Modeling a Fluidized-Bed Reactor for the Catalytic Polymerization ff Ethylene: Particle Size Distribution Effects

Particle size distributions in the output stream of commercial, fluidized-bed reactors for ethylene polymerization are analyzed using a mathematical model. The impact on the overall reactor performance of the universe of sizes for the particles in the bed, with only a fraction of them being extracted in the product flow, is studied. For the output stream, product size distribution is modeled using both triangular and generalized gamma functions. Extraction system parameters are employed to model the particle quantity and sizes. The importance of the proper modeling of the extraction system is shown through the analysis of the effects several output schemes have on the particle size distribution inside the fluidized-bed. Some of the main reactor variables, such as yield and temperature, are studied for several distributions. Operating variables, such as catalyst feed rate, are varied according to the reactor capacity in a typical, 12 meter bed, 130,000 ton/year reactor. Predictions indicate higher output rates for higher catalyst loads, as expected. A shift towards smaller particle sizes in the product and in the bed is observed when increasing catalyst load. Bed fluidization and heat exchange conditions are shown as affected by size distributions. Results show that it is appropriate to include both product and bed particle diameter distribution when studying the reactor performance.Fil: Grosso, Walter. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Chiovetta, Mario Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Towards a flexible open-source software library for multi-layered scholarly textual studies: An Arabic case study dealing with semi-automatic language processing

This paper presents both the general model and a case study of the Computational and Collaborative Philology Library (CoPhiLib), an ongoing initiative underway at the Institute for Computational Linguistics (ILC) of the National Research Council (CNR), Pisa, Italy. The library, designed and organized as a reusable, abstract and open-source software component, aims at solving the needs of multi-lingual and cross-lingual analysis by exposing common Application Programming Interfaces (APIs). The core modules, coded by the Java programming language, constitute the groundwork of a Web platform designed to deal with textual scholarly needs. The Web application, implemented according to the Java Enterprise specifications, focuses on multi-layered analysis for the study of literary documents and related multimedia sources. This ambitious challenge seeks to obtain the management of textual resources, on the one hand by abstracting from current language, on the other hand by decoupling from the specific requirements of single projects. This goal is achieved thanks to methodologies declared by the 'agile process', and by putting into effect suitable use case modeling, design patterns, and component-based architectures. The reusability and flexibility of the system have been tested on an Arabic case study: the system allows users to choose the morphological engine (such as AraMorph or Al-Khalil), along with linguistic granularity (i.e. with or without declension). Finally, the application enables the construction of annotated resources for further statistical engines (training set). © 2014 IEEE

Final Report of the Consulting Contract for an Energy-Efficient and Sustainable Design of the Consalud's new Headquarters Building in Santiago de Chile

Final Report of the Consulting Contract for an Energy Efficient and Sustainable Design of the Consalud's new Headquarters Building in Santiago de Chile, including: local climate characterisation; building form, orientation and solar control; description of the bioclimatic technologies (shading, glazing type alternatives, ventilation through the structural system, a hybrid HVAC system); thermal analysis (energy savings for the various technologies compared to a benchmark); conclusions

A ventilative cooling system in a School Building, Imola, Italy

Presentatin at the International Workshop on "Ventilative Cooling Need, Challenges and Solution Examples", held in Brussels and organised by AIVC, INIVE, IEA, and Venticool

The influence of different hourly typical meteorological years on dynamic simulation of buildings

This paper presents a parametric study on the effect of different TMY (Typical Meteorological Year) datasets on the results of energy dynamic simulation. The analysis was carried out running the software Design Builder with EnergyPlus code on a sample residential building located in three Italian cities and using two different TMY data sets: EnergyPlus and CTI (Italian ThermoTechnical Committee). As a support of the simulation results to be confirmed to a larger scale (the whole Italian territory), an analysis on the two TMY data sets was carried out by calculating CDH (Cooling Degree Hours) and HDD (Heating Degree Days) for 21 Italian locations together with annual global horizontal radiation and average annual mean daily wind velocity. The discrepancies found between the software data set and the more updated and locally validated CTI data set undermine the accuracy of simulation results hence flawing the energy performance assessment criteria based on those results

Life cycle environmental assessment of temporary building constructions

The paper analyses the impact of embodied energy over a building’s life cycle as an important factor in construction planning, particularly for temporary structures. In fact, a choice of low-embodied energy construction materials, technological components, and construction systems is essential to guarantee a very high-energy performance of those constructions. Temporary buildings are exempted from the application of the minimum requirements to reduce energy in use as set by the European directive 2010/31/EU due to their short expected service life. Hence, it becomes even more important to consider the impact of their embodied energy and the one of their end of life. Results from a case study, a temporary building designed for Milan Expo 2015, are presented to compare embodied energy of construction materials, including scenarios for their end-of-life, and predicted energy consumption at use stage

Horizontal earth-to-air heat exchanger in Imola, Italy. A 30-month-long monitoring campaign.

The present paper reports the results of a 30-month-long monitoring campaign of a EAHX (earth-to-air heat exchanger) system installed in a school building in Imola (ITA). The horizontal EAHX is divided into three fields for a total of 32 buried pipes. The system pre-treats the inlet air of three dedicated AHUs. The analysis follows a consolidate methodology used in a previous shorter monitoring of the first Imola’s field that was already published. In this study, a comparison between different years of monitoring is introduced, together with the soil temperature trends of the first field

Un protocollo MAC adattivo per reti di sensori

Il lavoro di tesi si propone di studiare i principali protocolli MAC per reti di sensori, evidenziandone le caratteristiche positive e cogliendone gli aspetti negativi. Approfondisce uno dei protocolli più utilizzati, il B-MAC, confrontandolo con una sua evoluzione: il B-MAC+. E' avanzata anche una tecnica adattiva, sviluppata sul protocollo B-MAC+, atta a migliorare le prestazioni in situazioni di traffico periodico non costante.Il protocollo e' stato implementato utilizzando gli strumenti messi a disposizione dal sistema operativo TinyOS. Misure analitiche e sperimentali sono state portate utilizzando i nodi TmoteSky, i quali montano il transceiver radio Chipson CC2420

LCA of food waste management in Italy, with a special focus on the effect of the bags used for the collection

More than 7 million tonnes of organic fraction were separately collected in Italy in 2018, following a robust increasing trend. Its treatment is progressively shifting towards anaerobic digestion instead of composting, with about 3 million tonnes currently being processed in integrated anaerobic/aerobic treatment plants or in purely anaerobic ones. The type of bag used for the organic waste collection is crucial in determining the overall performance of the system, since there is a mounting evidence that bioplastic bags, especially in the form of shoppers, might cause problems during the anaerobic treatment. On the other hand, paper bags allow for a smoother operation of the plant, since they don’t need to be removed upstream. This project aims to analyse the environmental performances of the full treatment chain of the organic waste processed with anaerobic digestion, starting from the assessment of the weight losses during the household storage, and considering the different behaviour of the bags at the treatment plant. In particular, the degradation potential and the corresponding biomethane production of the different typologies of bag were evaluated at the laboratory level, by means of BMP (Biochemical Methane Potential) tests carried out under different conditions. To assess the performances of the overall organic waste treatment chain, a comparative Life Cycle Assessment for the different types of collection bag (paper bags, bioplastic bags dedicated to the food waste collection, bioplastic shopper bags that can be reused for the food waste collection) was carried out. The following stages were included: the production and supply of raw materials used for the manufacturing of the collection bags and their packaging, the bags production, their distribution, their use at the household, and the collection and treatment of the food waste. As regards the latter, an anaerobic digestion process followed by post-composting was considered, including the valorization of useful outputs and the management of residues. For the recycling and recovery processes, two different modelling approaches were considered: the Circular Footprint Formula applied to Product Environmental Footprint (PEF) studies and the approach applied in the framework of the International Environmental Product Declaration (EPD) System. The results revealed how the use of paper bags for the storage of food waste generally leads to improvements in the impact associated to its overall management, but this is strongly affected by the different approaches in modeling systems where recycling occurs. As regards the impact contributions, the most impacting phases in the overall system are the bag production (for bioplastic) and the food waste collection. The analysis allowed also to state that shopper bags are less impacting than dedicated bioplastic bags because they are utilized, as the first purpose, for carrying the grocery shopping. Please click Additional Files below to see the full abstract. Please click Download on the upper right corner to see the presentation