The effect of heavy tars (toluene and naphthalene) on the electrochemical performance of an anode-supported SOFC running on bio-syngas

The effect of heavy tar compounds on the performance of a Ni-YSZ anode supported solid oxide fuel cell was investigated. Both toluene and naphthalene were chosen as model compounds and tested separately with a simulated bio-syngas. Notably, the effect of naphthalene is almost negligible with pure H2 feed to the SOFC, whereas a severe degradation is observed when using a bio-syngas with an H2:CO = 1. The tar compound showed to have a remarkable effect on the inhibition of the WGS shift-reaction, possibly also on the CO direct electro-oxidation at the three-phase-boundary. An interaction through adsorption of naphthalene on nickel catalytic and electrocatalytic active sites is a plausible explanation for observed degradation and strong performance loss. Different sites seem to be involved for H2 and CO electro-oxidation and also with regard to catalytic water gas shift reaction. Finally, heavy tars (C>=10) must be regarded as a poison more than a fuel for SOFC applications, contrarily to lighter compounds such benzene or toluene that can directly reformed within the anode electrode. The presence of naphthalene strongly increases the risk of anode re-oxidation in a syngas stream as CO conversion to H2 is inhibited and also CH4 conversion is blocked

Como a cultura organizacional influência na atuação dos líderes

Este artigo objetivou analisar na literatura a influência que a cultura organizacional tem sobre a atuação dos líderes empresariais. Havendo como objetivos específicos: Realizar um levantamento da literatura sobre cultura organizacional e liderança; Comparar, em diferentes estudos científicos, a influência que a cultura organizacional tem sobre a liderança empresarial; Identificar as culturas organizacionais que mais contribuem para o sucesso dos líderes, liderados e consequentemente para as empresas. A metodologia foi um estudo exploratório e bibliográfico, realizado através de análise qualitativa e bibliometria. Os resultados demonstraram que cultura e liderança se confundem no contexto da literatura, visto que o impacto ocorre da cultura sobre a liderança e da liderança sobre a cultura. Além disso, não há uma liderança ou uma cultura que seja melhor ou pior de modo geral, apenas lideranças e culturas que melhor se adaptam ao contexto atual da organização e da necessidade do setor que a empresa atua.This article aimed to analyze the literature the influence that the organizational culture has on the performance of business leaders. Going on as specific objectives: Conduct a survey of the literature on organizational culture and leadership; Compare, in different scientific studies, the influence that the organizational culture has on the business leadership; Identify the organizational cultures that contribute most to the success of the leaders, led and consequently for companies. The methodology was a bibliographical and exploratory study, conducted through qualitative analysis and Bibliometrics. The results showed that culture and leadership are in the context of literature, as the impact of culture occurs about leadership and leadership over the culture. In addition, there is no leadership or a culture that is better or worse in General, only leaders and cultures that best fits the current organization context and the need of the sector the company operates

Factors Affecting Sustainable Consumer Behavior in the MENA Region: A Systematic Review

Sustainable consumer behavior (SCB) gained significant attention given the relevance it bears for a broad set of actors. Since most of the relevant literature is rooted in western countries, researchers and policymakers implicitly assume that behaviors in developing countries tend to replicate those in developed countries. This review, based on seventy-one articles published since 2000, questions such assumption by analyzing the empirical research on SCBs in the Middle East and North Africa (MENA), a distinctive region that has been so far overlooked by mainstream research. Results reveal that most MENA-based papers are rooted in traditional frameworks of the rationalistic stream and that environmental values represent a key driver of SCB, while habits and socio-demographics are relegated to a negligible role. This study provides an added value by synthesizing the fragmented evidence on the topic and discussing aspects emerging as peculiar of the MENA and differentiating the latter from other societies

A Circular Approach for Making Fischer–Tropsch E-fuels and E-chemicals From Biogas Plants in Europe

In a mature circular economy model of carbon material, no fossil compound is extracted from the underground. Hence, the C1 molecule from non-fossil sources such as biogas, biomass, or carbon dioxide captured from the air represents the raw material to produce various value-added products through carbon capture and utilization routes. Accordingly, the present work investigates the utilization of the full potential of biogas and digestate waste streams derived from anaerobic digestion processes available at the European level to generate synthetic Fischer–Tropsch products focusing on the wax fraction. This study estimates a total amount of available carbon dioxide of 33.9 MtCO2/y from the two above-mentioned sources. Of this potential, 10.95 MtCO2/y is ready-to-use as separated CO2 from operating biogas-upgrading plants. Similarly, the total amount of ready-to-use wet digestate corresponds to 29.1 Mtdig/y. Moreover, the potential out-take of Fischer–Tropsch feedstock was evaluated based on process model results. Utilizing the full biogas plants’ carbon potential available in Europe, a total of 10.1 Mt/h of Fischer–Tropsch fuels and 3.86 Mt/h of Fischer–Tropsch waxes can be produced, covering up to 79% of the global wax demand. Utilizing only the streams derived from biomethane plants (installed in Europe), 136 ton/h of FT liquids and 48 ton/h of FT wax can be generated, corresponding to about 8% of the global wax demand. Finally, optimal locations for cost-effective Fischer–Tropsch wax production were also identified

Identifying Travel Demand Priorities in Maritime Transport - A Behavioural Approach

This chapter deals with the analysis of hidden aspects of travellers’ behav- iour that are the key determinant of the sustainability and efficiency of sustainable mobil- ity policies. We propose to complement the typically descriptive approach of flow-based and/or time-series analysis with techniques for analysing perceptions and intentions that can provide insights on travellers’, such as the behavioural determinants or the perceived priorities. Together with the general description of two models, we will present an ap- plication concerning travellers between Italy and Croatia, an interesting case in which travellers can choose between maritime, air and land alternatives

Technologies for Deep Biogas Purification and Use in Zero-Emission Fuel Cells Systems

A proper exploitation of biogas is key to recovering energy from biowaste in the framework of a circular economy and environmental sustainability of the energy sector. The main obstacle to widespread and efficient utilization of biogas is posed by some trace compounds (mainly sulfides and siloxanes), which can have a detrimental effect on downstream gas users (e.g., combustion engines, fuel cells, upgrading, and grid injection). Several purification technologies have been designed throughout the years. The following work reviews the main commercially available technologies along with the new concepts of cryogenic separation. This analysis aims to define a summary of the main technological aspects of the clean-up and upgrading technologies. Therefore, the work highlights which benefits and criticalities can emerge according to the intended final biogas application, and how they can be mitigated according to boundary conditions specific to the plant site (e.g., freshwater availability in WWTPs or energy recovery)

An Innovative Calcium Looping Process as Energy Storage System Integrated With a Solar-Powered Supercritical CO2 Brayton Cycle

Coupling solar thermal energy with the hybrid TC/CG-ES (thermochemical/compressed gas energy storage) is a breakthrough option used to overcome the main challenge of solar energy, i.e., intermittent resource and low density. This paper proposes an innovative storage system that improves the competitiveness of solar thermal energy technologies compared to conventional fossil-based power plants, potentially leading to deep decarbonization of the energy and industrial sectors. This study uses thermochemical energy storage based on the calcium looping (CaL) process and takes advantage of a number of factors: high energy density (2 GJ/m3), absence of heat loss (seasonal storage), high operation temperature (high efficiency of the power plant), and use of cheap and environmentally friendly reactant feedstock (CaO/CaCO3). This work deals with the integration of the solar CaL storage system with an unconventional supercritical CO2 (s-CO2) Brayton cycle. We analyze different s-CO2 Brayton cycle layouts suitable for direct integration with the storage system. Energy integration via pinch analysis methodology is applied to the whole system to optimize the internal heat recovery and increase the efficiency of the system. A parametric study highlights how the integration of solar CaL with an intercooling Brayton cycle shows better results than the combination with the Rankine cycle that we investigated previously, resulting in net and global system efficiencies equal to 39.5 and 51.5%. Instead, the new calculated net and global system efficiencies are 44.4 and 57.0%, respectively, for TC-CG-ES coupled with the Brayton power cycle

Atomic ordering in cu-al-mn studied by the Monte Carlo method

En este trabajo se estudian los procesos de ordenamiento atómico en la fase bcc del sistema ternario Cu-Al-Mn por medio de simulaciones de Monte Carlo. Se han utilizado dos enfoques diferentes: en primera instancia, se consideró que el ordenamiento atómico ocurre a causa de interacciones puramente químicas entre las tres especies atómicas. Posteriormente, se consideraron también interacciones de carácter magnético entre los átomos de Mn, y se analizó el modo en que éstas modifican las temperaturas de orden-desorden. Se muestra que, con una adecuada elección de los parámetros energéticos, el método reproduce las temperaturas de transición de orden de largo alcance determinadas experimentalmente en un amplio rango de composiciones.In this paper, the atomic ordering processes in the bcc phase of the Cu-Al-Mn ternary system are studied by means of Monte Carlo simulations. Two different approaches were used: first, it was assumed that the atomic ordering is caused by purely chemical interactions between the three atomic species. Later, magnetic interactions between Mn atoms were also taken into account, and its influence on order-disorder temperatures was analyzed. It is shown that, provided an appropriate choice of the energetic parameters, the method reproduces the experimentally determined long-range order transition temperatures over a wide range of compositions.Fil: Alés, A.. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica de Materiales; Argentina;Fil: Lanzini, Fernando Gabriel. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica de Materiales; Argentina; Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina;Fil: Romero, R.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; Argentina; Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Exactas. Instituto de Fisica de Materiales; Argentina

Solar-Powered Rankine Cycle Assisted by an Innovative Calcium Looping Process as an Energy Storage System

Solar energy is an intermittent resource, and thus an energy storage system is required for practical applications of the collected solar irradiance. This work deals with the integration of a thermo-chemical energy storage (TCES) system based on the calcium looping (CaL) process with a concentrated solar tower power (CSP) plant. The objective of this work is the integration of a conventional 320 MWe Rankine cycle with a direct calcination for energy harvesting. Particularly, this work addresses the use of CO2 as the working fluid of a compressed-gas energy storage (CGES) system for hybrid energy storage with the CaL process. The hybrid TC/CG-ES (thermo-chemical/compressed-gas energy storage) system can increase the competitiveness of the CSP with respect to conventional fossil-based power plants leading to a reduction in CO2 emissions. The thermal integration with the calcium looping (CaL) system is optimized by means of the pinch analysis methodology. The obtained results show a reduction in the electrical efficiency of about four percentage points with respect to the conventional Rankine power cycle without the CSP unit: the net electrical efficiency reduces from 43.7% to 39.5% while the global (thermal and electrical) efficiency of the plant reaches the peak value of 51.5% when low enthalpy energy is recovered (e.g., district heating network, district cooling network). This paper highlights the importance of the thermochemical CaO based material. With a conversion of CaO to CaCO3 of 80% the storage efficiency is defined as the ratio of the energy released during the carbonation and the CO2 expansion to the energy collected by the solar field and required during the CO2 compression, which is 87.3%