This study compares life-cycle (cradle-to-gate) energy consumption and environmental impacts for producing ethanol via fermentation-based processes starting with two lignocellulosic feedstocks: virgin timber resources or recycled newsprint from an urban area. The life-cycle assessment in this study employed a novel combination of computer-aided tools. These tools include fermentation process simulation coupled with an impact assessment software tool for the manufacturing process life-cycle stage impacts. The process simulation file was provided by the National Renewable Energy Laboratory (NREL) and was modified slightly to accommodate these different feedstocks. For the premanufacturing process life-cycle stage impacts, such as the fuels and process chemicals used, transportation, and some preparatory steps (wood chipping, etc.), a life-cycle inventory database (the Boustead Model) coupled with an impact assessment software tool were used (the Environmental Fate and Risk Assessment Tool). The Newsprint process has a slightly lower overall composite environmental index (created from eight impact categories) compared to the Timber process. However, the Timber process consumes less electricity, produces fewer emissions in total, and has less of a human health impact. The amount of life-cycle fossil energy required to produce ethanol is 14% of the energy content of the product, making the overall efficiency 86%. Process improvement strategies were evaluated for both feedstock processes, including recycle of reactor vent air and heat integration. Heat integration has the greatest potential to reduce fossil-derived energy consumption, to an extent that fossil-derived energy over the life cycle is actually saved per unit of ethanol produced. These energy efficiency values are superior to those observed in conventional fossil-based transportation fuels.
Research has shown that students are preparing less for class using traditional forms (i.e.: reading textbooks) and, as a result, are not ready for class. Providing additional support materials to be reviewed before class in a format preferred by first-year engineering students may improve student readiness and performance. Therefore, in addition to traditional reading assignments, students complete pre-lesson activities such as video tutorials, online quizzes, or short "how to" exercises.In response to a student survey given in fall 2013 on current course preparation and desired formats, materials were developed in spring 2014 for course ENG1101. The pre-lesson activities focused on videos and on-line quizzes for MATLAB. Results from the pilot suggest slightly positive improvements in readiness and performance. Therefore, pre-lesson activities have been expanded to include additional topics.Video tutorials, online quizzes, and additional pre-lesson activities were developed for the additional topics which included technical communication, spreadsheets, problem solving, statistics, as well as the MATLAB lessons. The pre-lesson activities were incorporated in course ENG1101 in fall 2014. Students were assigned the pre-lesson videos in addition to the traditional reading assignment (textbook reading to prepare for class) with several levels of encouragement to prepare for class ranging from no encouragement to required quizzes or short assignments to be completed before class. At the end of the semester, these students completed a survey similar to the pilot survey regarding what they did to prepare for lessons and what additional support materials they would like to have. This paper will focus on the impact of the pre-lesson activities, including short video tutorials and on-line quizzes, on student readiness and performance. The responses on the student preparedness surveys for the different groups will be compared to see if the developed materials improves student readiness. The three groups were: No change to the current course format Students could watch the videos Students could watch the videos and they had to complete a short, on-line quiz based on the video content. Additionally, student learning will be assessed by comparing performance on exam scores pertaining to topics for the fall 2013 traditional reading group and the fall 2014 experimental group.
A coat of paint adds considerable value to an automobile. In addition to consuming up to 60% of the energy needed by automobile assembly plants, however, the painting process also creates both economic and environmental impacts. This study investigated the degree of cost and environmental impact improvement that can be expected when modifications are considered for existing paint processes through heat integration. In order to accomplish this goal, a mathematical model was created to describe the energy use, costs, and environmental impacts from energy consumption in an automobile assembly painting facility. The model agrees with measured energy consumption data for process heating and electricity demand to within about 15% for one Michigan truck facility from which model input parameters were obtained. Thermal pinch analysis determined an energy conservation target of 58% of paint process energy demand. A heat exchanger network optimization study was conducted in order to determine how closely the network design could achieve this target. The resulting heat exchanger network design was profitable based on a discounted cash flow analysis and may achieve reductions in total corporate energy consumption of up to 16% if implemented corporatewide at a major automobile manufacturer.
is a senior lecturer in the Department of Engineering Fundamentals at Michigan Tech. As such, she has developed various course materials for all of the first year engineering classes. She has developed and taught an upper division Thermo/Fluids class for non-mechanical engineering students.
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