Análise termoeconômica integrada das plantas de cogeração e etanol em uma destilaria autônoma.

O objetivo deste trabalho é realizar uma análise termodinâmica integral de uma planta de cogeração acoplada a um sistema de destilação, numa destilaria autônoma. Trabalhos anteriores têm analisado os dois sistemas separadamente, enquanto outros utilizam ferramentas termoeconômicas para a seleção do melhor esquema e cálculo do custo final dos produtos (eletricidade, álcool hidratado) considerando o sistema de destilação como um modelo caixa-preta. O presente trabalho propõe uma avaliação simultânea de dois sistemas acoplados considerando os parâmetros que intervém na operação de cada um, utilizando como ferramenta uma metodologia exergoeconômica que permita melhorar a utilização energética na planta. O estudo inclui a análise de diferentes esquemas de destilação acoplada a plantas de cogeração baseadas em turbinas de extração/condensação, operando com parâmetros de vapor na faixa de 4,2-12,0 MPa. Indicadores de baseados na Segunda Lei, custos exergéticos e indicadores de produtividade são utilizados como referência na avaliação integrada das duas plantas. Os resultados das alternativas consideradas são comparados com um caso base, o qual consiste em uma "destilaria convencional" operando com baixos parâmetros de vapor (2,1 MPa, 300 °C) e tecnologia convencional de destilação (destilação atmosférica). As conclusões são realizadas tendo em conta a melhor solução esquemática e paramétrica para a operação integrada da destilaria com a planta de cogeração

Effect of the Incorporation of Titanium on the Optical Properties of ZnO Thin Films: From Doping to Mixed Oxide Formation

ZnO films with Ti atoms incorporated (TZO) in a wide range (0–18 at.%) have been grown by reactive co-sputtering on silicon and glass substrates. The influence of the titanium incorporation in the ZnO matrix on the structural and optical characteristics of the samples has been determined by Rutherford backscattering spectroscopy (RBS), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The results indicate that the samples with low Ti content (<4 at.%) exhibit a wurtzite-like structure, with the Ti4+ ions substitutionally incorporated into the ZnO structure, forming Ti-doped ZnO films. In particular, a very low concentration of Ti (<0.9 at.%) leads to a significant increase of the crystallinity of the TZO samples. Higher Ti contents give rise to a progressive amorphization of the wurtzite-like structure, so samples with high Ti content ( 18 at.%) display an amorphous structure, indicating in the XPS analysis, a predominance of Ti–O–Zn mixed oxides. The energy gap obtained from absorption spectrophotometry increases from 3.2 eV for pure ZnO films to 3.6 eV for those with the highest Ti content. Ti incorporation in the ZnO samples <0.9 at.% raises both the blue (380 nm) and green (approx. 550 nm) bands of the photoluminescence (PL) emission, thereby indicating a significant improvement of the PL efficiency of the samples

Municipal Solid Waste Management and Energy Recovery

The contribution of this chapter is to deepen and widen existing knowledge on municipal solid waste (MSW) management by analyzing different energy recovery routes for MSW. The main aspects related to the composition of waste are addressed, as well as the technological routes for thermochemical and biochemical energy usage. Within the thermochemical route, incineration is currently the most utilized technology for energy recovery of waste, with generation of electricity and heat and also a decrease in the volume of the produced waste. Gasification and pyrolysis are alternatives for the production of chemical products from wastes. The biological route is an interesting alternative for the utilization of the organic fraction of MSW, as aerobic or anaerobic processes enable the production of biogas and of a compound that can be utilized as a fertilizer. Depending on the size of the population, composition of waste, and products to be obtained (energy or chemical), more than one technology can be combined for a better energy usage of waste

Environmental assessment of pyrolysis in biorefineries based on palm oil wastes

The oil palm industry is one of the largest producers of residual biomass, leading to environmental and economic concerns. For this reason, the concept of biorefinery is emerging as a means to create new ways of converting biomass into new types of renewable products bioenergetics that can contribute to the reduction of greenhouse gases. In this context, this document presents a study that consisting of a biorefinery configuration in a Palm Oil Mill (POM), considering the fast pyrolysis process to produce bio-oil and biochar, and an extraction / trans-esterification stage to produce biodiesel and glycerin in the POM. The environmental impacts associated with a production process of a biorefinery system were calculated using the life cycle assessment methodology through the IMPACT 2002+ method, which analyzes the environmental impacts in four categories of damage (human health, ecosystem quality, climate change and resources). Therefore, to produce bio-oil, biodiesel and electricity were obtained 52 mPt, 120 mPt and 127 mPt of total impacts, respectively, demonstrating that the fast pyrolysis process to obtain bio-oil it does not generate considerably high environmental impacts compared with the other products obtained in the biorefinery in any of the categories of damage assessed

A methodology to estimate baseline energy use and quantify savings in electrical energy consumption in higher education institution buildings: Case study, Federal University of Itajubá (UNIFEI)

Accurately forecasting energy consumption in a building is an important strategy for achieving the goal of reducing energy demand and improving energy efficiency. University campuses represent specific groups of diverse buildings with significant energy consumption. Therefore, they provide an excellent testbed to characterize and understand the energy consumption of a group of mixed-use buildings. This paper presents a novel methodology that considers the recommendations of ISO 50001: 2011 and ISO 50006: 2014 for establishing energy baselines and energy performance indicators in higher education institution buildings to identify electrical energy consumption reduction potentials in buildings and establish energy management strategies related to electricity use. The study was implemented in three buildings at the Federal University of Itajubá (José Rodrigues Seabra Campus). Several methods and indicators were evaluated to monitor and measure energy performance in buildings. A wide range of factors that influence operating system energy consumption in the buildings were studied and taken into account, such as the types of activities carried out in the building, weather conditions, building materials, air conditioning system and occupancy, since these contribute directly and indirectly to the difficulty of accurately measuring the building’s energy consumption. The results showed that potential annual savings in electric energy consumption for the campus could be around 9.6%, which translates into a R$ 93,647.2 economic value and a 20.3 tCO2eq emissions reduction without economic investment. It was concluded that the methodology proposed for establishing and monitoring an energy efficiency indicator can be applied to any institute of higher education because it is flexible and adaptable since each institute can define the period of analysis for the indicator. This research is expected to provide theoretical guidance and a practical data reference for relevant evaluations of building energy efficiency

Oligomerización de propeno usando como catalizador ZSM-5 modificada con Cr y W

ABSTRACT: In this paper, the composition of ZSM-5 was modified with Cr and W by impregnation, isomorphous substitution and ion exchange, and the resulting catalysts were evaluated in the oligomerization of propene.RESUMEN: En el presente trabajo se modificó la composición de la ZSM-5 con Cr y W por impregnación, sustitución isomórfica e intercambio iónico, y los catalizadores resultantes se evaluaron en la oligomerización de propeno

Energy, economic, and environmental assessment of the integrated production of palm oil biodiesel and sugarcane ethanol

The key objective of this study was to evaluate and compare, within the concept of integrated biorefining, the potential environmental gains of the life cycle, economic feasibility and energy balance of the production of bioenergetics from palm and sugarcane. In this context, the research model developed in this work involved several assessment techniques; in terms of environmental assessment, the tool used was the Life Cycle Assessment (LCA) from the Well-To-Tank perspective, which is based on the LCA “cradle-to-gate” assignment method. The environmental assessment was performed using SimaPro v.8.0.3 software and the impacts were quantified using the IMPACT 2002+ method. On the other hand, energy performance evaluation was based on the 1st law indicators. Likewise, economic feasibility was based on the evaluation of the fixed capital investment index and the estimate of investment costs for the entire integrated system. Two different scenarios were proposed in order to compare and evaluate traditional systems with the integrated biorefinery. The first conversion scenario (baseline scenario) consisted of a traditional palm oil extraction plant in addition to an ethanol and sugar plant, concerning the use of fossil fuels in all stages of production. The second conversion scenario (improved scenario) explored the substitution of fossil energy sources as well as the energy recovery of residual biomass in more efficient energy conversion systems. The results indicated significant reductions of 29.5% and 29.1% in the global warming impact category when the baseline scenario was compared to the improved scenario. Additionally, the improved scenario achieved a reduction of 2.1 g CO2eq MJ−1 (ethanol) and 2.61 g CO2eq MJ−1 (biodiesel). On the other hand, the improved scenario presented better energy rates since it showed an increase of 3.82% in the global efficiency of the system and produced 106.32 kWh more per ton of processed raw material. Finally, when considering the Life Cycle Energy Efficiency, an increase of 83% was observed and in the case of the Renewability Factor showed an increase of 7.12 energy units. Integration is also economically feasible; however, it could be significantly improved through fiscal incentives founded on the reduction of fossil energy use, enhanced conversion yielding, and improvements in conversion technologies

Procedimientos de rescate en colecistectomía laparoscópica: cómo finalizar con seguridad por laparoscopía

Bailout procedures in laparoscopic cholecystectomy are diverse. Objectives: Describe bailout procedures used at the ISSSTE Hospital Puebla Regional during 2022. Material and methods: Descriptive, prospective, cross-sectional observational study, which included patients in whom the critical vision of safety could not be completed, therefore some bailout procedure had to be used to complete the laparoscopic cholecystectomy. Results: 193 laparoscopic cholecystectomies were performed, in 40 (20.7%) patients some bailout procedure was used, 4 (2%) patients were converted to open. In multivariate analysis, there was no significant relationship between the type of procedure and gender, age, and the severity; but there was a significant relationship between the Parkland score ≥4 and the following procedures: "Fundus first" plus "puncture and aspiration", reconstitutive cholecystectomy, infundibular approach, segment IV approach, placement of an additional port, partial cholecystectomy with/without cholangiography , and Cystic Lymph Node approach. Longer days of hospital stay were associated with reconstitutive cholecystectomy, partial cholecystectomy, and conversion. Bleeding was inversely related to the need for conversion and the use of 'puncture and aspiration'.Los procedimientos de rescate en colecistectomía laparoscópica son variados.&nbsp; Objetivos: Describir los procedimientos de rescate usados en el Hospital Regional ISSSTE Puebla durante el 2022.&nbsp; Material y métodos: Estudio observacional descriptivo, prospectivo de corte trasversal, en donde se incluyeron pacientes en los cuales no se pudo completar la visión crítica de seguridad y por lo tanto se tuvo que usar algún procedimiento de rescate para completar la colecistectomía por laparoscopía. Resultados: Se realizaron 193 colecistectomías laparoscópicas, en 40 (20.7%) pacientes se empleó algún procedimiento de rescate, se convirtieron 4 (2%) pacientes. Mediante el análisis multivariado no hubo relación significativa entre el tipo de procedimiento y el género, la edad, así como el grado de severidad de Tokyo; pero si hubo relación significativa el puntaje de Parkland ≥4 con los siguientes procedimientos: "Fundus first" más "punción y aspiración", colecistectomía reconstitutiva, abordaje infundibular, abordaje del segmento IV, colocación de un puerto adicional, colecistectomía parcial con o sin colangiografía, y el abordaje del ganglio cístico. Los días de estancia hospitalaria mayores se relacionaron con la colecistectomía reconstitutiva, colecistectomía parcial y la conversión. El sangrado se relacionó con la necesidad de conversión y con el uso de la "punción y aspiración"

Analysis of labour market needs for engineers with enhanced knowledge in renewable energy in some European and Latin-American Countries

One of the main challenges related to the renewable energy labour market is that of human capital and as a consequence the educational profile of future employees is of paramount importance. Unfortunately, the skill level gained at University does not always fit with the practical needs of industry thus reducing the benefit-cost ratio of new employees and slowing down the transition to a green economy. Within this context, ‘The Crux’ project co-funded by EU under the framework of the Erasmus + programme aims at improving the renewable energy engineering curriculum at different university levels in several Universities of Latin America and Europe. In order to better appreciate the potential impact of the project, a survey on the labour market need for specialists with enhanced knowledge and skills in renewable and sustainable energy technologies has been conducted in the related EU and Latin America countries. More precisely, 60 organizations have been interviewed and almost 70% of them are interested in employing engineers with enhanced knowledge on renewable energy in the next three years. The analysis has shown significant discrepancies between EU and Latin American organizations. In fact, while future employees in EU countries will be mainly related to solar energy and management, the former together with wind and biomass will represent the main renewable energy working sector in Latin American countries. Moreover, MSc level will be the most demanded in EU while bachelor education seems to satisfy the future industry requirements in Latin America. Despite each country having its own needs, the research carried out under this EU project confirms the potential of renewable energy education on the global labour market in the near future

Implicaciones metodológicas e inconsistencias de la Tercera Comunicación Nacional sobre Cambio Climático de Colombia

Las Comunicaciones Nacionales sobre Cambio Climático (CNCC) son un mecanismo para que los países informen sus avances en mitigación y adaptación, y constituyen uno de los elementos de base para la política sobre cambio climático a escala nacional. Colombia ha emitido tres CNCC. La tercera plantea un escenario que considera las proyecciones de diversos modelos incluidos en la quinta fase del Proyecto de Comparación de Modelos Acoplados (Coupled Model Intercomparison Project, CMIP), el cual se estima como el promedio de las proyecciones correspondientes a las cuatro trayectorias de concentración representativa (Representative Concentration Pathways,RCP) presentadas en el quinto reporte de evaluación del Panel Intergubernamental sobre Cambio Climático. Cada una de estas RCP representa una trayectoria de concentración de gases de efecto invernadero (GEI) para un escenario particular de crecimiento poblacional, económico y tecnológico que conduce a una posible trayectoria de evolución del sistema climático. En este estudio se comparan las proyecciones presentadas en la Tercera CNCC con las obtenidas directamente de los modelos empleados. Nuestros resultados demuestran que al utilizarse un promedio de RCP se pierden escenarios alternos que podrían ser importantes a la hora de considerar posibles futuros diferentes y anulan la utilidad de plantear diversas trayectorias de emisiones de GEI. Más aun, una comparación entre la Segunda y la Tercera CNCC muestra proyecciones de precipitación opuestas para diferentes regiones del país, lo cual es de particular importancia, pues el escenario de cambio climático planteado en la Tercera CNCC sirve de referencia para la toma de decisiones en materia de cambio climático a nivel nacional