In this paper a 600 MW oxy-type coal unit with a pulverized bed boiler and a membrane-cryogenic oxygen separator and carbon capture installation was analyzed. A membrane-cryogenic oxygen separation installation consists of a membrane module and two cryogenic distillation columns. In this system oxygen is produced with the purity equal to 95%. Installation of carbon capture was based on the physical separation method and allows to reduce the CO2emission by 90%. In this work the influence of the main parameter of the membrane process – the selectivity coefficient, on the efficiency of the coal unit was presented. The economic analysis with the use of the break-even point method was carried out. The economic calculations were realized in view of the break-even price of electricity depending on a coal unit availability.

In this paper the results of the thermodynamic analysis of the oxy-combustion type pulverized bed boiler integrated with a hybrid, membrane- cryogenic oxygen separation installation are presented. For the calculations a 600 MW boiler with live steam parameters at 31.1 MPa /654.9 oC and reheated steam at 6.15 MPa/672.4 oC was chosen. In this paper the hybrid membrane-cryogenic technology as oxygen production unit for pulverized bed boiler was proposed. Such an installation consists of a membrane module and two cryogenic distillation columns. Models of these installations were built in the Aspen software. The energy intensity of the oxygen production process in the hybrid system was compared with the cryogenic technology. The analysis of the influence of membrane surface area on the energy intensity of the process of air separation as well as the influence of oxygen concentration at the inlet to the cryogenic installation on the energy intensity of a hybrid unit was performed.

The paper presents a thermodynamic analysis of the integration of a cryogenic air separation unit into a negative CO ₂ emission gas power plant. The power cycle utilizes sewage sludge as fuel so this system fits into the innovative idea of bioenergy with carbon capture and storage. A cryogenic air separation unit integrated with the power plant was simulated in professional plant engineering and thermodynamic process analysis software. Two cases of the thermodynamic cycle have been studied, namely with the exhaust bleed for fuel treatment and without it. The results of calculations indicate that the net efficiencies of the negative CO ₂ emission gas power plant reach 27.05% (combustion in 95.0% pure oxygen) and 24.57% (combustion in 99.5% pure oxygen) with the bleed. The efficiencies of the cycle without the bleed are 29.26% and 27.0% for combustion in 95.0% pure oxygen and 99.5% pure oxygen, respectively. For the mentioned cycle, the calculated energy penalty of oxygen production was 0.235 MWh/kgO ₂ for the lower purity value. However, for higher purity namely 99.5%, the energy penalty of oxygen production for the thermodynamic cycle including the bleed and excluding the bleed was indicated 0.346 and 0.347 MWh/kgO ₂, respectively. Additionally, the analysis of the oxygen purity impact on the carbon dioxide purity at the end of the carbon capture and storage installation shows that for the case with the bleed, CO ₂ purities are 93.8% and 97.6%, and excluding the bleed they are 93.8% and 97.8%, for the mentioned oxygen purities respectively. Insertion of the cryogenic oxygen production installation is required as the considered gas power plant uses oxy-combustion to facilitate carbon capture and storage method.