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

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%

Study and modelling of the passenger safety devices of an electric vehicle by finite elements

Abstract Electric mobility gets mainly involved quadricycles and cars. Between these two vehicle types there are differences in terms of stability, performance, cost, autonomy and safety. The authors studied the implementation of passenger safety devices on a prototype for an electric vehicle derived from a heavy quadricycle. A finite element analysis starting from experimental results was carried out in order to determine the effectiveness in case of frontal and side crashes

Techno-economic comparison of buildings acting as Single-Self Consumers or as energy community through multiple economic scenarios

The European Union has set ambitious targets to move towards a society with high penetration of renewable energy sources. In the forthcoming energy transition, Energy Communities (EC), i.e., legal entities where different actors, including citizens, cooperate in energy generation, storage and management, will play a crucial role. The present work simulates the energy flows and assesses the potential economic benefits of a cluster of buildings acting collectively as an energy community – a specific case study is set in northern Italy by comparing the EC performance with a configuration where customers act as Single Self-Consumers (SSCs). Pending the transposition of EU Directives to binding national laws, due by 2021, different supporting tariffs (economic scenarios) have been simulated in order to determine which scheme will support more effectively the integration of Energy Communities in the national energy market. Results show that ECs (i.e., customers acting collectively as energy prosumers) are able to accelerate the diffusion of building-integrated renewable energy sources (RES), resulting in higher overall self-consumption rates than SSCs. Self-consumed electricity generates savings on the energy bill of EC, and we calculated positive economic performance indicators for all the analysed economic scenarios. The sensitivity analysis carried out on system and transport charges of the electricity bill shows their remarkable impact on the economics making the EC less attractive for investors and citizens without proper supporting schemes

Techno-economic assessment of biogas-fed CHP hybrid systems in a real wastewater treatment plant

The integration of solid oxide fuel cell (SOFC) systems and micro gas turbines in a reference wastewater treatment plant is proposed. The main scope is to utilize the available biogas in a real wastewater treat- ment plant (WWTP) to feed both the SOFCs and micro gas turbines (MGTs) to produce electrical power while covering the digester thermal demand of the plant. To do so, two cases namely SOFC-WWTP (in which the SOFC system is the only CHP unit), and SOFC-MGT-WWTP (integration of both SOFCs and microturbine systems) are proposed. Results show that use of microturbines along with the SOFC systems can increase the share of electricity covered by self-generation within the WWTP by up to 15% while keeping stable the coverage of the thermal load. Also, the energy efficiency of the novel system (SOFC- MGT-WWTP) is calculated to be 7% more than that of the SOFC-WWTP. Economic analysis results reveal that using microturbines, the payback time for whole the system could be reduced about 4 years. Also, for the short term scenario, the levelized cost of electricity for the SOFC-MGT-WWTP system is found to be 0.118 $/kWh which is about 12% less than that for the SOFC-WWTP system. However, for the long term scenario, the difference becomes remarkably les

A bottom-up appraisal of the technically installable capacity of biogas-based solid oxide fuel cells for self power generation in wastewater treatment plants

This paper proposes a bottom-up method to estimate the technical capacity of solid oxide fuel cells to be installed in wastewater treatment plants and valorise the biogas obtained from the sludge through an efficient conversion into electricity and heat. The methodology uses stochastic optimisation on 200 biogas profile scenarios generated from industrial data and envisages a Pareto approach for an a posteriori assessment of the optimal number of generation unit for the most representative plant configuration sizes. The method ensures that the dominant role of biogas fluctuation is included in the market potential and guarantees that the utilization factor of the modules remains higher than 70% to justify the investment costs. Results show that the market potential for solid oxide fuel cells across Europe would lead up to 1,300 MW of installed electric capacity in the niche market of wastewater treatment and could initiate a capital and fixed costs reduction which could make the technology comparable with alternative combined heat and power solutions

Assessment of kinetic model for ceria oxidation for chemical-looping CO2 dissociation

Chemical looping technologies are identified as to have an excellent potential for CO2 capture and fuels synthesis. Oxygen carriers are the fundamental component of a chemical looping process, and the choice of stable and efficient carriers with fast redox kinetics is the key to the successful design of the process. Hence, understanding the reaction kinetics is of paramount importance for the selection of an appropriate oxygen carrier material. This work provides a method for kinetic model selection based on a statistical approach to identify the reaction mechanism. The study experimentally investigates the oxidation kinetics of CeO2-d by CO2 and applies a statistical method for the selection of the best-fitting kinetic model for the reaction. The kinetic study is performed in the temperature range of 700–1000¿°C with a CO2 concentration between 20 and 40¿vol% in the feed. The measured peak rates of CO production on ceria were influenced both by temperature and concentration of reactant. The total CO production was more influenced by the temperature than by CO2 concentration, with a maximum CO yield of 33.66¿ml/g at 1000¿°C and 40% CO2. The identification of the oxidation kinetic model is performed by fitting different reactions models to the measured reaction rates and statistically comparing them using the Residual sum of squares (RSS), Akaike information criterion (AICc) and the F-test for the selection of the best-fitting one. Models corresponding to the nucleation and grain growth reaction mechanism provided a good fit of the data, with the Sestak-Berggren (SB) model showing the best approximation of the measured rate of reaction with an evaluated activation energy of 79.1¿±¿6.5¿kJ/mol for the CO2 oxidation.Peer ReviewedPostprint (author's final draft

Epithelial and stromal remodelling following femtosecond laser–assisted stromal lenticule addition keratoplasty (SLAK) for keratoconus

The purpose of this study was to evaluate corneal epithelium and stromal remodelling with anterior segment optical coherence tomography in patients who have undergone stromal lenticule addition keratoplasty (SLAK) for advanced keratoconus. This was a prospective non-comparative observational study. Fifteen eyes of 15 patients with advanced keratoconus underwent implantation with a cadaveric, donor negative meniscus-shaped intrastromal lenticule, produced with a femtosecond laser, into a stromal pocket dissected in the recipient cornea at a depth of 120 μm. Simulated keratometry, central corneal thickness (CTT), corneal thinnest point (CTP), central epithelial thickness (CET), central and peripheral lenticule thickness, anterior and posterior stromal thickness were measured. Regional central corneal epithelial thickness (CET) and variations in the inner annular area (IAT) and outer annular area (OAT) were also analysed. All parameters were measured preoperatively and 1, 3, and 6 months postoperatively. The average anterior Sim-k decreased from 59.63 ± 7.58 preoperatively to 57.19 ± 6.33 D 6 months postoperatively. CCT, CTP, CET, and OAT increased and IAT decreased significantly after 1 month. All parameters appeared unchanged at 6-months except that of OAT that further increased. Lenticule thickness was stable. In conclusion we observed that SLAK reshapes the cornea by central flattening with stromal thickening and epithelial thickness restoration

Biofuels Policy in Europe Under the Directive 2003/30: An Analysis of Goals, Hindrances, Instruments and Effects

Up to 2008/2009, biofuels were considered one of the best alternatives to oil consumption in a captive market like transports, being one of the pillars of the 20-20-20 initiative in Europe. Improvement of security of supply through partial substitution of imported oil; reduction of GHGs emissions; improvement of income and employment in the agricultural and rural sectors were the main drivers of the promotion of biofuels in Europe, as well as in the United States and in Brazil. In the European Union biofuels policy was supported through Directive 2003/30. However its effects proved to be disappointing: the consumption of biofuels was expected by the Directive to account for 5.75% share of road fuels in 2010 in the European MSs, but it came early clear that such a target could not be met. Above all, consensus about biofuels decreased sharply when their ability to strongly decrease overall GHGs emissions was questioned, and when they were blamed of being the main responsible of the 2007-2008 food price increase. Finally, a new Directive was approved on April 23rd, 2009, including the request of various certifications to prove the sustainability of biofuels. The paper deals deeply with the biofuel experience in Europe, providing a general analysis of the 2003/30 Directive. It includes an evaluation of the difficulties met in satisfying the requested targets, an assessment of the MSs policies to support biofuels, and a discussion about the main features of the (failed) birth of a new industry