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 oxy-combustion is to use oxygen instead of air for the combustion process and to achieve a high concentration of CO2 in the flue gas. In this technology an exemplary 1 GWe thermal power plant will require daily about 18 000 tons of oxygen. A potential implementation of oxy-combustion on significant for power generation scale, would create the necessity of the oxygen production capacity increase by at least an order of magnitude in comparison to the present production rate. The paper categorizes the oxygen production methods and validates them with respect to oxy-combustion requirements. Present development in cryogenic air separation installations will be presented. A special attention is paid to sorption methods (TSA, PTSA) making use of heat cogenerated in thermal power plants. A novel use of high capacity heat pumps in air separation systems is proposed

Development of oxy-combustion technology requires relatively lower purity oxygen production (90 – 95% O 2 ). There are two known methods to produce oxygen in such purity level - cryogenic and sorption. Cryogenic air separation technology is currently well developed and widely used for oxygen production in large quantities (up to 5 000 tons per day from a single technology train). The second method is pressure swing adsorption (PSA), which is well suited for smaller quantities of oxygen (below 500 tons per day). To optimize overall energy consumption, the PSA method can be combined with swing of temperature by using waste heat from combined heat-power generation (cogeneration) processes, leading to pressure temperature swing adsorption (PTSA). In small and medium scale oxygen production systems for oxy-combustion, both PTSA and cryogenic method can be used. The paper shows calculations and experimental validation of the efficiency and economics for both processes. The limitations of applicability for each of these technologies are indicated. The possibility of coupling the technologies, including thermal power plants, in order to improve the efficiency of the oxygen separation is discussed.

Liquefied natural gas (LNG) is one of the most influential fuels of the 21st century, especially in terms of the global economy. The demand for LNG is forecasted to reach 400 million tonnes by 2020, increasing up to 500 million tonnes in 2030. Due to its high mass and volumetric energy density, LNG is the perfect fuel for long-distance transport, as well as for use in mobile applications. It is also characterized by low levels of emissions, which is why it has been officially approved for use as a marine fuel in Emission Control Areas (ECAs) where stricter controls have been established to minimize the airborne emissions produced by ships. LNG is also an emerging fuel in heavy road and rail transport. As a cryogenic fuel that is characterized by a boiling temperature of about 120 K (−153 °C), LNG requires the special construction of cryogenic mobile installations to fulfill conflicting requirements, such as a robust mechanical construction and a low number of heat leaks to colder parts of the system under high safety standards. This paper provides a profound review of LNG applications in waterborne and land transport. Exemplary constructions of LNG engine supply systems are presented and discussed from the mechanical and thermodynamic points of view. Physical exergy recovery during LNG regasification is analyzed, and different methods of the process are both analytically and experimentally compared. The issues that surround two-phase flows and phase change processes in LNG regasification and recondensation are addressed, and technical solutions for boil-off gas recondensation are proposed. The paper also looks at the problems surrounding LNG installation data acquisition and control systems, concluding with a discussion of the impact of LNG technologies on future trends in low-emission transport.

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%.