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A membrane assisted process for green hydrogen production from a bioethanol derived feedstock is here developed and evaluated, starting from the conventional Steam Methane Reforming (SMR) process. Such a process is suitable for centralized hydrogen production, and is here analyzed for a large-scale H2 production unit with the capacity of 40.000 Nm3/h. The basic Steam Ethanol Reforming (SER) process scheme is modified in a membrane assisted process by integrating the Pd-membrane separation steps in the most suitable reaction steps. The membrane assisted process, configured in three alternative architectures (Open architecture, Membrane Reactor and Hybrid architecture) was evaluated in terms of efficiencies and hydrogen yields, obtaining a clear indication of improved process performance. The alternative membrane assisted process architectures are compared to the basic SER process and to the benchmark SMR process fed by natural gas, for an overall comparative assessment of the efficiency and specific CO2 emissions and for an economic analysis based on the operating expenditures.

Finding a numerical method to model solute transport in porous media with high heterogeneity is crucial, especially when chemical reactions are involved. The phase space formulation termed the multi-advective water mixing approach (MAWMA) was proposed to address this issue. The water parcel method (WP) may be obtained by discretizing MAWMA in space, time, and velocity. WP needs two transition matrices of velocity to reproduce advection (Markovian in space) and mixing (Markovian in time), separately. The matrices express the transition probability of water instead of individual solute concentration. This entails a change in concept, since the entire transport phenomenon is defined by the water phase. Concentration is reduced to a chemical attribute. The water transition matrix is obtained and is demonstrated to be constant in time. Moreover, the WP method is compared with the classic random walk method (RW) in a high heterogeneous domain. Results show that the WP adequately reproduces advection and dispersion, but overestimates mixing because mixing is a sub-velocity phase process. The WP method must, therefore, be extended to take into account incomplete mixing within velocity classes.

This paper discloses the research carried out at MCAT (INCAR-CSIC) in the last years, which has been aimed to develop a new microwave induced process (MIP) for the conversion of biosolids into syngas. The different organic substrates that can be processed, the operational conditions that lead to a maximum production of syngas and the characteristics of the syngas as well as the by-products obtained are discussed. Particular emphasis is placed on the partial recycling of the solid fraction and its role as microwave susceptor and as a catalyst of some of the gasification reactions taking place during the MIP of the organic residues. Additionally, some insights on the energy costs of the process are also given. Peer reviewed

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The growth of self-ordered anodic aluminum oxide (AAO) templates with pore diameters in the 140-400 nm range is achieved by anodization in phosphoric acid at low temperatures (-4 °C). The procedure used in this study is able to completely avoid the >burning> of the oxide, highly frequent in anodizations in phosphoric acid solutions at high voltages. The current density measured during the anodizations is rather low, 0.6-0.7 mA/cm2; therefore, low growth rates have been also measured (<2 μm/h). AAO templates present a relatively low porosity value of 8.4%. However, a considerable pore-enlargement-rate (vΔd = 0.636 ± 0.101 nm/h) has been observed as a consequence of the chemical dissolution of the pore walls during the anodization. Thus, the results reported here constitute an exhaustive study on the preparation of large-diameter-pore self-ordered AAO templates that enables both to access to pore diameters up to now inaccessible and to efficiently overcome the difficulties of their fabrication process ascribed to its aggressive reaction conditions. © 2011 Elsevier Inc. All rights reserved. Authors want to thank the ERC 2008 Starting Grant number 240497 for financial support. Peer Reviewed

AbstractSmart Grids are electrical grids that require a decentralised way of controlling electric power conditioning and thereby control the production and distribution of energy. Yet, the integration of Distributed Renewable Energy Sources (DRESs) in the Smart Grid introduces new challenges with regards to electrical grid balancing and storing of electrical energy, as well as additional monetary costs. Furthermore, the future smart grid also has to take over the provision of Ancillary Services (ASs). In this paper, a distributed ICT infrastructure to solve such challenges, specifically related to ASs in future Smart Grids, is described. The proposed infrastructure is developed on the basis of the Smart Grid Architecture Model (SGAM) framework, which is defined by the European Commission in Smart Grid Mandate M/490. A testbed that provides a flexible, secure, and low-cost version of this architecture, illustrating the separation of systems and responsibilities, and supporting both emulated DRESs and real hardware has been developed. The resulting system supports the integration of a variety of DRESs with a secure two-way communication channel between the monitoring and controlling components. It assists in the analysis of various inter-operabilities and in the verification of eventual system designs. To validate the system design, the mapping of the proposed architecture to the testbed is presented. Further work will help improve the architecture in two directions; first, by investigating specific-purpose use cases, instantiated using this more generic framework; and second, by investigating the effects a realistic number and variety of connected devices within different grid configurations has on the testbed infrastructure.

Abstract The need to increase energy system flexibility, alongside the need to lower fossil fuel use in the food sector, and the importance of refrigeration infrastructure presents an opportunity for Liquid Air Energy Storage (LAES) integrated with refrigerated warehouses. To quantify this opportunity in Europe we analyse energy scenarios and existing refrigeration infrastructure for four countries with diverse energy systems (UK, Spain, Bulgaria and Germany). We find that with growing levels of electricity generation from variable renewable sources and numerous refrigerated warehouses, LAES has the potential to provide value in many areas of the EU through the 2020s. However, LAES is still pre-commercial, and with the proportion of electricity from variable renewable sources still low in many countries it is likely that LAES will not be deployed widely alongside refrigerated warehouses under current market conditions. Countries such as the UK and Spain, which have the greatest need for additional energy system flexibility and the most refrigerated warehouses are likely to gain the most value initially.