Comparative analysis of cryogenic and PTSA technologies for systems of oxygen production

Abstract

Development of oxy-combustion technology requires relatively lower purity oxygen production (90 - 95% O2). 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.