Oxy combustion is the most promising technology for carbon dioxide, originated from thermal power plants, capture and storage. The oxygen in sufficient quantities can be separated from air in cryogenic installations. Even the state-of-art air separation units are characterized by high energy demands decreasing net efficiency of thermal power plant by at least 7%. This efficiency decrease can be mitigated by the use of waste nitrogen, e.g., as the medium for lignite drying. It is also possible to store energy in liquefied gases and recover it by liquid pressurization, warm-up to ambient temperature and expansion. Exergetic efficiency of the proposed energy accumulator may reach 85%.
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The international reality, as initiated by the collapse of the Cold War division of the world, now faces new challenges in the area of security. Increasingly often the necessity is pronounced to shape the international security based on the problems occurring on the global and regional levels. In both cases, related challenges should be emphasized and best efforts made to minimize and eliminate potential threats. The difference may only lie in the (geographical) scale of action. Indeed, global and regional securities are closely linked together. This article is an attempt to draw attention to selected aspects of contemporary problems of international security. The analysis will focus on the identification of several areas.
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W lutym 2011 r. minęła dwudziesta rocznica powstania Grupy Wyszehradzkiej (V4), wspólnotowej inicjatywy, która stanowi podstawę instytucjonalnej współpracy Czech, Polski, Słowacji i Węgier. Zasadniczym powodem jej powstania była koncentracja wysiłków państw członkowskim na wspólnym osiągnięciu członkostwa w NATO i UE. Po osiągnięciu tych celów powstało pytanie związane z podtrzymywaniem współpracy w zarysowanych wcześniej ramach. Zdecydowano, że Grupa Wyszehradzka będzie wciąż służyła kooperacji czterech państw, ale w nieco innych wymiarach. Analiza badawcza będzie skupiona na teorii konstruktywistycznej i teorii wspólnoty bezpieczeństwa Karla Deutscha.
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On February 2011 there was the twentieth anniversary of the Visegrad Group (V4), a community of states’ initiatives, which forms the basis for institutional cooperation between Czech Republic, Poland, Slovakia and Hungary. Its primary raison d’etat was the concentration of the efforts of member states to achieve a common membership in NATO and the EU. After these goals were reached, the question emerged with respect to continued cooperation within the previously established framework. It was decided that the Visegrad Group will continue to serve cooperation of the four countries, yet in slightly different dimensions. The analysis pertaining to this matter is based on the constructivist theory and theory of security communities by Karl Deutsch.
Oxy-combustion is presently considered as the most promising technology to enable the capture of CO2 from fossil fuel based power plants. The concept of oxycombustion is to use oxygen instead of air in the combustion process thus achieving a high concentration of CO2 in the flue gas. In this technology an exemplary 1 GWe thermal power plant will require daily about 18000 tons of oxygen. A potential implementation of oxy-combustion for power generation on significant scale, would necessitate the present oxygen production capacity increase by at least an order of magnitude. Oxygen is produced on industrial scale in the process of air separation using cryogenic, adsorption, membrane, and emerging technologies (like perovskite membranes). The paper categorizes oxygen production methods with respect to the oxy-combustion requirements. A techno-economic analysis of most perspective air separation technologies, with respect to desired thermodynamic states of the air separation products, is presented. The optimum oxygen purity resulting from oxy-combustion technology is estimated. The possibilities of energy consumption decrease by allowing higher fraction of impurities in the separated oxygen are analyzed. The presented considerations take into account an unprecedented scale of potential oxygen supply requirements caused by the CCS policy. The impact of the oxy-combustion technology on the thermal power plant efficiency is discussed.
W pracy zwrócono uwagę na zagrożenia wynikające z eksploatacji dużych instalacji kriogenicznych wypełnionych ciekłym helem, szczególnie systemów ziębienia akceleratorów cząstek i wynikającą z nich konieczność monitorowania wycieków helu do atmosfery. Przeanalizowano teoretyczne podstawy zastosowania techniki pomiaru prędkości dźwięku do wyznaczania udziału helu w powietrzu. Pokazano praktyczne zastosowanie takiej metody, potwierdzone przeprowadzonymi pomiarami na specjalnie zbudowanym stanowisku tomograficznym.
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Superconducting magnet systems for particle accelerators and detectors are cooled by large quantities of liquid helium that in case of some failures may be discharged from the cryogenic system directly to the atmosphere. To avoid potential hazards the presence of helium should be monitored. Theoretical basis of ultrasound techniques enabling the helium detection is given. The gas tomography test rig has been built and successfully operated.