RES (Renewable Energy Sources) Availability Assessments for Eco-fuels Production at Local Scale: Carbon Avoidance Costs Associated to a Hybrid Biomass/H2NG-based Energy Scenario

Eco-fuels are a sustainable solution to face increasing global energy consumptions and GHG emissions. This work was firstly focused on available renewables assessment linked to a local dimension. Furthermore, identifying the potential Eco-fuels capability, it was discussed how the capital expenditure for infrastructures is associated with carbon avoidance costs. A coastal municipality and an inland one, located in Central Italy, are selected as case studies. In order to assess PV and agro-forestry residues availability, a GIS-based analysis was performed. In this framework, a new energy scenario, based on H2NG blends use and ligneous biomass conversion, was presented. Specifically, the hydrogen for NG enrichment was produced by renewable electricity, while biomass energy content was evaluated considering gasification process. Finally, the governmental incentive schemes incidence (in force for bioenergy and hypothesized for hydrogen) on investments economic sustainability and on infrastructure deployment was compared in terms of carbon avoidance costs

Single Cylinder Internal Combustion Engine Fuelled with H2NG Operating as Micro-CHP for Residential Use: Preliminary Experimental Analysis on Energy Performances and Numerical Simulations for LCOE Assessment

The paper presents data resulting by the preliminary experimental campaign performed on a micro CHP (combined heat and power) pre-commercial version (5 kWel) designed for dwellings. The engine employs the lubricant oil as the jacket coolant to simplify the heat recovery architecture and it was equipped by a condensing heat exchanger as well. The tests have been carried out at rated and partial load up to 2.9 kWel (59% of rated load) in condensing mode, fuelling the NG engine with hydrogen percentages equal to 0% vol. and 15% vol. In order to evaluate the CHP energy performance, the analysis was conducted for 160 h, using an alkaline electrolyser for hydrogen production, a static heat meter and two mass flow meters for both hydrogen and NG. The aim of this paper is to illustrate how the use of the hydrogen enrichment in a micro CHP plant, based on ICE technology, represents a foreseeable bridge solution to the forthcoming SOFC deployment

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Potenzialità e sviluppi dei sistemi di generazione distribuita nel settore civile. Analisi di producibilità su scala di laboratorio e su scala urbana

Nel seguente elaborato, viene presentato il lavoro di ricerca svolto all’interno del corso di dottorato in Energetica e Fisica Tecnica. Le attività condotte hanno preso in esame le potenzialità dei sistemi di generazione distribuita di energia in campo civile, con particolare dettaglio per il settore residenziale. In una prima fase del lavoro si è condotta un’analisi della diffusione dei diversi sistemi di generazione distribuita sul territorio nazionale, evidenziando l’andamento nel tempo della numerosità di tali installazioni e sottolineando quali tecnologie hanno avuto maggiore sviluppo. Si è investigato sia sui sistemi non programmabili, sia sui sistemi di tipo programmabile. Successivamente, si è scelto di analizzare approfonditamente i sistemi di micro-cogenerazione. Nello specifico si è condotta una sperimentazione in scala di laboratorio su un prototipo di micro-cogeneratore a combustione interna. Il prototipo è stato testato in diverse condizioni di carico termico e con combustibili diversi. Relativamente alle diverse fonti energetiche, si è operata una sperimentazione sia a Gas Naturale (combustibile di progetto) sia mediante una miscela di Idrometano. Allo scopo di valutare le potenzialità dei sistemi micro-cogenerativi, rispetto alle tecnologie a equivalenti (come caldaia a condensazione e impianti fotovoltaici), sono state realizzate due analisi tecnico-economiche di cui una parametrica e una di tipo dinamico. In coerenza con i dati statistici analizzati, si può affermare che gli impianti fotovoltaici in particolare e in generale i sistemi alimentati da energie rinnovabili, hanno subito un incremento consistente a partire dal 2007. La tecnologia fotovoltaica è quella che allo stato attuale ha avuto una maggiore diffusione nel settore civile ed in particolare in quello residenziale. In linea teorica, una razionale gestione delle coperture dei singoli edifici di piccole comunità urbane, può produrre un risparmio di energia primaria annuo non trascurabile. La non programmabilità della produzione e lo sfasamento temporale con i carichi elettrici di utenza, risulta essere uno dei limiti di tale tecnologia. Questo aspetto è ancora più rilevane per le piccole applicazioni di eolico, in questo caso inoltre la variabilità territoriale della risorsa eolica è un ulteriore limite alla sua diffusione nel settore residenziale. Le soluzioni di micro-cogenerazione distribuita, rappresentano una valida alternativa alle tradizionali generazione di energia separata nel settore civile. Il mercato della micro-cogenerazione offre soluzioni ideali per applicazioni in piccola scala. In particolare i motori a combustione interna sono la soluzione che garantisce un adeguato compromesso tra maturità tecnologica e contenimento dei costi di investimento iniziale, rispetto alle restanti soluzioni cogenerative. La possibilità di alimentazione a Gas Naturale ne favorisce una potenziale diffusione in tutto il tessuto urbano. Le soluzioni con recupero di calore latente, rendono tali sistemi coerenti con le potenze e rendimenti termici per utenze residenziali. L’utilizzo di miscele innovative come l’Idrometano permette, un incremento dell’efficienza elettrica non trascurabile ai fini della promozioni di sistemi cogenerativi ad alto rendimento, in coerenza con gli attuali orientamenti normativi ed incentivanti. Dal punto di vista termico, l’utilizzo di miscele di Idrometano produce, in assenza di modifiche sul sistema di alimentazione, un inevitabile decadimento della potenza termica. Dal punto di vista del costo di gestione annuo, dalle simulazioni condotte, si evince che rispetto a soluzioni separate di energia, in cui non sono previsti sistemi di generazione elettrica localizzati, i sistemi CHP conducono a risparmi non trascurabili a partire dal 65 % di autoconsumo elettrico (7 % di risparmio per un auto consumo del 65 %). Le utenze più indicate per tali applicazioni sono quelle caratterizzate da un costo del kWh elettrico maggiore di 0.20 €/kWh, in particolare i maggiori benefici si ottengono nelle Zone climatiche E, dove il numero di ore di accensione del sistema di riscaldamento è maggiore. La possibilità di accedere ad accise ridotte permette un considerevole incremento del risparmio economico (10% di risparmio per un auto consumo del 65 %). Rispetto ad un sistema di generazione fotovoltaica di potenza simile, integrato all’interno di un utenza residenziale delle medesime caratteristiche, le simulazioni condotte hanno evidenziato come la soluzione cogenerativa risulta fortemente svantaggiata. Soltanto per le Zone E poste in Italia settentrionale, si ha una convenienza in termini di costo annuo di gestione dei sistemi di micro-cogenerazione se è garantito un autoconsumo non inferiore al 85 %. In conclusione, la scelta tra le diverse soluzioni di generazione distribuita di tipo elettrico, richiede un analisi approfondita delle caratteristiche dell’utenza finale, in termini di fabbisogni richiesti e di andamento dei carichi. Soltanto mediante una simile analisi, si possono ottenere i migliori benefici dalla soluzione tecnologica scelta

Eco friendly service buildings and facilities for sustainable tourism and environmental awareness in protected areas

Starting from the multi-year experience in environmentally friendly building projects gained by CITERA of the Faculty of Architecture (Sapienza University of Rome), the main goal of this paper is to apply this expertise for the planning of environmentally sound service buildings and facilities in natural protected areas, in order to increase tourist facilities avoiding the subsequent environmental impacts that too often are produced in areas with high environmental and landscaping values. Therefore, this paper will take into account the relationships between service buildings for tourism and their eventual ecological impacts in the surrounding areas, in order to pinpoint innovative envelope technologies as well as technical smart solutions for a sustainable promotion of tourist facilities, including, in addition to service buildings, even the requalification of paths and water routes. The other central aim of the project is to propose practical methods for the use of these service buildings and facilities as favourable places to disseminate environmental protection notions. Furthermore, the project foresees the application of a case study in the Bracciano-Martignano Regional Park. The obtained results may be used by other protected areas administrations as possible solutions for improving environmental sustainability of their tourism management plans. © 2011 WIT Press

H2NG (hydrogen-natural gas mixtures) effects on energy performances of a condensing micro-CHP (combined heat and power) for residential applications: An expeditious assessment of water condensation and experimental analysis

In order to accomplish significant primary energy saving and GHG (greenhouse gas) emissions reduction, CHP (combined heat and power) technology can be adopted largely for industrial and civil sectors. Waiting for the cutting-edge appliances (i.e. Fuel Cell) wide deployment, ICEs (internal combustion engines) fuelled with an environmentally-friendly fuel, such as H2NG (hydrogen-natural gas mixtures) could represent the bridge technology towards the forthcoming pure hydrogen economy. This paper deals with the results of an experimental campaign carried out on a Single Cylinder ICE, fuelled with NG (natural gas) and H2NG @ 15% vol. In detail, energy performances were assessed at rated and partial loads. From data analysis, it emerged that the electrical efficiency increased up to 2.28%, at the expense of the heat recovery one, having added hydrogen. Additionally, due to the higher water content in exhaust gas when H2NG is burned, it was investigated on how heat recovery efficiency has been affected by condensing operating conditions. Finally, to estimate this benefit, an expeditious procedure was developed building three maps for H2NG blends condensing properties from 0% up to 30% vol. of H2. Their outputs provided the condensation efficiency value and the absolute gain of heat recovery one with varying exhaust gas temperatures and hydrogen fraction in the mixture

A preliminary energy and environmental assessment of a micro wind turbine prototype in natural protected areas

This paper presents a preliminary energy and environmental analysis of a vertical-axis micro wind turbine with a nominal electric power of 3.7 kW. This prototype is called AM300. The main aim of the paper is to assess the amount of electric energy production of the AM300 and its feasible use in low wind speed areas. Furthermore, analyzing its low environmental impact, a potential installation in a natural protected area was considered. The turbine power curve was estimated by anemometric measurements. Furthermore, foreseeable prototype hybridization with PV array was analyzed. The environmental performance was assessed evaluating the soil, hydro geological, biodiversity and noise impacts. Finally, an analysis of the CO2 emissions avoided is reported. The obtained results show good sustainability perspectives

Energy contribution of OFMSW (Organic Fraction of Municipal Solid Waste) to energy-environmental sustainability in urban areas at small scale

Urban waste management is one of the most challenging issues in energy planning of medium and large cities. In addition to the traditional landfill method, many studies are investigating energy harvesting from waste, not as a panacea but as a foreseeable solution. Thermo-chemical conversion to biogas, or even bio-methane under certain conditions, could be an option to address this challenge. This study focuses on municipal solid waste conversion to biogas as a local energy supply for the cities. Three urban models and their subdivision into urban areas were identified along with a typical Organic Fraction of Municipal Solid Waste (OFMSW) matrix for each urban area. Then, an energy analysis was carried out to provide an optimization map for an informed choice by urban policy-makers and stakeholders. The results highlighted how the urban context and its use could affect the opportunity to produce energy from waste or to convert it in fuel. So, in this case, sustainability means waste turning from a problem to a renewable resource.Building Physic