38 research outputs found
Team formation on the basis of Belbinâs roles to enhance studentsâ performance in project based learning
[EN] This paper presents a method that instructors have designed and implemented to form balanced teams based on Belbin's roles, with the aim of boosting positive interdependence and individual accountability within the teams and improving their performance in a project-based learning environment. Students' performance has been measured through the scores obtained during the project, individual exam and Individual Accountability Factor (IAF) and compared with cohorts of previous years, in which team composition was self-selected by students. Belbin teams (18/19-19/20) have performed significantly better than self-selected teams (16/17-17/18). Additionally, students' feedback experience and opinion has been collected. Students belonging to Belbin teams acknowledge that they attend classes more regularly, they need less time for study outside the classes and they show a higher interest for the subject at the end of the course. They also agree that working on Belbin teams has helped them to mainly improve interpersonal relationships and social skills, followed by positive interdependence and individual accountability. This team forming method gives students the opportunity to identify their own strengths and weaknesses and understand the roles (behaviours) of their teammates as well as their strengths and weaknesses. Besides, it encourages learners to focus explicitly on group work skills.Authors wish to acknowledge the financial support provided by the Vice Rector for Innovation, Social Outreach and Cultural Activities and by the Educational Advisory Service (SAE/HELAZ) of the University of the Basque Country (UPV/EHU) through the Project of Educational Innovation PIE2017/18No17 and PIE2019/20No88. Authors would also like to thank the training and support provided by the team of Belbin Spain & LATAM (M. Albaina, L. Jimenez-Orruno, L. Juez) . Authors show their gratitude to Prof. Dr. Aitor Aritzeta, for his advice based on his research experience on Belbin's role. Finally, the authors also thank the students who participated in this research
Hiri-hondakinen balorizazioa digestio anaerobioaren bidez
Urtez urte mundu-mailan ekoizturiko hiri-hondakin solidoen (HHS) kantitatea handituz doa. Beraz, gaur egun hiri-hondakinen kudeaketa egokia gizartearen erronka nagusietarikoa da. Halaber, erregai fosilen erabilerak ingurumenean eragindako kalteak nabarmenak dira. Horrez gaiz, jakina da energia-iturri hau agortzen ari dela. Digestio anaerobioa (DA) hiri-hondakinak kudeatzeko erabiltzen den metodoa da, eta energia berriztagarri gisa hartzen da; izan ere, hiri-hondakinetatik energia-iturria (biogasa) ekoizten da. Lan honetan, hiri-hondakinen zati organikoaren balioztapenerako DAren metodoa aztertuko da. Lehendabizi, hondakin solidoen arazoa eta haiek balioztatzeko aukera desberdinak aztertuko dira. Ondoren, DAren oinarriak zehaztuko dira, eta udal-hondakinen DA prozesuko lau etapak aztertu. Amaitzeko, operazio-baldintzek eta digestio-sistema desberdinek duten eragina aztertuko da.; The amount of municipal solid wastes (MSWs) is annually increasing worldwide. Therefore, a suitable municipal solid waste management is one of the main concerns of our society. Furthermore, the environmental problems derived from the use of fossil fuels are outstanding, together with the depletion of this energy source. Anaerobic digestion (AD) is one of the most promising management methods, which is considered as a rewenable energy source, as energy (biogas) is produced after treating the MSWs. In this work we analyse the AD method for the valorization of the organic fraction of MSWs. First, the problematic of solid wastes and different ways for their management are reported. Secondly, the basis of AD are established, which consists of four steps. Finally, the effect of operating conditions and the different digestion systems are analysed
A CONICAL SPOUTED BED REACTOR FOR THE VALORISATION OF WASTE TIRES
A pilot plant provided with a conical spouted bed reactor has been used for the valorisation of waste tires by thermal pyrolysis in continuous mode. The effect of pyrolysis temperature on product distribution and properties has been studied in the temperature range from 425 to 600 ÂșC. This variable has proven to have an important effect on product distribution. Thus, pyrolysis oil yield was reduced from 64.3 wt% at 425 ÂșC to 55.9 wt% at 600 ÂșC. However, the quality of carbon black was improved operating at high temperatures (increasing BET surface area values). High yields of certain interesting chemicals have been obtained in the liquid fraction, such as limonene (19.3 wt%), isoprene (5.7 wt%) and styrene (6.1 wt%)
Waste Plastics Valorization by Fast Pyrolysis and in Line Catalytic Steam Reforming for Hydrogen Production
This chapter summarizes the most recent results obtained in the plastic waste pyrolysis-reforming strategy for hydrogen production. An original two-reactor configuration consisting of a conical spouted bed reactor for the pyrolysis step and a fluidized bed reactor for the pyrolysis volatile reforming is proposed. The fundamental aspects and challenges of this joint process are discussed in detail, and the prospects for the full-scale implementation of this valorization route are assessed. Thus, the influence the main reforming parameters (temperature, space time and steam/plastic ratio) have in the pyrolysis-reforming of HDPE on product yields and catalyst stability are reported. Moreover, the role played by plastic composition on process performance is also described by studying the influence of following polymers: high density polyethylene (HDPE), polypropylene (PP), polyethylene terephthalate (PET) and polystyrene (PS). The operating conditions used for the valorization of different plastics have been as follows: pyrolysis temperature of 500°C, reforming temperature of 700°C, space time of 16.7 gcatalyst min gplasticâ1and steam/plastic ratio of 4
Conversion of HDPE into Value Products by Fast Pyrolysis Using FCC Spent Catalysts in a Fountain Confined Conical Spouted Bed Reactor
Continuous catalytic cracking of polyethylene over a spent fluid catalytic cracking (FCC) catalyst was studied in a conical spouted bed reactor (CSBR) with fountain confiner and draft tube. The effect of temperature (475-600 degrees C) and space-time (7-45 g(cat) min g(HDPE)(-1)) on product distribution was analyzed. The CSBR allows operating with continuous plastic feed without defluidization problems and is especially suitable for catalytic pyrolysis with high catalyst efficiency. Thus, high catalyst activity was observed, with waxes yield being negligible above 550 degrees C. The main product fraction obtained in the catalytic cracking was made up of C-5-C-11 hydrocarbons, with olefins being the main components. However, its yield decreased as temperature and residence time were increased, which was due to reactions involving cracking, hydrogen transfer, cyclization, and aromatization, leading to light hydrocarbons, paraffins, and aromatics. The proposed strategy is of great environmental relevance, as plastics are recycled using an industrial waste (spent FCC catalyst).This work was carried out with the financial support from Spain's ministries of Science, Innovation and Universities RTI2018-101678-BI00(MCIU/AEI/FEDER, UE) and RTI2018-098283-JI00(MCIU/AEI/FEDER, UE)) and Science and Innovation (PID2019-107357RB-I00 (MCI/AEI/FEDER, UE)), the European Union's Horizon 2020 research and innovation programme under the Marie Skodowska-Curie grant agreement No. 823745, and the Basque Government (IT1218-19 and KK-2020/00107)
Effect of CeO2 and MgO promoters on the performance of a Ni/Al2O3 catalyst in the steam reforming of biomass pyrolysis volatiles
A Ni/Al2O3 catalyst has been modified incorporating CeO2 and MgO promoters in order to improve its performance in the steam reforming of biomass pyrolysis volatiles. Ni/Al2O3, Ni/CeO2-Al2O3 and Ni/MgO-Al2O3 catalysts have been prepared and fresh and deactivated catalysts have been characterized by N2 adsorption/ desorption, X-ray Fluorescence (XRF), Temperature Programmed Reduction (TPR), X-ray powder diffraction (XRD), Temperature Programmed Oxidation (TPO), Transmission Electron Microscopy (TEM) and a technique based on Fourier Transform Infrared Spectroscopy-Temperature Programmed Oxidation (FTIR-TPO). The results obtained revealed a similar initial activity for the three catalysts tested (conversion higher than 98%), whereas stability has been greatly improved by incorporating CeO2 as promoter, as it enhances the gasification of coke precursors. However, Ni/MgO-Al2O3 catalyst is slightly less stable than Ni/Al2O3, presumably as a result of its lower reducibility due to the formation of MgAl2O4 spinel phase. Catalysts deactivation has been associated with coke deposition, although sintering phenomenon became also evident when the Ni/CeO2-Al2O3 catalyst was tested. The coke deposited on the catalysts does not present any specific morphology, which is evidence of its amorphous structure in the three catalysts studied.This work was carried out with financial support from the Ministry of Economy and Competitiveness of the Spanish Government (CTQ2016-75535-R (AEI/FEDER, UE) and CTQ-2015-69436-R (MINECO/FEDER, UE)), Ministry of Science, Innovation and Universities of the Spanish Government (RTI2018-101678-B-I00 (MCIU/AEI/FEDER, UE)), the European Unionâs Horizon 2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement No 823745, and the Basque Government (IT1218-19)
Appraisal of agroforestry biomass wastes for hydrogen production by an integrated process of fast pyrolysis and in line steam reforming
The pyrolysis and in line steam reforming of different types of representative agroforestry biomass wastes (pine wood, citrus wastes and rice husk) was performed in a two-reactor system made up of a conical spouted bed and a fluidized bed. The pyrolysis step was carried out at 500 °C, and the steam reforming at 600 °C with a space time of 20 gcatalyst min gvolatilesâ1 and a steam/biomass ratio (S/B) of 4. A study was conducted on the effect that the pyrolysis volatiles composition obtained with several biomasses has on the reforming conversion, product yields and H2 production. The different composition of the pyrolysis volatiles obtained with the three biomasses studied led to differences in the initial activity and, especially, in the catalyst deactivation rate. Initial conversions higher than 99% were obtained in all cases and the H2 production obtained varied in the 6.7â11.2 wt% range, depending on the feedstock used. The stability of the catalysts decreased depending on the feedstock as follows: pine wood â« citrus waste > rice husk. A detailed assessment of the mechanisms of catalyst deactivation revealed that coke deposition is the main cause of catalyst decay in all the runs. However, the volatile composition derived from the pyrolysis of citrus waste and rice husk involved the formation of an encapsulating coke, which severely blocked the catalyst pores, leading to catalyst deactivation during the first minutes of reaction.his work was carried out with the financial support of the grants PID2022-140704OB-I00 and PID2022-139454OB-I00 funded by MCIU/AEI/10.13039/501100011033 and âERDF, a way of making Europeâ, the grants TED 2021-132056BâI00 and PLEC 2021-008062 funded by MCIN/AEI/10.13039/501100011033 and âEuropean Union NextGenerationEU/PRTRâ, and the grants IT1645-22 and KK-2023/00060 funded by the Basque Government. Moreover, this project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 823745
CeO2 and La2O3 promoters in the steam reforming of polyolefinic waste plastic pyrolysis volatiles on Ni-based catalysts
[EN] Based on the promising results of La2O3 and CeO2 promoted Ni/Al2O3 catalysts in the reforming
of biomass pyrolysis volatiles, the performance of these catalysts and the non-promoted one was
2 evaluated in the pyrolysis and in-line steam reforming of polypropylene (PP). The experiments
were carried out in a continuous bench scale pyrolysis-reforming plant using two space times of
4.1 and 16.7 gcat min gplasticâ1 and a steam/PP ratio of 4. The prepared catalysts and the deposited
coke were characterized by N2 adsorption-desorption, X-ray fluorescence (XRF), X-ray
diffraction (XRD), temperature programmed oxidation (TPO) and transmission electron
microscopy (TEM). The Ni/Al2O3 catalyst showed suitable performance regarding pyrolysis
product conversion and hydrogen production, and led to moderate coke deposition. It is to note
that La2O3 incorporation remarkably improved catalyst performance compared to the other two
catalysts in terms of conversion (> 99 %), hydrogen production (34.9 %) and coke deposition
(2.24 wt%).This work was carried out with the financial support from Spainâs ministries of Economy and Competitiveness (CTQ2016-75535-R (AEI/FEDER, UE), Science, Innovation and Universities (RTI2018-101678-B-I00 (MCIU/AEI/FEDER, UE)) and, Science and Innovation PID2019-107357RB-I00 (MCI/AEI/FEDER, UE)), the European Unionâs Horizon 2020 research and innovation programme under the Marie SkĆodowska-Curie grant agreement No. 823745, and the Basque Government (IT1218-19 and KK-2020/00107)
Syngas production by bio-oil steam gasification in a fountain confined conical spouted bed reactor
The combination of delocalized units for the fast pyrolysis of biomass to produce bio-oil followed by centralized units for the gasification of bio-oil appears as an economically attractive option for the full-scale production of syngas because transportation of bio-oil is less costly than that of biomass. First goal of this study lies in the validation of a bio-oil feeding device made up of a line-thermostated at 60â80 °C and a non-atomizing injector cooled by water. This injector allows feeding the crude bio-oil in continuous mode into the conical spouted bed reactor without being clogged by the pyrolytic lignin in the bio-oil. The effect of gasification temperature on gas properties, tar composition, and carbon conversion efficiency were assessed in the 800â900 °C range. The results show that temperature promotes tar reduction (from 40.7 to 12.5 g/Nm3), carbon conversion efficiency (from 91.2 to 96.3 %) and gas yield (from 1.37 to 1.85 Nm3/kg on a dry basis) as temperature is increased from 800 to 900 °C. A novel aspect of this study is the detailed characterization of the tar evolution with temperature, which, to our knowledge, is an aspect that has not been approached in the literature related to raw bio-oil gasification.This work was carried out with the financial support from SpaiĆs ministries of Science and Innovation (PID2019-107357RB-I00 (MCIU/AEI/FEDER, UE), TED2021-132056B-I00 (MCI/AEI/FEDER, UE) and PLE21210-008062 (European Union Next GenerationEU/PRTR)) and the Basque Government (IT1645-22). Moreover, this project has received funding from the European Unionâs Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 823745