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In this paper, the performances of two iron-based syngas-fueled chemical looping (SCL) systems for hydrogen (H2) and electricity production, with carbon dioxide (CO2) capture, using different reactor configurations were evaluated and compared. The first investigated system was based on a moving bed reactor configuration (SCL-MB) while the second used a fluidized bed reactor configuration (SCL-FB). Two modes of operation of the SCL systems were considered, namely, the H2 production mode, when H2 was the desired product from the system, and the combustion mode, when only electricity was produced. The SCL systems were modeled and simulated using Aspen Plus software. The results showed that the SCL system based on a moving bed reactor configuration is more efficient than the looping system with a fluidized bed reactor configuration. The H2 production efficiency of the SCL-MB system was 11 % points higher than that achieved in the SCL-FB system (55.1 % compared to 44.0 %). When configured to produce only electricity, the net electrical efficiency of the SCL-MB system was 1.4 % points higher than that of the SCL-FB system (39.9 % compared to 38.5 %). Further, the results showed that the two chemical looping systems could achieve >99 % carbon capture efficiency and emit ~2 kg CO2/MWh, which is significantly lower than the emission rate of conventional coal gasification-based plants for H2 and/or electricity generation with CO2 capture.

We show that a simple ethanol (EtOH) refluxing treatment at mild temperature (120 °C) allows producing blue-colored and reduced titanium dioxide (TiO2-x) exhibiting improved visible-light (VIS) photocatalytic properties. The treatment causes an increase in the density of Ti(III) species and the appearance of two optical absorption features: a broad absorption band--responsible for the blue coloration--extending from the green region (~2.3 eV) up to the near-infrared and a subgap absorption tail close to the band gap energy. The experimental results combined with a computation of the density of states via hybrid Hartree-Fock density functional support the hypothesis that the EtOH reflux treatment leads to formation of surface and subsurface oxygen (O) vacancies. We also show that the excitation-resolved photoluminescence technique allows a high-contrast detection of a subgap optical excitation band peaked at about 430 nm (~2.9 eV), associated with anatase photoluminescence, whose intensity increases after the EtOH reflux treatment. This result gives a very direct support to the debated hypothesis identifying O vacancy states as the energy levels involved in the radiative transition of anatase TiO2. Improved photocatalytic degradation by the processed TiO2 under VIS illumination is demonstrated, and the possible mechanism involved in the formation of surface O vacancies is discussed. The method outlines a very simple, low-cost, and fast procedure to target the formation of O vacancies in the TiO2 surface region.

Sustainability of energy systems has a strategic role in the current energy-environmental policies as it involves key issues such as security of energy supply, mitigation of environmental impact (with special regard to air quality improvement) and energy affordability. In this framework modelling activities are more than ever a strategic issue in order to manage the large complexity of energy systems as well as to support the decision-making process at different stages and spatial scales (regional, national, Pan-European, etc.). The aim of this article is to present a new model for the Italian energy system implemented with a common effort in the framework of an integrated project under the Sixth Framework Programme. In particular, the main features of the common methodology are briefly recalled and the modelling structure, the main data and assumptions, sector by sector, are presented. Moreover the main results obtained for the baseline (BAU) scenario are fully descfibed.

Butanol is considered a superior biofuel, as it is more energy dense and less hygroscopic than bioethanol, resulting in higher possible blending ratios with gasoline. However, the production cost of the acetone-butanol-ethanol (ABE) fermentation process is high, mainly due to the low butanol titer, yield, and productivity in bioprocesses. The classic recovery by distillation is an energy-intensive process that has largely restricted the economic production of biobutanol. Other methods based on gas stripping, liquid-liquid extraction, adsorption, and membranes are also energy intensive due to the bulk removal of water. This study proposes a novel process for the butanol recovery by enhanced distillation, using only several operating units in an optimized sequence to reduce costs. This work considers a plant capacity of 40 ktpy and purities of 99.4 %wt butanol, 99.4 %wt acetone and 91.4 %wt ethanol. The process was simulated and optimized using Aspen Plus as PSE tool. The enhanced process proposed here is cost effective and can be readily employed at large scale to improve the economics of biobutanol production.

AbstractA metal‐free organic sensitizer, suitable for the application in dye‐sensitized solar cells (DSSCs), has been designed, synthesized and characterized both experimentally and theoretically. The structure of the novel donor–acceptor–π‐bridge–acceptor (D–A–π–A) dye incorporates a triphenylamine (TPA) segment and 4‐(benzo[c][1,2,5]thiadiazol‐4‐ylethynyl)benzoic acid (BTEBA). The triphenylamine unit is widely used as an electron donor for photosensitizers, owing to its nonplanar molecular configuration and excellent electron‐donating capability, whereas 4‐(benzo[c][1,2,5]thiadiazol‐4‐ylethynyl)benzoic acid is used as an electron acceptor unit. The influences of I3−/I−, [Co(bpy)3]3+/2+ and [Cu(tmby)2]2+/+ (tmby=4,4′,6,6′‐tetramethyl‐2,2′‐bipyridine) as redox electrolytes on the DSSC device performance were also investigated. The maximal monochromatic incident photon‐to‐current conversion efficiency (IPCE) reached 81 % and the solar light to electrical energy conversion efficiency of devices with [Cu(tmby)2]2+/+ reached 7.15 %. The devices with [Co(bpy)3]3+/2+ and I3−/I− electrolytes gave efficiencies of 5.22 % and 6.14 %, respectively. The lowest device performance with a [Co(bpy)3]3+/2+‐based electrolyte is attributed to increased charge recombination.

The implementation of resource management strategies aimed at reducing the impacts of the anthropogenic activities system requires a comprehensive approach to evaluate on the whole the environmental burdens of productive processes and to identify the best recovery strategies from both an environmental and an economic point of view. In this framework, an analytical methodology based on the integration of Life Cycle Assessment (LCA), ExternE and Comprehensive Analysis was developed to perform an in-depth investigation of energy systems. The LCA methodology, largely utilised by the international scientific community for the assessment of the environmental performances of technologies, combined with Comprehensive Analysis allows modelling the overall system of anthropogenic activities, as well as sub-systems, the economic consequences of the whole set of environmental damages. Moreover, internalising external costs into partial equilibrium models, as those utilised by Comprehensive Analysis, can be useful to identify the best paths for implementing technology innovation and strategies aimed to a more sustainable energy supply and use. This paper presents an integrated application of these three methodologies to a local scale case study (the Val D'Agri area in Basilicata, Southern Italy), aimed to better characterise the environmental impacts of the energy system, with particular reference to extraction activities. The innovative methodological approach utilised takes advantage from the strength points of each methodology with an added value coming from their integration as emphasised by the main results obtained by the scenario analysis.

In this paper, we propose innovative solutions for reusing an inactive offshore gas platform and its associated infrastructures as a scientific research hub, where an integrated energy system and innovative environmental monitoring methods are envisaged. To this end, the Azalea A platform, located in the northern Adriatic Sea, is considered a good pilot site. This study analyzes the engineering solutions on Azalea A for the combined production of solar and wind energy coupled with hydrogen production from seawater electrolysis. It analyzes the potential for storage and transport on land of the produced hydrogen using the sealines connected to the platform. However, this study does not deal with the current structural conditions of the platform (corrosion, stability etc.), which should be evaluated before these solutions are put into practice. The main outcomes of this work consist in a feasibility study for the reuse of existing infrastructures as a self-sufficient research hub using green energy systems, which include considerations about the measures needed to ensure the protection of the marine environment. Data show a positive feedback about the technical feasibility of the proposal in safety conditions. Furthermore, encouraging outcomes derive also by the economic evaluation that estimates sustainable costs comparing to those implicated with the decommissioning of the infrastructures in the order of tens millions euro. In addition, the proposed reuse seems to be a good opportunity to promote both energy transition toward renewable energy systems and environmental protection, avoiding decommissioning impacts and promoting an innovative monitoring program for the Adriatic Sea.

Climate change will impact forests and may impair their ability to provide essential ecosystem services in the decades to come. Addressing this challenge requires adjustments to forest management strategies as of now, but it is still unclear to what extent this is already in progress. Using data from surveys of 1131 forest owners and managers from seven European countries, we assessed how they perceive their role in adapting forest management to climate change. The surveys focused on foresters' observations of climate change impacts, the degree to which climate change is a part of their operational and strategic management, and their ability to address related risks and opportunities. We found evidence of a strong continent-wide climate change awareness among respondents, with 73% foresters convinced that climate change will impact their forest. However, only about one-third (36%) reported having modified their management practices, though figures vary widely between countries, from 14% in Portugal to 57% in Slovakia. Among the constraints limiting their actions, lack of knowledge and information emerged as a major barrier towards forest adaptation. Differences between countries could be linked to their socio-economic and political contexts. Our results further suggest that severely damaging events, such as windstorms, fires and pest outbreaks, present relevant opportunities to engage people with climate change and encourage action. Further work needs to be done in strengthening the relationship between scientific research and practice, working out context dependent measures to foster adaptation to changing climate and disturbance regimes in forest management.