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This paper presents the results of chemical looping combustion (CLC) research. Nowadays, CLC is one of the best prospective combustion technologies, because it enables the production of a concentrated carbon dioxide (CO 2 ) stream, following water condensation, without any energy penalty for its separation. The objective of this work was to study chemical looping reaction performance with the application of novel perovskite-type oxygen carriers (OCs). Sr(Fe 1-x Cu x )O 3-δ family members were tested for hydrogen combustion for power generation purposes. Sr(Fe 1-x Cu x )O 3-δ , which is a perovskite-type oxide, was prepared using the calcination method, where x = 0, 0.1 and 0.33. Reactivity tests were performed using a thermogravimetric analyser (TGA, Netzsch STA 409 PG Luxx) under isothermal conditions in multiple reduction–oxidation cycles. Both the temperature (600–800 °C) and number of redox cycles (five cycles) effects on the reaction performance of recently developed OC samples were evaluated in the study. TGA data were used for the assessment of the oxygen transport capacity value, redox reaction rates and stability. Sr(Fe 1-x Cu x )O 3-δ showed an excellent stable chemical looping performance. The changing of oxygen content (3.8–4.86 wt%) occurred within approximately 2 min, with the chemical properties of the material maintained during the cycling combustion tests. In addition, new SrFeO 3-δ OCs, doped with copper (Cu) perovskite-type materials, were analysed using multiple methods: X-ray powder diffraction (XRD); scanning electron microscopy (SEM); surface area by Brunauer–Emmett–Teller (BET) method; and melting behaviour study. In terms of physical properties, the new OCs can resist both high CLC process temperatures and mechanical forces, which are essentially useful. The analysis showed that Sr(Fe 1-x Cu x )O 3-δ carriers performed at extremely high melting temperatures (>1280 °C). Results of crushing strength testing showed that developed materials had a pronounced mechanical resistivity with a crushing strength higher than 1 N and will perform well in fluidized beds (4.31–6.23 N). In this paper, it was demonstrated that known mixed oxygen-ionic and electronic conducting membrane materials such as Sr(Fe 1-x Cu x )O 3-δ might also be applied as oxygen carriers. Overall results demonstrated Fe-Cu-based perovskites might be successfully used as OCs in the chemical looping combustion process. [ABSTRACT FROM AUTHOR]

Paper presents parametric evaluation of a modified design of a conceptual micro-combined heat and power unit (micro-CHP) with solid oxide fuel cells. The system incorporates oxygen transport membranes to supply high purity oxygen for post-combustion of lean fuel leaving the SOFC stack. The concentrations of CO 2 in the flue gases leaving the system, approaches 99% (on dry gas basis). High temperature oxygen transport membranes, made of perovskite materials, enable oxygen permeation rate exceeding 6 Nml/(cm 2 min). The oxygen permeation is strongly related to the ratio of oxygen partial pressures at the retentate and permeate sides. Results of a parametric evaluation of the system, including the analysis of effects of membrane characteristics on the electrical efficiency, are presented and discussed. Oxygen transport membranes require high pressure at the feed site, therefore an increase of auxiliary power consumption should be expected to achieve high oxygen flow through the membrane. Electrical penalty in range 6–12%-point was observed, in comparison with a conventional micro-CHP system without oxy-combustion. These numbers are often quoted for large power systems operating in a CCS-ready mode with state-of-the-art oxygen separation methods such as pressure swing adsorption (PSA). Electrical efficiency of the system discussed in this paper was evaluated and effects of oxygen permeation rate on the electrical efficiency were analyzed. [ABSTRACT FROM AUTHOR]

In the present paper, a CO 2 cryogenic capture for flue gas of an LNG-fired power generation system is proposed, in which LNG cold energy can be fully utilized during the gasification process. First of all, the flue gas is compressed to facilitate the CO 2 solid formation and separation. Sequentially, the CO 2 -removed flue gas expands to supply most of the cold energy needed for the cryogenic process. In comparison with traditional CO 2 -capture systems in LNG-fired power generation cycle, the new system does not require gasifying excessive amount of LNG. Based on the HYSYS simulation, the CO 2 capture pressure and temperature are investigated as the key parameters to find the appropriate working conditions of the CO 2 -capture system. The results show that the system can achieve a 90% CO 2 recovery rate or higher if the flue gas temperature can be lowered to less than −140 °C. [ABSTRACT FROM AUTHOR]

Abstract: After the Fukushima nuclear plant accident, Japan is facing an unprecedented situation with its energy supply. This paper provides an overview of Japan’s current energy landscape with descriptions of the kinds and production of energy. Since it is inevitable that the use of nuclear energy will decrease, we shall propose a best mix of electric sources of the large-scale and centralized network as well as the decentralized network as an alternative. The hub for this proposal is regional power centers (RPC) to control the electric supply as well as fuel transportation and storage on an area-by-area basis. As technologies that will realize this power center, we will discuss fuel cells, hydrogen production and storage and furthermore, the potential of CCS, which is requisite technology for carbon dioxide emissions reduction. [Copyright &y& Elsevier]

Abstract: Carbon dioxide is more and more pointed out as one of the factors mostly responsible of climate changes. As a consequence the reduction of CO2 emissions, especially in the energy generation field, is becoming a worldwide must. This paper presents an overview on the main issues that are expected to affect, from this standpoint, power generation scenario and a spur for a critical comparison among ways to capture CO2 by proposing new aspects to be considered within the evaluation criteria. In particular attention is drawn on the fully innovative opportunities that are offered by Molten Carbonate Fuel Cells (MCFCs) as a unique option suitable to effectively combine carbon capture from thermal plants and typical benefits of hydrogen and fuel cell power generation. As an example, such a new option is compared with one of the most common technologies forecast for reducing carbon dioxide emissions and relevant results are shortly presented. [Copyright &y& Elsevier]