An interdisciplinary complex problem as a starting point for learning: Impact of the PBL method in second-year Environmental engineering students

[EN] Three courses of the second year degree in Environmental Engineering (Geology and Pedology, Ecology and Economics and Business Administration) have been remodeled using the Problem-Based Learning methodology. The proposed problem is a real-life and integrative problem related to their specialization which must be solved in these three courses at the same time. The results reveal that during this experience students were considerably more active, cooperative and involved, and the success rate doubled that of similar engineering courses of the Faculty. Regarding students’ opinion, it should be emphasized that they perceive that this method is functional and encouraging. A high percentage of the students describe the experience as positive or very positive. Additionally, they stated that the Problem-Based Learning promoted the development of skills that, in their own view, are essential for their career, such as teamwork and communication.This research study has been funded by the UPV/EHU through the educational innovation project entitled “Environmental Problem Based Learning: ∫ disciplines”. Grateful acknowledgement is also made to ERAGIN (Encourage in Basque) and BEHATU (Observe in Basque) active learning professional development programmes.Saez De Camara, E.; Lopez-Urionabarrenechea, A.; Azpiazu, MN.; Ruiz De Arbulo, P.; Insunza, G. (2015). An interdisciplinary complex problem as a starting point for learning: Impact of the PBL method in second-year Environmental engineering students. Multidisciplinary Journal for Education, Social and Technological Sciences. 2(2):153-175. doi:10.4995/muse.2015.3697.1531752

Fiber reclamation from composite materials by thermal treatment: experimental and mathematical optimization of operating parameters

Las fibras de carbono y de vidrio que se encuentran en los residuos que se generan en los sectores industriales que fabrican o utilizan materiales compuestos reforzados con fibra pueden recuperarse a través del tratamiento térmico. Este tratamiento consiste en el calentamiento del material en atmósfera inerte (pirólisis) hasta la temperatura suficiente para que se descomponga la resina polimérica y la posterior oxidación de los productos carbonosos generados en esta descomposición en presencia de aire. El resultado de este tratamiento es la eliminación completa de la resina y la recuperación de las fibras, que mantienen buenas propiedades físico-químicas. En este trabajo se ha utilizado el diseño estadístico de experimentos para determinar la influencia que tienen las tres variables de operación principales involucradas en la recuperación de fibras por tratamiento térmico (temperatura de pirólisis, temperatura de oxidación y tiempo de oxidación) sobre el rendimiento de eliminación de resina polimérica. La estrategia experimental utilizada ha sido el diseño factorial completo 2k, donde k=3, las variables de operación estudiadas. El método se ha aplicado a residuos procedentes del sector eólico y del sector aeronáutico, tanto de piezas curadas como pre-pregs caducados, y reforzadas con fibra de carbono y fibra de vidrio. Con los resultados obtenidos en la experimentación con termobalanza se ha determinado la importancia relativa de las variables estudiadas para cada una de las muestras y se han definido las ecuaciones matemáticas que permiten predecir el rendimiento de eliminación de resina en función del valor que tomen estas variables

Economic and energy benefit of a method for treating the vapors coming from the recycling of carbon fiber waste by pyrolysis

The growing utilization of carbon fiber reinforced polymers (CFRP) in industry involves the generation of high quantities of this kind of waste. This tendency has fomented the investigation of different alternatives to recycle CFRP waste with the aim of reclaiming the carbon fibers, a material with high specific economic value. Among the alternatives, pyrolysis is the only one runnig at commercial scale nowadays. This process consists on heating the waste in an inert or oxygen-poor atmosphere, which causes the decomposition of the polymeric resin of the material and consequently the reclamation of the carbon fibers. The resin decomposes into organic vapors, which are normally incinerated and released to the atmosphere. The objective of this paper is to present the economic and energy benefit of a method for treating the vapors coming from the resin decomposition, through which high value chemicals can be obtained, avoiding the vapors incineration and emission. By means of this recently patented method a gas fraction with a higher energetic content than that of the vapors without treatment can be obtained. Besides, this gaseous fraction contains high quantities of hydrogen, which could be separated and sold. The commercialization of this hydrogen could increase 6 times the economic value of the gaseous fraction compared to the gas fraction without treatment