule rubber production. These studies identified the need for additional value from the rubber co-products, specifically the resin, for sustainable and commercial viability of the biorefinery concept. This study developed process models for resin-based essential oils, insect repellant, and adhesive co-products that are integrated with sustainability assessments to understand the commercial viability. A techno-economic analysis and cradle-to-gate life cycle assessment (LCA) of these three different co-product pathways assumed a facility processing 66 tonnes/day of resin (derived from the processing of 1428 tonnes per day of guayule biomass) and included resin separation through co-product formation. The evaluation outcomes were integrated into an established guayule rubber production model to assess the economic potential and environmental impact of the proposed guayule resin conversion concepts. The minimum selling price for rubber varied by co-product: $3.54 per kg for essential oil, $3.40 per kg for insect repellent, and $1.69 per kg for resin blend adhesive. The resin blend adhesive co-product pathway had the lowest greenhouse gas emissions. These findings show a pathway that supports the development of a biorefining concept based on resin-based adhesives that can catalyze a US based natural rubber industry.Item Open Access Bioplastic production from microalgae with fuel co-products: a techno-economic and life-cycle assessment(Colorado State University. Libraries, 2019) Beckstrom, Braden Dale, author; Quinn, Jason C., advisor; Marchese, Anthony, committee member; Sheehan, John, committee memberConcerns over depleting oil reserves and national security have spurred renewed vigor in developing bio-based products. One specific area of growing concern is the consumption of petroleum based plastics, which is expected to consume 20% of global annual oil by 2050. Algae systems represent a promising pathway for the development of a bioplastic feedstock but have many technological challenges. Algae-based plastics offer a promising alleviate that would decrease oil consumption, improve environmental impact, and in some cases even improve plastic performance. This study investigates the economic viability and environmental impact of an algae biorefinery that integrates the complementary functions of bioplastic and fuel production. The bioplastic and biofuel biorefinery modeled herein includes nine different production scenarios. Performance of the facility was validated based on experimental systems with modeling work focusing on mass and energy balances of all required sub-processes in the production pathway. Results show the minimum selling price of the bioplastic feedstock is within the realm of economic competition with prices as low as $970 USD tonne-1. Additionally, LCA results indicate drastic improvements in environmental performance of the produced bioplastic feedstock, with reductions ranging between 67-116% compared to petroleum based plastics. These results indicate that an algae biorefinery focused on bioplastic feedstock production and fuels has the potential to operate both economically and sustainably. Sensitivity analysis results, alternative co-products (given that fuels represent minimal value) and product market potential are discussed.Item Open Access Economic viability of multiple algal biorefining pathways and the impact of public policies(Colorado State University. Libraries, 2018) Cruce, Jesse R., author; Quinn, Jason C., advisor; Bradley, Thomas, committee member; Burkhardt, Jesse, committee memberThis study makes a holistic comparison between multiple algal biofuel pathways and examines the impact of co-products and methods assumptions on the economic viability of algal systems. Engineering process models for multiple production pathways were evaluated using techno-economic analysis (TEA). These pathways included baseline hydrothermal liquefaction (HTL), protein extraction with HTL, fractionation into high-value chemicals and fuels, and a small-scale first-of-a-kind plant coupled with a wastewater treatment facility. The impact on economic results from policy scenarios was then examined. The type of depreciation scheme was shown to be irrelevant for durations less than 9 years, while short-term subsidies were found to capture 50% of the subsidy value in 6 years, and 75% in 12 years. Carbon prices can decrease fuel costs as seen by the production facility through carbon capture credits. TEA tradeoff assessments determined that $7.3 of capital costs are equivalent to $1 yr-1 of operational costs for baseline economic assumptions. Comparison of algal fuels to corn and cellulosic ethanol demonstrates the need for significant co-product credits to offset high algal capital costs. Higher value co-products were shown to be required for algal fuel economic viability.Item Open Access Engineering system modeling for sustainability assessment(Colorado State University. Libraries, 2016) Barlow, Jay, author; Quinn, Jason C., advisor; Willson, Bryan, committee member; Reardon, Kenneth F., committee memberThe increase in global greenhouse gas emissions has driven interest in the development of renewable energy sources. The commercial development of emerging renewable technologies like algal biofuels requires the identification of an economically viable production pathway. This study examined the sustainability of generating renewable diesel via hydrothermal liquefaction (HTL) of algal biomass from an attached growth architecture. Pilot-scale growth studies and laboratory-scale HTL experiments validated an engineering system model, which facilitated analysis of economic feasibility and environmental impact of the system at full scale. Techno-economic analysis (TEA) results indicate an optimized minimum fuel selling price (MFSP) of $11.90 gal-1, and life-cycle assessment (LCA) found a global warming potential (GWP) of -44 g CO2-e MJ-1 and net energy ratio of 0.33. Results from this work identified current gaps in sustainability assessment through TEA and LCA. Two needs were identified to improve sustainability assessment: the internalization of a carbon emission price into TEA and the consideration of the time-value of carbon emissions in LCA. With these effects considered, MFSP and GWP increase by 23% for the modeled biofuels system. Results from a harmonized model of an array of energy technologies indicate that prices for fossil-based energy increase 200% and GWP increases 25% when these factors are considered, whereas low-emitting technologies increase minimally in both metrics. Based on these findings, the development of improved sustainability assessment methodology is proposed.Item Open Access Environmental and economic evaluation of algal-based biofuels through geographically resolved process and sustainability modeling(Colorado State University. Libraries, 2023) Quiroz, David, author; Quinn, Jason C., advisor; Windom, Bret, committee member; Willson, Bryan, committee member; Reardon, Kenneth, committee memberAdvanced algal renewable fuels have been the subject of extensive research during the last decades. Their advantages over conventional biofuel feedstocks position algal biomass as a promising feedstock for the development of a sustainable and circular bioeconomy. Despite recent technological improvements, techno-economic analyses (TEAs) show that algae-derived fuels fail to be cost-competitive with petroleum fuels. Moreover, results from life-cycle assessments (LCAs) indicate declining greenhouse gas emissions when compared to petroleum fuels, but their water, health and air pollution impacts are still uncertain. This is explained by the fact that most published TEAs and LCAs of algal systems are not supported by high-resolution models and can only provide average sustainability metrics based on results from restricted data sources. These assessments often lack the resolution to correctly analyze the temporal and regional variations of biomass yields which have a direct impact on TEA and LCA metrics. Based on the current state of the field, there is a critical need to develop dynamic models that can inform sustainability assessments and consequently assist decision-making and technology development. This first part of this research work focuses on establishing the foundations for spatially explicit and temporally resolved LCA and TEA by developing and validating models that capture the thermal and biological dynamics of open algal cultivation systems. The modeling work is heavily focused on providing accurate predictions of evaporation losses in open algae raceway ponds and investigating the effects of evaporation rates on pond temperatures and growth rates. To date, this is the first modeling effort focused on predicting the evaporation losses of open algal ponds at the commercial scale. The outputs from the thermal model are then used to inform a biological algae growth model that is validated with experimental data representing the current biomass productivity potential. When integrated with hourly historical weather data, the modeling tools provide spatiotemporal mass and energy balances of the algal cultivation, dewatering, and conversion to fuel processes. These results are then leveraged with sustainability tools such as LCA and TEA to provide sustainability metrics at a high temporal and spatial scale. After developing a robust modeling framework, the modeling tool is leveraged with two distinct water LCA methods to provide a comprehensive assessment of the water impacts of algae-derived renewable diesel production across the United States. First, a water footprint analysis is conducted to understand the direct freshwater and rainwater consumption of algal cultivation and provide a framework for comparison to traditional biofuel feedstocks. The second method provides a county-level water scarcity footprint by analyzing the impact of algal systems on local water demand and availability. This assessment allows for the proper identification of potential algal sites for algal cultivation and locations where the deployment of algal systems will exacerbate local water stress. Ultimately, this research chapter provides the first holistic investigation of the water consumption and environmental water impacts of algal systems across the U.S. and establishes benchmarks for comparison to other fuels. Finally, the work comprising the third research chapter includes a novel global sustainability assessment that integrates the developed process modeling framework with regional-specific TEA and LCA. The spatially explicit TEA considers regional labor costs, construction factors, and tax rates to assess the economic viability of algal biofuels across 6,685 global locations. Similarly, a well-to-wheels LCA was performed by accounting for the regional life cycle impacts associated with electricity generation, hydrogen, and nutrient production across ten different environmental categories including health, air pollution, and climate impacts. This framework enables the identification of algal sites with optimal productivity potential, environmental impacts, and economic viability. Discussion focuses on the challenges and opportunities to reduce costs and environmental impacts of algal biofuels in various global regions.Item Open Access Evaluating the sustainability of agricultural systems using life cycle assessment and techno-economic analysis(Colorado State University. Libraries, 2021) Summers, Hailey, author; Quinn, Jason C., advisor; Marchese, Anthony J, committee member; Paustian, Keith, committee member; Willson, Bryan, committee memberIn a time of expansive population growth, our global resources have never been so strained; our contributions to a changing climate so significant. The International Panel on Climate Change recently addressed the need for focused effort toward reducing global resource depletion and greenhouse gas emissions (GHGs). As such, special attention has been given to some of the largest GHG emitting sectors in the world: energy, industry, and agriculture. This work focuses on using sustainability analysis to further understand agricultural processes and products, both novel and emerging. To quantify the environmental component of sustainability, life cycle assessment (LCA) is used because it is a well-established method for evaluating processes and products with respect to emissions. Similarly, techno-economic analysis (TEA) is used to understand the economic viability of various processes and products. In harmony, these assessments are used to evaluate the sustainable performance of various agricultural processes and products by identifying pathways to reduce environmental impact while concurrently increasing economic viability. Results enable targeted research to be highlighted that can advance early-stage development toward a sustainable adoption. The dissertation proposal is divided into three topics all with a common theme: Using LCA and TEA to assess the sustainability of, and advance, agricultural systems. A drought tolerant crop currently grown in India, guar, was investigated to understand relative environmental impact and economic viability in the American Southwest compared to existing crops. Guar is cultivated as a source of guar gum, used primarily in hydraulic fracking fluid for shale oil and gas recovery, with demand currently met through importation. Therefore, a feasibility analysis was performed for a domestic guar supply in Arizona and New Mexico using LCA and TEA. The integrated assessment provided insight on environmental and economic performance of guar for comparison to existing crops. Results indicate that environmentally, guar has lower GHGs than many crops currently cultivated in the American Southwest. Economically, guar gum can be produced for less than the five-year average U.S. import price, with minimizing or eliminating irrigation identified as a critical area for further research. A best case scenario and sensitivity analysis are also investigated using LCA and TEA to evaluate early-stage development of adopting guar in the American Southwest. LCA is also a valuable assessment tool for emerging agricultural systems. A detailed LCA was performed for a first-of-its-kind study investigating the GHGs of commercial indoor cannabis cultivation. Since legalization, the cannabis industry has seen substantial growth with many products being cultivated inside industrialized warehouses. An engineering process model was built to track material and energy requirements of a typical indoor cannabis facility which was then translated to GHGs using LCA methodology. Results of a U.S.-wide analysis indicate that indoor cannabis production leads to substantial GHGs regardless of where it is cultivated, with regions such as the Mountain West and Midwestern United States being much more GHG intensive than East or West Coasts. Individual processes that lead to the majority of GHGs are heating, ventilation, and air conditioning (HVAC), high intensity grow lights and the addition of carbon dioxide for increased plant growth rates. Results of this work have informed the industry, consumers, and policymakers of the environmental impact from this practice while providing insight on ways to reduce GHG emissions. Despite LCA and TEA being proven methodologies for assessing novel, emerging and established processes and products, limitations do exist. Particularly, in the context of agriculture, LCA does not traditionally account for water use outside of the emissions associated with procurement and use. In the American Southwest specifically, it is critical to understand water use and associated environmental impact to make informed decisions regarding ecosystem and societal sustainability. Recently, the development of an advanced LCA method, water scarcity footprint (WSF), has enhanced that ability to understand spatial and temporal considerations of freshwater consumption. However, this method is actively emerging and therefore limitations exist, particularly for arid regions where water demand is typically higher than the amount of water available. A novel method was proposed that can improve resolution and decision-making capabilities for freshwater environmental impact when evaluating arid regions. Results include method comparisons that highlight the improved resolution between the developed method and the traditional WSF method. Furthermore, a case study shows variation of the two methods when applied to alfalfa production in the American Southwest that reveals the severity of drought in the region. The proposed method enables improved resolution when considering spatial and temporal freshwater use in arid regions which enhances decision-making capabilities for product development. Throughout this work, traditional and advanced sustainability metrics, LCA, TEA and WSF, were used to understanding the environmental impact and economic viability of various agricultural-related products. Results from these assessments, from novel and existing technology investigation, provide quantifiable results for holistic comparisons and internal process improvement. These results can serve as decision-making tools during the research and development and commercialization stages, all leading toward providing a more sustainable future.Item Open Access From waste to energy: a techno-economic analysis and life cycle analysis of liquid biochemical production from wet wastes through enhanced anaerobic digestion(Colorado State University. Libraries, 2022) Soliman, Abdallah, author; Quinn, Jason C., advisor; Reardon, Kenneth, committee member; Windom, Bret, committee memberWet wastes such as manure and food wastes present problems due to disposal costs and environmental impacts. Low value products and methane leaks limit the sustainability and viability of current anaerobic digestion for treatment of wet waste. Electrochemically enhanced conversion of wet wastes diverts carbon from low-value methane into volatile fatty acids that are subsequently upgraded to improve anaerobic digestion sustainability and generate biochemicals which are seamlessly compatible with the current infrastructure. A chain elongation pathway and a bioconversion pathway are used to produce caproic acid and n-butanol, respectively. Techno-economic analysis and life cycle assessment are used to demonstrate the economic and environmental viability of the technology. The economic analysis generates market competitive minimum selling prices of $1.05 per kg for the caproic acid pathway and $2.25 per kg for the n-butanol pathway. The baseline environmental analysis yields an environmentally unfavorable GWP of 72.1 g CO2-eq·MJcaproic acid-1 for the chain elongation pathway whereas the GWP of the bioconversion pathway (24.0 g CO2-eq·MJn-butanol-1) qualifies it as a renewable fuel under the RFS program. Using scenario and sensitivity analyses, critical research areas were highlighted to guide future work and improve the performance and sustainability of the technology.Item Open Access Geographical assessment of algal productivity and water intensity across the United States(Colorado State University. Libraries, 2021) Quiroz, David, author; Quinn, Jason C., advisor; Marchese, Anthony, committee member; Reardon, Kenneth, committee memberWater consumption due to evaporation in open algal cultivation systems represents a significant research gap in the resource assessment literature. Existing algal evaporation models often lack high spatiotemporal resolution or are not validated with experimental systems. This study presents a geographical and temporal assessment of the water requirements for commercial-scale production of algae biomass through a dynamic integrated thermal and biological modeling framework. Water demands were calculated through a validated dynamic thermal model which predicts temperature with an accuracy of -0.96 ± 2.72 °C and evaporation losses with a 1.46 ± 5.92 % annual accuracy. The biological model was validated with experimental data representing the current state of technology and shows an average error of -4.59 ± 8.13 %. The integrated thermal growth model was then utilized to simulate the water demands for biomass production of a 400-hectare algae farm at 198 different locations across the United States over a period of 21 years. Simulation outputs were used to determine algal protein yields, based on protein content, and fuel production via hydrothermal liquefaction. This foundation is integrated with life cycle methodology to determine the water footprint of algal biomass, proteins, and biofuels and to compare them to those of traditional energy crops and conventional fuels. Results indicate that less water-intensive cultivation can be achieved in the Gulf Coast region, where the average water footprints of the three simulated pathways were determined to be 155 m3 water tonne-1 biomass, 371 m3 water tonne-1 algal proteins, and 11 m3 GJ-1 biofuel. The water footprints of algal systems were found to be more favorable when compared to traditional biomass feedstocks such as soybeans and corn. However, when compared to petroleum-based fuels, results emphasize the need for more water-efficient strategies to reduce the water demands of algal cultivation. This work also incorporates a novel temperature tolerance assessment to identify the geographically specific temperature limits for algal strains in a commercial-scale facility. Results highlight the importance of high temporal and spatial resolution when modeling culture temperature, evaporative loss, and algae growth rate.Item Open Access Integrated techno-economic analysis and life cycle assessment of emerging technologies with temporal resolution(Colorado State University. Libraries, 2020) Sproul, Evan, author; Quinn, Jason C., advisor; Marchese, Anthony J., committee member; Jathar, Shantanu H., committee member; Denning, A. Scott, committee memberTechno-economic analysis (TEA) and life cycle assessment (LCA) are analytical tools used to quantify the economic and environmental performance of emerging technologies. TEA and LCA help guide the development of these technologies by identifying areas where additional research will significantly reduce economic costs and environmental impacts. Although often used in tandem, TEA and LCA output separate results that rely upon disconnected metrics. When considering the impact of time, the disconnect between TEA and LCA methods is critical and can significantly impact results. In this dissertation, three phases of research are conducted to illustrate and reconcile the disconnect between TEA and LCA. In the first phase, standard TEA and LCA methods are used to evaluate the economic and environmental performance of natural rubber derived from guayule (Parthenium argentatum). This evaluation is used to identify the strengths and weaknesses of interpreting disconnected TEA and LCA results. In the second phase, two new methods are created to overcome this disconnect by integrating temporally resolved TEA and LCA. These methods are applied to electric power and guayule rubber production to highlight the impacts of integrating temporally resolved TEA and LCA. In the third phase, integrated TEA and LCA is used to perform a deep-dive evaluation on low-emissions technology options for natural gas combined cycle power plants. In this phase, TEA and LCA with temporal resolution are used to identify cost targets for biomethane, carbon capture and storage (CCS), and bioenergy with CCS (BECCS) under different emissions pricing scenarios. Taken together, the three phases of research in this dissertation represent a wide range of applications and methodologies, each with varying objectives and complexity. Understanding the details of these approaches will help guide future analysis where economic costs, environmental impacts, and time are important considerations in technological development.Item Open Access Investigation and applications of current and novel sustainability sciences(Colorado State University. Libraries, 2020) DeRose, Katherine K., author; Quinn, Jason C., advisor; Marchese, Anthony J., committee member; Jathar, Shantanu, committee member; Peebles, Christie, committee memberEngineering-based sustainable solutions are required to ensure continued access to energy, food and clean water for a growing population. Techno-economic analysis and life cycle assessment provide a means of evaluating emerging technologies to determine if they can economically and sustainably provide solutions to current and future resource demands. Concurrently, performance targets can be identified to help drive technology forward in a sustainable fashion. A major advantage of sustainability analyses is the ability to perform early-stage technology evaluation prior to intensive research investment. The application of these techniques can be applied to a variety of technologies including renewable bio-based fuels. It is also necessary to understand the limitations of these sustainability sciences to properly interpret analysis results. This work focuses on the applications of sustainability sciences to multiple technologies including foundational investigation of the methodology behind assessments. The first technology evaluation showcases the iterative nature and relationship between sustainability sciences and research for a novel biofuel conversion process using algae as a feedstock. The second technology evaluation seeks to improve sustainability metrics of the widespread corn-ethanol process; and is also used as a case study to identify limitations in current sustainability sciences. The final technology evaluation is a novel application of sustainability sciences to identify technology solutions for environmental disruptions. Microalgae has been a feedstock of interest for renewable fuels production, but the technology remains impeded due to high growth costs. Most research has been focused on increasing biomass productivity and lipid content and/or reducing capital and operation costs associated with traditional growth systems. An alternative approach is to consider an entirely new growth method; attached-growth systems. Sustainability modeling was used to identify the optimal processing opportunities for the production of renewable fuels from algae grown in this method through the use of economic and environmental analyses. Results indicated that ash reduction, energy intensive processing and high growth costs needed to be addressed to improve economic viability. A secondary effort focused on advancing the research and modelling to further refine results based on this focus. Results show minimum fuel selling prices ranging between $9.13 to $31.22 per gallon of gasoline equivalent, dependent on scenario and process assumptions. Sustainability analyses can also be applied to improve current technologies. Corn ethanol represents a mature technology with a long production history as a first-generation alternative fuel but has been widely criticized for high production costs and only marginal sustainability improvements over traditional petroleum-based fuels. One approach for improving these metrics is to focus on increased utilization of co-products through additional processing. Sustainability analysis results indicate an additional co-product fermentation process may be considered as a value-add for refiners but is dependent on economic and product market assumptions. This process was also used as a case study to explore how life cycle methodology affects environmental impact results. Life cycle assessment (LCA) results have a broad variability with well-to-pump results ranging between 42 to 210 g CO2-eq MJ fuel-1, dependent on co-product allocation methodology. This variability within the results can affect a product's ability to meet environmental standards, such as the Renewable Fuel Standard, and represents a critical area for improved methodological guidance. In addition to technology, sustainability sciences can also be applied to identify economically viable solutions for environmental disruptions such as harmful algae blooms (HAB's). HAB's affect both fresh and saltwater bodies around the world, causing a variety of environmental and economic damages to surrounding ecosystems and communities. The primary driver of HAB's is eutrophication, or excess nutrients in the water, and the principal approach to mitigating HAB's is reducing nutrients before they collect en masse downstream. Technology solutions can be employed to remove nutrients from waterways, but feasibility of technology deployment is dependent on the economic viability. Applications of sustainability sciences allows researchers to identify potential solutions to reduce HAB events which are both effective and economically viable. Results show that on average, Lake Erie communities lose $142 M (± $29M) year-1 from HAB's without mitigation. Use of attached-algae systems show an average savings of $12-42M per year from HAB mitigation and represent the most promising technology investigated. Attached-algae systems are the only nutrient reduction technology to show net-positive cash flow when compared with traditional nutrient removal systems. This research dissertation outlines tasks associated with the different applications of sustainability sciences. First, sustainability analyses are used to identify current research roadblocks associated with a technology and are used to identify optimal processing options and provide feedback to researchers to improve these metrics. Next, the tool set was adapted to a novel biorefining process and used to evaluate a value-add proposition for a current technology and showcase current limitations of LCA methodology. And finally, they were leveraged to create a framework for evaluating costs and benefits of technology adoption for pro-active mitigation of environmental disruptions.Item Open Access Multi-objective optimization of the economic feasibility for mobile on-site oil and gas produced water treatment and reuse(Colorado State University. Libraries, 2021) Cole, Garrett M., author; Quinn, Jason C., advisor; Bandhauer, Todd, committee member; Tong, Tiezheng, committee memberDevelopment of unconventional oil and gas wells has resulted in large volumes of produced and flowback water that require careful handling to minimize environmental and human health risks due to high concentrations of salt and other contaminants. Common practice is to truck the wastewater from well sites to Environmental Protection Agency (EPA) Class II underground injection control (UIC) wells. The cost of transportation often accounts for much of the handling costs. As an alternative, on-site desalination followed by surface water discharge of the water product for downstream reuse has the potential to lower handling cost by reducing the volume of water requiring transport to UIC wells while additionally alleviating strain on water supplies in arid regions. In contrast to centralized FP water treatment, capacity factor for on-site desalination is highly dependent on management strategy and shale bed characteristics. Therefore, this work studies how accounting for capacity factor might determine the attributes of an optimal management strategy and the cost of produced water treatment. The volume of wastewater to be treated by desalination, the method for desalination unit deployment, desalination unit capacity, and desalination technology (membrane distillation, mechanical vapor compression, and reverse osmosis) are decision variables defining a management strategy. This work explores different produced and flowback water management strategies in Weld County, Colorado, to determine a set of Pareto optimal produced water management strategies from a techno-economic and environmental perspective optimizing economics and water reclamation. Results show that as the desired level of water reclamation increases there is an increase in the marginal cost of water reclamation. Ultimately, the optimal volume of wastewater to be reused was determined to be between 50% and 88% of the total produced costing between $5.82 and $9.79 per m3, respectively, in Weld County, CO where business as usual operation (injection) cost is $7.68 per m3. Generally, optimal management strategies, when accounting for capacity factors, utilized packaged desalination units of 100 m3/d capacity with deployment location reevaluated on a 1-6 month planning horizon.Item Open Access Techno-economic and life cycle assessment of a novel offshore macroalgae biorefinery(Colorado State University. Libraries, 2019) Greene, Jonah M., author; Quinn, Jason C., advisor; Baker, Daniel, committee member; Petro, John, committee memberInnovative and effective solutions to providing renewable fuels represent a critical need. The cultivation and conversion of salt water macroalgae into liquid transportation fuels may offer a viable alternative to petroleum-based diesel, but the potential of this technology in terms of economic feasibility and environmental impact has not been thoroughly investigated. This work evaluates the sustainability of a free-floating macroalgae cultivation to fuel concept. While free-floating biomass cultivation structures may offer solutions for reducing infrastructure requirements and expenses, extreme ocean conditions pose great risks and unknowns. This study focuses on emerging technologies for large scale cultivation and harvesting of macroalgae biomass including drone assisted seeding and harvesting operations, recycled carbon fiber long-lines with sensor equipped buoys, and adhesive spore seeding methods. The harvested biomass is then converted to fuels through hydrothermal liquefaction. Three different system pathways have been explored to determine the impacts of the various emerging technologies on the sustainability of the system and provide direction for future research and development. Results from the techno-economic analysis show a baseline minimum fuel selling price of $6.38 per Gallon of Gasoline Equivalent (GGE) with a range from $5.10 GGE-1 to $11.00 GGE-1 based on optimistic and conservative assumptions regarding biomass yield, length of the growing season, and technology readiness level. The 90% confidence interval from the Monte Carlo Analysis performed by varying the top 10 high-impact parameters, suggests a range of $6.02 GGE-1 to $11.17 GGE-1 for the baseline pathway. The well-to-wheel life cycle assessment (LCA) shows net greenhouse gas emissions of 22 gCO2-eq MJ-1 for the baseline pathway and a range of 18 to 32 gCO2-eq MJ-1 for the optimistic and conservative pathways, respectively. The Monte Carlo LCA results show a range of 19 to 27 g CO2-eq MJ-1 based on the 90% confidence interval. Discussion focuses on the feasibility of the various technologies and utilizes results from the analysis to weigh the risks and rewards associated with the proposed concept, in an effort to guide research and development for macroalgal cultivation and conversion systems.Item Open Access The dual lens of sustainability: economic and environmental insights into novel carbon reduction technologies using systems modeling, data science, and multi-objective optimization(Colorado State University. Libraries, 2024) Limb, Braden Jeffery, author; Quinn, Jason C., advisor; Simske, Steven J., advisor; Gallegos, Erika E., committee member; Ross, Matthew R. V., committee memberIn an era marked by escalating climate change and increasing energy demands, the pursuit of sustainable solutions in energy production and environmental management is more critical than ever. This dissertation delves into this challenge, focusing on innovative technologies aimed at reducing carbon emissions in key sectors: power generation, wastewater treatment, and aviation. The first segment of the dissertation explores the integration of thermal energy storage with natural gas power plants using carbon capture, a crucial advancement given the dominant role of fossil fuel-based power plants in electricity generation. Addressing the economic and operational drawbacks of current carbon capture and storage (CCS) technologies, this study evaluates various thermal storage configurations. It seeks to enhance plant performance through energy arbitrage, a novel approach to offset the large heat loads required for carbon capture solvent regeneration. By optimizing these technologies for current and future grid pricing and comparing their feasibility with other production methods, this research aims to strike a balance between maintaining reliable power generation and adhering to stringent environmental targets. Results show that resistively charged thermal storage can both increase CCS flexibility and power plant profits through energy arbitrage when compared to power plants with CCS but without thermal storage. Beyond electrical systems, addressing climate change also necessitates improving the energy efficiency of water treatment technologies. Therefore, the dissertation investigates the potential of nature-based solutions as sustainable alternatives to traditional water treatment methods in the second section. This section probes into the efficacy of green technologies, such as constructed wetlands, in reducing costs and emissions compared to conventional gray infrastructure. By quantifying the impact of these technologies across the U.S. and evaluating the role of carbon financing, the research highlights a pathway towards more environmentally friendly and economically viable water treatment processes. Results show that nature-based water treatment technologies can treat up to 37% of future nutrient loading while both decreasing water treatment costs and emissions compared to traditional water treatment techniques. The transportation sector will play a key role in addressing climate change as it is the largest contributor to greenhouse gas emissions. While most of the transportation sector is expected to transition to electric vehicles to decrease its carbon footprint, aviation remains hard to decarbonize as electric passenger aviation is expected to be range limited. Therefore, the final segment of the dissertation addresses the challenge of meeting the U.S. Department of Energy's Sustainable Aviation Fuel (SAF) goals. It involves a comprehensive analysis of various bioenergy feedstocks for SAF production, using GIS modeling to assess their economic and environmental impacts across diverse land types. The study employs multi-objective optimization to strategize the deployment of these feedstocks, considering factors like minimum fuel selling price, greenhouse gas emissions, and breakeven carbon price. Furthermore, agent-based modeling is used to identify policy incentives that could encourage farmer adoption of bioenergy crops, a critical step towards meeting the SAF Grand Challenge goals. This dissertation offers a comprehensive analysis of novel carbon reduction technologies, emphasizing both economic viability and environmental sustainability. By developing integrated models across key sectors affected by climate change, it explores the benefits and trade-offs of various sustainability strategies. Incorporating geospatial and temporal dimensions, the research uses multi-objective optimization and systems thinking to provide targeted investment strategies for the greatest impact. The results provide important insights and actionable plans for policymakers and industry leaders, contributing to a sustainable and low-carbon future in essential areas of the global economy.