Exergy Life Cycle Assessment of a Waste-to-Energy Plant

In this paper, thermodynamic performances of a Waste-to-Energy power plant are evaluated by means of Exergy Life Cycle Assessment (ELCA). Environmentally Extended Input-Output Analysis is proposed as the computational structure of ELCA, allowing to account for the embodied exergy of electricity production and for the Exergy Return on (non-renewable Exergy) Investment (ExROI). Results of the analysis reveal that non-renewable resources requirement of the WtE plant is not negligible. Nonetheless, the plant is able to produce a net amount of electricity that pays back such resources requirements about a hundred times

Guidelines for reporting and analysing laboratory test results for biomass cooking stoves

One of the key challenges in the evaluation of Improved Cooking Stoves (ICSs) performance is the correct interpretation of test results. Indeed, a large amount of the reports or studies in the literature provide results that do not allow drawing any statistically significant conclusion, thus leading to possible misinterpretations. These Guidelines are conceived as a support to all the actors involved in sector of biomass stoves performance evaluation, from the technicians and researchers engaged in laboratory testing, to those who need to better understand and interpret test results in order to select a promising stove model for field trials. The concepts and the methodology here proposed draw upon the most recent studies in the scientific literature on this topi

IL RUOLO DELL’UNIVERSITÀ NELLA COOPERAZIONE ALLO SVILUPPO E LA RAPPRESENTANZA NEL CNCS

Questo testo è l’esito della collaborazione congiunta dei referenti delle Università nel Consiglio Nazionale per la Cooperazione allo Sviluppo (CNCS), e più un generale di una riflessone condivisa con tutti coloro che hanno partecipato alle attività dei gruppi di lavoro.Anche se il quadro politico e organizzativo della cooperazione allo sviluppo (CS) dell’Italia appare in grande cambiamento da quando la prima versione è stata scritta (fine 2017), con il cambio di governo e di direzione in capo all’Agenzia Italiana per la Cooperazione allo Sviluppo (AICS), ci è sembrato opportuno proporre comunque questo testo come promemoria di alcuni principali passaggi che hanno formalmente coinvolto le Università nella riflessione sull’impostazione delle attività di CSdell’Italia. Questa funzione dipromemoria ci sembra particolarmente importante proprio nel momento in cui il quadro della CS italiana è destinato a cambiare ancora  anche in seguito alla individuazione del vice Ministro con delega alla cooperazione (Prof.ssa Emanuela Del Re) alla ormai prossima designazione del nuovo Direttore dell’AICS.A tal fine il testo è organizzato in tre parti che riassumono tre importanti passaggi: la costituzione del CNCS e il ruolo dell’Università al suo interno, la Conferenza nazionale svoltasi a gennaio 2018 e le attività connesse con la creazione delle piattaforme “conoscenza per lo sviluppo”, volute dall’AICS con la richiesta di manifestazione di interesse espressamente indirizzate alle Università.Un quarto fondamentale passaggio èrappresentato dal Convegno CUCS svoltosi a Milano nel 14-15 settembre 2017, che ha impegnato le 30 università della Rete CUCS e ha visto l’organizzazione di varie sessioni tematiche attorno al tema “Migrazioni, pace e sviluppo. Nuove sfide e nuovi volti per la cooperazione”. Per un approfondimento sul Convegno CUCS di Milano rinviamotuttavia al prossimo numero di JUNCO dedicato alla pubblicazione degli Atti del Convegno CUCS

Exergy and Thermoeconomic Analyses of Central Receiver Concentrated Solar Plants Using Air as Heat Transfer Fluid

The latest developments in solar technologies demonstrated that the solar central receiver configuration is the most promising application among concentrated solar power (CSP) plants. In CSPs solar-heated air can be used as the working fluid in a Brayton thermal cycle and as the heat transfer fluid for a Rankine thermal cycle as an alternative to more traditional working fluids thereby reducing maintenance operations and providing the power section with a higher degree of flexibility To supply thermal needs when the solar source is unavailable, an auxiliary burner is requested. This configuration is adopted in the Julich CSP (J-CSP) plant, operating in Germany and characterized by a nominal power of 1.5 MW, the heat transfer fluid (HTF) is air which is heated in the solar tower and used to produce steam for the bottoming Rankine cycle. In this paper, the J-CSP plant with thermal energy storage has been compared with a hybrid CSP plant (H-CSP) using air as the working fluid. Thermodynamic and economic performances of all the simulated plants have been evaluated by applying both exergy analysis and thermoeconomic analysis (TA) to determine the yearly average operation at nominal conditions. The exergy destructions and structure as well as the exergoeconomic costs of products have been derived for all the components of the plants. Based on the obtained results, the thermoeconomic design evaluation and optimization of the plants has been performed, allowing for improvement of the thermodynamic and economic efficiency of the systems as well as decreasing the exergy and exergoeconomic cost of their products

Modelling Financing Schemes for Energy System Planning: A Mini-Grid Case Study

Energy modeling has been playing a crucial role in defining solutions for effective energy planning. Bottomup energy system planning models, namely those models characterized by high technological detail, typically present exogenous techno-economic parameters which rely on data gathered by the user, from specific costs to efficiencies. However, poor to no attention has been given to the date to the financial parameters of energy models, which are often assumed and barely justified (e.g., “discount rate equal to 10%”, full stop). Still, model outputs are drastically sensitive to variations of finance-related parameters and must provide the financing structure that a decision-maker should implement for funding the advised energy planning strategies. This results particularly crucial for mini-grid sizing in sub-Saharan African countries, where the challenge of the energy transition entails the construction of massive new capacities to improve energy access rates and tiers of service, demanding an enhanced collaboration between private and public sectors. The case study, applied on an off-grid mini-grid in Mozambique, proposes a comparison between scenarios with increasing financial detail and a possible conceptualization of the hard link between detailed financial modelling and a bottom-up energy model for mini-grid optimization. Different financing schemes are modelled and their impact on the energy modelling outputs assessed. Project finance hence emerges as a useful approach that could upgrade the financing structure of domestic power projects in African countries. This may lead to many benefits: more sustainable and affordable interest rates where corporate finance is missing, improved risk management, diversified funding mix, and facilitated financial support from international institutions

The tale of tail-anchored proteins: coming from the cytosol and looking for a membrane

A group of integral membrane proteins, known as C-tail anchored, is defined by the presence of a cytosolic NH2-terminal domain that is anchored to the phospholipid bilayer by a single segment of hydrophobic amino acids close to the COOH terminus. The mode of insertion into membranes of these proteins, many of which play key roles in fundamental intracellular processes, is obligatorily posttranslational, is highly specific, and may be subject to regulatory processes that modulate the protein's function. Although recent work has elucidated structural features in the tail region that determine selection of the correct target membrane, the molecular machinery involved in interpreting this information, and in modulating tail-anchored protein localization, has not been identified yet

Fuel saving due to pinch analysis and heat recovery in a petrochemical company

Nowadays, decreasing the amount of natural resources and increasing the price of it, motivates to consider energy conservation as a main concern of many process industries, especially oil, refinery and petrochemical plants. Pinch Analysis (PA) is a powerful method for identifying and selecting technical solution to improve efficiencies and provide an optimum procedure for energy saving. This paper analyses, the effectiveness of applying PA to optimize energy consumption for a given set of process streams in a Petrochemical Company in Iran. In this study, firstly, the interested process streams have been selected, maximum heating and cooling load are computed, and then composite curves have been drawn - by Matlab code - which provides a visual profile of the availability of heating or cooling from the process streams. Secondly, the cost of recovered heat is computed in terms of fuel saving, which confirms applying PA could save significant amount of fuel expenses for the company. Finally, the corresponded Heat Exchanger Network (HEN) has been designed, and the investment costs for heat exchangers have been computed in order to find out payback time of the investment costs which is approximately 17 months for this case study