To date, the production of algal biofuels is not economically sustainable due to the cost of production and the low cost of conventional fuels. As a result, interest has been shifting to high value products in the algae community to make up for the low economic potential of algal biofuels. The economic potential of high-value products does not however, eliminate the need to consider the environmental impacts. The majority of the environmental impacts associated with algal biofuels overlap with algal bioproducts in general (high-energy dewatering) due to the similarities in their production pathways. Selecting appropriate product sets is a critical step in the commercialization of algal biorefineries.

This thesis evaluates the potential of algae multiproduct biorefineries for the production of fuel and high-value products to be economically self-sufficient and still contribute to climate change mandates laid out by the government via the Energy Independence and Security Act (EISA) of 2007. This research demonstrates:

1) The environmental impacts of algal omega-3 fatty acid production can be lower than conventional omega-3 fatty acid production, depending on the dewatering strategy.

2) The production of high-value products can support biofuels with both products being sold at prices comparable to 2016 prices.

3) There is a tradeoff between revenue and fuel production

4) There is a tradeoff between the net energy ratio of the algal biorefinery and the economic viability due to the lower fuel production in a multi-product model that produces high-value products and diesel vs. the lower economic potential from a multi-product model that just produces diesel.

This work represents the first efforts to use life cycle assessment and techno-economic analysis to assess the economic and environmental sustainability of an existing pilot-scale biorefinery tasked with the production of high-value products and biofuels. This thesis also identifies improvements for multiproduct algal biorefineries that will achieve environmentally sustainable biofuel and products while maintaining economic viability.

In the burgeoning field of sustainability, there is a pressing need for healthcare to understand the increased environmental and economic impact of healthcare products and services. The overall aim of this dissertation is to assess the sustainability of commonly used medical products, devices, and services as well as to identify strategies for making easy, low cost changes that result in environmental and economic savings for healthcare systems. Life cycle environmental assessments (LCAs) and life cycle costing assessments (LCCAs) will be used to quantitatively evaluate life-cycle scenarios for commonly utilized products, devices, and services. This dissertation will focus on several strategic and high impact areas that have potential for significant life-cycle environmental and economic improvements: 1) increased deployment of reprocessed medical devices in favor of disposable medical devices, 2) innovations to expand the use of biopolymers in healthcare materials and devices, and 3) assess the environmental and economic impacts of various medical devices and services in order to give healthcare administrators and employees the ability to make more informed decisions about the sustainability of their utilized materials, devices, and services.

Fossil resources have enabled the development of the plastic industry in the last century. More recently biopolymers have been making gains in the global plastics market. Biopolymers are plastics derived from plants, primarily corn, which can function very similarly to fossil based plastics. One difference between some of the dominant biopolymers, namely polylactic acid and thermoplastic starch, and the most common fossil-based plastics is the feature of compostability. This means that biopolymers represent not only a shift from petroleum and natural gas to agricultural resources but also that these plastics have potentially different impacts resulting from alternative disposal routes. The current end of life material flows are not well understood since waste streams vary widely based on regional availability of end of life treatments and the role that decision making has on waste identification and disposal.

This dissertation is focused on highlighting the importance of end of life on the life-cycle of biopolymers, identifying how compostable biopolymer products are entering waste streams, improving collection and waste processing, and quantifying the impacts that result from the disposal of biopolymers. Biopolymers, while somewhat available to residential consumers, are primarily being used by various food service organizations trying to achieve a variety of goals such as zero waste, green advertising, and providing more consumer options. While compostable biopolymers may be able to help reduce wastes to landfill they do result in environmental tradeoffs associated with agriculture during the production phase. Biopolymers may improve the management for compostable waste streams by enabling streamlined services and reducing non-compostable fossil-based plastic contamination. The concerns about incomplete degradation of biopolymers in composting facilities may be ameliorated using alkaline amendments sourced from waste streams of other industries. While recycling still yields major benefits for traditional resins, bio-based equivalents may provide addition benefits and compostable biopolymers offer benefits with regards to global warming and fossil fuel depletion. The research presented here represents two published studies, two studies which have been accepted for publication, and a life-cycle assessment that will be submitted for publication.

Engineering education can provide students with the tools to address complex, multidisciplinary grand challenge problems in sustainable and global contexts. However, engineering education faces several challenges, including low diversity percentages, high attrition rates, and the need to better engage and prepare students for the role of a modern engineer. These challenges can be addressed by integrating sustainability grand challenges into engineering curriculum.

Two main strategies have emerged for integrating sustainability grand challenges. In the stand-alone course method, engineering programs establish one or two distinct courses that address sustainability grand challenges in depth. In the module method, engineering programs integrate sustainability grand challenges throughout existing courses. Neither method has been assessed in the literature.

This thesis aimed to develop sustainability modules, to create methods for evaluating the modules’ effectiveness on student cognitive and affective outcomes, to create methods for evaluating students’ cumulative sustainability knowledge, and to evaluate the stand-alone course method to integrate sustainability grand challenges into engineering curricula via active and experiential learning.

The Sustainable Metrics Module for teaching sustainability concepts and engaging and motivating diverse sets of students revealed that the activity portion of the module had the greatest impact on learning outcome retention.

The Game Design Module addressed methods for assessing student mastery of course content with student-developed games indicated that using board game design improved student performance and increased student satisfaction.

Evaluation of senior design capstone projects via novel comprehensive rubric to assess sustainability learned over students’ curriculum revealed that students’ performance is primarily driven by their instructor’s expectations. The rubric provided a universal tool for assessing students’ sustainability knowledge and could also be applied to sustainability-focused projects.

With this in mind, engineering educators should pursue modules that connect sustainability grand challenges to engineering concepts, because student performance improves and students report higher satisfaction. Instructors should utilize pedagogies that engage diverse students and impact concept retention, such as active and experiential learning. When evaluating the impact of sustainability in the curriculum, innovative assessment methods should be employed to understand student mastery and application of course concepts and the impacts that topics and experiences have on student satisfaction.

Overall, biofuels play a significant role in future energy sourcing and deserve thorough researching and examining for their best use in achieving sustainable goals. National and state policies are supporting biofuel production as a sustainable option without a holistic view of total impacts. The analysis from this research connects to policies based on life cycle sustainability to identify other environmental impacts beyond those specified in the policy as well as ethical issues that are a concern. A Life cycle assessment (LCA) of switchgrass agriculture indicates it will be challenging to meet U.S. Renewable Fuel Standards with only switchgrass cellulosic ethanol, yet may be used for California's Low Carbon Fuel Standard. Ethical dilemmas in food supply, land conservation, and water use can be connected to biofuel production and will require evaluation as policies are created. The discussions around these ethical dilemmas should be had throughout the process of biofuel production and policy making. Earth system engineering management principles can help start the discussions and allow anthropocentric and biocentric viewpoints to be heard.

Natural rubber and rubber products can be produced from the guayule plant (Parthenium argentatum Gray), which is a low input perennial shrub native to Mexico and the American Southwest. Guayule rubber has the potential to replace Hevea (Hevea brasiliensis) rubber, the most common natural rubber, and synthetic rubber, which is derived from petroleum, in a wide variety of products, including automobile tires. Rubbers make up approximately 47% of the analyzed conventional passenger tire's weight, with 31% from synthetic rubber and 16% from natural Hevea rubber. Replacing the current rubber sources used for the tire industry with guayule rubber could help reduce dependency on imported rubber in addition to reducing greenhouse gas emissions. Moreover, residues from guayule rubber are being researched as a bioenergy feedstock to further improve the environmental footprint of guayule rubber products. This study used life cycle assessment (LCA), a useful tool to determine environmental impacts from a product or process, to quantify and compare environmental impacts of the raw material extraction, transportation and manufacturing of a conventional and a guayule rubber based passenger tire. The impact results of this comparative LCA identified the major environmental impacts and contributing process and informed how the impacts from the tire production can be reduced through utilization of natural rubber co-products as electricity off-sets and reducing guayule rubber's environmental impacts through agricultural and transportation modifications. Results showed that tire raw material extraction contributed the majority of impacts in all categories, where the production of guayule rubber for guayule tires, and the production of synthetic rubber for conventional tires, were the main contributors. Guayule rubber impacts occurred mainly from electricity consumption for agricultural irrigation, while synthetic rubber is a petroleum-based material resulting in high impacts. Transportation impacts had little significance compared to other stages in the life cycle, except for smog impacts, which occurred mainly from truck transport for guayule tires, and transoceanic transport for conventional tires. Tire manufacturing impacts occurred mainly from electricity use in the facilities and were reduced with the use of guayule rubber in guayule tires.

In vitro, or cultured, meat refers to edible skeletal muscle and fat tissue grown from animal stem cells in a laboratory or factory. It is essentially meat that does not require an animal to be killed. Although it is still in the research phase of development, claims of its potential benefits range from reducing the environmental impacts of food production to improving human health. However, technologies powerful enough to address such significant challenges often come with unintended consequences and a host of costs and benefits that seldom accrue to the same actors. In extreme cases, they can even be destabilizing to social, institutional, economic, and cultural systems. This investigation explores the sustainability implications of cultured meat before commercial facilities are established, unintended consequences are realized, and undesirable effects become reified and locked in. The study utilizes expert focus groups to explore the social implications, life cycle analysis to project the environmental implications, and economic input-output assessment to explore tradeoffs between conventionally-produced meat and factory-grown food products. The results suggest that, should cultured meat be widely adopted by consumers, food is likely to be increasingly a product of human design, perhaps becoming integrated into existing human institutions such as health care delivery and education. Environmentally, cultured meat could require smaller quantities of agricultural inputs and land than livestock. However, those avoided costs could come at the expense of more intensive energy use as biological processes are replaced with industrial systems. Finally, the research found that, since livestock production is a driver of significant economic activity, shifting away from traditional meat production in favor of cultured meat production could result in a net economic contraction.

Life Cycle Assessment (LCA) quantifies environmental impacts of products in raw material extraction, processing, manufacturing, distribution, use and final disposal. The findings of an LCA can be used to improve industry practices, to aid in product development, and guide public policy. Unfortunately, existing approaches to LCA are unreliable in the cases of emerging technologies, where data is unavailable and rapid technological advances outstrip environmental knowledge. Previous studies have demonstrated several shortcomings to existing practices, including the masking of environmental impacts, the difficulty of selecting appropriate weight sets for multi-stakeholder problems, and difficulties in exploration of variability and uncertainty. In particular, there is an acute need for decision-driven interpretation methods that can guide decision makers towards making balanced, environmentally sound decisions in instances of high uncertainty. We propose the first major methodological innovation in LCA since early establishment of LCA as the analytical perspective of choice in problems of environmental management. We propose to couple stochastic multi-criteria decision analytic tools with existing approaches to inventory building and characterization to create a robust approach to comparative technology assessment in the context of high uncertainty, rapid technological change, and evolving stakeholder values. Namely, this study introduces a novel method known as Stochastic Multi-attribute Analysis for Life Cycle Impact Assessment (SMAA-LCIA) that uses internal normalization by means of outranking and exploration of feasible weight spaces.